Isolation and Characterization of Polymorphic Microsatellite Loci from Metapenaeopsis barbata Using PCR-Based Isolation of Microsatellite Arrays (PIMA)

The red-spot prawn, Metapenaeopsis barbata, is a commercially important, widely distributed demersal species in the Indo-West Pacific Ocean. Overfishing has made its populations decline in the past decade. To study conservation genetics, eight polymorphic microsatellite loci were isolated. Genetic characteristics of the SSR (simple sequence repeat) fingerprints were estimated in 61 individuals from adjacent seas of Taiwan and China. The number of alleles, ranging from 2 to 4, as well as observed and expected heterozygosities in populations, ranging from 0.048 to 0.538, and 0.048 and 0.654, respectively, were detected. No deviation from Hardy–Weinberg expectations was detected at either locus. No significant linkage disequilibrium was detected in locus pairs. The polymorphic microsatellite loci will be useful for investigations of the genetic variation, population structure, and conservation genetics of this species

A new calocaridid shrimp of the genus Calaxiopsis Sakai & de Saint Laurent, 1989 (Crustacea, Decapoda, Thalassinidea) from deep waters off Taiwan

Lin, Feng-Jiau, Komai, Tomoyuki (2006): A new calocaridid shrimp of the genus Calaxiopsis Sakai & de Saint Laurent, 1989 (Crustacea, Decapoda, Thalassinidea) from deep waters off Taiwan. Zoosystema 28 (2): 399-408, DOI: http://doi.org/10.5281/zenodo.540325

Formosaxius Lin & Chan, 2010, n. gen.

<i>Formosaxius</i> n. gen. <p> <b>Type species</b>: <i>Formosaxius dorsum</i> n. sp. Gender: masculine.</p> <p> <b>Diagnosis</b>. Rostrum triangular, acute, laterally spinose, longer than eyestalks, not much depressed below level of carapace, continuous with distinct lateral carinae on gastric region of carapace. Carapace smooth; dorsal surface strongly convex, anterior part sloping down to rostrum; cervical groove visible laterally over almost half distance to anterolateral margin; supraocular spines barely differentiated from other spines; lateral carina smooth; submedian carina present, consisting of row of spines; median carina with few spines anteriorly; postcervical carina present at least in posterior half. First abdominal pleuron rounded ventrally; second pleuron broad, rounded; third to fifth pleura posteriorly rounded. Telson with 2 minute, marginal spiniform setae at each posterolateral angle; posterior margin rounded, unarmed medially. Eyestalk cylindrical, articulating; cornea pigmented. Antenna with scaphocerite long, acute. Third maxilliped with exopod not clearly bent at base of flagellum. Gill formula summarized in Table 1; pleurobranchs present on fifth to seventh thoracic somites (above bases of second to fourth pereopods); podobranchs and arthrobranchs well developed; epipods present on second maxilliped through fourth pereopod. First pereopod (only one side known at present) with laterally compressed palm; dorsal margin of carpus to dactylus smooth, with subdistal tooth on palm; cutting edges of fingers each with row of corneous spinules. Third to fifth pereopods with propodi lacking transverse rows of spiniform setae; dactyli of third and fourth pereopods subconical, slender, slightly twisted, only that of fourth pereopod with spiniform setae. Fourth pereopod with well-developed grooming apparatus on propodus. Third to fifth pleopods each with well-developed appendix interna. Uropodal exopod with transverse suture.</p> <p>Thoracic somites</p> <p>1 2 3 4 5 6 7 8</p> <p>Maxillipeds Pereopods</p> <p> 1 2 3 1 2 3 4 5 Pleurobranchs 0 0 0 0 1 1 1 0 Arthrobranchs 0 1 2 2 2 2 2 0 Podobranchs 0 0 r r r r r 0 Epipods 1 1 1 1 1 1 1 0 Exopods 1 1 1 0 0 0 0 0 <b>Remarks</b>. At present 23 genera are known in Axiidae (Poore 1994; Sakai 1994; Kensley 1996b; Sakai & Ohta 2005; Komai & Tachikawa 2007, 2008; Clark <i>et al.</i> 2007; De Grave <i>et al.</i> 2009). Only female specimens of <i>F. dorsum</i> are presently known, so no information on male pleopods is available. Nevertheless, the presence of pleurobranchs, the general armature of the rostrum and the arrangement of the carapace gastric carinae, the simple antennal scaphocerite, and the lack of spines on the dorsal margins of the cheliped palms link <i>Formosaxius</i> to <i>Bouvieraxius</i> Sakai & de Saint Laurent, 1989. In these two genera, the lateral margin of the rostrum is spinose, but the supraocular spine is not differentiated; the submedian gastric carina consists of a row of spines; and the lateral gastric carina is unarmed. However, the possession of appendices internae on the third to fifth pleopods immediately distinguishes the new genus from <i>Bouvieraxius</i>. Furthermore, the ventrally rounded first pleuron seems to differentiate the new genus from <i>Bouvieraxius</i>. The fingers of the cheliped (only one side is known) are armed with a row of corneous spinules on the cutting edges, a character not known at present for other axiid species. This character may be of generic significance. <i>Planaxius</i> Komai & Tachikawa, 2008 is also similar to <i>Formosaxius</i> n. gen. in having pleurobranchs and appendices internae on the third to fifth pleopods. However, <i>Planaxius</i> differs from the new genus in the lack of gastric submedian carinae on the carapace. The unarmed median gastric carina and the possession of spinules on the lateral faces of the dactyli of the third to fifth pereopods are also major characters separating <i>Planaxius</i> from <i>Formosaxius</i> n. gen. In the new genus, the median gastric carina is armed with two spines and one obtuse tubercle; the dactyli of the third and fifth pereopods are devoid of spinules on the lateral faces.</p> <p> <b>Etymology</b>. The name is derived from the combination of <i>Formosa</i> (old name of Taiwan) and the generic name <i>Axius</i>, in reference to the type locality of the new species.</p>Published as part of <i>Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352</i> on pages 2-3, DOI: <a href="http://zenodo.org/record/193489">10.5281/zenodo.193489</a&gt

Eiconaxius Bate 1888

Genus Eiconaxius Bate, 1888 Remarks. Kensley (1996 b) briefly summarized the taxonomy of the genus, and listed 23 species. Since then, Sakai & Ohta (2005) added a further new species, Eiconaxius hakuhou, from the Sulu Sea, the Philippines. As indicated by Kensley (1996 b), dentition of the median carina and rostral margins, development of the submedian and lateral carinae, shape of the abdominal pleura seem to be particularly useful in species discrimination. Two specimens of this genus are now known from Taiwanese waters. In spite of the paucity of the material, comparison with literature and specimens from other localities led to the conclusion that the Taiwanese material represents two separate new species.Published as part of Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352 on page 18, DOI: 10.5281/zenodo.19348

A new mud lobster of the genus Thalassina Latreille, 1806 (Crustacea: Decapoda: Gebiidea: Thalassinidae) from marine seagrass beds in Dongsha (Pratas) Island, South China Sea

Lin, Feng-Jiau, Komai, Tomoyuki, Chan, Tin-Yam (2016): A new mud lobster of the genus Thalassina Latreille, 1806 (Crustacea: Decapoda: Gebiidea: Thalassinidae) from marine seagrass beds in Dongsha (Pratas) Island, South China Sea. Raffles Bulletin of Zoology 64: 98-104, DOI: http://doi.org/10.5281/zenodo.450442

Axiidae Huxley 1879

Family Axiidae Huxley, 1879 Remarks. The family Calocarididae was revived and redefined by Kensley (1989), although his hypothetical scheme for derivation of the family suggested that the genera assigned to Calocarididae form a clade but is subordinated within Axiidae. Nevertheless, subsequent authors have continued to recognize Calocarididae as a distinct family (e.g., Poore 1994, 2008; Komai 2000; Sakai & Ohta 2005; De Grave et al. 2009), because the morphological evidence strongly suggests that genera assigned to the family clearly form a monophyletic group. Based on molecular data, Tsang et al. (2008) analysed relationships between two calocaridid species (Calastacus crosnieri and Paracalocaris sagamiensis) and three axiids, finding the two calocaridids to sister taxa and the axiids to form a paraphyletic grade. Robles et al. (2009) showed that the calocaridid, Calocaris caribbaeus, is nested among seven species of Axiidae, also suggesting the paraphyly of Axiidae. Sakai & Ohta (2005) separated Eiconaxius in its own family, Eiconaxiidae, because the genus is characterized by rounded dactyli of the third to fifth pereopods, representing a unique feature for the genus. However, Poore & Collins (2009) showed that this characteristic is also seen, in part, in the axiid Platyaxius Sakai, 1994. They finally synonymized Calocarididae and Eiconaxiidae with Axiidae.Published as part of Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352 on page 2, DOI: 10.5281/zenodo.19348

Ambiaxius propinquus Lin & Chan, 2010, n. sp.

Ambiaxius propinquus n. sp. (Figs. 4, 5, 13 C) Type material. Holotype: hermaphrodite (cl 11.8 mm), TAIWAN 2001, stn CD 129, 6 May 2001, 22o 56.13 ’N, 122 o 3.69 ’E, 1271–1275 m, (NTOU A00044). Description of holotype. Rostrum (Fig. 4 A–C) 0.35 as long as carapace, slender, upturned, extending to midlength of fourth segment of antennal peduncle, armed with 1 (left) or 2 (right) tiny lateral spines, continuous with base of supraocular spine; dorsal surface channeled medially. Carapace (Fig. 4 A–C) smooth except for slight rugosity on branchiostegite; supraocular spines prominent; gastric region convex, sloping to rostral base; lateral gastric carina very short, limited to base of supraocular spine; submedian gastric carina blunt, slightly rugose anteriorly, gradually becoming obsolete posteriorly; median gastric carina also blunt, unarmed, becoming obsolete gradually, not reaching cervical groove; cervical groove very shallow, but extending to pterygostomial region; very shallow branchial groove also present; no postcervical groove on dorsal midline; pterygostomial margin rounded. Thoracic sternum (Fig. 4 D) with shield on seventh somite weakly delimited, medially divided by deep groove. First abdominal pleuron (Fig. 4 E) short, produced ventrally as projection with narrowly rounded ventral margin; second pleuron broad, anteroventrally rounded, lateral surface shallowly depressed; third to fifth pleura rounded; sixth pleura also rounded. Telson (Fig. 4 F) 1.8 times longer than wide, widest proximally, then approximately parallel-sided, lateral margin unarmed, posterior margin strongly convex without posteromedian spine, posterolateral region unarmed; dorsal face without spines on obsolete oblique ridges. Eyestalks (Fig. 4 A, C) very short, immovably attached to cephalothorax, contiguous, hardly visible in dorsal view; cornea depressed dorsoventrally, unpigmented, unfaceted, division between cornea and eyestalk unclear. Antennular peduncle (Fig. 4 A, C) slightly falling short of midlength of fourth segment of antennal peduncle; first segment with small spine on statocyst lobe distolaterally; flagella missing. Antennal peduncle (Fig. 4 A, C) with first segment unarmed; second segment with very small dorsolateral distal spine; scaphocerite small, directed slightly upwards, less than half length of second segment; third segment with sharp spine on distomesial angle; fourth segment about 1.8 times longer than second segment; fifth segment about 0.3 length of fourth segment; flagellum missing. Third maxilliped (Fig. 5 A) moderately slender; coxa with 1 ventromesial spinule; basis also with very small ventromesial spinule; ischium unarmed on ventral margin; crista dentata with about 30 small, corneoustipped teeth; merus with 1 small subdistal spine on ventral margin; carpus unarmed; exopod with multiarticulate flagellum. Only left cheliped preserved. Cheliped (Fig. 5 B, C) elongate. Coxa bearing minute denticle on ventrodistal margin. Basis unarmed. Ischium with 2 minute denticles on ventral margin medially. Merus 4.9 times longer than high, with 1 subdistal spine (but fairly close to distal margin) on dorsal margin, unarmed on ventral margin. Carpus about 2.3 times longer than high, unarmed. Chela subequal in length to carapace and about 4.0 times longer than high (dorsal spine excluded), ventral margin faintly sinuous. Palm slightly becoming higher distally, 2.1 times longer than high, with 1 subdistal spine; lateral surface slightly convex, smooth, with few tufts of stiff setae, no carina along ventral margin; mesial face also smooth, with row of long stiff setae along ventral margin extending onto fixed finger. Fixed finger (Fig. 5 D) smooth on lateral surface, with row of tufts of setae medially; mesial face faintly elevated along midline; cutting edge with row of very small triangular teeth interspersing 1 to 4 minute denticles in proximal 0.7 and row of tiny denticles in distal 0.3. Dactylus subequal in length to palm, with rows of tufts of long stiff setae on lateral and mesial faces; mesial face slightly elevated along midline; cutting edge thin, sharply edge, with row of minute denticles, tip crossing with that of fixed finger when closed; small hiatus formed proximally between fingers when dactylus closed. Second pereopod (Fig. 5 E) slender, unarmed on ischium to carpus; carpus about 0.6 length of chela; chela wider than carpus, with tufts of long setae on margins, fingers slightly longer than palm, each with row of minute corneous spinules on cutting edge. Third pereopod missing. Fourth pereopod (Fig. 5 F) somewhat elongate, unarmed on ischium to carpus; propodus distally with cluster consisting of stiff setae and few stout setulose setae located distally (Fig. 5 G, H), possibly representing grooming apparatus, but otherwise nearly smooth on lateral surface; dactylus (Fig. 5 G, H) slender, about 0.3 times as long as propodus, slightly twisted, bearing numerous tufts of stiff setae along extensor and flexor margins. Fifth pereopod (Fig. 5 I) not subchelate, unarmed on ischium to carpus; propodus distally with grooming apparatus consisting of cluster of short to long setae, extending onto lateral and mesial faces, and transverse row of short, setulose, stout setae on ventrodistal margin (Fig. 5 J, K); dactylus (Fig. 5 J, K) very slender, elongate, about 0.4 times as long as propodus, flexor surface excavated near base, proximomesial margin slightly expanded, dorsal surface with numerous stiff setae. Gonopores present on coxae of third and fifth pereopods (Fig. 4 D). Pleurobranchs absent. Two arthrobranchs above bases of third maxilliped to fourth pereopod. Podobranchs on third maxilliped to third pereopod slender, simple, without trace of gill elements. First pleopod (Fig. 5 L) with first segment (protopod) strongly flattened, slightly twisted; second segment (ramus) about 0.3 length of first segment, rounded triangular, leaf-like, small proximomesial protrusion representing appendix interna, terminally divided into two lobes by deep V-shaped incision. Second pleopod (Fig. 5 M) with inner ramus consisting of elongate, somewhat twisted first segment of endopod while distal segment of endopod fused with appendix masculina (= distal fused segment); thumb-like appendix interna located at proximomesial margin of distal fused segment; distal fused segment tapering distally, boot-like in shape, distinctly shorter than first segment of endopod, with double row of spiniform setae on strongly sinuous mesial margin and with several terminal setae. Third to fifth pleopods very slender, without appendices internae. Uropodal endopod (Fig. 4 G) 2.4 times as long as wide, without lateral spines, dorsal ridge unarmed. Uropodal exopod (Fig. 4 G) without lateral spines, posterolateral angle with 1 spine, but no spiniform setae apparent; transverse suture unarmed. Coloration. Body generally ivory-whitish, with anterior part of carapace including eyes somewhat dark greenish (Fig. 13 C). Distribution. Known only from southeastern Taiwan at depths of 1271–1275 m. Remarks. The present specimen from Taiwan is very similar to the respective holotypes of A. alcocki and A. franklinae. However, it differs from the descriptions of the holotype of Ambiaxius alcocki from the Bay of Bengal in two points (McArdle 1900; Alcock 1901). In the Taiwanese specimen, the postcervical carapace is rounded in the dorsal surface, whereas it was mentioned that the carapace was bluntly carinate along the midline in the holotype, clearly suggesting the presence of a postcervical carina on the carapace. In fact, Sakai (1995) identified a Japanese specimen, which has a clearly delimited postcervical carina on the carapace, as A. alcocki, although he later referred it to a new species, A. surugaensis (cf. Sakai & Ohta 2005). The second point is the absence of an enlarged tooth on the cutting edge of the dactylus of the cheliped in the present specimen, which was said to be present in the holotype. The significance of the second point is rather questionable, because only the left cheliped is preserved in the present specimen. However, the development of the postcervical carina on the carapace is considered to be species specific in Axiidae and Calocarididae, and its absence alone seems to justify the separation of the Taiwanese specimen from A. alcocki. Direct comparison with the holotype likely will reveal further morphological differences. Moreover, the identities of A. alcocki reported from discrete localities such as South Africa and New Caledonia (cf. Stebbing 1915, 1917; Barnard 1950; Sakai & de Saint Laurent 1989; Sakai & Ohta 1995) will need to be verified (e.g., Kensley 1996 a). The lack of the postcervical carina on the carapace aligns the Taiwanese specimen with A. franklinae. However, it differs from the latter by the shorter and less curved rostrum. In the Taiwanese specimen, the rostrum does not reach the distal end of the fourth segment of the antennal peduncle, whereas in the holotype of A. franklinae it is longer, nearly reaching the distal end of the fifth segment of the antennal peduncle. Furthermore, the spiniform setae on the concave anterior margin of the boot-shaped appendix masculina of the second pleopod seem to be more numerous in the Taiwanese specimen than in A. franklinae. Therefore, it is concluded that the Taiwanese form is a separate species. Another species of the genus, Ambiaxius surugaensis, can be immediately distinguished from the present new species and the other two species by the arthrobranchs bearing rudimentary gill elements. In the other three species, the arthrobranchs are distinctly lamellate. The presence of the postcervical carina also distinguishes A. surugaensis from A. propinquus n. sp. and A. franklinae. The much broader distal segment of the first pleopod is also characteristic to A. surugaensis, although the detailed structure of the appendage remains unknown for the holotype of A. alcocki. FIGURE 5. Ambiaxius propinquus n. sp., holotype hermaphrodite (cl 11.8 mm), NTOU A0 0 0 44. A, right third maxilliped, lateral view; B, chela and carpus of left cheliped, lateral view; C, merus of left cheliped, lateral view; D, fixed finger of left chela, lateral view; E, left second pereopod, lateral view; F, left fourth pereopod; G, same, distal part of propodus and dactylus, lateral view; H, same, mesial view; I, left fifth pereopod, lateral view; J, same, distal part of propodus and dactylus, lateral view; K, same, mesial view. Scale bars: A–C, E, F, I = 2 mm; D, G, H, J, K–M = 1 mm. Etymology. From the Latin, propinquus, meaning similar or related, in reference to the close similarity of the new species to A. alcocki and A. franklinae.Published as part of Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352 on pages 8-13, DOI: 10.5281/zenodo.19348

Calastacus formosus Lin & Chan, 2010, n. sp.

Calastacus formosus n. sp. (Figs. 6 –8, 13 D) Type material. Holotype: hermaphrodite (cl 7.1 mm), TAIWAN 2001, stn CP 104, 24° 48.86 ’N, 122 °05.31’E, 365–447 m, 19 May 2001 (NTOU A00083). Paratypes: 2 hermaphrodites (cl 6.0, 6.5 mm), 1 ovigerous hermaphrodite (cl 9.0 mm), TAIWAN 2001, stn CP 102, 24° 48.38 ’N, 122 °07. 97 ’E, 326–331 m, 19 May 2001 (NTOU A00110). Description of holotype. Rostrum (Fig. 6 A–D) 0.2 times as long as carapace and about 0.4 times of distance between rostral base and cervical groove, spike-like with acute tip, unarmed anterior to supraocular spine, not continuous with lateral gastric carinae on carapace. Carapace (Fig. 6 A–D) smooth; gastric region convex, higher than rostral base; supraocular spines prominent; lateral and submedian gastric carinae absent; median gastric carina unarmed, extending over midway between rostral base and cervical groove; cervical groove distinct, extending nearly to pterygostomial part of carapace; no postcervical carina; pterygostomial margin with small spine. Thoracic sternum (Fig. 7 A) with poorly delimited shield on seventh somite, medially separated by deep groove; sixth somite with spade-shaped prominence. First abdominal pleuron (Fig. 6 E) short, produced ventrally as acute projection; second pleuron broad, anteroventrally rounded; third to fifth pleura rounded; sixth pleura also rounded. Telson (Fig. 6 F) 1.6 times longer than wide, widest proximally, then approximately parallel-sided, lateral margin unarmed, posterior margin strongly convex without posteromedian spine, posterolateral region with 1 minute spiniform seta; dorsal face without spines on obsolete oblique ridges. Eyestalks (Fig. 6 C, D) subglobose, 0.4 length of rostrum, immovably attached to cephalothorax, not contiguous; cornea unpigmented, unfaceted, division between cornea and eyestalk unclear. Antennular peduncle (Fig. 6 C) reaching distal margin of fourth segment of antennal peduncle; first segment with small submarginal spine on statocyst lobe dorsodistally; flagella missing. Antennal peduncle (Fig. 6 C, D) with first segment bearing 2 spines on ventrodistal margin (lateral spine longer than mesial spine); second segment with dorsolateral distal spine slender, slightly curved inward in dorsal view, slightly directed dorsally in lateral view, reaching to midlength of fourth segment; scaphocerite slender, directed slightly upwards, slightly falling short of distal margin of fourth segment; third segment with sharp spine on distomesial angle; fourth segment slightly longer than second segment (excluding dorsolateral distal spine); fifth segment about half length of fourth segment; flagellum missing. Third maxilliped (Fig. 8 A) moderately slender; coxa with 1 small ventromesial spine; basis also with small ventromesial spine; ischium unarmed on ventral margin; crista dentata with about 20 corneous-tipped teeth; merus with 2 long subdistal spines on ventral margin; carpus unarmed. Chelipeds (Fig. 7 B–E) subequal, similar, fairly elongate. Right cheliped (Fig. 7 D, E) with coxa bearing spine on ventrodistal margin. Basis also with small spine ventrodistally. Ischium with row of 3 slender spines on ventral margin. Merus with 1 subdistal spine (slightly hooked) and row of 5 slender spines increasing in size distally on ventral margin. Carpus unarmed. Chela 0.9 times as long as carapace and 3.6 times longer than high, ventral margin slightly curving. Palm slightly becoming higher distally, 1.8 times longer than high, with 1 subdistal spine on faintly carinate dorsal margin and 1 spine on lateral surface adjacent to base of fixed finger; lateral surface slightly convex, with few tufts of long setae and row of low tubercles bearing tufts of setae adjacent to ventral margin, extending onto fixed finger; mesial face also with spine adjacent to base of fixed finger. Fixed finger with row of small tubercles and tufts of long setae on mesial face along ventral margin, latter extending onto palm; cutting edge with row of rounded teeth. Dactylus with 3 longitudinal rows of long stiff setae on lateral surface; mesial face medially carinate, also with rows of long stiff setae; cutting edge with broad concavity proximally, forming narrow hiatus when closed, tip closing with tip of fixed finger. Left cheliped (Fig. 7 A, B) only slightly shorter than major cheliped, otherwise generally similar. Ischium with 4 spines on ventral margin. Merus with 1 subdistal spine on dorsal margin and 7 spines on ventral margin. Armament and setation of other segments identical with those on major cheliped. Second pereopod (Fig. 8 B) slender, unarmed on ischium to carpus; carpus about 0.6 length of chela; chela with tufts of long setae on margins, fingers slightly shorter than palm, each with row of minute corneous spinules on cutting edge. Ambulatory legs (third to fifth pereopods) somewhat elongate. Third pereopod (Fig. 8 C) unarmed on ischium to carpus; propodus with row of spiniform setae on lateral surface distally (Fig. 8 D); dactylus (Fig. 8 D, E) subconical, slender, about 0.3 times as long as propodus, slightly twisted, setose. Fourth pereopod (Fig. 8 F) unarmed on ischium to carpus; propodus distally with cluster consisting of stiff setae and longer, stout setulose setae, possibly representing grooming apparatus, and with sets of 1 or 2 spiniform setae and longer stiff setae on lateral surface distally (Fig. 8 G); dactylus (Fig. 8 G, H) subconical, setose, slightly twisted (tip broken, thus proportion against propodus unknown). Fifth pereopod (Fig. 8 I) not subchelate, unarmed on ischium to carpus; propodus distally with grooming apparatus consisting of cluster of short to long setae, extending onto lateral and mesial faces (Fig. 8 J, K); dactylus (Fig. 8 J, K) very slender, elongate, about 0.4 times as long as propodus, flexor surface excavated near base, proximomesial margin expanded, dorsal surface with row of tufts of stiff setae. Gonopores present on coxae of third and fifth pereopods (Fig. 7 A). Pleurobranchs absent; podobranchs and arthrobranchs present on second maxilliped through fourth pereopods, podobranchs bearing papillae representing rudimentary gill filaments; epipods present on first maxilliped through fourth pereopod. First pleopod (Fig. 7 F) with first segment (protopod) strongly flattened; second segment (ramus) 0.7 length of first segment, leaf-like, deeply concave on mesial margin proximally, proximomesial protrusion representing appendix interna conspicuous on broad triangular anterior fold, lateral fold forming definite shoulder on lateral margin. Second pleopod (Fig. 7 G, H) with inner ramus consisting of 2 -segmented endopod plus distally articulated appendix masculina, all components more or less in line with peduncle, with thumblike appendix interna at base of second segment of endopod; second segment of endopod with slightly concave dorsal (or anterior) margin bearing numerous stiff, curving setae; appendix masculina tapering distally with row of sparse stiff setae laterally and mesially, and with terminal tuft of stiff setae; exopod very slender, half length of endopod. Third to fifth pleopods very slender, without appendices internae. Uropodal endopod (Fig. 6 G) about 2.0 times as long as wide, without lateral spines, dorsal ridge unarmed, distal margin subtruncate; exopod (Fig. 6 G) without lateral serration, posterolateral angle with 1 spine, but no spiniform setae apparent; transverse suture with about 10 slender spiniform setae (Fig. 6 H). Note on paratypes. One paratype lacks right first and fifth pereopods; other two missing first chelipeds and several pereopods. Antennal peduncle with first segment bearing 2 spines on ventrodistal margin (lateral spine longer than mesial spine, and mesial spine small to distinct). First chela 0.7 times as long as carapace and 3.3 times longer than high, ventral margin slightly curving; palm slightly becoming higher distally, 1.8 times longer than high, with 1 subdistal spine on dorsal margin and 1 spine on lateral surface near base of fixed finger; carpus unarmed; merus with 1 subdistal spine on dorsal margin and 7 spines on ventral margin; ischium with 3 spines on ventral margin. Uropodal endopod about 2.0 times as long as wide, without lateral spines, dorsal ridge unarmed, distal margin subtruncate; exopod without lateral serration, posterolateral angle with 1 spine and 1 small spiniform seta; transverse suture with 10 or more slender spiniform setae. Coloration. Body and appendages entirely pale yellowish to pale yellowish pink; cornea of eye opaque. Inner margins of fingers of second chelae dark purplish. Distribution. Known only from northeastern Taiwan; at depths of 326– 447 m. Remarks. The present new species agrees well with the diagnosis of Calastacus, provided by de Saint Laurent (1972), Kensley (1989), Poore (1994) and Poore & Collins (2009). The genus is currently represented by seven species worldwide, C. stilirostris Faxon, 1893 (type species) from the eastern Pacific off Mexico to Peru, C. laevis de Saint Laurent, 1972 from the eastern Atlantic and Mediterranean, C. colpos Kensley, 1996 from the northwestern Gulf of Mexico, C. mexicanus Kensley, 1996 from the Gulf of Mexico, C. crosnieri Kensley & Chan, 1998 from Taiwan, C. inflatus Komai, Lin & Chan, 2009 from the South China Sea off the Pratas Islands, and C. myalup Poore & Collins, 2009 from south Western Australia (Kensley 1996 a; Kensley & Chan 1998; Ngoc-Ho 2003; Komai et al. 2009; Poore & Collins 2009). The new species appears closest to C. myalup in the presence of a pterygostomial spine on the carapace and the suture of the uropodal exopod, which bears 10 or more slender spiniform setae. Nevertheless, C. formosus n. sp. differs from C. myalup in the shape of the uropodal endopod. In C. formosus, the posterior margin of the uropodal endopod is subtruncate, but it is rounded in C. myalup. Furthermore, the supraorbital spine on the carapace only just exceeds the orbital margin of the carapace in C. formosus n. sp., rather than overreaching the middle of the eye in C. myalup. The ornamentation of the appendix masculina of the second pleopod consists only of stiff setae in C. formosus, but it includes spiniform setae in C. myalup. This is the second species of Calastacus known from Taiwan. The other species is C. crosnieri, which is golden yellow in color and very different from the pale yellowish body of C. formosus. Considering the general scarcity of species of the genus around the world, the presence of two species from the same region is rather remarkable. Etymology. The species is named after its type locality Taiwan derived from a former name, “ Formosa ”.Published as part of Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352 on pages 13-18, DOI: 10.5281/zenodo.19348

Ambiaxius Sakai

Genus <i>Ambiaxius</i> Sakai & de Saint Laurent, 1989 <p> <b>Remarks</b>. <i>Ambiaxius</i> was originally established by Sakai & de Saint Laurent (1989) to accommodate two species, <i>Calocaris alcocki</i> McArdle, 1900 and <i>Calocaris aberrans</i> Bouvier, 1905. Kensley (1989) also described a new genus <i>Callistocaris</i> for <i>Calocaris alcocki</i>, but his paper was published two months later than Sakai & de Saint Laurent’s work. Thus <i>Callistocaris</i> is a junior objective synonym of <i>Ambiaxius</i>. Since then, four new species have been described in this genus, <i>A. franklinae</i> Sakai, 1994 from Australia, <i>A. japonicus</i> Kensley, 1996 from Japan, <i>A. foveolatus</i> Kensley, Lin & Yu, 2000 from Taiwan, and <i>A. surugaensis</i> Sakai & Ohta, 2005 from Japan. Sakai & Ohta (2005) proposed a new genus, <i>Briancaris</i>, for <i>A. aberrans</i>, <i>A. japonicus</i> (type species) and <i>A. foveolatus</i>. Sakai & Ohta (2005) argued that <i>Briancaris</i> differs from <i>Ambiaxius</i> in the short, triangular rostrum with denticulate lateral margins and the structure of the second pleopod. In <i>Ambiaxius</i>, the rostrum is slender and upturned, bearing one or two tiny lateral spines. With regard to the second pleopod, they noted that “distal segment of endopod enlarged with a boot-shaped appendix masculina with a small protrusion, on which is a small appendix interna, that is slightly distant from basal segment” for <i>Ambiaxius</i>, while that “distal segment of the endopod enlarged with a small appendix interna, which is attached close to the proximal segment basally” for <i>Briancaris</i>. However, these conditions are barely distinguishable. Except for the shape of the rostrum, the diagnostic features of <i>Ambiaxius</i> and <i>Briancaris</i> are virtually identical, and thus the status of <i>Briancaris</i> is questionable. Sakai & Ohta (2005) gave the confusing comment that “Kensley’s <i>Callistocaris</i> is obviously different from Sakai & de Saint Laurent’s (1989) <i>Ambiaxius</i> ”, even though these two genera were based on the same type species (<i>i.e.</i>, <i>Calocaris alcocki</i>). We prefer to synonymize <i>Briancaris</i> with <i>Ambiaxius</i>.</p>Published as part of <i>Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352</i> on page 8, DOI: <a href="http://zenodo.org/record/193489">10.5281/zenodo.193489</a&gt

Eiconaxius rubrirostris Lin & Chan, 2010, n. sp.

Eiconaxius rubrirostris n. sp. (Figs. 9, 10, 13 E) Type material. Holotype: male (cl 5.4 mm), TAIWAN 2000, stn CP 55, 24° 24.40 ’N, 122 ° 18.0’E, 638–824 m, 4 August 2000 (NTOU A0 0 114). Description. Rostrum (Fig. 9 A, B) lanceolate, apically narrowly rounded, straight, reaching slightly beyond distal margin of first segment of antennular peduncle; lateral margins nearly smooth, slightly upturned. Carapace (Fig. 9 A, B) with gastric region very slightly convex; cervical groove faint; median carina entire, broadened posteriorly, but not distinctly bifurcate; submedian carina absent; lateral carinae reaching posteriorly to about anterior one-third of carapace length, slightly constricted posterior to orbit; submarginal carina distinct. First and second abdominal somites damaged. Second to fourth pleura (Fig. 9 C) angular (second and third) or rounded posteroventrally (fourth), none forming acute ventral or posteroventral tooth, fifth pleura generally rounded ventrally; anterolateral margin of fourth and fifth pleura each with minute tooth ventrally; sixth abdominal somite short, with 3 obtuse small protuberances on posterodorsal margin, unarmed on pleural ventral margin. Telson (Fig. 9 D) with greatest width at anterior 0.25 length, with 8 serrations, including 1 tiny posterolateral one, on lateral margin; moderately small posteromedian tooth present. Eye (Fig. 9 A) reaching midlength of rostrum; cornea subglobose, not faceted, lacking pigment. Antennular peduncle (Fig. 9 A, B) with distal two segments subequal in length to first segment; flagella nearly as long as carapace. Antennal peduncle (Fig. 9 A, B) moderately stout; distolateral prolongation of second segment acute, overreaching distal margin of second segment of antennular peduncle; third segment with small spine at ventromesial distal angle; antennal acicle large, acuminate, reaching nearly to distal margin of fifth segment of antennal peduncle or far overreaching distal margin of antennular peduncle; flagellum moderately slender (distal half missing). Third maxilliped (Fig. 10 A) moderately slender for genus; ischium with crista dentata consisting of row of tiny denticles Major (right) cheliped (Fig. 10 B, C) massive. Ischium unarmed on ventral margin. Merus strongly compressed laterally; dorsal margin strongly convex, bearing minute denticle distal to midlength, but otherwise smooth, terminating distally in minute tooth; ventromesial margin sharply carinate, with 1 minute subterminal denticle; laterodistal projection subacute. Carpus cup shaped, much wider than long, ventral angle faintly dentate. Chela slightly longer than carapace (including rostrum). Palm 1.05 times longer than high, dorsal margin sharply carinate, terminating distally in small subacute tooth, with tiny denticle somewhat proximal to dorsodistal tooth, lateral surface convex with several scattered tubercles in distal half; ventrolateral carina sharp, extending to distal 0.20 of fixed finger, accompanied with deep groove; mesial surface also with scattered tubercles in distal half. Fixed finger nearly straight but distally slightly upturned, with 1 blunt, small but distinct tooth arising at about mid-length, otherwise minutely dentate; finger cleft shallowly excavate; lateral face flanked by blunt upper ridge along cutting edge and ventrolateral ridge concave. Dactylus nearly as long as palm, terminating in slightly curved calcareous claw, dorsal margin sharply carinate; lateral surface shallowly sulcate along dorsal carina; cutting edge with 1 obtuse tooth proximally, otherwise unarmed. Minor (left) cheliped (Fig. 10 D) slightly shorter and less stout than major cheliped. Ischium with 1 minute denticle slightly distal to midlength. Merus strongly compressed laterally; dorsal margin sinuous, sharply carinate, bearing 3 minute denticles distal to midlength, terminating distally in minute denticle; ventromesial margin sharply carinate, with 2 tiny subdistal spinules; laterodistal projection subacute. Carpus cup shaped, much wider than long, ventral angle faintly dentate. Chela subequal in length to carapace (including rostrum). Palm slightly becoming wider distally, 1.1 times higher than long; dorsal margin sharply carinate, smooth, terminating distally in minute denticle; lateral surface generally convex, smooth; ventrolateral carina sharp, extending to midlength of fixed finger; mesial surface smooth. Fixed finger slightly deflexed, almost straight but distally slightly upturned, with row of small, triangular or rounded teeth over entire length; finger cleft with 3 -spined cusp laterally; lateral face flanked by sharp upper ridge along cutting edge and ventrolateral ridge shallowly concave. Dactylus about 1.4 times as long as palm, terminating in slightly curved calcareous claw, dorsal margin sharply carinate; lateral surface with distinct longitudinal carina on midline; cutting edge faintly dentate. Second to fourth pereopods of similar length, moderately stout. Second pereopod (Fig. 10 E) unarmed on ischium to carpus; chela about 1.5 times longer than carpus, with scattered tufts of setae; fixed finger slightly deflexed, with row of minute corneous spinules on cutting edge; dactylus about 0.6 times as long as palm, setose, also with row of minute corneous spinules on cutting edge. Third pereopod (Fig. 10 F) unarmed on ischium to carpus; propodus about 1.5 times longer than carpus, with 5 sets of slender spiniform setae on lateral surface ventrally and 1 spiniform seta at ventrodistal margin; dactylus (Fig. 10 H) strongly compressed laterally, suboval, terminating in clearly demarcated claw, with about 8 spiniform setae on flexor margin and 1 set of 2 slender spiniform setae on lateral surface. Fourth pereopod (Fig. 10 G) similar to third pereopod; propodus with 7 sets of spiniform setae and 1 ventrodistal spiniform seta; dactylus with 9 spiniform setae on flexor margin and 1 set of 3 spiniform setae on lateral surface. Fifth pereopods missing. First pleopod absent. Second to fifth pleopods slender, biramous, each with appendix interna; appendix masculina on second pleopod subequal to appendix interna, bearing about 10 stiff setae. Uropodal exopod (Fig. 9 D) with about 13 serrations on lateral and posterior margins, posteriormost one larger than others, mesial margin nearly regularly convex; endopod (Fig. 9 D) with about 7 serrations increasing in size posteriorly. Coloration. Body generally whitish, but rostrum distinctly reddish; cornea of eye opaque. Distribution. Known only from northeastern Taiwan; at depths of 638- 824 m. Remarks. Affinities of this new species are given under Eiconaxius kensleyi n. sp. Etymology. The Latin “ rubrirostris ” refers to the distinctly red rostrum in this new species.Published as part of Lin, Tomoyuki Komai Feng-Jiau & Chan, Tin-Yam, 2010, Five new species of Axiidae (Crustacea: Decapoda: Axiidea) from deep-water off Taiwan, with description of a new genus, pp. 1-28 in Zootaxa 2352 on pages 18-21, DOI: 10.5281/zenodo.19348