taxonID	type	description	language	source
0207BC208C497B46CBCFFBF04B60FD96.taxon	description	(Figures 2 – 4)	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	etymology	Etymology. The new species is named in honour of Dr José Sarukhán in recognition of his outstanding contribution to the study of the biodiversity of Mexico.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	materials_examined	Material examined. Holotype male, size 7.7 mm (Cat. No. CNCR 35726), from Lake Chapultepec (19.424 ° N, 99.187 ° W), 10 August 2016, 2253 m a. s. l. collector: A. Marrón-Becerra. Paratypes (n = 10 males, n = 10 females): males – mean size 6.4 ± 0.5 mm, mean head length: 0.6 ± 0.03 mm (n = 10), females – mean size 6.2 ± 0.4 mm, mean head length 0.5 ± 0.04 (n = 10) (permanent slides Cat. No. CNCR 35731, paratypes and SEM preparations Cat. No. CNCR 35732), locality same as holotype. Other material revised Xochimilco (19.264 ° N, 99.094 ° W), 10 August 2016, 2240 m a. s. l., collector A. Marrón-Becerra (Cat. No. CNCR 35733). Lake Chalco, Mexico City (19.264 ° N, 98.974 ° W), 29 March 2016, 2231 m a. s. l., temp. 24 ° C, pH 8.7, conductivity 1793 µS / cm, dissolved oxygen 2.8 mg / L, collectors: A. Marrón-Becerra and F. Charqueño-Celis (Cat. No. CNCR 35734).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	distribution	Type locality (Figure 1 a). Lake Chapultepec, Mexico City, Mexico (19.424 ° N, 99.187 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	diagnosis	Diagnosis. Pleonite 1 and 2 with dorsoposterior carina. Coxa 4 excavated posteriorly. Eyes pigmented. Antenna 1 shorter than antenna 2. Antenna 2 less than half body length. Maxilla 1 palp short, reaching less than half of length between base of palp and tip of setae in outer plate, with 1 short stout distal seta and setules; inner plate slender with 2 – 3 strong pappose distal setae. Maxilla 2 inner plate with 2 strong pappose setae on inner margin. Gnathopod 1, propodus hammer shaped, palm slope transverse, inner face with 5 – 6 serrate setae, comb scales on distoposterior and distoanterior border, carpus inner face lobe with 5 serrate setae. Gnathopod 2, basis hind margin with 3 – 5 setae, merus with 1 medial seta, excavation of palm wide. Uropods without curved setae. Uropod 3, peduncle and ramus subequal in length, styliform. Telson slightly wider than long, distal margin rounded with 2 long simple setae widely separated. Coxal gills on segments 2 – 6. Sternal gills on segments 3 – 7.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	description	Description of male Body (Figures 2 a, and 17 a), tergites of pleon 1 and 2 with dorsoposterior carina. Epimeral plates 1 – 3 acuminate. Coxae 1 – 3 (Figures 2 a, and 17 a) subequal in shape, subrectangular, longer than wide; coxa 4 wider than coxae 1 – 3, with deep posterior excavation; acumination absent; coxa 5 with two subequal lobes, anterior lobe slightly shorter than posterior, coxa 6 anterior lobe reduced. Head typically gammaridean (Figures 2 a, and 17 a), shorter than first two thoracic segments, reaching to middle of second pereonite, rostrum absent. Eyes pigmented, black, medium, rounded, located between insertions of antennae 1 and 2. Antenna 1 (Figure 2 a – b) less than half the body length, shorter than antenna 2, but longer than peduncle of antenna 2, almost reaching to middle of third pereonite; peduncle as long as head; article 1 and 2 subequal in length, article 1 wider than articles 2 – 3, article 2 longer and wider than article 3, (proportions 1.8: 1.6: 1), article 1 with 2 short cuspidate setae ventrally, 1 smaller, and one cluster with 3 cuspidate setae at distal end; flagellum longer than peduncle with 9 – 10 articles gradually shorter towards distal portion; aesthetascs present on articles 4 – 7 (one pair), and 8 – 9 (one aesthetasc). Antenna 2 (Figure 2 a, c) almost 1.3 times longer than antenna 1, slightly shorter than one-third body length, reaching fourth pereonite; peduncle almost reaching to middle of first pereonite, peduncle articles increase gradually in length and decrease in width; article 3 shorter but wider than 4 and 5, article 4 slightly longer than article 3, article 5 longer than article 4 (almost 1.5 times); flagellum with 11 – 12 articles, longer than peduncle (almost 1.5 times); without aesthetascs. Buccal parts: upper lip (Figure 2 f) distal margin rounded, with numerous setules. Lower lip (Figure 2 g), subquadrate, outer lobes without notches or excavations; mandibular projection of outer lobes rounded. Mandibles (Figure 2 h – i) without palp, asymmetric. Incisor toothed, 6 teeth present. Left lacinia mobilis with 5 teeth; setal row on left mandible with 3 main pappose setae plus accessory setae. Right mandible with 6 teeth, right lacinia mobilis reduced, with 2 pairs of asymmetric L-shaped teeth; setal row on right mandible with 2 main pappose setae plus accessory setae and with setulae near molar process. Both molar processes large, cylindrical and triturative, with accessory pappose setae. Maxilla 1 (Figures 2 d, and 19 b), palp short, uniarticulate, longer than wide, distally pointed with 1 short and stout distal seta, setules present; palp length almost half of distance between base of palp and base of seta on outer plate, but less than half distance between base of palp and tip of seta on outer plate (Figures 2 d, and 19 b); inner plate slender, shorter than outer plate, with 2 – 3 pappose distal setae; outer plate with 9 stout serrate setae and with setules. Maxilla 2 (Figure 2 e) plates subequal; inner plate shorter and slender, with 2 pappose setae on mid-distal margin, and with 7 shorter serrulate setae on distal margin; outer and inner plates with large simple distal setae (type A 2) and abundant setules on both distal surfaces and margins. Maxilliped (Figures 2 j, and 20 b) inner plate lobe longer than outer plate lobe; distal margin slightly convex, on both plates; inner plate distal margin with 3 cuspidate setae of equal size and with plumose setae, inner margin with several pappose setae; outer plate, inner and distal margins with numerous simple setae. Palp composed of four articles subequal in maximum length; first article with 3 simple setae at inner distal end and 1 seta at outer distal end; second article with numerous simple setae on inner margin and 3 on outer distal end; third article with several setae on distal margin, distal end of outer margin with 3 simple setae and comb scales, inner margin with at least 12 setae and 6 at distal end; fourth article unguiform, longer than nail, with comb scales; nail almost reaching 2 / 3 of fourth article, with serration at distal half. Gnathopod 1 (Figure 3 a) subchelate, hammer shaped. Basis elongated, maximum length almost 3.5 times longer than maximum width; posterior margin with 1 seta, distal end with one cluster of 2 setae. Ischium short, subquadrate, distal posterior end with 2 clusters of 2 setae. Merus longer than wide, almost distal half of length of ventral surface with comb scales; distal margin with 5 – 6 setae. Carpus longer than wide, longer and slightly wider than propodus; with strong, short, and wide posterior lobe forming one scoop-like structure open to inside; inner surface with 5 – 6 serrate setae, Propodus 1.5 times longer than wide; inner surface near distal margin with 5 – 6 serrate setae in one row; distal anterior end with two clusters of approximately 5 setae; distal anterior and posterior surfaces with comb scales; palm transverse, posterior distal end with 1 robust seta and cup for dactylus. Dactylus claw-like; nail present; with 1 plumose seta, and comb scales. Gnathopod 2 (Figures 3 b, and 21 b) subchelate; palm slightly oblique. Basis elongate, more than 3 times longer than wide; posterior margin with 3 – 5 long setae. Ischium short, subquadrate, shorter than merus. Merus short; posterior margin with 1 seta and distal end of posterior margin with 8 simple setae; posterior inner and outer surfaces with comb scales. Carpus shorter than propodus; anterodistal end with 3 setae; posterior lobe scooplike, elongate, with several submarginal pappose setae and comb scales. Propodus robust, length slightly less than 1.5 times maximum wide, subrectangular; palm slightly shorter than posterior margin; slope slightly irregular, with several long simple setae, and few short and medium setae; distal margin of palm with one truncated process near insertion of dactylus and with one wide posterior excavation at base (Figure 22 b); palm posterior distal end with 2 strong setae, comb scales and cup for dactylus. Dactylus claw-like, congruent with palm, without comb scales; outer margin with 1 plumose seta; inner margin crenulate with separated setules. Pereopods 3 – 7 (Figure 3 e – i) simple, gradually longer posteriorly. Pereopod 5 shorter than 4 and 6. Pereopod 3 (Figure 3 e), basis elongate; mid-posterior margin with 1 – 2 simple setae. Merus longer than ischium (almost 3 times the maximum length); anterior margin with 2 setae; posterior margin with 6 setae; anterodistal and posterodistal ends each with one cluster of 4 – 5 setae, lobe less than one-fourth length of carpus. Carpus shorter and slenderer than merus; posterior margin with 5 stout setae plus accessory setae; posterodistal end with at least 5 slender setae; anterodistal end with at least 2 setae. Propodus shorter than anterior margin of merus, slenderer than carpus; posterior margin with 7 stout setae; anterodistal end with 5 simple setae. Dactylus claw-like, length slightly overreaching half of propodus; nail present. Pereopod 4 (Figure 3 f) similar in shape to pereopod 3 but slightly longer; coxa 4 wider than coxa 3 with posterior excavation; basis posterior margin with 1 – 2 simple setae; merus mid-anterior margin without setae; propodus posterior margin with 6 setae. Pereopods 5 – 7 (Figure 3 g – i) similar in shape; basis posterior lobe rounded and denticulated. Pereopod 7 (Figure 3 i) basis lobe widely expanded, almost reaching ischium distal margin; wider than lobes of pereopods 5 and 6; basis lobe, width almost 1.5 times as wide as basis (measured at cleft between basis and basis lobe); posterior margin with 19 serrations, each with 1 setule (17) but 2 serrations with 1 stout seta on distal margin; anterior margin with two clusters of 2 stout setae on distal half and 1 at distal end. Dactylus length almost half of propodus length. Pleopods 1 – 3 (Figure 4 e) not modified, biramous, elongated, rami multi-annulated, with numerous plumose setae; pleopod 1, inner margin of peduncle at distal end with 2 short retinacula (coupling hooks). Uropod 1 (Figure 4 a) longer than uropod 2 (Figure 4 b); peduncle longer than rami, with 3 dorsal setae, inner and outer distal ends each with 1 seta; rami subequal, inner ramus slightly shorter, with 2 dorsal and 4 distal setae, outer ramus with 3 dorsal and 4 distal setae; male without curved setae on inner ramus. Uropod 2 (Figure 4 b) longer than peduncle of uropod 1; peduncle as long as rami, with 2 dorsal setae and 2 additional distal setae; rami subequal, inner ramus slightly longer, with 2 – 3 dorsal and 4 distal setae, outer ramus with 3 dorsal and 5 distal setae. Uropod 3 (Figures 4 c, and 23 b) slightly shorter than peduncle of uropod 2; peduncle rectangular, wider than ramus with 5 strong distal setae of variable length; inner ramus absent; outer ramus uniarticulate, slender, slightly shorter than peduncle, 2 times the length of larger seta of peduncle, basal width near 2 times width of apex of ramus, with 3 slender apical setae and 1 connate seta. Telson (Figures 4 d, and 24 b) entire, as long as wide, distal margin rounded with 2 long simple setae widely separated by almost one-third of maximum width of telson; and two lateral clusters of 3 plumose setae symmetrically distributed. Coxal gills sac-like, present on segments 2 – 6. Sternal gills tubular, present on segments 3 – 7. Female (Figure 17 b) similar to male. Gnathopod 1 (Figure 3 c), ischium distal half of posterior surface with comb scales; carpus with 3 serrate setae on inner face lobe; propodus with 4 – 5 serrate setae in row over the inner face. Gnathopod 2 (Figure 3 d) smaller than male gnathopod 2, parachelated, palm reverse oblique; basis posterior margin with 2 – 3 setae; ischium distal half of posterior surface with comb scales; propodus slightly longer than twice maximum width, outer face with 3 serrate setae in one row and 3 large setae near palm, anterior and posterior distal half with comb scales. Pereonite 2 with one anterior excavation or notch for amplexus. Pereopod 7 lobe with 13 serrations and setules, and 2 stout setae on distal margin. Oostegites subtriangular with curled setae on margins. Intraspecific variation. Gnathopod 2 of male, basis hind margin up to 5 setae (some organisms from Chalco). Pereopod 3 merus posterior margin up to 4 setae (organisms from Chalco).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	biology_ecology	Habitat. freshwater, epigean, littoral, found associated with roots of Lemna sp.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	distribution	Distribution. Mexico City, Mexico.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C497B46CBCFFBF04B60FD96.taxon	discussion	Remarks Hyalella sarukhani sp. nov. (from Mexico City) can be easily distinguished from species in the Hyalella azteca complex by the telson with rounded distal margin and the presence of 2 long setae wide apart (almost one-third of maximum width of telson). This species has more serrations in the posterior margin of the lobe of pereopod 7 but less stout setae on the distal margin than H. azteca. This species bears setules on the palp of maxilla 1, in contrast with Hyalella wakulla (Drumm and Knight, 2019). The morphological differences from the other Hyalella species described in this work are summarised in Tables S 1 and S 2 (Table 1).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	description	(Figures 5 – 7)	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	etymology	Etymology. The new species is named in honour of Dr Fernando Alvarez Noguera for his important contribution to carcinological study in Mexico.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	materials_examined	Material examined. Holotype male, size 4.4 mm (Cat. No. CNCR 35727), from Lake La Encantada in state of Veracruz, Mexico (18.458 ° N, 95.185 ° W), 24 July 2015, 332 m a. s. l., temp. 30 ° C, pH 7. Collectors: A. Marrón-Becerra, E. Lemus-Santana and M. HermosoSalazar. Paratypes (n = 30 males, n = 30 females): males – mean size 4.4 ± 0.5 mm, mean head length 0.6 ± 0.03 mm (n = 27), females – mean size 4.5 ± 0.5 mm, mean head length 0.5 ± 0.04 (n = 25) (permanent slides Cat. No. CNCR 35735, paratypes and SEM preparations CNCR 35736), locality same as holotype.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	distribution	Type locality (Figure 1 c). Lake La Encantada, state of Veracruz, Mexico (18.458 ° N, 95.185 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	diagnosis	Diagnosis. Pleonite 1 and 2 with dorsoposterior carina. Coxa 4 excavated posteriorly. Eyes pigmented. Antenna 1 shorter than antenna 2. Antenna 2 less than half body length. Maxilla 1 palp short, overreaching half of length between base of palp and base of setae in outer plate, with 1 stout distal seta; base of the seta covered by a cylindrical structure, setules present; inner plate slender with 3 strong pappose distal setae. Maxilla 2 inner plate with 2 strong pappose setae on inner margin. Gnathopod 1, propodus hammer shaped, palm slope transverse, inner face with 4 serrate setae, comb scales on distoposterior and distoanterior border, carpus inner lobe with 3 – 4 serrate setae. Gnathopod 2, basis hind margin with 2 setae and denticles in polygonal pattern. Uropods without curved setae. Uropod 3, peduncle and ramus subequal in length, styliform. Telson as long as wide, distal margin truncated, with 2 long simple apposed setae. Coxal gills on segments 2 – 6. Sternal gills on segments 3 – 7.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	description	Description of male Body (Figures 5 a, and 17 c), tergites of pleon 1 and 2 with dorsoposterior carina. Epimeral plates 1 – 3 slightly acuminate. Coxae 1 – 3 (Figures 5 a, and 17 c) subequal in shape, subrectangular, longer than wide, coxa 4 wider than coxae 1 – 3 with deep posterior excavation, acumination absent. Coxa 5 with two subequal lobes. Coxa 6 anterior lobe reduced, coxa 7 anterior lobe absent. Head typically gammaridean (Figures 5 a, and 17 c), smaller than first two thoracic segments, rostrum absent. Eyes pigmented, medium, rounded, located between insertions of antennae 1 and 2. Antenna 1 (Figure 5 a – b) less than half body length, shorter than antenna 2 (80 % length of antenna 2), but longer than peduncle of antenna 2, almost reaching to middle of third pereonite; peduncle longer than head, reaching to middle of length of first pereonite; article 1 and 2 subequal in length, article 1 wider than articles 2 – 3, article 2 longer and wider than article 3, proportions (1.3: 1.26: 1), article 1 with 3 short setae ventrally, 1 smaller, and one cluster with 3 cuspidate setae at distal end, articles 1 – 3 mid-ventral margin with slender setae; flagellum longer than peduncle with 9 articles becoming gradually shorter towards distal portion; aesthetascs on flagellum, present on articles 2 – 6 (one pair), 7 – 8 (one). Antenna 2 (Figure 5 a, c) almost 1.27 times longer than antenna 1, reaching one-third body length, reaching fourth pereonite; peduncle reaching second pereonite, peduncle articles increase gradually in length and decrease in width; article 3 shorter but wider than 4 and 5, article 4 longer than article 3, article 5 slightly longer than article 4 (almost 1.3 times); flagellum with 8 – 10 articles, slightly longer than peduncle, without aesthetascs. Buccal parts: upper lip (Figure 5 f), distal margin rounded with numerous setules. Lower lip (Figure 5 g) subquadrate, outer lobes without notches or excavations, mandibular projection of outer lobes rounded. Mandibles (Figure 5 h – i), without palp, asymmetric; incisor toothed, 6 teeth present. Left lacinia mobilis with 5 teeth; setal row on left mandible with 3 main pappose setae plus accessory setae. Right mandible with 5 teeth, right lacinia mobilis reduced, with 2 pairs of asymmetric L-shape teeth; setal row on right mandible with 2 main pappose setae plus accessory setae and with setulae near molar process. Molar process large, cylindrical and triturative, with accessory pappose seta in both molars. Maxilla 1 (Figures 5 d, and 19 c), palp short, uniarticulate, longer than wide, distally pointed with 1 short distal stout distal seta (A 5 type), with a cylindrical structure near the base that covers almost one-third of distal seta, setules present; palp length slightly exceeds one-half of distance between base of palp and base of seta on outer plate (Figures 5 d, and 19 c); inner plate slender, shorter than outer plate, with 3 pappose distal setae; outer plate with 9 distal stout serrate setae and with setules. Maxilla 2 (Figure 5 e) plates subequal; inner plate shorter and slender with 2 pappose setae on mid-distal inner margin, distal margin with abundant setae and 6 serrulate setae; outer plate without serrate setae but with 2 long pappose setae; outer and inner plates with large simple distal setae (type A 2) and abundant setules on both distal surfaces and margins. Maxilliped (Figures 5 j, and 20 c) inner plate lobe longer than outer plate lobe, distal margin slightly convex, in both plates, inner plate distal margin with 3 cuspidate setae of equal size and with plumose setae, inner margin with several pappose setae; outer plate, inner and distal margins with numerous simple setae. Palp composed of four articles subequal in maximum length, first article with 3 simple setae at inner distal end and without seta on outer distal end; second article with numerous simple setae on inner margin and 3 on the outer distal end; third article with several setae on distal margin, distal end of outer margin with 4 simple setae and comb scales, inner margin with at least 8 setae and at least 5 at distal end; fourth article unguiform slightly longer than nail, with comb scales, inner margin near distal half with 2 setae, and 1 seta near nail base on outer margin; nail exceeds 2 / 3 of fourth article, with serration at distal half. Gnathopod 1 (Figure 6 a) subchelate, hammer shaped. Basis elongated, maximum length almost 3 times longer than maximum width; posterior margin with 1 seta, distal end with one cluster of 2 setae. Ischium short, subquadrate, slightly longer than wide, length almost same as maximum width of basis and maximum length of merus, distal posterior end with one cluster of 4 setae. Merus longer than wide, ventral surface with comb scales, distal margin with 7 setae. Carpus longer than wide, longer than propodus; with strong, short, and wide posterior lobe and forming one scoop-like structure, open to inside; lobe, inner surface with 2 – 3 serrate setae. Propodus 1.5 times longer than wide, inner surface near distal margin with 3 – 4 serrate setae (3 in a row), outer surface near half of margin with 1 seta; distal anterior end with two clusters of approximately 8 setae; distal anterior and posterior surfaces with comb scales; palm transverse, posterior distal end with 1 robust seta and cup for dactylus. Dactylus claw-like; nail present; with 1 plumose seta, and comb scales. Gnathopod 2 (Figures 6 b, and 21 c) subchelate; palm slightly oblique. Basis elongate, more than 3 times longer than wide; posterior margin with 1 – 2 long setae and denticles in polygonal pattern. Ischium short, subquadrate, shorter than merus. Merus short; posterior margin with 1 seta and distal end of posterior margin with 5 simple setae; posterior inner and outer surfaces with comb scales. Carpus shorter than propodus; anterodistal end with 5 setae; posterior lobe scoop-like, elongate, almost 1.5 times width of merus, with several submarginal pappose setae and comb scales. Propodus robust, almost 1.3 times as long as wide, subrectangular, palm slightly shorter than posterior margin; slope slightly irregular, with several long simple setae, and some short and medium setae; distal margin of palm with one truncated process near insertion of dactylus and with narrow posterior excavation at base (Figure 22 c); palm posterior distal end with 2 strong setae, comb scales, and cup for the dactylus. Dactylus claw-like, congruent with palm, without comb scales; outer margin with 1 plumose seta; inner margin with setules widely separated, crenulation absent. Pereopods 3 – 7 (Figure 6 e – i) simple, gradually longer posteriorly; pereopod 5 shorter than 4 and 6. Pereopod 3 (Figure 6 e), basis elongate; mid-posterior margin with 1 simple seta. Merus anterior margin with 1 long simple seta; posterior margin with 3 setae; anterodistal and posterodistal end with one cluster of 4 setae. Carpus slightly shorter and slenderer than merus; posterior margin with 4 stout setae plus accessory seta; anterodistal end with at least 5 slender setae, posterodistal end with at least 2 setae. Propodus slenderer than carpus; posterior margin with 4 setae; anterodistal end with 6 simple setae. Dactylus clawlike, length less than half of propodus; nail present. Pereopod 4 (Figure 6 f) similar in shape to pereopod 3 but slightly longer, coxa 4 wider than coxa 3 with posterior excavation; basis posterior margin with 1 simple seta; merus mid anterior margin with 1 stout setae; propodus posterior margin with 3 – 5 setae. Pereopods 5 – 7 (Figure 6 g – i) similar in shape, basis posterior lobe rounded and denticulated; pereopod 7 (Figure 6 i) basis lobe widely expanded, almost reaching ischium distal margin; wider than lobes in pereopods 5 and 6; basis lobe width as wide as 1.5 times the basis (measured at cleft between basis and basis lobe); posterior margin with 10 – 12 serrations, each with 1 setule but 2 – 4 serrations with 1 stout seta on distal margin; anterior margin with three clusters of 2 stout setae and one cluster of 2 setae at distal end. Dactylus length less than half of propodus length. Pleopods 1 – 3 (Figure 7 e) not modified, biramous, elongated, rami multi-annulated, with numerous plumose setae; pleopod 1, inner margin of peduncle at distal end with 2 short retinacula (coupling hooks). Uropod 1 (Figure 7 a) longer than uropod 2 (Figure 7 b); peduncle longer than rami, dorsal margin with 2 setae; inner and outer distal ends each with 1 seta; rami subequal, inner ramus slightly longer, with 2 dorsal and 4 distal setae, outer ramus with 2 dorsal and 4 distal setae; male without curved setae on inner ramus. Uropod 2 (Figure 7 b) as long as peduncle of uropod 1; peduncle slightly longer than outer rami, with 1 dorsal seta, inner and outer distal ends each with 1 seta; rami subequal; inner ramus slightly longer with 2 dorsal and 3 distal setae; outer ramus with 2 dorsal and 4 distal setae. Uropod 3 (Figures 7 c, and 23 c) peduncle rectangular, wider than ramus, with 5 strong distal setae of variable length; inner ramus absent; outer ramus uniarticulate, slender, slightly shorter than peduncle, with 4 slender apical setae and 1 connate seta. Telson (Figures 7 d, and 24 c) entire, as long as wide, distal margin pointed, with 2 long simple setae apposed; two clusters of 3 plumose setae symmetrically distributed. Coxal gills sac-like, present on segments 2 – 6 (Figure 6 h, dotted line). Sternal gills tubular, present on segments 3 – 7 (Figure 6 h, dotted line). Female (Figure 17 d) similar to male. Gnathopod 1 (Figure 6 c), carpus with 3 serrate setae on the inner face lobe. Propodus with 4 serrate setae in a row over the inner face, and 3 long setae on a row on the outer face. Gnathopod 2 (Figure 6 d) smaller than male gnathopod 2, parachelated, palm reverse oblique, basis posterior margin with 1 seta; propodus longer than twice maximum width, outer face with 3 – 4 serrate setae in a row and 1 large seta near the palm, anterior and posterior distal half with comb scales. Pereonite 2 with one anterior excavation or notch for amplexus. Pereopod 7 lobes with 9 serrations and setules, and with 2 stout setae on the distal margin. Oostegites subtriangular, almost reaching one-half length of merus, with setae curled on the margins. Intraspecific variation. The palp of maxilla 1 is short and varies in length and form in the same organism or if is moulting; can reach a maximum length of almost 2 times width and presents constricted margin in the middle.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	biology_ecology	Habitat. Freshwater, epigean, littoral, associated with Eichhornia crassipes (Mart.) Solms.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	distribution	Distribution. Lake La Encantada, state of Veracruz, Mexico (18.458 ° N, 95.185 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C407B5DCBD8FDF64D0DFD86.taxon	discussion	Remarks Hyalella alvarezi sp. nov. (La Encantada, Veracruz) shares morphological traits with the other species from Veracruz and with H. wakulla from Florida, such as the dorsal mucronations (except in H. garyi sp. nov.), and the telson with 2 distal setae apposed, similar to H. azteca s. s. (except in H. sarukhani sp. nov., and H. garyi sp. nov.). This species can be distinguished primarily by the presence of one cylindrical base covering almost one-third of the distal setae in palp of maxilla 1, the polygonal pattern (denticles) over the surface of basis in male gnathopod 2 (similar to H. gauchensis Streck and Castiglioni, 2017, H. georginae Streck and Castiglioni, 2017 and H. rioantensis Penoni and Bueno, 2020 – i. e. the three from southern Brazil), and one slender excavation in the palm of male gnathopod 2. On the other hand, this species shares morphological characters with H. sarukhani sp. nov. (Tables 1, S 1 – S 2).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	description	(Figures 8 – 10)	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	etymology	Etymology. The new species is named in honour of Dra Vivianne Solís-Weiss, in recognition of her studies of marine and estuarine invertebrates in Mexico.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	materials_examined	Material examined. Holotype male, size 4.9 mm (Cat. No. CNCR 35728) from Lake San Julian, state of Veracruz, Mexico (19.256 ° N, 96.265 ° W), 24 July 2015, 5 m. a. s. l., temp. 37 ° C, pH 7.8. Collectors: A. Marrón-Becerra, E. Lemus-Santana and M. Hermoso-Salazar. Paratypes (n = 30 males, n = 30 females): males – mean size 4.5 ± 0.6 mm (n = 27), mean head length 0.6 ± 0.03 mm (n = 10), females – mean size 4.3 ± 0.4 mm, mean head length 0.6 ± 0.03 (n = 30) (permanent slides Cat. No. CNCR 35737, paratypes and SEM preparations CNCR 35738), locality same as holotype.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	distribution	Type locality (Figure 1 b). Lake San Julian, state of Veracruz, Mexico (19.256 ° N, 96.265 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	diagnosis	Diagnosis. Pleonite 1 and 2 with dorsoposterior carina. Coxa 4 excavated posteriorly. Eyes pigmented. Antenna 1 shorter than antenna 2. Antenna 2 less than half body length. Maxilla 1 palp short, overreaching half of length between base of palp and tip of setae in outer plate, with 1 large stout distal seta and setules; inner plate slender with 3 strong pappose distal setae. Maxilla 2 inner plate with 2 strong pappose setae on inner margin. Gnathopod 1, propodus hammer shaped, palm slope transverse, inner face with 4 serrate setae, comb scales on distoposterior and distoanterior border, carpus inner face lobe with 3 serrate setae. Gnathopod 2, basis hind margin with 2 serrate setae. Uropods without curved setae. Uropod 3, peduncle slightly shorter than ramus, ramus styliform. Telson slightly longer than width, distal margin rounded with 2 long simple apposed setae. Coxal gills on segments 2 – 6. Sternal gills on segments 3 – 7.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	description	Description of male Body (Figures 8 a, and 17 e), tergites of pleon 1 and 2 with dorsoposterior carina. Epimeral plates 1 – 3 slightly acuminate. Coxae 1 – 3 (Figures 8 a, and 17 e) subequal in shape, subrectangular, longer than wide; coxa 4 wider than coxae 1 – 3 with deep posterior excavation; acumination absent. coxa 5 anterior lobe slightly shorter than posterior; coxa 6 anterior lobe reduced; coxa 7 anterior lobe absent. Head typically gammaridean (Figures 8 a, and 17 e), shorter than first two thoracic segments, rostrum absent. Eyes pigmented, medium, rounded, located between insertions of antennae 1 and 2. Antenna 1 (Figure 8 a – b) less than half body length, shorter than antenna 2, but longer than peduncle of antenna 2; peduncle longer than head, almost reaching second pereonite; articles 1 and 2 subequal in length, article 1 wider than articles 2 – 3, article 2 longer and wider than article 3 (proportions 1.6: 1.3: 1), article 1 almost reaching half ventral surface with 1 short cuspidate seta and with one cluster with 3 cuspidate setae at ventral-distal end, articles 2 – 3 without mid-ventral margin setae; flagellum longer than peduncle with 6 articles gradually shorter towards distal portion; aesthetascs present on articles 3 – 5 (one). Antenna 2 (Figure 8 a, c) almost 1.2 times longer than antenna 1, reaching one-third body length, almost reaching fifth pereonite; peduncle almost reaching the second pereonite, peduncle articles increase gradually in length and decrease in width; article 3 shorter but wider than 4 and 5, article 4 slightly longer than article 3, article 5 longer than article 4 (less than 1.5 times); flagellum with 7 – 9 articles, slightly longer than peduncle (almost 1.5 times); without aesthetascs. Buccal parts: upper lip (Figure 8 f) distal margin rounded with numerous setules. Lower lip (Figure 8 g), subquadrate, outer lobes without notches or excavations, mandibular projection of outer lobes rounded. Mandibles (Figure 8 h – i), without palp, asymmetric. Incisor toothed, 6 teeth present. Left lacinia mobilis with 5 teeth; setal row on left mandible with 3 main pappose setae plus accessory setae. Right mandible with 6 teeth, right lacinia mobilis reduced, with 2 pairs of asymmetric L-shape teeth; setal row on right mandible with 2 main pappose setae plus accessory setae and with setulae near molar process. Both molar processes large, cylindrical and triturative, with accessory pappose setae. Maxilla 1 (Figure 8 d and 19 d), palp uniarticulate, longer than wide, distally pointed with 1 stout distal seta, seta length reaching one-third of palp length, setules present; palp length almost reach 2 / 3 of distance between base of palp and base of seta on outer plate, almost half distance between base of palp and tip of seta on outer plate (Figure 8 d); inner plate slender, shorter than outer plate with 2 – 3 pappose distal setae; outer plate with 9 stout distal serrate setae and with setules (Figure 8 d). Maxilla 2 (Figure 8 e) plates subequal; inner plate shorter and slender, with 2 pappose setae on mid-distal margin, and with 7 shorter paposerrate setae; outer and inner plates with large simple distal setae (A 2 type) and abundant setules on both distal surfaces and margins. Maxilliped (Figures 8 j, and 20 d) inner plate lobe longer than outer plate lobe; distal margin slightly convex; inner plate distal margin with 3 cuspidate setae of equal size and with plumose setae, inner margin with several pappose setae; outer plate, inner and distal margins with numerous simple setae. Palp composed of four articles subequal in maximum length; first article with 3 simple setae at inner distal end and 1 seta at outer distal end; second article with numerous simple setae on inner margin and 3 on outer distal end; third article with several setae on distal margin, outer margin with 4 simple setae and comb scales, inner margin with 5 – 6 setae and at least 9 at distal end; fourth article unguiform, longer than nail, with comb scales, inner margin near distal half with 3 setae and 1 near nail base on outer margin; nail exceeds 2 / 3 of fourth article, with serration at distal half. Gnathopod 1 (Figure 9 a) subchelate, hammer shaped. Basis elongated, maximum length almost 3.5 times longer than maximum width; posterior margin with 1 seta, distal end with one cluster of 4 setae. Ischium short, subquadrate; distal posterior end with two clusters of 2 setae. Merus longer than wide, ventral surface with comb scales; distal margin with 5 setae. Carpus longer than wide, longer and slightly wider than propodus, with strong, short, and wide posterior lobe, forming one scoop-like structure, open to inside; lobe inner surface with 3 serrate setae. Propodus maximum length less than 1.5 times longer than wide; inner surface near distal margin with 4 serrate setae in one row, distal anterior end with one cluster of approximately 7 setae, distal anterior and posterior surfaces with comb scales; palm transverse, posterior distal end with 1 robust seta and cup for dactylus. Dactylus claw-like; nail present with 1 plumose seta, and comb scales. Gnathopod 2 (Figures 9 b, and 21 d) subchelated; palm slightly oblique. Basis elongate, more than 3 times longer than wide; posterior margin with 1 – 2 setae. Ischium short, subquadrate, shorter than merus. Merus short, posterior margin with 8 simple setae; distal third of posterior inner and outer surfaces with comb scales. Carpus shorter than propodus; anterodistal end with 3 setae; posterior lobe scoop-like, elongate, with several submarginal pappose setae and comb scales. Propodus robust, length slightly exceeds 1.5 times as long as wide (1.6 times), subrectangular; palm slightly shorter than posterior margin; slope slightly irregular, with several long simple setae, and few and médium setae; inner face with 4 submarginal thinner simple setae; palm, distal margin, with one truncated process near insertion of dactylus, and without posterior excavation at base, angle stepped (Figure 22 d); palm, posterior distal end with 2 strong setae, comb scales and cup for the dactylus. Dactylus claw-like, congruent with palm, without comb scales, outer margin proximal third with one plumose seta, inner margin crenulate with separated setae. Pereopods 3 – 7 (Figure 9 e – i) simple, gradually longer posteriorly. Pereopod 5 shorter than 4 and 6. Pereopod 3 (Figure 9 e), basis elongate, mid-posterior margin with 1 simple seta. Merus; anterior margin with 2 setae; posterior margin with 4 setae, anterodistal end with one cluster of 2 setae and posterodistal end with one cluster of 4 – 5 setae. Carpus shorter and slenderer than merus; posterior margin with 4 stout setae plus accessory setae; posterodistal end with at least 4 slender setae; anterodistal end with at least 2 setae. Propodus shorter than posterior margin of merus; posterior margin with 4 setae; anterodistal end with 5 simple setae. Dactylus claw-like, length almost half of length of propodus; nail present. Pereopod 4 (Figure 9 f) similar in shape to pereopod 3 but slightly longer; coxa 4 wider than coxa 3 with posterior excavation; basis posterior margin with 1 simple seta; merus mid-anterior margin with 1 seta; propodus posterior margin with 5 stout setae. Pereopods 5 – 7 (Figure 9 g – i) similar in shape, basis posterior lobe rounded and denticulated. Pereopod 7 (Figure 9 i) basis lobe widely expanded, almost reaching ischium distal margin; wider than lobes of pereopods 5 and 6; basis lobe, width almost 1.5 times as width as basis (measured at cleft between basis and basis lobe); posterior margin with 15 serrations, each with 1 setule (13) but 2 serrations with 1 stout seta on distal margin; anterior margin, distal end with three clusters of stout setae on distal half and one cluster of 3 stout setae at distal end. Dactylus length almost half of propodus length. Pleopods 1 – 3 (Figure 10 e) not modified, biramous, elongated, rami multi-annulated, with numerous plumose setae; pleopod 1, inner margin of peduncle at distal end with 2 short retinacula (coupling hooks). Uropod 1 (Figure 10 a) longer than uropod 2; peduncle longer than rami, dorsal margin with 3 dorsal setae, inner and outer distal ends each with 1 seta; rami subequal, inner ramus slightly longer, with 2 dorsal and 3 distal setae, outer ramus with 2 dorsal and 4 distal setae; male without curved setae on inner ramus. Uropod 2 (Figure 10 b) slightly longer than peduncle of uropod 1; peduncle as long as outer ramus, with 1 dorsal seta and inner and outer distal ends each with 1 seta; rami subequal, inner ramus slightly longer with 2 dorsal and 3 distal setae, outer ramus with 2 dorsal and 4 distal setae. Uropod 3 (Figures 10 c, and 23 d) length similar to peduncle of uropod 2; peduncle rectangular, wider than ramus, with 4 strong distal setae of variable length; inner ramus absent; outer ramus uniarticulate, slender, slightly longer than peduncle, more than 2 times (almost 3 times) length of larger setae of peduncle, basal width near 3 times width of apex of ramus, with 3 slender apical setae and 1 connate seta. Telson (Figures 10 d, and 24 d) entire, longer than wide, narrowing posteriorly, with 2 long simple apposed setae; outer surface with two clusters of 3 plumose setae near middle distal portion, near margin, symmetrically distributed. Coxal gills sac-like, present on segments 2 – 6. Sternal gills tubular, present on segments 3 – 7. Female (Figure 17 f) similar to male. Gnathopod 1 (Figure 9 c), carpus with 2 serrate setae on inner face lobe; propodus with 3 serrate setae in a row over the inner face. Gnathopod 2 (Figure 9 d) smaller than male gnathopod 2, parachelated; palm reverse oblique; basis posterior margin with 1 seta; propodus slightly longer than twice maximum width, outer face with 2 serrate setae in a row and 1 large seta near the palm; anterior and posterior distal half with comb scales. Pereonite 2 with an anterior excavation or notch for amplexus. Pereopod 7 lobes with 10 serrations and setules, and with 3 stout setae on the distal margin. Oostegites subtriangular with setae curled on the margins. Intraspecific variation. The palp of maxilla 1 is short but presents differences in length and form; especially if the organism is moulting, it could reach almost 2 times its length and present a constricted margin in the middle.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	biology_ecology	Habitat. Freshwater, epigean, littoral, associated with roots of Typha dominguensis Pers, found in the sediment.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	distribution	Distribution. Lake San Julian, state of Veracruz, Mexico (19.256 ° N, 96.265 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C5B7B5BCBCCFDE54E53F971.taxon	discussion	Remarks Hyalella viviannae sp. nov. is similar to H. azteca and the other species from state of Veracruz; however, this species can be recognised by the relatively long distal seta in the palp of maxilla 1, the absence of one notch in the palm of gnathopod 2 in males (angle step), the relative length of the ramus in uropod 3 (longer than peduncle), and the form of the telson – longer than wide with 2 apposed setae and the distal margin rounded.)	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	description	(Figures 11 – 13)	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	etymology	Etymology. The new species is named in honour of Dr José Luis Villalobos Hiriart, in recognition of his valuable and outstanding contributions to the marine and freshwater carcinology of Mexico.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	materials_examined	Material examined. Holotype male, size 5.4 mm (Cat. No. CNCR 35729), from Lake Catemaco in state of Veracruz, Mexico (18.366 ° N, 95.084 ° W), 24 July 2015, 337 m a. s. l., temp. 34 ° C, pH 7. Collectors: A. Marrón-Becerra, E. Lemus-Santana and M. HermosoSalazar. Paratypes (n = 30 males, n = 30 females): males – mean body total length 5.1 ± 0.5 mm, mean head length 0.6 ± 0.03 mm (n = 27), females – mean body total length 4.5 ± 0.5 mm, mean head lenght 0.5 ± 0.04 (n = 30) (permanent slides Cat. No. CNCR 35739, paratypes and SEM preparations CNCR 35740), locality same as holotype.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	distribution	Type locality (Figure 1). Lake Catemaco, state of Veracruz, Mexico (18.366 ° N, 95.084 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	diagnosis	Diagnosis. Pleonite 1 and 2 with dorsoposterior carina. Coxa 4 excavated posteriorly. Eyes pigmented. Antenna 1 shorter than antenna 2. Antenna 2 less than half body length. Maxilla 1 palp short, overreaching half of length between base of palp and base of setae in outer plate, with 1 short stout distal seta and setules; inner plate slender with 3 strong pappose distal setae. Maxilla 2 inner plate with 2 strong pappose setae on inner margin. Gnathopod 1, propodus hammer shaped, palm slope transverse, inner face with 2 pappose setae, comb scales on distoposterior and distoanterior border, carpus inner face lobe with 5 pappose setae. Gnathopod 2, basis hind margin with 1 medial seta, excavation of palm wide. Uropods without curved setae. Uropod 3, peduncle longer than ramus, styliform. Telson as long as wide, distal margin acute, with 2 long simple apposed setae. Coxal gills on segments 2 – 6. Sternal gills on segments 3 – 7.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	description	Description Body (Figures 11 a, and 18 a), tergites of pleon 1 and 2 with dorsoposterior carina. Epimeral plates 1 – 3 slightly acuminate. Coxae 1 – 3 (Figures 11 a, and 18 a) subequal in shape, subrectangular, longer than wide; coxa 1 shorter than coxae 2 – 3; coxa 4 wider than coxae 1 – 3 with deep posterior excavation, acumination absent; coxa 5 with two subequal lobes, anterior lobe slightly shorter than posterior; coxa 6 anterior lobe reduced; coxa 7 anterior lobe absent. Head typically gammaridean (Figures 11 a, and 18 a), shorter than first two thoracic segments, rostrum absent. Eyes pigmented, medium, rounded, located between insertions of antennae 1 and 2. Antenna 1 (Figure 11 a – b) less than half the body length, shorter than antenna 2, but longer than peduncle of antenna 2, almost reaching to middle of third pereonite; peduncle longer than head, reaching to middle of length of first pereonite; article 1 and 2 subequal in length, article 1 wider than articles 2 – 3, article 2 longer and wider than article 3, proportions (1.3: 1.26: 1), article 1 with 3 short setae, 1 smaller, and one cluster with 3 cuspidate setae ventrally at distal end, articles 1 – 3 mid-ventral margin with slender setae; flagellum longer than peduncle with 9 articles gradually shorter towards distal portion; aesthetascs on flagellum, present on articles 2 – 6 (one pair), 7 – 8 (one). Antenna 2 (Figure 11 a, c) almost 1.27 times longer than antenna 1, reaching one-third body length, reaching fourth pereonite; peduncle reaching second pereonite, peduncle articles increase gradually in length and decrease in width; article 3 shorter but wider than 4 and 5, article 4 longer than article 3, article 5 slightly longer than article 4; flagellum with 8 – 10 articles slightly longer than peduncle (subequal), without aesthetascs. Buccal parts: upper lip (Figure 11 f), distal margin rounded with numerous setules. Lower lip (Figure 11 g) subquadrate, outer lobes without notches or excavations; mandibular projection of outer lobes rounded. Mandibles (Figure 11 h – i) without palp, asymmetric. Incisor toothed, 6 teeth present. Left lacinia mobilis, with 5 teeth; setal row on left mandible with 3 main pappose setae plus accessory setae. Right mandible with 6 teeth, right lacinia mobilis reduced than left, with 2 pairs of asymmetric L-shape teeth; setal row on right mandible with 2 main pappose setae plus accessory setae and with setulae near molar process. Both molar processes large, cylindrical and triturative, with accessory pappose setae. Maxilla 1 (Figures 11 d, and 19 e), palp vestigial, uniarticulate, longer than wide, distally pointed and with 1 distal stout distal seta (A 5 type), setules present; palp length overreaches half of the distance between base of palp and base of seta on outer plate, or reaching to middle; inner plate slender, shorter than outer plate, with 3 – 4 pappose distal setae (2 distal and 2 subdistal); outer plate with 9 distal stout serrate setae and with setules. Maxilla 2 (Figure 11 e) plates subequal; inner plate shorter and slender with 2 pappose setae on mid-distal inner margin, and with 6 serrulate setae on distal margin; outer plate without serrate setae but with 2 long pappose setae; outer and inner plates with abundant large simple setae (type A 2) and setules on both distal surfaces and margins. Maxilliped (Figures 11 j, and 20 e) inner plate lobe longer than outer plate lobe; distal margin slightly convex; inner plate distal margin with 3 cuspidate setae of equal size and with plumose setae, inner margin with several pappose setae; outer plate, inner and distal margins with numerous simple setae. Palp composed of four articles subequal in maximum length; first article with 2 simple setae at the inner distal end and 1 seta at outer distal end; second article with numerous simple setae on inner margin and 1 on outer distal end; third article with several long setae on distal margin, outer margin with 1 simple seta and comb scales, inner margin with 5 setae and 5 at distal end; fourth article unguiform slightly longer than nail, with comb scales, inner margin near distal half with 3 setae, and 2 setae near nail base on outer margin; nail exceeds two-thirds of fourth article, with serration at distal half. Gnathopod 1 (Figure 12 a) subchelate, hammer shaped. Basis elongated, maximum length almost 3 times longer than maximum width posterior margin with 2 setae, distal end without cluster of setae. Ischium short, subquadrate; distal posterior end with one cluster of 2 setae. Merus longer than wide, ventral surface with comb scales; distal margin with 8 setae. Carpus longer than wide, longer than propodus; with strong, short, and wide posterior lobe forming one scoop-like structure open to inside; inner surface with 5 serrate setae. Propodus less than 1.5 times longer than wide (1.36 times); inner surface near distal margin with 2 serrate setae in one row, distal anterior end with 2 clusters of approximately 8 setae; distal anterior and posterior surfaces with comb scales; palm transverse, posterior distal end with 1 robust seta and cup for dactylus. Dactylus clawlike; nail present; with 1 plumose seta, with comb scales. Gnathopod 2 (Figures 12 b, and 21 e) subchelated; palm slightly oblique. Basis elongate, more than 3 times longer than wide; posterior margin with 0 – 1 medial seta. Ischium short, subquadrate, shorter than merus. Merus short, posterior margin with 8 simple setae, posterior inner and outer surfaces with comb scales. Carpus shorter than propodus; anterodistal end with 6 setae; posterior lobe scoop-like, elongate, length similar to merus maximum length, almost 1.5 times width of merus, with several submarginal pappose setae and comb scales. Propodus robust, almost 1.5 times as long as wide, subrectangular; palm similar length to or slightly longer than posterior margin; slope slightly irregular, with several long simple setae, and some short and medium setae; distal margin of palm with one truncated process near insertion of dactylus, and with wide posterior excavation at base (Figure 22 e); palm posterior distal end with 2 strong setae, comb scales and cup for the dactylus. Dactylus claw-like, congruent with palm without comb scales; outer margin with 1 plumose seta; inner margin crenulated, with setules. Pereopods 3 – 7 (Figure 12 e – i) simple, gradually longer posteriorly. Pereopod 5 slightly shorter than 4 and 6. Pereopod 3 (Figure 12 e) basis elongate; mid-posterior margin without simple seta. Merus anterior margin almost at half with 1 seta; posterior margin with 3 long simple setae; anterodistal and posterodistal ends with one cluster of 4 and 7 setae, respectively. Carpus slightly shorter and slenderer than merus; posterior margin with 2 stout setae plus accessory setae; posterodistal end with at least 7 slender setae, anterodistal end with at least 6 setae. Propodus, slenderer than carpus; posterior margin with 3 stout setae; anterodistal end with 5 simple setae. Dactylus claw-like; length less than half of propodus; nail present. Pereopod 4 (Figure 12 f) similar in shape to pereopod 3 but slightly longer; coxa 4 wider than coxa 3 with posterior excavation; basis posterior margin without simple seta; merus mid-anterior margin without setae; propodus posterior margin with 3 stout setae. Pereopods 5 – 7 (Figure 12 g – i) similar in shape; basis posterior lobe rounded and denticulated. Pereopod 7 (Figure 12 i) basis lobe widely expanded, overreaching ischium distal margin; basis lobe width 1.7 times as wide as basis (measured at cleft between basis and basis lobe); posterior margin with 13 serrations with setules and without stout seta on distal margin; anterior margin with 2 stout setae and one cluster of 2 setae at distal end. Dactylus length almost one-third of propodus length. Pleopods 1 – 3 (Figure 13 e) not modified, biramous, elongated, rami multi-annulated, with numerous plumose setae; pleopod 1, inner margin of peduncle at distal end with 2 short retinacula (coupling hooks). Uropod 1 (Figure 13 a) longer than uropod 2; peduncle longer than rami, dorsal margin with 2 dorsal setae, inner and outer distal ends each with 1 seta; rami subequal, inner ramus slightly longer, with 2 dorsal and 5 distal setae; outer ramus with 2 dorsal and 3 distal setae; male without curved setae on inner ramus. Uropod 2 (Figure 13 b) as long as peduncle of uropod 1; peduncle shorter than outer rami, with 1 dorsal seta and 1 seta at distal end; rami subequal, inner ramus slightly longer with 2 dorsal and 6 distal setae, outer ramus with 2 dorsal and 4 distal setae. Uropod 3 (Figures 13 c, and 23 e) slightly longer than or as long as peduncle of uropod 2; peduncle rectangular, wider than ramus, with 5 strong distal setae of variable length; inner ramus absent; outer ramus uniarticulate, slender, slightly shorter than peduncle; basal width almost 3 times width of apex of ramus, with 3 slender apical setae (one longer) and 1 connate seta. Telson (Figures 13 d, and 24 e) entire, longer than wide, distal margin pointed or truncated, with 2 long simple apposed setae; outer surface bearing two clusters of 3 plumose setae, near margin, symmetrically distributed. Coxal gills sac-like, present on segments 2 – 6. Sternal gills tubular, present on segments 3 – 7. Female (Figure 18 b) similar to male. Gnathopod 1 (Figure 12 c), carpus with 7 serrate setae on inner face lobe; propodus with 4 serrate setae in row over inner face. Gnathopod 2 (Figure 12 d) smaller than male gnathopod 2, parachelated, palm reverse oblique, basis posterior margin without seta; propodus longer than twice maximum width, inner face with 4 serrate setae in a row and 1 simple seta, outer face with 4 setae in one row and 3 large setae near palm, anterior and posterior distal half with comb scales. Pereonite 2 with anterior excavation or notch for amplexus. Pereopod 7 lobes with 11 serrations and setules, and without stout setae on distal margin. Oostegites subtriangular with curled setae on margins.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	biology_ecology	Habitat. Freshwater, epigean, littoral, associated with sediment and Eichhornia crassipes (Mart.) Solms.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	distribution	Distribution. Lake Catemaco, state of Veracruz, Mexico (18.366 ° N, 95.084 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C527B52CBCEFF1C4FBCFB43.taxon	discussion	Remarks This species has parasites of the genus Lagenophrys, possibly Lagenophrys patina (Stokes, 1887); they are abundant in the coxae and the basis of pereopods; the protozoos are even attached to the setae. This species is morphologically similar to H. azteca, with two dorsal mucronations on the pleon and the telson with the distal margin acute with 2 distal apposed setae. But this species differs in the following: telson is longer than wider, isquium is longer than its width, uropod 2 is similar in length to peduncle of uropod 1, peduncle is shorter than ramus in uropod 2, and this species has more articles in the antennae despite its shorter size (Tables 1, S 1).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	description	(Figures 14 – 16)	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	etymology	Etymology. The new species is named in honour of Dr Gary A. Wellbon for his valuable contributions to the knowledge of the Hyalella genus.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	materials_examined	Material examined. Holotype male, size 4.7 mm (Cat. No. CNCR 35730), from Lake Catemaco, state of Veracruz, Mexico (18.366 ° N, 95.084 ° W), 24 July 2015, 335 m a. s. l., temp. 34 ° C, pH 7. Collectors: A. Marrón-Becerra, E. Lemus-Santana and M. HermosoSalazar. Paratypes (n = 30 males, n = 30 females): males – mean size 4.8 ± 0.6 mm, mean head length 0.5 ± 0.1 mm (n = 27), females – mean size 4.5 ± 0.2 mm, mean head length 0.5 ± 0.06 (n = 27) (permanent slides Cat. No. CNCR 35741, paratypes and SEM preparations CNCR 35742), locality same as holotype.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	distribution	Type locality (Figure 1). Lake Catemaco, state of Veracruz, Mexico (18.366 ° N, 95.084 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	diagnosis	Diagnosis. Pleonite 1 and 2 without dorsoposterior carina. Coxa 4 excavated posteriorly. Eyes pigmented. Antenna 1 shorter than antenna 2. Antenna 2 less than half body length. Maxilla 1 palp short, reaching less than half of length between base of palp and base of setae in outer plate, without distal seta, setules present; inner plate slender with 3 strong pappose distal setae. Maxilla 2 inner plate with 2 strong pappose setae on inner margin. Gnathopod 1, propodus hammer shaped, palm slope transverse, inner face with 3 serrate setae, comb scales on distoposterior and distoanterior border, carpus inner face lobe with 3 serrate setae. Gnathopod 2, basis hind margin without setae. Uropods without curved setae. Uropod 3, peduncle and ramus subequal in length, styliform. Telson as long as wide, distal margin pointed or truncated, with 2 long simple apposed setae. Coxal gills on segments 2 – 6. Sternal gills on segments 3 – 7.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	description	Description of male Body (Figures 14 a, and 18 c, e), tergites of pleon 1 and 2 without dorsoposterior carina. Epimeral plates 1 – 3 slightly acuminate. Coxae 1 – 3 (Figures 14 a, and 18 c) subequal in shape, subrectangular, longer than wide; coxa 4 wider than coxae 1 – 3 with deep posterior excavation; acumination absent. Coxa 5 with two subequal lobes, anterior lobe slightly shorter than posterior, anterior lobe reduced; coxa 7 anterior lobe absent. Head typically gammaridean (Figures 14 a, and 18 c), shorter than length of first two thoracic segments, rostrum absent. Eyes pigmented, medium, rounded, located between insertions of antennae 1 and 2. Antenna 1 (Figure 14 a – b) less than half body length, shorter than antenna 2, but longer than peduncle of antenna 2, almost reaching to middle of third pereonite; peduncle longer than head, reaching half the length of first pereonite; articles 1 and 2 subequal in length, article 1 wider than articles 2 – 3, article 2 longer and wider than article 3 (1.1: 1.2: 1), article 1 with 3 short setae ventrally, 1 smaller, and one cluster with 3 cuspidate setae at distal end, articles 1 – 3 mid-ventral margin with slender setae; flagellum slightly longer than peduncle with 8 – 9 articles gradually shorter towards distal portion; aesthetascs present on articles 2 – 6 (one pair), 7 – 8 (one). Antenna 2 (Figure 14 a, c) almost 1.27 times longer than antenna 1, reaching one-third body length, reaching the fourth pereonite; peduncle articles increase gradually in length and decrease in width; article 3 shorter but wider than 4 and 5, article 4 longer than article 3, article 5 slightly longer than article 4; flagellum with 8 – 10 articles, slightly longer than peduncle; without aesthetascs. Buccal parts: upper lip (Figure 14 f), distal margin rounded with numerous setules. Lower lip (Figure 14 g) subquadrate, outer lobes without notches or excavations, mandibular projection of outer lobes rounded. Mandibles (Figure 14 h – i) without palp, asymmetric. Incisor toothed, 6 teeth present. Left lacinia mobilis with 5 teeth; setal row on left mandible with 3 main pappose setae plus accessory setae. Right mandible with 6 teeth, right lacinia mobilis more reduced than left, with 2 pairs of asymmetric L-shaped teeth; setal row on right mandible with 2 main pappose setae plus accessory setae and with setulae near the molar process. Both molar processes large, cylindrical and triturative, with accessory pappose setae. Maxilla 1 (Figures 14 d, and 19 f), palp short, vestigial, uniarticulate, longer than wide, distally rounded, setules present, without stout distal seta (A 5 type); palp length no more than one-third of distance between base of palp and base of setae on outer plate; inner plate slender, shorter than outer plate, with 3 pappose distal setae (2 distal and 1 – 2 subdistal); outer plate with 9 distal stout serrate setae and with setules. Maxilla 2 (Figure 14 e) plates subequal; inner plate shorter and slender, with 2 pappose setae on mid-distal inner margin, without serrulate setae on distal margin; outer plate without serrulate setae but with 2 long pappose setae; outer and inner plates with large simple setae (A 2 type), and setules on both distal surfaces and margins. Maxilliped (Figures 14 j, and 20 f) inner plate lobe longer than outer plate lobe; distal margin slightly convex; inner plate distal margin with 3 cuspidate setae of equal size and with plumose setae; inner margin with several pappose setae; outer plate, inner and distal margins with numerous simple setae. Palp composed of four articles subequal in maximum length; first article with 6 simple setae at inner distal end and 1 seta at outer distal end; second article with numerous simple setae on inner margin and 1 on outer distal end; third article with several long simple setae, distal end of outer margin with 1 simple seta and comb scales, inner margin with 5 setae and 5 at distal end; fourth article unguiform, slightly longer than the nail, with comb scales, inner margin near distal half with 4 setae and 2 near nail base on outer margin; nail exceeds 2 / 3 of fourth article, with serration at distal half. Gnathopod 1 (Figure 15 a) subchelate, hammer shaped. Basis elongated, maximum length almost 3 times longer than maximum width; posterior margin without seta, distal end without cluster of setae. Ischium short, subquadrate; distal posterior end with one cluster of 2 setae. Merus longer than wide, ventral surface with comb scales; distal margin with 8 setae. Carpus longer than wide, longer than propodus; with strong, short, and wide posterior lobe forming one scoop-like structure open to inside; inner surface with 3 serrate setae. Propodus less than 1.5 times longer than wide, anterior margin distal third with 1 medial seta; inner surface with 3 serrate setae in one row, outer surface with 1 seta on margin near halfway point; distal anterior end with two clusters of approximately 8 setae; distal anterior and posterior surfaces with comb scales; palm transverse, posterior distal end with 1 robust seta and cup for dactylus. Dactylus claw-like; nail present; anterior surface near proximal third with 1 plumose seta, with comb scales over anterior surface. Gnathopod 2 (Figures 15 b, and 21 f) subchelated; palm slightly oblique. Basis elongate, more than 3 times longer than wide; posterior margin without seta. Ischium short, subquadrate, shorter than merus. Merus short; posterior margin with 8 simple setae, posterior inner and outer surfaces with comb scales. Carpus shorter than propodus; anterodistal end with 6 setae; posterior lobe scoop-like, elongate, length similar to merus maximum length, almost 1.5 times width of merus, with several submarginal pappose setae and comb scales. Propodus robust, length almost 1.5 times as long as wide, subrectangular; palm similar in length to slightly longer than posterior margin; slope slightly irregular, with several long simple setae, and some short and medium setae; distal margin of palm with one truncated process near insertion of dactylus, and with wide posterior excavation (Figure 22 f); palm posterior distal end with 2 strong setae, comb scales and cup for the dactylus. Dactylus claw-like, congruent with palm, without comb scales; outer margin with 1 plumose seta; inner margin crenulate with setules. Pereopods 3 – 7 (Figure 15 e – i) simple, gradually longer posteriorly, pereopod 5 slightly shorter than 4 and 6. Pereopod 3 (Figure 15 e), basis elongate; mid-posterior margin without simple seta. Merus anterior margin with 1 stout seta, posterior margin with 2 long simple setae respectively and 1 medial shorter seta; anterodistal and posterodistal ends with one cluster of 4 and 7 setae, respectively. Carpus slightly shorter and slenderer than merus; posterior margin with 2 stout setae plus accessory seta; posterodistal end with at least 7 slender setae; anterodistal end with at least 6 setae. Propodus slenderer than carpus; posterior margin with 3 setae; anterodistal end with 5 simple setae. Dactylus claw-like, length almost half of propodus; nail present. Pereopod 4 (Figure 15 f) similar in shape to pereopod 3 but slightly longer; coxa 4 wider than 3 with posterior excavation; basis posterior margin without simple seta; merus midanterior margin without setae; propodus posterior margin with 4 stout setae. Pereopods 5 – 7 (Figure 15 g – i) similar in shape; basis posterior lobe rounded and denticulated. Pereopod 7 (Figure 15 i) basis lobe widely expanded, almost reaching ischium distal margin; basis lobe, width 1.6 times as width as basis (measured at cleft between basis and basis lobe); posterior margin with 8 serrations, each with 1 setule without stout seta on distal margin; anterior margin with 2 stout setae and one cluster of 2 setae at distal end. Dactylus length less than half of propodus length. Pleopods 1 – 3 (Figure 16 e) not modified, biramous, elongated, rami multi-annulated, with numerous plumose setae; pleopod 1, inner margin of peduncle at distal end with 2 short retinacula (coupling hooks) at distal end. Uropod 1 (Figure 16 a) longer than uropod 2; peduncle longer than rami, with 2 dorsal setae, inner and outer distal ends each with 1 seta; rami subequal, inner ramus slightly longer, with 2 dorsal and 4 distal setae, outer ramus with 2 dorsal and 4 distal setae; male without curved setae on inner ramus. Uropod 2 (Figure 16 b) as long as peduncle of uropod 1; peduncle shorter than outer rami, with 1 dorsal seta and 1 seta at distal end; rami subequal, inner ramus slightly longer with 2 dorsal and 4 distal setae, outer ramus with 2 dorsal and 3 distal setae. Uropod 3 (Figures 16 c, and 23 f) slightly shorter than peduncle of uropod 2; peduncle rectangular, wider than ramus with 3 strong distal setae of variable length; inner ramus absent; outer ramus uniarticulate, slender, slightly shorter than peduncle, 2 times length of larger seta of peduncle, basal width almost 2 times width of apex of ramus, with 3 slender apical setae (1 longer) and 1 connate seta. Telson (Figures 16 d, and 24 f) entire, longer than wide, distal margin rounded, with 2 long simple apposed or separated setae; with two clusters of 3 plumose setae near middle distal portion, near margin, symmetrically distributed. Coxal gills sac-like, present on segments 2 – 6. Sternal gills tubular, present on segments 3 – 7. Female (Figure 18 d) similar to male. Gnathopod 1 (Figure 15 c), carpus with 7 serrate setae on the inner face lobe. Gnathopod 2 (Figure 15 d) smaller than male gnathopod 2, parachelated, palm reverse oblique, basis posterior margin without seta; propodus longer than twice maximum width, inner face with 3 serrate setae in a row, outer face with 3 setae in a row and 3 large setae near the palm, anterior and posterior distal half with comb scales. Pereonite 2 with one anterior excavation or notch for amplexus. Pereopod 7 lobes with 10 – 13 serrations and setules, and without stout setae on the distal margin. Oostegites subtriangular with setae curled on the margins.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	biology_ecology	Habitat. Freshwater, epigean, littoral, associated with sediment and Eichhornia crassipes (Mart.) Solms.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	distribution	Distribution. Lake Catemaco, state of Veracruz, Mexico (18.366 ° N, 95.084 ° W).	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
0207BC208C547B64C829FAA04B38F9CA.taxon	discussion	Remarks This species is similar to H. villalobosi sp. nov.; however, H. garyi sp. nov. can be distinguished by the absence of dorsal mucronations on the pleon, the shape of the upper lip (subquadrate), the shape of the lower lip (subtriangular in H. villalobosi sp. nov.), the absence of 1 distal seta in the palp of maxilla 1 (similar to H. azteca s. s.) but with setules (absent in H. wakulla Drumm and Knight-Gray, 2019), the inner plate of maxilla 2 wider, the absence of setae in the hind margin of male gnathopod 2, the length of the merus vs isquium in the pereiopod 3 (close to 2 times), the relative witdth of the base of uropod 3 (less than 2 times), and the distal margin of telson rounded, in contrast to the other species from Veracruz with the margin acute (similar to H. azteca s. s.). In the species from lake Catemaco (H. villalobosi sp. nov. and H. garyi sp. nov.) the articles of the palp in maxilliped are apparently longer than articles in H. azteca and the other species described herein.	en	Marrón-Becerra, Aurora, Hermoso-Salazar, Margarita (2022): Morphological comparison and description of five new species of Hyalella (Crustacea: Amphipoda) from Veracruz and Mexico City. Journal of Natural History 56 (25 - 28): 1215-1263, DOI: 10.1080/00222933.2022.2078241, URL: http://dx.doi.org/10.1080/00222933.2022.2078241
