taxonID	type	description	language	source
03B2EE18FFF8FFA726347019ED2807F6.taxon	type_taxon	Type species Lygdamis indicus Kinberg, 1867; by monotypy.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF8FFA726347019ED2807F6.taxon	diagnosis	Diagnosis Operculum completely divided into two free lobes. Two rows of opercular paleae. Outer paleae arranged in semicircles, with straight or slightly curved, cylindrical blades and smooth or serrated margins. Inner paleae arranged in one row along inner margin of opercular lobes with straight and cylindrical blades. One pair of nuchal hooks without limbation. Multiple tentacular filaments (compound). Median ridge with lateral eyespots. Median organ cylindrical, tip truncate or tapered. Four parathoracic segments (Kirtley 1994; Capa & Hutchings 2019).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	description	urn: lsid: zoobank. org: act: 431 F 3 C 52 - F 1 BF- 4 B 86 - 81 D 2 - A 601 CCA 93204 Figs 1 – 2	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	diagnosis	Diagnosis Seven outer paleae cylindrical at base, flattened sharp tips, and serrate margins. Four inner paleae cylindrical, blunt tips and faintly serrate margins. Median organ shorter than lobes, cylindrical, without lateral eyespots, with truncate and pigmented tip.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	etymology	Etymology This species name is after Dr Daniel Guadalupe Pech Pool, head of the BIOMARCCA collection, who kindly lent me the holotype specimen. The species name is a noun in the genitive case (ICZN 1999, Art. 31.1.2).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	materials_examined	Material examined Holotype MEXICO • complete spec. (body length 5.5 mm); Veracruz, northeast of Tecolutla; 20 ° 45 ′ 37.91 ″ N, 96 ° 57 ′ 41.8 ″ W; depth 47 m; 18 Mar. 2018; ALH leg.; ECOSUR- 302.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	description	Description BODY. Holotype complete (ECOSUR- 302), preserved material colorless, 5.5 mm long, 0.8 mm wide, 17 abdominal segments, caudal peduncle 0.5 mm long (Fig. 1). OPERCULUM. Opercular disc oblique, two rows of translucent, pale yellow paleae; outer row with 6 – 7 paleae per lobe, inner row with four paleae per lobe (Fig. 1 A – C). Outer paleae cylindrical at base with flattened, sharp tip; blade straight with serrated margins (Fig. 2 A – C). Inner paleae 1.6 times as long as outer paleae, cylindrical; blade straight, with faintly serrate margins and blunt tips (Fig. 2 A, D). Opercular stalk twice longer than wide (Fig. 1 A – B). Five to six opercular papillae decrease in size ventrally (Fig. 1 C); first pair of papillae about four times as long as others, with dark tips (Fig. 1 B). Nine rows of buccal tentacles. Palps slightly longer than median organ, as long as opercular stalk lobes (Fig. 1 D). A pair of nuchal hooks, large, sharp (Fig. 1 B – C). Median ridge with marginal eyespots. Median organ shorter than lobes, almost four times as long as wide, cylindrical, tip truncate and pigmented, without lateral eyespots (Fig. 1 D). THORAX. First thoracic segment with one lobe-shaped neuropodium and capillary chaetae (Fig. 1 E). Second segment with capillary neurochaetae, two triangular-shaped lateral lobes, and paired branchiae. PARATHORAX. With four segments, all with branchiae. Notopodia with six lanceolate and five capillary chaetae (Fig. 2 E). Neurochaetae with four lanceolate and five capillaries, half the length of notochaetae (Fig. 2 F). ABDOMEN. Abdominal segments with paired branchiae up to segment 4 (Fig. 1 A, F). Neurochaetae capillary, ornamented with irregular thecal laminar extensions. Notopodia with series of uncini with 6 – 7 transverse rows of teeth (Fig. 2 G). Caudal peduncle colorless, small, cylindrical (Fig. 1 F).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	discussion	Remarks Uebelacker (1984) recorded Lygdamis indicus Kinberg, 1867 for the west coast of Florida, northeastern Gulf of Mexico. Her specimens had “ 14 – 31 pairs of outer paleae slender, faintly serrate, and distally pointed in juveniles, smooth with tips often bent in adults; … 6 – 16 pairs of inner paleae stouter, blunttipped, smooth in adults, faintly serrate in juveniles; … a median tentacle (or median organ) stout with dark brown tip ” (Uebelacker 1984: 49 - 5). The faintly serrated outer and inner paleae of specimens that Uebelacker (1984) described as juveniles resemble the opercular paleae of L. pechi sp. nov. However, L. pechi sp. nov. has outer paleae with flattened tips, and fewer opercular paleae (6 – 7 outer paleae per lobe, four inner paleae per lobe). Kirtley (1994) included some of the Uebelacker’s records in L. rayrobertsi Kirtley, 1994 from Florida. Kirtley also indicated that the record of L. indicus in the Gulf of Mexico was a misidentification. However, he failed to explain any morphological variations of the opercular paleae described by Uebelacker (1984), so it is not possible to determine whether the juvenile specimen described by Uebelacker also belongs to L. rayrobertsi. In the brief description of L. rayrobertsi, Kirtley (1994) mentioned smooth outer paleae with sharp, slightly bent, conical tips; broad, flat inner paleae with smooth margins; and a median organ ending in discoidal, pigmented, truncate tip. Lygdamis pechi sp. nov. and L. rayrobertsi share a robust median organ; however, they differ in the morphology of their opercular paleae (see key above). Kirtley (1994) did not describe the number of opercular paleae of L. rayrobertsi. Dos Santos et al. (2014) recorded L. rayrobertsi (8 mm long) for Brazil and describe it with 14 outer paleae, six inner paleae per lobe and opercular papillae of similar size (Dos Santos et al. 2014: fig. 2 b), whereas L. pechi sp. nov. (5.5 mm long) has only seven outer paleae, four inner paleae per lobe and the first pair of papillae longer than other ones.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFBFFA026E17406EC420359.taxon	distribution	Distribution Gulf of Mexico, northeast of Tecolutla, Veracruz, at 47 m depth (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFCFFA3265D719CED28006C.taxon	type_taxon	Type species Phalacrostemma norvegicum Strømgren, 1971; by original designation.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFCFFA3265D719CED28006C.taxon	diagnosis	Diagnosis Operculum completely divided into two free lobes. Two rows of opercular paleae. Outer paleae arranged in semicircles; straight, cylindrical, or slightly compressed blade with transverse irregular thecae bands. Few inner paleae arranged in one short row near to dorsal junction of inner marginal lobes, with straight and cylindrical blades. One or more pairs of nuchal spines. Tentacular filaments arranged in single rows (simple). Palps grooved, longer than operculum. Median ridge short with some lateral eyespots. Median organ absent. Four parathoracic segments (Kirtley 1994; Capa & Hutchings 2019).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFCFFA3265D719CED28006C.taxon	discussion	Remarks Mariansabellaria Kirtley, 1994 included, until now, only four species: M. norvegica (Strømgren, 1971) from the Norwegian Sea, M. chilena Kirtley, 1994 from southern Chile, M. harrisae Kirtley, 1994 from Santa Monica Bay, California, and M. tenhovei Kirtley, 1994 from Yaquina Bay, Oregon. It is necessary to re-describe the species of Mariansabellaria because Kirtley did not include the same characters in all species descriptions. Standardization in the descriptions will facilitate the identification and comparison of the species, and will also allow the development of identification keys with clearer and easier to observe characters.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	description	urn: lsid: zoobank. org: act: 85 B 7 E 010 - D 51 F- 48 C 4 - 8 EF 4 - 0 BA 9 A 76 B 3 FAF Figs 3 – 4	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	diagnosis	Diagnosis More than 50 pairs of outer paleae per lobe. Outer paleae with irregularly expanded margins resembling small denticles. Four to five inner paleae per lobe. Inner paleae with conspicuous transverse thecae and slightly curved tip. Three pairs of buccal tentacles.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	etymology	Etymology The species name is referred to the Caribbean Sea, where the species was found.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	materials_examined	Material examined Holotype MEXICO • complete spec. (body length 10 mm); Quintana Roo, East of the Center Cay, Banco Chinchorro; RV Edwin Link, stn. 2782; 18 ° 34.41 ′ N, 87 ° 26.80 ′ W; depth 274 m; 23 Aug. 1990; ECOSUR- 303.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	description	Description BODY. Holotype complete (ECOSUR- 303), integument slightly eroded. Body light brown, 10 mm long, 2.5 mm wide, fourth parathoracic segments, 12 abdominal segments, caudal peduncle 5 mm long (Fig. 3). OPERCULUM. Opercular disc truncates, two rows of translucent, amber paleae: outer row with 54 – 56 paleae on each lobe, inner row with 4 – 5 paleae on each lobe (Fig. 3 A, C). Outer paleae cylindrical, 2 mm long (Fig. 4 A). Proximal region with compact thecae partially surrounding the blade, margins slightly expanded, denticulate (Fig. 4 B, E). Middle region with thecae partially surrounding the blade, margins expanded, pectinate (Fig. 4 C). Tip pinnate (Fig. 4 D). Inner paleae cylindrical, finely tapering, with conspicuous thecae partially surrounding subdistal margins and slightly curved, smooth tip (Fig. 4 F – H). Opercular stalk light brown, twice as long as wide (Fig. 3 A). Seven opercular papillae on right lobe, three papillae on left; fragile, easily detachable tissue. Three pairs of tentacles, simple, grooved (Fig. 3 C). Nuchal spines cylindrical, embedded in opercular tissue; two on left lobe and three in right one (Fig. 3 D). Median ridge short, with some marginal eyespots. Median organ absent. THORAX. First thoracic segment with long, triangular-shaped lateral lobe and capillary neurochaetae. Second chaetiger with short, triangular-shaped lateral lobe, without chaetae (Fig. 3 E). PARATHORAX. With four segments, body wall eroded, branchiae translucent, fragile (Fig. 3 E). Pigmented tissue, in dorsal view, with seven reddish transverse lines (Fig. 3 A). Notopodia with lanceolate and capillary chaetae (Fig. 4 I). Neuropodia with only capillary chaetae. ABDOMEN. Abdominal region bent, body wall damaged, branchiae translucent, fragile, present only in first four segments. Abdominal segments colorless. Neurochaetae capillary, ornamented with irregular thecal laminar extensions (Fig. 4 J – K). Notopodia with series of uncini with 9 – 10 transverse rows of teeth (Fig. 4 L). Caudal peduncle whitish, slightly annulate (Fig. 3 F).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	discussion	Remarks Mariansabellaria caribbea sp. nov. shares the presence of transverse margins on the inner paleae with M. chilena, M. tenhovei, and M. norvegica, and the outer paleae with thecae that do not surround the blade, also called ‘ hemithecae’ by Kirtley (1994) for M. chilena. However, M. tenhovei, M. chilena and M. caribbea sp. nov. differ in the number of buccal tentacles. Kirtley (1994) described M. tenhovei with five pairs of buccal tentacles and M. chilena with six pairs, while M. caribbea sp. nov. only has three pairs. Mariansabellaria caribbea sp. nov. is characterized by having more than 50 pairs of outer paleae with irregularly expanded margins resembling small denticles, 4 – 5 inner paleae, and only three pairs of buccal tentacles. Although the outer paleae of M. norvegica also have irregular margins resembling denticles, Strömgren (1971) did not describe the number of opercular paleae. However, the two species differ in the morphology of the thecae of the outer paleae, and in the number of teeth on the abdominal uncini, seven pairs in M. norvegica and 9 – 10 pairs in M. caribbea sp. nov. Kirtley (1994) only provided the number of opercular paleae for M. harrisae, with 24 pairs of outer and 10 pairs of inner paleae. In addition to the difference in the number of opercular paleae, M. harrisae has smooth inner paleae and five buccal tentacles per lobe, while M. caribbea sp. nov. has inner paleae with conspicuous thecae and three tentacles.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFFFFFAC26227268EA6503BA.taxon	distribution	Distribution Banco Chinchorro, Quintana Roo, at 274 m depth. This is the first record of the genus Mariansabellaria in the western Atlantic (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF0FFAF267671B9ED2800B7.taxon	type_taxon	Type species Phalacrostemma cidariophilum Marenzeller, 1895, by monotypy.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF0FFAF267671B9ED2800B7.taxon	diagnosis	Diagnosis Operculum completely divided into two free lobes. Two rows of opercular paleae. Outer paleae arranged in spiral, with straight, cylindrical blades and ornamented thecae. Few (2 – 8) inner paleae arranged in one short row near to dorsal junction of inner marginal lobes, with straight, cylindrical, or slightly flattened blades. Two to six pairs of nuchal hooks with limbation. Few tentacular filaments arranged in a single row (simple), absent in some species. Median organ small, conical. Four parathoracic segments (Kirtley 1994; Capa & Hutchings 2019).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	description	urn: lsid: zoobank. org: act: 8255 C 32 E- 0216 - 4353 - A 681 - 3 A 5 E 42915 E 88 Figs 5 – 7, 8 E, G – J	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	diagnosis	Diagnosis Outer paleae with pectinate margins on distal thecae, hirsute tips. Inner paleae cylindrical with conspicuous thecae, slightly expanded margins, and blunt tip. Tentacular filaments absent.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	etymology	Etymology This species name is after my brother Daniel Chávez-López. It is a noun in the genitive case (ICZN 1999, Art. 31.1.2).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	materials_examined	Material examined Holotype LESSER ANTILLES • incomplete spec. (body length 10 mm); southwest of Grenada; RV Pillsbury, stn 478; 11 ° 33 ′ N, 62 ° 09 ′ W; depth 597 m; 2 Aug. 1966; UMML- 22.1179. Paratypes LESSER ANTILLES • 9 specs; same collection data as for holotype; UMML- 22.1180 • 1 spec. (using mid-operculum for SEM); same collection data as for holotype; UMML- 22.1181 • 1 spec.; same collection data as for holotype; ECOSUR- 304. Additional material BAHAMAS – Southeastern Bahamas • 4 specs; RV Columbus Iselin, stn 163; 23 ° 37 ′ N, 77 ° 13 ′ W; depth 1342 m; 6 Feb. 1974; UMML- 22.1182 • 1 spec.; same collection data as for preceding; ECOSUR-P 3236.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	description	Description BODY. Holotype incomplete (UMML- 22.1179), 10 mm long, 2.5 mm wide, six abdominal segments, caudal peduncle 3.5 mm long (Fig. 5). OPERCULUM. Opercular disc truncate. Outer paleae arranged spirally, 29 – 30 paleae on each lobe. Inner paleae arranged diagonally, two paleae on right lobe, one palea on left. Outer paleae amber, cylindrical, 2.5 mm long (Figs 6 A – E, 7 C – F). Proximal region with compact thecae, margins slightly expanded, denticulate (Figs 6 B, 7 C – D). Thecae of middle region with margins expanded, denticulate (Figs 6 C, 7 E). Thecae of mid-distal region with margins expanded, pectinate (Figs 6 D, 7 F); tips hirsute (Figs 6 F, 7 E). Inner paleae amber, cylindrical, with conspicuous thecae, slightly expanded margins; tips blunt, smooth (Figs 6 F – G, 7 G). Opercular stalk brown, slightly wider than long (Fig. 5 A – D). Opercular papillae in one row peripheral to outer paleae; nine papillae on each lobe. Papillae conical and tapered, 5 – 6 times as long as wide (Fig. 5 C). First papilla appears in dorsal region of opercular peduncle, at level of nuchal hooks (Fig. 5 F). Four pairs of amber nuchal hooks, compressed, tip slightly curved, with long limbation. Limbation exceeds curvature of hook tip, 2.5 times as long as tip (Figs 6 H, 7 B). Palps robust, tapered, twice as long as wide (Figs 5 C – D, 7 A). Pair of broad buccal flaps (Fig. 5 D). Tentacular filaments absent. Median organ conical, tapered without eyespots. THORAX. First thoracic segment with two long, triangular-shaped lateral lobes and capillary neurochaetae (Fig. 5 C – D). Second segment with 2 – 3 triangular-shaped lateral lobes and paired branchiae, without chaetae (Fig. 5 C). PARATHORAX. With four segments, all with paired branchiae. Notopodia with six lanceolate chaetae and six capillary chaetae (Fig. 6 I). Neurochaetae capillary. ABDOMEN. Abdominal segments brownish with paired branchiae up to segment 4. Neurochaetae capillary, ornamented with irregular thecal laminar extensions (Fig. 6 J). Notopodia with series of uncini with 10 rows of teeth (Fig. 6 K). Caudal peduncle cylindrical, brownish, broken, only posterior region attached to abdomen (Fig. 5 B, E). Variation Body incomplete 4 – 10 mm long, 0.5 – 2 mm wide, 3 – 6 abdominal segments. Operculum with 16 – 30 outer paleae per lobe, 1 – 3 inner paleae per lobe, generally two pairs, and 3 – 5 pairs of nuchal hooks. Outer paleae 1 – 2.5 mm long.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	discussion	Remarks Phalacrostemma danieli sp. nov. shares the morphology of the outer paleae with P. paulinae Kirtley, 1994, and the morphology of the abdominal uncini with P. tenera (Augener, 1906). Phalacrostemma paulinae Kirtley, 1994 was described from the Northwestern Atlantic Ocean (Kirtley 1994: 38 ° 41 ′ N, 70 ° 38 ′ W), from a single specimen collected by RV Atlantis II, stn 95 at 2160 m depth. Its original description is brief and only included a partial description of the outer palea, so it is necessary to redescribe P. paulinae to know the rest of the characters. According to Kirtley (1994: 162), the type material of P. paulinae was in the Natural History Museum, Los Angeles (NHM) without a specific catalog number. During his stay at NHM (Feb. – Mar. 2022) Dr Sergio Salazar-Vallejo, along with the polychaete collection manager Leslie H. Harris, searched for the type material of P. paulinae and found the holotype vial with catalog number LACM-AHF POLY 1691 (Fig. 8 A). Unfortunately, the vial was empty, which means the holotype is missing, and there are no other specimens from nearby localities or the same oceanographic expedition in the museum. In P. paulinae the outer paleae have the proximal thecae with denticulate and slightly expanded margins (Fig. 8 B); thecae of the middle region with expanded pectinate margins (Fig. 8 C), and the mid-distal thecae with expanded elongate and pectinate margins (Fig. 8 D). The morphology of the outer paleae of P. danieli (Fig. 8 G – I) resembles that of P. paulinae; although there are some differences in the denticles of the mid-distal thecae. Phalacrostemma danieli sp. nov. has straight denticles, 5 – 9 times as long as wide (Fig. 8 I), whereas P. paulinae has slightly inclined denticles, 10 – 16 times as long as wide (Fig. 8 D). Another difference is the locality and bathymetric range where the species were found. According to Kirtley (1994: 162), P. paulinae was collected in the North Atlantic (38 ° 41 ′ N, 70 ° 38 ′ W) at 2160 m depth; however, the vial label contains different coordinates (38 ° 33 ′ N, 68 ° 32 ′ W) and depth (3753 m) (Fig. 8 A), even though both refer to the same station and oceanographic cruise: RV Atlantis, stn Atl. 95. Based on the above, P. paulinae could be distributed from 38 ° 41 ′ N, 70 ° 38 ′ W to 38 ° 33 ′ N, 68 ° 32 ′ W at 2160 m or 3753 m depth, while P. danieli sp. nov. was collected in the Lesser Antilles (11 ° 33 ′ N, 62 ° 09 ′ W) at 597 m depth and the Bahamas (23 ° 37 ′ N, 77 ° 13 ′ W) at 1342 m. Phalacrostemma tenera (Augener, 1906) was described from Barbados at 365.8 m depth. Phalacrostemma danieli sp. nov. shares the abdominal uncini with a curved dorsal region and 10 rows of teeth (Fig. 8 J) with P. tenera (Fig. 8 K). Although these species are distributed at similar depths at relatively close localities, they differ mainly in the shape of the nuchal hooks. Phalacrostemma tenera has a short, slightly falcate tip, at a 57 ° angle, and a slightly wider limbation than the tip (Fig. 8 F), whereas P. danieli sp. nov. has a curved tip, at a 45 ° angle, and a wider tip than the limbation (Fig. 8 E). The lack of detail mainly in the morphology of the opercular paleae of P. tenera and P. paulinae prevents the determination of their diagnostic characters and therefore hinders their comparison with the other species of the genus. In addition, the type material of P. tenera (Kirtley 1994: 165) and P. paulinae (Salazar-Vallejo 2022 pers. com.) is missing. Therefore, topotype material is necessary. Based on the morphological differences found and considering the area of distribution and bathymetric ranges, I assigned the analyzed specimens to P. danieli sp. nov.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFF3FFAA263C714EEB6302A5.taxon	distribution	Distribution Southwest of Grenada Island at 597 m depth (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE8FFB32649760FE98507E6.taxon	description	Figs 9 – 11, 12 E – H	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE8FFB32649760FE98507E6.taxon	materials_examined	Material examined NORTH ATLANTIC – Bahamas • 2 specs; northwest of North Cat Cay; RV Gerda, stn 242; 25 ° 37 ′ N, 79 ° 22 ′ W; depth 494 m; on sea urchin spine; 30 Jan. 1964; UMML- 22.1183 • 1 spec. (using mid operculum for SEM); same collection data as for preceding; UMML- 22.1184 • 1 spec.; same collection data as for preceding; ECOSUR-P 3237. – Florida Strait • 6 specs; southeast of Long Key; RV Gerda, stn 456; 24 ° 39 ′ N, 80 ° 47 ′ W; depth 132 m; on sea urchin spine; 23 Jan. 1965; UMML- 22.1185 • 1 spec.; same collection data as for preceding; ECOSUR-P 3238 • 1 spec.; southeast of Long Key; RV Gerda, stn 457; 24 ° 37 ′ N, 80 ° 46 ′ W; depth 178 m; on sea urchin spine; 23 Jan. 1965; UMML- 22.1186 • 1 spec.; south of Duck Key; RV Gerda, stn 480; 24 ° 31 ′ N, 80 ° 55 ′ W; depth 192 m; 26 Jan. 1965; UMML- 22.1187 • 2 specs; south of Saddlebunch Key; RV Gerda, stn 861; 24 ° 00 ′ N, 81 ° 36 ′ W; depth 536; on a gastropod shell; 29 Aug. 1967; UMML- 22.1200. – East Florida • 7 specs; east of Boynton Beach; RV Gerda, stn 158; 26 ° 31 ′ N, 79 ° 23 ′ W; depth 535 m; 25 Jun 1963; UMML- 22.1188 • 4 specs; east of Fort Lauderdale; RV Gerda, stn 718; 26 ° 08 ′ N, 79 ° 19 ′ W; depth 448 m; 3 Aug. 1965; UMML- 22.1189. – South Grand Bahamas • 1 spec.; south of Xanadu Beach; RV Gerda, stn 694; 26 ° 27 ′ N, 78 ° 42 ′ W; depth 658 m; on sea urchin spine; 21 Jul 1965; UMML- 22.1190.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE8FFB32649760FE98507E6.taxon	description	Description BODY. Complete specimen (UMML- 22.1183), broken in middle part of abdomen, 13 mm long, 1 mm wide, 12 abdominal segments, caudal peduncle 8 mm long (Fig. 9 A). OPERCULUM. Opercular disc truncate (Fig. 9 B, E). Opercular crown with some broken or missing paleae (Fig. 9 E). Outer paleae arranged spirally, 19 paleae on right lobe, 31 paleae in on. Inner paleae arranged diagonally, three paleae on each lobe (Figs 9 E – F, 10 A). Outer paleae amber, cylindrical, 1.5 mm long (Fig. 10 A). Proximal region with compacts thecae, margins non-expanded (Fig. 10 B). Thecae of middle region with margins slightly expanded, denticulate (Figs 10 C, 11 C). Tip with thecae partially surrounding blade, margins expanded, pectinate (Fig. 11 D). Inner paleae amber, cylindrical, with conspicuous, compact thecae, margins non-expanded; tips blunt, smooth (Figs 10 D, 11 F). Opercular stalk pale brown, 1.5 times as long as wide. Opercular papillae in one row peripheral to outer paleae; 10 papillae on each lobe. Papillae conical, robust, tapered, 2.5 – 4 times as long as wide (Fig. 9 B – C). First papilla appears on inner region of opercular peduncle, at level of nuchal hooks (Fig. 11 A – B). Five pairs of amber nuchal hooks, compressed, tip slightly falcate, with short limbation. Limbation not reaching tip curvature, almost three times as long as tip (Figs 10 E, 11 E). Palps robust, tapered, four times as long as wide (Fig. 10 A – E). Pair of broad buccal flaps (Fig. 11 D). Tentacular filaments absent. Median organ conical, colorless, without eyespots. THORAX. First thoracic segment with long, triangular-shaped lateral lobe and capillary neurochaetae. Second segment with two triangular-shaped lateral lobes and paired branchiae, without chaetae (Fig. 9 C). P ARATHORAX. Four segments, all with paired branchiae. Notopodia with five lanceolate chaetae and five capillary chaetae (Fig. 10 F). Neurochaetae capillary. ABDOMEN. Abdominal segments brown, with paired branchiae up to segment 2. Neurochaetae capillary, ornamented with irregular thecal laminal extension. Notopodia with series of uncini with 8 – 9 rows of teeth (Fig. 10 G). Caudal peduncle cylindrical, brownish (Fig. 9 A). Variation Body 6 – 14 mm long, 1 – 2 mm wide. Incomplete specimens with 5 – 18 abdominal segments; complete specimens with 11 – 12 abdominal segments and caudal peduncle 5 – 8 mm. Operculum with 15 – 35 outer paleae per lobe, 1 – 4 inner paleae per lobe, and 3 – 6 pairs of nuchal hooks. Outer paleae 1 – 1.5 mm long. Opercular papillae with 7 – 13 per lobe.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE8FFB32649760FE98507E6.taxon	discussion	Remarks Phalacrostemma dorothyae was described by Kirtley (1994) from Florida Keys. Its original description is brief and only included the partial description of opercular paleae and nuchal hooks. The revised specimens share the morphology of the outer paleae with P. dorothyae. Both species have elongated, irregular thecae at the tip of the outer paleae that partially cover the blade, only the inner side (Fig. 12 A, E); thecae with finely denticulate expanded margins in the middle region (Fig. 12 B, F); and proximal compact thecae with irregular margins (Fig. 12 C, G). However, my specimens differ from P. dorothyae in the inner paleae; P. dorothyae has inner paleae with “ irregular, slightly swollen thecae with distal margins with smoothly rounded distal denticles ” (Kirtley 1994: 153) (Fig. 12 D), while my specimens have compact thecae with irregular margins in the inner paleae (Fig. 12 H). The nuchal hooks of my specimens are slightly different from those of P. dorothyae. Kirtley’s (1994: fig 9.3.2 d) P. dorothyae has nuchal hooks with shorter tips, about three times as long as wide, while in what is herein regarded as P. dorothyae they are six times as long as wide. Another possible difference between the revised specimen here and P. dorothyae is in the buccal tentacles. According to the key in Kirtley (1994: 149), P. dorothyae is grouped with species having 3 – 5 simple buccal tentacles, whereas my specimens lack them. Unfortunately, in the description of P. dorothyae, Kirtley (1994) did not mention anything about the number of buccal tentacles. Phalacrostemma dorothyae and my specimens have similar outer paleae and may even be found in the same geographic area at similar depths (P. dorothyae from the Florida Keys at 200 – 350 m, holotype; P. dorothyae from Southeast Florida at 130 – 530 m, this study), and on same substrates (urchin spines). Despite some minor morphological differences above, I have assigned them to the same species.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE8FFB32649760FE98507E6.taxon	distribution	Distribution Southeast of Florida and Grand Bahamas, at 132 – 536 m depth, on sea urchin spine and gastropod mollusk shells (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFEFFFBF264475F5EB4D0027.taxon	description	Figs 13 – 15	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFEFFFBF264475F5EB4D0027.taxon	materials_examined	Material examined NORTH ATLANTIC – Southeastern Bahamas • 1 spec.; RV Columbus Iselin, stn 47: 23 ° 43 ′ N, 77 ° 09 ′ W; depth 3000 m; 24 Feb. 1973; UMML- 22.1191 • 1 spec. (using mid operculum for SEM); same collection data as for preceding; UMML- 22.1192 • 1 spec.; RV Columbus Iselin, stn 250; 23 ° 52 ′ N, 76 ° 56 ′ W; depth 1305 m; 31 Oct. 1974; UMML- 22.1193 • 1 spec.; same collection data as for preceding; ECOSUR-P 3239.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFEFFFBF264475F5EB4D0027.taxon	description	Description BODY. Incomplete specimen (UMML- 22.1191), 13 mm long, 3 mm wide, six abdominal segments (Fig. 13 A – F). OPERCULUM. Opercular disc truncate (Fig. 13 A – B). Opercular crown with some broken or missing paleae. Outer paleae arranged spirally, 22 paleae on right lobe, 14 paleae on left. Inner paleae arranged diagonally, two paleae on each lobe. Outer paleae amber, cylindrical, 3 – 4 mm long (Figs 14 A – E, 15 A – D). Proximal region with compacts thecae, margins non-expanded (Fig. 14 B, D). Thecae of middle region with margins non-expanded (Fig. 15 E) to slightly irregularly expanded (Figs 14 C, 15 F). Thecae of mid-distal region elongate with margins irregularly expanded (Fig. 15 G); tips hirsute (Figs 14 D, 15 H). Inner paleae amber, cylindrical, with thecae inconspicuous; tips lanceolate (Figs 14 E, 15 I). Opercular stalk brown. Opercular papillae in two rows, each row with 11 – 13 opercular papillae on each lobe (Fig. 13 B). Papillae conical, tapered, 2 – 4 times as long as wide (Figs 13 B, 15 B). First papilla appears in dorsal region of opercular peduncle, at level of nuchal hooks. Six pairs of amber nuchal hooks, compressed, tips sharp falcate, with limbation. Limbation not reaching tip curvature, 1.5 times as long as tip (Figs 14 G, 15 C). Palps robust, tapered, three times as long as wide (Fig. 13 D). Pair of broad buccal flaps (Fig. 13 D). Tentacular filaments absent. Median organ conical, brownish, without eyespots. Building organ U-shaped, brown. THORAX. First thoracic segment with three long, triangular-shaped lateral lobes and neurochaetae capillary (Fig. 13 E). Second segment with two long triangular-shaped lateral lobes and paired branchiae, without chaetae. PARATHORAX. With four segments, all with paired branchiae. Notopodia with seven lanceolate chaetae and three capillary chaetae (Fig. 14 H). Neurochaetae capillary. ABDOMEN. Abdominal segments brown, all with paired branchiae. Neurochaetae capillary, ornamented with irregular thecal laminar extensions. Notopodia with series of uncini with 7 – 8 rows of teeth (Fig. 14 I). Tubes With foraminiferans (Fig. 14 J). Variation Body incomplete 8 – 13 mm long, 1.5 – 3 mm wide, 3 – 7 abdominal segments. Operculum with 21 – 30 outer paleae per lobe, 2 – 4 inner paleae per lobe, and 5 – 6 pairs of nuchal hooks, commonly five. Outer paleae 2 – 4 mm long. Opercular papillae with 9 – 13 per lobe. First thoracic segment with 2 – 4 triangularshaped lateral lobes.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFEFFFBF264475F5EB4D0027.taxon	discussion	Remarks Phalacrostemma perkinsi Kirtley, 1994 (1362 – 1364 m) was described based on specimens collected by RV Columbus Iselin at station 322 (Fig. 22). In this work, I reviewed specimens from the same expedition and cruise from two stations near the type locality of P. perkinsi (The Bahamas, 1342 – 3000 m depth, Fig. 22). As the description of P. perkinsi is brief, only the morphology of the outer opercular paleae can be compared. Phalacrostemma perkinsi is characterized by outer paleae with numerous short, distal slightly expanded margins, thecae with weakly expanded margins in the middle region, and proximal transversal thecae with unexpanded margins. All these characteristics are shared with my Bahamian specimens; however, the latter have irregularly expanded thecae on the mid-distal region of the outer paleae that are not described or illustrated in P. perkinsi. Kirtley’s (1994) identification key for Phalacrostemma species groups P. perkinsi with those species having 3 – 5 tentacular filaments. The specimens reviewed here do not have buccal tentacles, so this feature could be a difference between the specimens identified by Kirtley. Redescription of P. perkinsi based on type material is necessary to confirm the presence of two rows of opercular papillae and the presence of buccal tentacles. Because P. perkinsi was described based on specimens from the same cruise as those reviewed in this work, and they have similar opercular paleae, I have assigned them to the same species.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFEFFFBF264475F5EB4D0027.taxon	distribution	Distribution The Bahamas, at 1342 and 3000 m depth (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE4FFBB260C72CFED28076F.taxon	type_taxon	Type species Hermella varians Treadwell, 1901; by original designation.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE4FFBB260C72CFED28076F.taxon	diagnosis	Diagnosis Operculum with lobes partially fused. Two rows of opercular paleae. Outer paleae arranged in semicircles, blades straight, flat. Few (4 – 5) cylindrical inner paleae in single short row on ventral side of operculum, with blades straight, flat. One pair of large nuchal hooks with tips pointing inwards towards the prostomium. Tentacular filaments arranged in single rows (simple). Median organ small, conical at dorsal junction of opercular lobes. Palps grooved, longer than operculum. Four parathoracic segments (Kirtley 1994; Capa et al. 2012).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	description	urn: lsid: zoobank. org: act: C 1846882 - 4 FD 6 - 4 BBF-AAD 3 - 52 C 523251 A 89 Figs 18 – 19	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	diagnosis	Diagnosis Outer paleae lanceolate, compressed with sharp tips, elongated and slender. Inner paleae cylindrical, smooth, with blunt tip. Two to four tentacular filaments per lobe.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	etymology	Etymology This species is named in memory of my grandfather Israel López, an exemplary man. The species name is a noun in the genitive case (ICZN 1999, Art. 31.1.2).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	materials_examined	Material examined Holotype CARIBBEAN SEA • complete spec. (very damaged); Virgin Islands; RV Pillsbury, stn 1401; 18 ° 51 ′ N, 65 ° 04 ′ W; depth 4180 m; 12 Jul. 1972; UMML- 22.1195. Paratype CARIBBEAN SEA • 1 spec.; same collection data as for holotype; UMML- 22.1196.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	description	Description BODY. Holotype complete (UMML- 22.1195), very damaged, 40 mm long, 0.5 mm wide, four parathoracic segments, five abdominal segments (Fig. 18 A – D). OPERCULUM. Opercular disc oblique. Opercular crown with almost all opercular paleae broken (Fig. 18 B – C). Outer paleae arranged in semicircles, seven paleae on left lobe, 18 on right (Fig. 18 B – F). Inner paleae in short ventral line on each inner margin of opercular lobes, three paleae on left lobe, four on right (Fig. 18 B, F). Outer paleae amber, lanceolate, compressed, 3 mm long. Blade six times as long as wide (Fig. 19 A – B). Tip sharp, elongate, slender (Fig. 19 B). Inner paleae amber, cylindrical, smooth, tip blunt (Fig. 19 C – D). Opercular stalk orange to pale yellow, almost three times as long as wide (Fig. 18 B). Opercular papillae not observed. One pair of nuchal hooks amber, long, robust, with short limbation, tip strongly curved (Figs 18 B, 19 E). In lateral view, nuchal hooks distally curved at angle of ~ 115 ° (Fig. 19 F). Palps and median organ not observed. Tentacular filaments damaged, simple, slender; two tentacles on left lobe, four on right (Fig. 18 C). THORAX. First thoracic segment without cirrus or chaetae. Second segment with two triangular-shaped lateral lobes and paired branchiae. PARATHORAX. With four segments, branchiae not seen. Notopodia with lanceolate and capillary chaetae. Neurochaetae capillary. ABDOMEN. Abdominal segments yellowish, not very well defined. Neuropodia small, with capillary chaetae, ornamented with irregular thecal laminar extensions (Fig. 19 G – H). Notopodia robust, uncini not seen. Variation Specimen incomplete 28 mm long, 4 mm wide, 3 abdominal segments (Fig. 18 E – F).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	discussion	Remarks In the Caribbean Sea and the Gulf of Mexico, Tetreres varians (Treadwell, 1901) was the only species of the genus recorded. Tetreres israeli sp. nov. and T. varians differ mainly in the morphology of the outer blades, being lanceolate in T. israeli sp. nov. (Fig. 19 A – B) and oblong in T. varians (Augener 1906: pl. 7, fig. 131; Kirtley 1994: fig. 12.10.3 a, d – f). The morphology of the paleae of T. israeli sp. nov. resembles those of T. perryi Kirtley, 1994 (Northwest Atlantic). Both species have lanceolate outer paleae with elongate tips; however, T. perryi has outer paleae with transverse irregular thecae, whereas T. israeli sp. nov. has no transverse thecae.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFE7FF8426E5756DEC18060E.taxon	distribution	Distribution Only known from the type locality, Virgin Islands, at 4180 m depth (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	description	urn: lsid: zoobank. org: act: 080 B 2 BD 8 - DA 8 B- 4 E 30 - B 51 C-AC 79 F 6 ED 37 DA Figs 20 – 21	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	diagnosis	Diagnosis Outer paleae oblong, compressed with acute tips. Inner paleae slightly oblong, smooth, with blunt tips. Five tentacular filaments. First thoracic segment with a pair of long tapered cirri.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	etymology	Etymology This species name is after my brother Oscar Chávez-López. It is a noun in the genitive case (ICZN 1999, Art. 31.1.2).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	materials_examined	Material examined Holotype FLORIDA STRAIT • complete spec.; southwest of Marquesas Keys; RV Gerda, stn 968; 24 ° 17 ′ N, 82 ° 34 ′ W; depth 378 m; 2 Feb. 1968; UMML- 22.1197. Paratypes FLORIDA • 1 spec.; southeastern Miami; RV Gerda, stn 265; 25 ° 40 ′ N, 80 ° 00 ′ W; depth 332 m; 28 Mar. 1964; UMML- 22.1198 • 1 spec. (body fragmented in two parts after the operculum); same collection data as for preceding; ECOSUR- 305. Additional material NORTH ATLANTIC – Florida Strait • 1 dry spec.; southeastern Key West; RV Gerda, stn 15; 25 ° 05 ′ N, 80 ° 00 ′ W; depth 288 m; 30 May 1962; UMML- 22.1199.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	description	Description BODY. Holotype complete (UMML- 22.1197) 12 mm long, 0.5 mm wide, four parathoracic segments, 22 abdominal segments, 4 mm caudal peduncle (Fig. 20). OPERCULUM. Opercular disc oblique (Fig. 20 A – B, F). Outer paleae arranged in semicircles, 22 paleae on each lobe (Fig. 20 F). Inner paleae in short ventral line on each inner margin of opercular lobes, three paleae on each lobe (Fig. 20 F). Outer paleae pale yellow, oblong, compressed, 1 mm long. Blade three times as long as wide, with thecae transverse, compact; tips acute (Fig. 21 A – B). Inner paleae pale yellow, slightly oblong, smooth, tips blunt (Fig. 21 C – D). Opercular stalk pale yellow, three times as long as wide (Fig. 20 B – D). Opercular papillae in one row peripheral to outer paleae, 11 papillae on each lobe. Papillae conical and tapered, 3 – 4 times as long as wide (Fig. 20 F). One pair of yellow nuchal hooks, long, robust, with short limbation, tips falcate (Figs 20 B, 21 E – G). In lateral view, nuchal hook distally curved at angle of ~ 135 ° (Fig. 21 E). Palps pale yellow, broken. Tentacular filaments simple, pale yellow, grooved; three tentacles on left lobe, five tentacles on right (Fig. 20 D). Median organ small, conical (Fig. 20 B). THORAX. First thoracic segment with long, triangular-shaped lateral lobe, and capillary chaetae. Second segment with three lateral lobes, and paired branchiae; first lobe after branchiae three times as long as other ones (Fig. 20 A – B). PARATHORAX. With four segments, all with paired branchiae. Notopodia with four lanceolate chaetae and six capillary chaetae (Fig. 21 H). Neurochaetae capillary. ABDOMEN. Abdominal segments yellowish. Last ten abdominal segments colorless, translucent. Neurochaetae capillary, ornamented with irregular thecal laminar extension (Fig. 21 I). Notopodia with series of uncini with eight rows of teeth (Fig. 21 J). Caudal peduncle colorless, translucent. Anus with two rigid white balls of sediment (Fig. 20 A). Variation Specimens incomplete 7 – 10 mm long, 0.4 – 0.5 mm wide, seven abdominal segments. Only holotype complete. Operculum with 19 – 22 outer paleae per lobe, 3 – 5 inner paleae per lobe. Opercular papillae 8 – 12 per lobe. Only holotype with three tentacular filaments on left lobe; rest of specimens with five per lobe. Lateral cirrus of second thoracic segment 2 – 3 times as long as other cirri. Tubes With foraminiferans (UMML- 22.1198, UMML- 22.1199, Fig. 21 K).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	discussion	Remarks Tetreres oscari sp. nov. is very similar to T. varians; however, both species can be distinguished by the morphology of the outer paleae, the length of the thoracic cirri, and mainly by the number of tentacular filaments. The outer paleae of T. oscari sp. nov. have acute tips, whereas the paleae of T. varians are illustrated with mucronate tips (Augener 1906: pl. 7 fig. 131; Kirtley 1994: fig. 12.10.3 a, d – f). The number of outer paleae also differs among these species. According to Hartman (1944: 333), the type specimen of T. varians has 25 – 30 outer paleae per lobe, whereas T. oscari sp. nov. has 19 – 22 per lobe. Further, T. oscari sp. nov. is characterized by two lateral lobes on the second thoracic segment, and one of them is three times as long as the other, whereas T. varians has three lateral lobes of similar size (Kirtley 1994: fig. 12.10.1 a – b). The number of tentacular filaments is the most obvious character. Although the number of tentacular filaments of T. varians has not been described, according to the drawings of Augener (1906: pl. 7 fig. 130) and Kirtley (1994: fig. 12.10.1 a – b), T. varians has about 10 thin tentacular filaments on each lobe, whereas T. oscari sp. nov. has only five broad ones.	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
03B2EE18FFD8FF8126FA744DEA830384.taxon	distribution	Distribution Southeast Florida, 288 – 378 m depth (Fig. 22).	en	Chávez-López, Yessica (2022): New species of sabellariids (Annelida: Sabellariidae) from the Caribbean Sea and the Gulf of Mexico. European Journal of Taxonomy 831: 109-148, DOI: https://doi.org/10.5852/ejt.2022.831.1873, URL: http://dx.doi.org/10.5852/ejt.2022.831.1873
