taxonID	type	description	language	source
038390583476E4789BF4FE84FC6CFA85.taxon	discussion	Remarks. The genus was rediagnosed by Poore et al. (2019: 99) after thorough molecular and morphological analysis (Robles et al. 2020). The genus is recognised by the combination of a narrow rostrum, eyestalks with acute apices, a narrow maxilliped 3 ischium-merus, a simple or bifid spine on the merus of the major cheliped, and strong spiniform setae on the face of the uropodal endopod and on the face of the telson. As noted above, Poore et al. (2019: tab. 1, 2) included seven species, all from the Indo-West Pacific: S. amboinae, S. andamaniensis, S. caledonica, S. contipes, S. pygmaea, S. spinophthalma and S. tonkinae. Some, however, have been synonymised with others and later removed from synonymy (see S. amboinae, S. caledonica and S. tonkinae below). In his major axiidean review, Sakai (2011 a) regarded the four specific taxa, Scallasis amboinae, Callianassa caledonica, Callianassa (Cheramus) pygmaea and Callianassa (Scallasis) tonkinae as valid species of Trypaea Dana, 1852. Characterisation of these species is limited without reference to type material – we have relied for most on published works but believe many descriptions and figures omit critical characters not usually noted in callianassid descriptions in the past and which have been often overlooked. For example, the facial spiniform setae on the uropodal rami were unexpected or considered unimportant by earlier authors and are difficult to observe without appropriate lighting or staining. The scaphocerite is acute and short in species we have observed but not mentioned in most descriptions. There appear few reliable differences between species in the rostrum (triangular, sharp, reaching the cornea) and eyestalks (tapering to acute anterior lobes) but we see species differences in maxilliped 3 and in the chelipeds. Adding to the difficulty differentiating species is the paucity of individuals, and differences between sexes, growth stages and individuals. Nevertheless, we have prepared short diagnoses of the seven species of Scallasis recognised here. Scallasis caledonica, S. inermis n. sp. and S. spinophthalma are known from both sexes. Pleopod 1 is present in males of all three but variously developed, possibly due to the maturity of the specimens examined. Pleopod 2 is present in two species, not in S. caledonica. Chelipeds are apparently sexually dimorphic only in S. inermis n. sp. but this species may be the only one where a fully adult male is known.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583476E47F9BF4FA23FC8DFA2E.taxon	description	(Figs 1 – 3)	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583476E47F9BF4FA23FC8DFA2E.taxon	materials_examined	Type material. Holotype: Indonesia, Ambon (as Amboina), 6 October 1874, HMS Challenger stn, male (5.2 mm), NHM 1888.22. Other material examined. Papua New Guinea, Madang Province, Alexishafen, 05 ° 05.3 ' S 145 ° 48.0 ' E, 8 – 13 m, 16 November 2012 (stn PS 14), ovigerous female (5.5 mm), MNHN IU- 2013 - 610 (Genbank sequences, MN 237932, MN 238140). Madang Harbour, E of Nui I., 05 ° 12.3 ' S 145 ° 47.9.0 ' E, 10 – 15 m, 11 November 2012 (stn PD 14), postovigerous female (3.5 mm), MNHN IU- 2013 - 12303.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583476E47F9BF4FA23FC8DFA2E.taxon	diagnosis	Diagnosis. Pleomere 6 1.1 – 1.2 times as long as wide, with lateral notches posteriorly. Telson 1.2 times as long as wide; greatest width 1.3 times posterior width. Maxilliped 3 ischium-merus 3 times as long as wide; merus free distal margin oblique. Female major cheliped ischium lower margin with 7 spines; merus lower margin with fine oblique proximal spine, sometimes with small accessory proximal tooth; palm 0.7 – 1 times as long as carpus. Minor cheliped ischium lower margin with 3 – 5 spines; merus lower margin with 1 oblique spine at midpoint. Uropodal endopod anterior margin with small spine about two-thirds along; dorsal surface with 1 long proximal spiniform seta, usually plus 1 shorter submarginal seta; exopod anterior margin with small spiniform seta about three-quarters along.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583476E47F9BF4FA23FC8DFA2E.taxon	description	Redescription. Rostrum narrowly triangular, spiniform, directed forward, with slight ventral carina, falling slightly short of distal ends of eyestalks. Carapace shorter than length of pleomeres 1 and 2 combined; orbital margins concave; anterolateral projections rounded; excavation inferior to anterolateral projections deep, U-shaped; cervical groove across 0.75 length of carapace, without postrostral transverse groove; linea thalassinica distinct, extending to posterolateral margin of carapace. Thoracic sternite 7 subpentagonal with rounded anterior margin; ventral surface with shallow median groove. Length ratio of pleomeres 1 – 6 measured along midline 1: 2.3: 1.3: 1: 1.8: 2.0. Pleomere 1 narrowing anteriorly in dorsal view; pleuron with poorly defined ventral margin. Pleomere 2 pleuron posterolateral margin rounded. Pleomeres 3 – 5 pleura each with patch of plumose setae. Pleomere 6 1.1 – 1.2 times as long as wide, narrowing posteriorly, with shallow lateral oblique groove at about posterior 0.2. Telson trapezoidal, narrowing posteriorly, 1.2 times as long as wide, broadest at anterior 0.2; greatest width 1.3 times posterior width; dorsal surface medially with 2 pairs each of spiniform setae and long setae in short transverse row anterior to midlength; lateral margin unarmed; 2 pairs of small spiniform setae at rounded posterolateral angles; posterior margin shallowly concave medially, with minute median spine. Eyestalks each with flat, acute distal projection, contiguous, reaching distal margin of article 1 of antennular peduncle; lateral margin convex. Cornea subterminal, submedial, darkly pigmented, third – half as wide as eyestalk. Antennular peduncle) slightly longer than to antennal peduncle; article 1 distal margin visible in dorsal view; article 2 about as long as article 1; article 3 3.3 times as long as article 2; articles 2 and 3 with longitudinal ventral row of sparse long setae. Antennal peduncle with distal 2 articles subcylindrical; article 4 1.5 times as long as article 5; scaphocerite minute, acute. Maxilliped 3 without exopod; ischium-merus narrowly subrectangular, non-operculiform, 3.0 times as long as wide; ischium tapering, twice as long as wide, crista dentata row of 14 uneven erect spines; merus, about half as long as ischium measured along dorsal margin, about as wide as long, wider than merus, distolateral margin obliquely truncate, unarmed; carpus cup-shaped, slightly shorter than merus; propodus narrowing distally, 1.7 times as long as wide, longer than carpus; dactylus slender, digitiform, about 0.7 times as long as propodus, with dense oblique setae along distal half of lower margin. Pereopods 1 (chelipeds) greatly unequal, dissimilar. Female major cheliped carpus-chela as long as carapace length. Ischium upper margin sinuous, unarmed; lower margin with row of 7 oblique spines. Merus shorter than ischium; upper margin convex, unarmed; lower margin with narrow oblique spine proximal to midpoint. Carpus 2.3 times as long as wide; upper and lower margins carinate, smooth. Chela about as long as carpus; palm 0.6 times as length of carpus, 1.5 times as long as wide; upper margin carinate, almost glabrous; lateral surface smooth, convex; mesial surface slightly convex; lower margin carinate, with submarginal row of tufts of setae extending onto fixed finger; fixed finger 0.7 times as long as palm, occlusal margin unarmed. Dactylus as long as palm, curved distally, closing on fixed finger; upper surface with blunt ridge laterally and with tufts of long setae; occlusal margin sinuous. Female minor cheliped carpus-chela slightly shorter than that of major cheliped. Ischium slightly curving; upper margin smooth, lower margin armed with row of 5 oblique spines. Merus 0.8 times as long as ischium; upper margin convex, unarmed; lower margin with narrow oblique spine at midpoint. Carpus 1.7 times as long as merus, 4.2 times as long as wide; upper margin straight, rounded; lower margin convex proximally, carinate. Palm wider distally, 1.6 times as long as wide; upper margin straight, bluntly carinate, with row of setae; lower margin carinate, with row of tufts of setae extending onto fixed finger; lateral and mesial surfaces slightly convex, smooth; fixed finger about as long as palm, slightly curving, with acute tip; occlusal margin slightly concave; lateral surface with row of tufts of setae along cutting edge. Dactylus 1.2 times as long as palm, as long as fixed finger; dorsal margin rounded, with row of long setae; occlusal margin unarmed. Pereopod 2 ischium short, lower distal angle produced; merus with sinuous lower margin, upper margin almost straight; carpus subtriangular, twice as long as wide; chela subtriangular; palm 2.5 times as wide as upper margin; occlusal margins of fingers bordered by thin corneous ridge; dactylus 2.5 times as long as palm. Pereopod 3 carpus subtriangular, lower margin concave, twice as long as wide; propodus suboval with produced lower proximal margin, upper margin 1.3 times width, lateral face obtusely carinate medially, lower margin convex, faintly undulate, with 1 slender spiniform seta subdistally; dactylus nearly straight, about 0.7 times as long as propodus upper margin. Pereopod 4 coxa flattened ventrally, immovable; basis and ischium partially fused, extended posterolaterally; merus longer than ischium; carpus wider distally; propodus compressed, as long as carpus, with dense grooming setae distally on lower margin, scattered stiff setae on outer surface; dactylus slightly curving, 0.4 times as long as propodus. Pereopod 5 slender, with chela as long as carpus, slightly curving; dactylus about 0.3 times as long as palm, with minute teeth. Female pleopod 1 uniramous; peduncle straight; exopod almost as long as peduncle, with slight shoulder slightly proximal to midlength on inner margin. Female pleopod 2 subequally biramous; peduncle curved outward, inner margin angular; endopod tapering distally, slightly shorter and broader than exopod; exopod slightly curved inward. Pleopods 3 – 5 with appendix interna slender, rod-like. Uropod endopod and exopod subovate, overreaching posterior margin of telson. Endopod about 1.8 times as long as wide; upper surface shallowly concave in mesial half, with 1 long spiniform seta near anteroproximal angle, sometimes with adjacent ancillary spiniform seta; anterior margin slightly sinuous, with small subdistal spine at about distal 0.35; posterodistal margin convex, with fringe of setae, with 2 short distal spiniform setae. Exopod 1.6 times as long as wide, exceeding endopod by half length; anterior margin convex, bearing 1 subdistal spiniform seta; posterior margin with about 10 blade-like distal setae, connected to distal margin continuously or by rounded corner; upper surface faintly slightly carinate in midline, sometimes with submarginal spiniform seta near anterior margin; dorsal plate extending about one-third – one-half distal exopod width, with distal row of stiff setae separated from setal row of distal margin. Variation. The shapes, position of the uropodal tooth, and the number of dorsal spiniform setae on the exopod of the uropodal rami differ between the holotype and the two newly discovered specimens. With few individuals we attribute this to individual differences, possibly size-related. The size and shape of the eyestalks appear to differ between individuals; the apical tubercles (Fig. 2 G) were only visible at high magnification. The posterior concavity of the telson was more pronounced in some individuals than others; Sakai’s (1999: fig. 5 e) illustration of the telson of the holotype is much longer than it actually is, which could be artistic error.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583476E47F9BF4FA23FC8DFA2E.taxon	distribution	Distribution. Indonesia, Papua New Guinea, possibly Gulf of Thailand; at depths of 8 – 13 m.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583476E47F9BF4FA23FC8DFA2E.taxon	discussion	Remarks. The holotype is incomplete and now somewhat damaged (Fig. 1 A – D). The chelipeds and pereopods 2 – 4 are not present. Bate’s (1888) description and illustrations are not especially informative. The “ globular ” eyestalk is not obvious on the holotype 130 years later. Sakai (2011 a) suggested the description did not match Bate’s figures and interpreted Bate’s drawing (1888: pl. 2 fig. 3 i) as maxillipeds 3 with exopods – it is more probably of maxillipeds 2 and 3. Pleopod 1 is missing (or absent), pleopod 3 biramous with narrow rami, and pleopods 3 – 5 have a long appendix interna. Sakai’s (1999) reillustration of the holotype confirms that the maxilliped 3 is relatively narrow (ischium-merus 3.5 times as long as wide) with an oblique distal meral margin, the rostrum is attenuated to reach almost the end of the eyestalk, and the eyestalk has a triangular terminal lobe with its apex not adjacent to its pair. His illustration of the uropod and telson are inaccurate. Our own observations (GCBP 2011, 2017) show the rostrum to be directed anteriorly and the telson to be shorter (1.1 times as long as wide, said to be ‘ quadrate’ by Bate) than figured by Sakai, having an excavate posterior margin, short median spine and two short spiniform setae on each posterolateral corner. The telson is half as long as the elongate pleomere 6. The uropodal endopod has two long proximal spiniform setae on the upper surface and the exopod a definite short dorsal plate close to the anterodistal angle (not as in Sakai, 1999: fig. 5 e). The scaphocerite is acute. The ovigerous females from Papua New Guinea reveal details not observed on the holotype. The uropodal exopod carries a prominent marginal subdistal spiniform seta and (in one specimen) another dorsally near the anterior margin (both lost or not observed on the holotype). The uropodal endopod has a tooth at the end of the anterior margin and one strong facial spiniform seta (two on one side of one individual). Sakai (1999) treated Callianassa (Cheramus) pygmaea De Man, 1928, collected at Ambon, the same locality as S. amboinae, as a junior synonym of Callianassa amboinae. In as far as its description reveals the rostrum, eyes, maxilliped 3, minor cheliped, pereopod 3, telson and uropod are virtually indistinguishable from S. amboinae. Notably, De Man figured tooth at the end of the anterior margin and the easily missed spiniform setae on the dorsal surface of the uropodal endopod, and the spiniform setae at the end of the anterior margin of the exopod. The species are treated as synonymous here. Sakai (1999) referred specimens from southern Vietnam to “ Callianassa ” amboinae, but we did not re-examine these specimens. Sakai (2005) identified specimens from various Indo-West Pacific localities as “ Callianassa ” amboinae: Gulf of Thailand, 20 m depth, “ off Burail Bay, Fiji Is., New Caledonia, 200 m depth ” [sic], Arafura Sea, 54 m depth, Bay of Bengal, 50 m depth, and West Malay Peninsula, 14 m depth. The geographic and bathymetric range of this collection is considerable but we have not been able to re-examine this material. The illustrated specimen (Sakai 2005: figs 15, 16; labeled ZMUC 10 b) is said to be the 3.8 mm ovigerous female from the Gulf of Thailand (ZMUC CRU- 3775) in the text. The female chelipeds are more elongate than the female from Papua New Guinea (Fig. 2 A, B) but otherwise this female cannot be distinguished.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583471E47F9BF4FA70FB1AF841.taxon	distribution	Type locality. Andaman Sea, 09 ° 00 ’ N 97 ° 53 ’ E, 65 – 70 m.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583471E47F9BF4FA70FB1AF841.taxon	diagnosis	Diagnosis. Pleomere 6 1.2 times as long as wide. Telson 1 times as long as wide; greatest width 1.2 times posterior width. Maxilliped 3 ischium-merus 3 times as long as wide; merus free distal margin oblique. Female major cheliped ischium lower margin with 4 strong spines; merus lower margin with simple proximal spine; palm 1 times as long as carpus. Uropodal endopod anterior margin with small spine about two-thirds along.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583471E47F9BF4FA70FB1AF841.taxon	distribution	Distribution. Known only from the type locality in the Andaman Sea.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583471E47F9BF4FA70FB1AF841.taxon	discussion	Remarks. Sakai (2010) reidentified as Trypaea andamaniensis specimens from the Andaman Sea first identified by him as Callianassa tonkinae. The uropod, telson and maxilliped 3 appear identical to those of S. amboinae but the female cheliped is more robust and with a stronger more proximal meral spine. A juvenile male was reported without pleopod 1 and with a bi-articulate pleopod 2 (cf. S. caledonica, S. inermis n. sp. below).	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FF34FBC6FB00.taxon	materials_examined	Type material. Holotype: New Caledonia, Lagon Est, 21 m, 13 January 1987, female (cl 5.0 mm), MNHN-Th 1072. Paratype: Same data as holotype, 1 female lacking pleon (cl 5.0 mm), MNHN-Th 1073; 1 male lacking pleon (cl 4.0 mm), 2 males (cl 4.5, 5.0 mm), MNHN-Th 1074.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FF34FBC6FB00.taxon	diagnosis	Diagnosis. Pleomere 6 as long as wide. Telson 0.8 times as long as wide; greatest width 1.2 times posterior width. Maxilliped 3 ischium-merus 3 times as long as wide; merus free distal margin transverse, rounded. Female major cheliped ischium lower margin with 6 – 8 small spines; merus lower margin with simple proximal spine; palm 0.9 times as long as carpus. Male major cheliped merus lower margin as in female; dactylus as in female. Minor cheliped ischium lower margin with 10 small serrations; merus lower margin with 1 oblique spine at midpoint. Male pleopod 1 of 1 minute article. Male pleopod 2 absent. Uropodal endopod anterior margin with small spine about two-thirds along; dorsal surface with 1 long proximal spiniform seta, usually plus 1 shorter submarginal seta; exopod anterior margin with small spiniform seta about three-quarters along.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FF34FBC6FB00.taxon	distribution	Distribution. Known only from the type locality in New Caledonia.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FF34FBC6FB00.taxon	discussion	Remarks. Scallasis caledonica was originally described on the basis of five specimens from Lagon Est, New Caledonia (Ngoc-Ho 1991; as Callianassa). We have re-examined the type material and can confirm the accuracy of Ngoc-Ho’s figures, the only exception being the presence of two long facial spiniform setae and another distally on the anterior margin of the uropodal endopod. The male possesses a minute, pear-shaped pleopod 1 but lacks pleopod 2. Ngoc-Ho (1991) noted that the chelipeds were only slightly sexually dimorphic. Differences from S. amboinae are subtle: the distal margin of the merus of maxilliped 3 is less oblique, and the major cheliped is more compact, its meral tooth being proximal and triangular, rather than spine-like. Sakai (1999) considered Callianassa caledonica a junior synonym of “ Callianassa ” pygmaea while Dworschak (2007) considered it a valid species. Sakai’s (2010) treatment of Callianassa caledonica was not consistent: under the account of Trypaea andamaniensis, he stated “ T. caledonica is considered to be a separate species ”, whereas under the account of Trypaea tonkinae he viewed it as a questionable synonym.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FAA4FC5BF8EB.taxon	distribution	Type locality. Andaman Sea, 07 ° 30 ’ N 098 ° 57 ’ E, 20 – 38 m.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FAA4FC5BF8EB.taxon	diagnosis	Diagnosis. Pleomere 6 1.3 times as long as wide, with lateral notches at about midlength. Telson 0.8 times as long as wide; greatest width 1.1 times posterior width. Maxilliped 3 ischium-merus 3.5 times as long as wide; merus free distal margin oblique.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FAA4FC5BF8EB.taxon	distribution	Distribution. Presently known only from the type locality in the Andaman Sea.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583470E47E9BF4FAA4FC5BF8EB.taxon	discussion	Remarks. Scallasis contipes was originally described on the basis of four female specimens, one ovigerous, and two supplemental specimens (also female); none was intact. The rostrum, eyestalks and maxilliped 3 are typical of the genus. Chelipeds are unknown and Sakai’s (2002) figures do not show spiniform setae or marginal tooth on the uropodal rami, but this might be an omission. The telson appears to taper only slightly. Sakai (2002) separated Scallasis contipes from S. andamaniensis on an obliquely truncate distal margin on maxilliped 3 (vs truncate). Both were collected in the Andaman Sea, S. contipes at shallower depths.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	vernacular_names	[New Japanese name: Mame-sunamoguri]	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	description	(Figs 4 – 9) http: // zoobank. org / urn: lsid: zoobank. org: act: 68 C 54 DF 6 - 7729 - 4 E 82 - 8785 - 87 AAD 5 CC 1 A 14	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	materials_examined	Type material. Holotype: Japan, Okinawa Island, Ohura Bay, Umi-saboten diving point (stn D 1), 3 – 20 m, 18 June 2009, SCUBA diving, yabby pump, male (cl 3.7 mm; photographed), coll. Y. Fujita and T. Naruse, CBM-ZC 14140. Paratypes: Japan, Okinawa Island, Ohura B ay, Tettou-oki diving point, 23 m, muddy sand, 9 November 2013, SCUBA diving, yabby pump, coll. Y. Fujita, 1 male (cl 3.7 mm; photographed), RUMF-ZC- 04571; same data, 3 males (cl 3.6, 3.6, 3.7 mm), 1 ovigerous female (cl 3.6 mm), CBM-ZC 14141 – 14144.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	diagnosis	Diagnosis. Pleomere 6 1.1 times as long as wide. Telson 1 times as long as wide; greatest width 1.5 times posterior width. Maxilliped 3 ischium-merus 2.6 times as long as wide; merus free distal margin oblique. Female major cheliped ischium lower margin with 1 – 5 small spines; merus lower margin unarmed; palm 0.7 times as long as carpus. Male major cheliped merus lower margin with bifid proximal spine; palm 1.4 – 1.6 as long as carpus; dactylus with 2 notches on cutting margin. Minor cheliped ischium lower margin with 2 or 3 small spines; merus lower margin unarmed. Male pleopod 1 of 1 minute article, or of 2 small articles. Male pleopod 2 biramous. Uropodal endopod anterior margin with small spine about two-thirds along; dorsal surface with 1 – 3 minute proximal spiniform setae; exopod anterior margin with small spiniform seta about three-quarters along.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	description	Description. Rostrum narrowly triangular, spiniform, directed forward, with slight ventral carina, falling slightly short of distal ends of eyestalks. Carapace subequal in length to pleomeres 1 and 2 combined; orbital margins concave; anterolateral projections triangular with subacute tip; excavation inferior to anterolateral projections deep, U-shaped; deep cervical groove across 0.8 length of carapace, without postrostral transverse groove; linea thalassinica distinct, extending to posterolateral margin of carapace. Thoracic sternite 7 subpentagonal with slightly projecting anteromedian margin; ventral surface with shallow median groove. Pleomere 1 narrowing anteriorly in dorsal view; pleuron with poorly defined ventral margin. Pleomere 2 pleuron posterolateral margin slightly expanded, without tuft of setae. Pleomeres 3 – 5 pleura each with patch of plumose setae; posterolateral margins slightly expanded; pleuron 3 with tuft of long setae adjacent to posterolateral margin, pleura 4 and 5 with tuft or longitudinal row of setae on posterior parts, respectively. Pleomere 6 about 1.1 times as long as wide, subquadrate, slightly narrowing posteriorly, lacking ventrolateral projection; lateral margin with shallow notch at about posterior 0.2. Telson trapezoidal, narrowing posteriorly, approximately as long as wide, broadest at anterior 0.2; greatest width 1.5 times posterior width; dorsal surface medially with some spiniform setae in short transverse row anterior to midlength; lateral margin unarmed; 2 pairs of small spiniform setae at rounded posterolateral angles; posterior margin shallowly concave medially, unarmed or armed with minute median spine. Eyestalks flattened distally, tapering to acutely or subacutely pointed distal projection, contiguous, slightly overreaching distal margin of article 1 of antennular peduncle; dorsal surface narrowly separated from rostrum, sloping anteriorly; lateral margin convex. Cornea subterminal, submedial, darkly pigmented, wider than half width of eyestalk. Antennular peduncle slightly longer than or subequal to antennal peduncle; article 1 short, hardly visible in dorsal and lateral views; article 2 shorter than article 1; article 3 2.7 times as long as article 2; articles 2 and 3 with longitudinal ventral row of sparse long setae; antennular flagella both slightly shorter than peduncle; dorsal flagellum thicker and slightly shorter than ventral flagellum. Antennal peduncle with distal two articles subcylindrical; article 4 1.9 times as long as article 5; scaphocerite minute, spiniform. Maxilliped 1 with exopod moderately broad; epipod unequally bilobed. Maxilliped 2 moderately slender; exopod short, not reaching midlength of ischium-merus. Maxilliped 3 without exopod; ischium-merus narrowly subrectangular, non-operculiform, 2.8 times as long as wide; ischium tapering, 1.8 times as long as wide, crista dentata consisting of row of 11 strong erect spines; merus about 0.5 times as long as ischium measured along dorsal margin, about 1.2 times as wide as long, wider than merus, distolateral margin obliquely truncate, unarmed; carpus cupshaped, slightly shorter than merus; propodus narrowing distally, 2.0 times as long as wide, longer than carpus; dactylus slender, digitiform, about 0.7 times as long as propodus. Pereopods 1 (chelipeds) greatly unequal, dissimilar. Male major cheliped massive, carpus-chela combined length twice carapace length. Ischium becoming rather abruptly wider distally in general contour, upper margin strongly sinuous, unarmed; lateral surface gently convex; lower margin with row of 1 – 5 small spines. Merus as long as ischium; upper margin slightly convex, unarmed; lateral surface forming deep concavity ventral to distinct median ridge to accommodate proximoventral margin of carpus; mesial surface generally flat; lower margin with moderately strong, bifid, forwardly directed spine proximally and row of small tubercles distal to proximal spine. Carpus subquadrate, 1.0 – 1.2 times as wide as long; upper and lower margins sharply carinate, smooth, proximal lower margin broadly rounded; lateral surface smooth, convex; mesial surface nearly flat. Chela 2.2. times as long as carpus; palm subquadrate, 1.4 – 1.6 times as long as carpus, 1.2 – 1.4 times as long as wide; upper margin sharply carinate, almost glabrous; lateral surface smooth, convex; mesial surface slightly convex, with small shallow depression at base of fixed finger; lower margin sharply carinate, with row of short to moderately long setae extending onto fixed finger; fixed finger 0.5 – 0.8 times as long as palm, gently curving, terminating in acute tip; occlusal margin smooth, unarmed; lateral surface convex, with tufts of long setae along cutting edge; mesial surface depressed along occlusal margin, with tufts of setae in proximal half. Dactylus 0.5 – 0.9 times as long as palm, strongly hooked distally, crossing fixed finger, with acute tip; upper surface with blunt ridge laterally and with tufts of long setae; lateral surface with longitudinal row of tufts of long setae along cutting edge; occlusal margin sinuous, unarmed or armed with 2 large, truncate teeth; mesial surface slightly elevated in midline, also with tufts of setae along cutting edge. Female major cheliped much slender than male major cheliped. Ischium armed with 1 spine on lower margin. Merus with lower margin slightly convex, unarmed. Carpus approximately twice as long as wide, widened distally. Chela 1.5 times as long as carpus. Palm 1.2 times as wide as long; no palmer process or excavation at base of fixed finger; fixed finger nearly straight. Dactylus subequal in length to palm; occlusal margin slightly sinuous, unarmed; setation of fingers less developed than in males. Minor cheliped similar in male and female, slender; carpus-chela combined length 1.1 carapace length. Ischium slightly curving; upper margin smooth, lower margin with row of 2 or 3 small spines. Merus 0.9 times as long as ischium; upper and lower margins gently convex, unarmed. Carpus wider distally, 1.8 times as long as merus, 3.3 times as long as wide; upper margin nearly straight, rounded; lower margin slightly convex, carinate. Palm slightly widened distally, 1.4 times as long as wide; upper margin nearly straight, bluntly carinate, with row of setae; lower margin sharply carinate, with row of long setae extending onto fixed finger; lateral and mesial surfaces slightly convex, smooth. Fixed finger longer than palm, slightly curving, terminating in acute tip; occlusal margin without conspicuous teeth or spines; lateral surface with row of tufts of setae along cutting edge. Dactylus 1.6 times as long as palm, as long as fixed finger; dorsal margin rounded, with row of long setae; occlusal margin unarmed. Pereopod 2 ischium short, lower distal angle produced; merus with sinuous lower margin, upper margin almost straight; carpus subtriangular, twice as long as wide; chela subtriangular; palm 1.8 times as wide as upper margin; occlusal margins of fingers bordered by thin corneous ridge; dactylus twice as long as palm. Pereopod 3 carpus subtriangular, 2.2 times as long as wide, lower margin concave, twice as long as wide; propodus suboval with produced lower proximal margin, upper margin 1.4 times width, lateral face obtusely carinate medially, lower margin convex, faintly undulate, with 1 slender spiniform seta subdistally; dactylus nearly straight, about 0.6 times as long as propodus upper margin. Pereopod 4 coxa flattened ventrally, immovable; basis and ischium partially fused, extended posterolaterally; merus longer than ischium; carpus wider distally; propodus compressed, as long as carpus, with dense grooming setae distally on lower margin, scattered stiff setae on outer surface; dactylus slightly curving, 0.3 times as long as propodus. Pereopod 5 moderately slender, with chela subequal in length to carpus, slightly curving; dactylus about 0.3 times as long as palm. Male pleopod 1 papilla-like or very small, 2 - articulated, distal article (ramus) much shorter than proximal article (= peduncle). Female pleopod 1 unequally biramous; peduncle gently arcuate; endopod very small, slender, weakly arcuate; exopod longer than peduncle, with slight shoulder slightly proximal to midlength on inner margin. Male pleopod 2 absent, or very small, terminally bilobed, or distinctly biramous (rami basally fused to peduncle). Female pleopod 2 subequally biramous; peduncle strongly curved outward, inner margin angular; endopod tapering distally, slightly shorter and broader than exopod; exopod slightly curved inward. Pleopods 3 – 5 biramous, rami narrow; appendices internae slender, rod-like, projecting beyond mesial margin of endopod, bearing coupling hooks on apical margin. Uropod endopod and exopod subovate, overreaching posterior margin of telson. Endopod about 1.8 times as long as wide; upper surface shallowly concave in mesial half; anterior margin slightly sinuous, usually with small subdistal spine at about distal 0.2 (subdistal spine absent in female specimen); posterodistal margin convex, with fringe of setae. Exopod 1.3 times as long as wide, exceeding endopod by half length; anterior margin convex, bearing 1 small subdistal spiniform seta; posterior margin with about 10 blade-like distal setae, connected to distal margin by rounded corner; upper surface faintly slightly carinate in midline; dorsal plate extending about half distal exopod width, with distal row of stiff setae separated from setal row of distal margin. Variation. Individual variation observed in the present material is summarized in Table 1. The major cheliped exhibits strong sexual dimorphism; the male major cheliped is much heavier and more strongly armed than the female major cheliped. The male major cheliped shows also notable individual variation in the shape of the carpus and palm, and the length and armature of the dactylus, as in other callianassid taxa (e. g., Sakai 1969; Komai 2017). The ischium of the major cheliped is armed with two to five spines on the lower margin in males, while only one spine in female. The posteromedian spine on the telson is absent, or if present, minute. The development of the pleopods 1 and 2 in males also shows substantial variation not related to the size. In the male specimen (cl 3.7 mm; CBM-ZC 14140), the pleopod 1 is minute but still bi-articulate, whereas in the other four specimens (cl 3.6 – 3.7 mm; RUMF-ZC 04571, CBM-ZC 14141 – 14143), it is greatly reduced to a papilla-like bud. Three conditions are recognized in the development of the pleopod 2. In two specimens (cl 3.7 mm, CBM-ZC 14140; cl 3.7 mm, RUMF-ZC 04571), the pleopod 2 is very small but still distinctly bi-ramous (though basal articulation of each ramus is hardly recognizable); in one specimen (cl 3.7 mm; CBM-ZC 14143), it is greatly reduced to a minute, flattened piece with a bilobed terminus; in the two specimens (cl 3.6 mm, CBM-ZC 14141; cl 3.6 mm, CBM-ZC 14142, the pleopod 2 is completely absent, even a trace being not recognised. Colour in life. Carapace, pleon and tail fan generally semi-translucent, with tint of pink; cornea of eye black; major cheliped pinkish white; minor cheliped and other pereopods translucent with tint of pink (Fig. 9).	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	distribution	Distribution. Ohura Bay, Okinawa Island, Ryukyu Islands, 3 – 23 m.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	discussion	Remarks. Differences between the new species and all other species in Scallasis are discussed below. Scallasis amboinae is substantially similar to S. inermis n. sp., but the possession of fewer spines on the lower margin of the major cheliped ischium (one to four versus seven), the absence of a spine on the lower margin of the minor cheliped merus (versus spine present) and the possession of few minute spiniform setae on the uropodal endopod dorsal surface (versus one of spiniform setae rather elongate) distinguish the new species from S. amboinae. Scallasis amboinae is known with certainty from Indonesia and Papua New Guinea (Bate 1888; Poore et al. 2019; this study). No information on the minor cheliped is available for S. andamaniensis. Nevertheless, the new species seems to differ from the latter species in the presence of a spiniform seta on the outer margin of the uropodal exopod (versus no spiniform seta present: Sakai 2002: fig. 24 C). The chelipeds of the new species are strongly sexually dimorphic: the female major cheliped of the new species is substantially different from the cheliped of the female holotype of S. andamaniensis in the much more slender form with fewer ischium lower spines (one small spine versus four strong spines), the absence of the merus lower spine and the proportionally shorter palm being distinctly shorter than the carpus (versus subequal in length to carpus) (Fig. 6 E versus Sakai 2002: fig. 25 B – D). Scallasis andamaniensis is so far known only from the Andaman Sea off Thailand, at depth of 65 – 70 m (Sakai 2010). Ngoc-Ho (1991; as Callianassa) stated that the chelipeds of Scallasis caledonica were slightly sexually dimorphic. Scallasis inermis n. sp. is distinguished from S. caledonica by the following particulars (cf. Ngoc-Ho 1991): lower spines of the cheliped ischia are fewer in S. inermis n. sp. than in S. caledonica (one to five spines versus six to eight spines in the major side; two or three spines versus six spines in the minor side) (Figs 5 A, C, 6 A, E, F versus Ngoc-Ho 1991: fig. 2 j, k); the spine on the lower margin of the male major cheliped is bifid in the new species (Figs 5 A, 6 A), rather than simple, acuminate in S. caledonica (cf. Ngoc-Ho 1991: 2 j); the female major cheliped is much less stout in S. inermis n. sp. than in S. caledonica (Fig. 6 E versus Ngoc-Ho 1991: fig. 2 j); the minor cheliped merus is unarmed on the lower margin in S. inermis n. sp. (Figs 5 C, 6 F), while there is a conspicuous spine in S. caledonica (cf. Ngoc-Ho 1991: fig. 2 k); Scallasis caledonica is known only from New Caledonia, at depth of 21 m (Ngoc-Ho 1991). None of available specimens of S. contipes was intact (Sakai 2002); in particular, no information on the chelipeds is available. Nevertheless, S. inermis n. sp. can be differentiated from S. contipes by the proportionally shorter pleomere 6 (1.1 times as long as wide versus 1.3 times as long) with a lateral notch located at the posterior 1 / 4 (versus located at the midlength) (Fig. 4 E versus Sakai 2002: fig. 35 C) and the possession of one small spine on the uropodal endopod outer margin and of one small spiniform seta on the uropodal exopod outer margin (versus uropodal rami unarmed on outer margin; Sakai 2002: 35 C). Sakai (2002) did not mention on or figure spiniform setae on the uropodal endopod dorsal surface, but these could be easily overlooked. Scallasis contipes is known only from the Andaman Sea, at depths of 20 – 38 m (Sakai 2002). Scallasis spinophthalma is characteristic within the genus in having a sub-operculiform ischium-merus of the maxilliped 3 (Sakai 1970: text-fig. 4 a; Komai et al. 2002: 9 F, G). Scallasis inermis n. sp. further differs from S. spinophthalma in the possession of a spiniform seta on the outer margin of the uropodal exopod (versus both unarmed in S. spinophthalma) (Fig. 4 G versus Fig. 10 D), the absence of spiniform setae on the dorsal midline of the uropodal endopod (versus there are two long spiniform setae on the dorsal midline) (Fig. 4 G versus Fig. 10 D) and the shape and armature of chelipeds. The ischium lower margin of either cheliped is armed with one to five small spines in S. inermis n. sp. (Figs 5 A, C, 6 A, E, F), rather than five to eight spines in S. spinophthalma (Sakai 1970: text-fig. 3 d, e; Komai et al. 2002: fig. 10 A – C; Fig 10 B, C); the male major cheliped merus bears a bifid proximal spine on the lower margin in S. inermis n. sp. (Figs 5 A, B, 6 A, B), whereas trifid spine in S. spinophthalma (Sakai 1970: text-fig. 3 d; Komai et al. 2002: fig. 10 A, B); the minor cheliped merus is unarmed in S. inermis n. sp. (Figs 5 C, 6 F), whereas armed with one spine in S. spinophthalma (cf. Komai et al. 2002: 10 C; Fig 10 C). Scallasis spinophthalma is known only from the southern area of the Sea of Japan, at depths of 84 – 210 m. The description of Scallasis tonkinae by Grebenyuk (1975) depicts: the eyestalks with a terminally located cornea and lacking the distomesial projection (Grebenyuk 1975: figs. 3 – 12, 3 – 13), relatively long pleomere 6 (1.3 times as long as wide; Grebenyuk 1975: fig. 3 – 16) and the distinct posteromedian concavity of the telson (Grebenyuk 1975: fig. 3 – 16). The unique holotype is a female, having a major cheliped being as stout as that in males of S. inermis n. sp., of which the merus bears a prominent distally bifid spine on the lower margin (Grebenyuk 1975: fig. 3 – 8). The female major cheliped of S. inermis n. sp. is much more slender; the merus lower margin bears only one small spine.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
03839058347FE4769BF4FF34FCA1FCE7.taxon	etymology	Etymology. The specific epithet “ inermis ” (= unarmed) refers to the unarmed lower margin of the minor cheliped merus in the new species, which is characteristic in Scallasis.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583467E46B9BF4F8A8FE82FDA3.taxon	description	(Fig. 10)	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583467E46B9BF4F8A8FE82FDA3.taxon	materials_examined	Material examined. TRV Toyoshio-maru 2001 - 11 cruise, stn 10, Sea of Japan off Hagi, Yamaguchi Prefecture, 34 ° 40.00 ’ N 131 ° 10.00 ’ E, 99 m, 5 July 2001, dredge, 1 male (cl 3.3 mm), 1 female (cl 2.8 mm), 5 ovigerous females (cl 3.3 – 3.6 mm), CBM-ZC 6166; stn 12, off Kawajiri-misaki, Yamaguchi Prefecture, 34 ° 28.40 ’ N 130 ° 52.10 ’ E, 84 m, 7 July 2001, dredge, 1 female (cl 2.8 mm), 4 ovigerous females (cl 2.3 – 3.5 mm), CBM-ZC 6170.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583467E46B9BF4F8A8FE82FDA3.taxon	distribution	Type locality. Off Tsushima Islands (34 ° 58 ' N 129 ° 26.9 ' E), southern part of the Sea of Japan, at depth of 210 m.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583467E46B9BF4F8A8FE82FDA3.taxon	diagnosis	Diagnosis. Pleomere 6 as long as wide. Telson 0.8 times as long as wide; greatest width 1.4 times posterior width. Maxilliped 3 ischium-merus 2.2 times as long as wide; merus free distal margin rounded, slightly produced. Major cheliped strongly sexually dimorphic. Female major cheliped ischium lower margin with 5 – 7 strong spines; merus lower margin with conspicuous spine at midpoint, followed by few smaller spines proximally; palm subequal in length to carpus. Male major cheliped merus lower margin with trifid spines proximally; palm 1.6 as long as carpus; dactylus with smooth occlusal margin. Minor cheliped ischium lower margin with serration of 5 – 8 spines; merus lower margin with 1 oblique spine at midpoint. Male pleopod 1 of 2 small articles. Male pleopod 2 biramous. Uropodal endopod anterior margin with minute spine at posterior two-thirds; upper surface with 2 long spiniform setae on midline and 1 submarginal minute spiniform seta proximal to midlength; exopod anterior margin unarmed, upper surface with 1 long submarginal spiniform seta at midpoint.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583467E46B9BF4F8A8FE82FDA3.taxon	distribution	Distribution. Southern part of the Sea of Japan; at depths of 99 – 210 m.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583467E46B9BF4F8A8FE82FDA3.taxon	discussion	Remarks. Scallasis spinophthalma was originally described on the basis of six female specimens (including three ovigerous specimens) and four detached chelipeds. An ovigerous specimen (cl 4.3 mm) was designated as holotype. The species is notable for the broad maxilliped 3 ischium-merus and the distal margin of the merus much more rounded than in any other congeneric species (Sakai 1970, fig. 4 a; Komai et al. 2002: fig. 9 F, G). The species possesses a bi-articulate male pleopod 1 and biramous pleopod 2, more developed than in other species. Komai et al. (2002) did not illustrate female chelipeds, here illustrated (Fig. 10 B, C); the telson and left uropod are re-illustrated (Fig. 10 A, D) to show armature (facial spiniform setae and a spine on the uropodal endopod anterior margin) which were overlooked.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583465E46B9BF4FDC0FC0EFA74.taxon	distribution	Type locality. Gulf of Tonkin.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583465E46B9BF4FDC0FC0EFA74.taxon	diagnosis	Diagnosis. Pleomere 6 1.3 times as long as wide. Telson 0.7 times as long as wide; greatest width 1.3 times posterior width. Maxilliped 3 ischium-merus 3.2 times as long as wide; merus free distal margin transverse, rounded. Female major cheliped ischium lower margin with 4 small spines; merus lower margin with bifid proximal spine; palm 1.2 times as long as carpus.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583465E46B9BF4FDC0FC0EFA74.taxon	distribution	Distribution. Known with certainty only from the type locality.	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
038390583465E46B9BF4FDC0FC0EFA74.taxon	discussion	Remarks. Placement of Callianassa (Scallasis) tonkinae in Scallasis relies on Grebenjuk’s (1975) figures of the maxilliped 3, pereopod 3 and telson, and to a lesser extent the major cheliped and uropod. The proximal bifid meral spine on the female major cheliped is similar to that seen in male S. caledonica and S. inermis n. sp. The structure of the eyestalk appears unique in Scallasis in the terminal location of the cornea and the lack of a distomesial projection. No dorsal plate, facial spiniform setae or margin tooth were figured on the uropod – we assume they were overlooked. Dworschak (2007) suggested that Callianassa tonkinae was a junior synonym of Callianassa amboinae. Sakai (2010) referred the material identified as Callianassa tonkinae from the Andaman Sea by Sakai (2002) to a new taxon Trypaea andamaniensis. Sakai (2011 b) identified specimens from the Red Sea, 53 m, and Vietnam, 46 m as “ Trypaea ” tonkinae. The Red Sea is far west of other records of this genus but we were unable to examine this material. Grebenyuk’s types are apparently lost; they were not found in the Zoological Museum of the Moscow State University where Grebenyuk worked (I. Marin, pers. comm. 26 Jan 2020).	en	Komai, Tomoyuki, Poore, Gary C. B., Fujita, Yoshihisa (2020): Redescription of the poorly known ghost shrimp species, Scallasis amboinae Bate, 1888, review of the genus, and description of a new species from the Ryukyu Islands, Japan (Decapoda: Axiidea: Callianassidae). Zootaxa 4766 (3): 401-420, DOI: 10.11646/zootaxa.4766.3.1
