On a collection of Homolidae from the South China Sea, with descriptions of two new species of Homologenus A. Milne-Edwards, in Henderson, 1888, and the identities of Homologenus malayensis Ihle, 1912, and Lamoha superciliosa (Wood-Mason, in Wood-Mason & Alcock, 1891) Author Ng, Peter K. L. Author Forges, Bertrand Richer de text Raffles Bulletin of Zoology 2017 2017-07-14 65 243 268 journal article 10.5281/zenodo.5356049 2345-7600 5356049 CC246EF9-E704-4DDC-BD25-61B6102A382F Homologenus brevipes n. sp. ( Figs. 16 , 17 , 18G–I , 19I–P , 20F–H , 21G–I , 22D–F ) Homologenus malayensis – Ho et al., 2004: 642 , fig. 1A. – Ahyong et al., 2009: 86 , fig. 54, 55. (not Homologenus malayensis Ihle, 1912 ) Material examined. Holotype : ovigerous female (15.0 × 10.7 mm ) ( NTOU ), station PCP 344, 22°15.95′N 120°0.11′E , 995–1073 m , southern Taiwan, trawl, coll. TAIWAN 2006 Cruise , 8 March 2006 . Paratypes : 1 ovigerous female ( 14.8 mm , rostrum broken) ( ZRC 2013.0298 ), station PCP 344, 22°15.95′N 120°0.110′E , 995–1073 m , coll. TAIWAN 2006 Cruise , 8 March 2006 . – 1 ovigerous female (16.8 × 15.0 mm) ( ZRC 2009.1161 ), station CP 141, 22°12.04′N 119°59.96′E , 985–1110 m , eastern Taiwan, trawl, TAIWAN 2001 Cruise , 24 November 2001 . – 1 male (12.7 × 10.0 mm) ( ZRC 2009.1162 ), station CD 136, 22°7.75′N 120°0.87′E , 998–1211 m , eastern Taiwan, trawl, coll. TAIWAN 2001 Cruise , 22 November 2001 . – 3 ovigerous females (17.0 × 15.0 mm, 17.4 × 14.3 mm , 16.8 × 13.9 mm ) ( ZRC 2009.1160 ), station CP 134, 22°16.56′N 120°6.11′E , 736–1040 m , eastern Taiwan, trawl, coll. TAIWAN 2001 Cruise , 22 November 2001 . – 1 ovigerous female (15.4 × 13.5 mm ) ( ZRC 2016.0572 ), station CD 192, 22°17.19′N 120°1.01′E , 960–1302 m , southern Taiwan, trawl, coll. TAIWAN 2002 Cruise , 28 August 2002 . – 1 ovigerous female (13.8 × 10.2 mm ) ( ZRC 2016.0573 ), station PCP 445 ( NTOU B00069), 22°17.10′N 120°0.17′E , 982–999 m , southern Taiwan, trawl, coll. TAIWAN 2006 Cruise , 14 July 2008 . – 1 ovigerous female (12.4 × 9.9 mm , broken rostrum), 1 male (7.6 × 5.9 mm ) ( ZRC 2016.0574 ), southern Taiwan , 22°17.17′N 120°00.18′E – 22°13.24′N 120°00.32′E , coll. trawl, 5 July 2013 . – 1 ovigerous female (16.1 × 10.9 mm ) ( ZRC 2016.0575 ), station OCP 280, 24°23.71′N 122°14.22′E , 1213–1261 m , eastern Taiwan, trawl, coll. TAIWAN 2005 Cruise , 14 June 2005 . Fig. 20. Right P5 pseudochela (propodus and dactylus) of Homologenus species. A , H. malayensis Ihle, 1912 , female (16.0 × 13.9 mm) (ZRC 2016.0196), Papua New Guinea; B, H. malayensis Ihle, 1912 , male (carapace width 6.2 mm, rostrum damaged) (ZRC 2016.0194), Papua New Guinea; C, H. exilis n. sp. , holotype ovigerous female (13.5 × 10.4 mm) (NTOU), South China Sea; D, H. exilis n. sp. , paratype female (15.1 × 11.4 mm) (ZRC 2016.0569); E, H. exilis n. sp. , paratype male (10.2 × 7.4 mm) (ZRC 2016.0568), South China Sea; F, H. brevipes n. sp. , holotype ovigerous female (15.0 × 10.7 mm) (NTOU), Taiwan; G, H. brevipes n. sp. , paratype ovigerous female (15.4 × 13.5 mm) (ZRC 2016.0572), Taiwan; H, H. brevipes n. sp. , paratype male (7.6 × 5.9 mm) (ZRC 2016.0574), Taiwan. Diagnosis. Small species, covered with numerous long and short setae ( Fig. 16 ). Carapace longer than wide; male carapace longitudinally ovate; anterior half of female carapace distinctly less wide than posterior half; surface of carapace granular; gastro-cardiac and branchio-cardiac grooves well marked; with short, sharp median gastric spine and 2 short epigastric spines; short spine at angle of buccal cavity; line of prominent granules marking border of pterygostomian region ( Figs. 16 , 17A , 18G–I ). Rostrum very long, curved, sharp, with 2 short accessory pseudorostral spines pointing anteriorly ( Figs. 16 , 17A, B , 18G–I ). Well-developed pseudorostral spines in supra-ocular position almost straight, directed obliquely anteriorly; supraorbital margin with short spine ( Figs. 16 , 17A, B , 18G–I ). Basal antennal spine strong ( Fig. 17A ). Subhepatic spine slender ( Fig. 17A ). Anterolateral spine long, sharp, pointing obliquely outwards, relatively more anteriorly in angle ( Figs. 16 , 17A , 18G–I ). Anteroexternal angle of merus of third maxilliped with 1 sharp curved spine ( Fig. 17C ). Female cheliped short; chela slightly inflated: chela with 5 small spines on ventral margin and 4 spines on dorsal margin; fingers long, slender, curved inwards; carpus with 3 long spines on external face; merus with 8 strong spines on outer margin and 6 spines on inner margin ( Fig. 17D, E ). Male cheliped short; chela inflated, triangular in cross-section, fingers closely appressed when closed; margins of merus spinose; carpus with 4 prominent spines; dorsal margin of chela with 4 spines, ventral margin with 4 spines ( Fig. 21I ). Ambulatory legs (P2–P4) long, slender; P5 reduced, in dorsal position, merus unarmed, not reaching base of anterolateral spine when folded on carapace; dactylus long, relatively wider, curved, sharp, reaching proximal spine of propodus, forming pseudochela ( Figs. 16 , 19L, P , 20F–H ); female: P2 merus with 3 spines on dorsal margin, outer surface with 2 or 3 spinules, ventral margin with 3 or 4 spinules; P3 merus with 2 or 3 spines on dorsal margin, outer surface with 1 spinule, ventral margin with 4 spines; P4 merus with 3 spines on dorsal margin, outer surface with 2 spinules, ventral margin with 2 spines ( Figs. 16A, B , 19I–K ); male: P2 merus with 4 or 5 spines on dorsal margin, outer surface with 2 spinules, ventral margin with 4 or 5 spinules; P3 merus with 4 spines on dorsal margin, outer surface with 2 spinules, ventral margin with 5 or 6 spinules; P4 merus with 4 spines on dorsal margin, outer surface with 2 spinules, ventral margin with 4 spines ( Figs. 16C , 19M–O ); P2–P4 propodus long, dactylus long, falciform ( Fig. 16 ). Armature of pleonites as follows: female somite 2 with 1 median spine, somite 3 with 4 low spines, somite 4 with 4 very low spines, somite 5 with 4 very low spines, telson, somites 1, 5 and 6 unarmed ( Fig. 17F ); male somite 2 with 1 median spine, somite 3 with 5 low spines, somite 4 with 4 low spines, somite 5 with 4 low spines, telson, somites 1 and 6 unarmed ( Fig. 21G, H ). G1 relatively stout, distal part tapering to cone-like structure ( Fig. 22D, E ). Fig. 21. A–C, Homologenus malayensis Ihle, 1912 , male (carapace width 6.2 mm, rostrum damaged) (ZRC 2016.0194), Papua New Guinea; D–F, H. exilis n. sp. , paratype male (10.2 × 7.4 mm) (ZRC 2016.0568), South China Sea; G–I, H. brevipes n. sp. , paratype male (7.6 × 5.9 mm) (ZRC 2016.0574), Taiwan. A, D, G, telson and pleonal somites 5 and 6; B, E, H, pleonal somites 2–6; C, F, I, outer view of left chela. Fig. 22. Gonopods of Homologenus species. A –C, H. exilis n. sp. , paratype male (10.2 × 7.4 mm) (ZRC 2016.0568), South China Sea; D–F, H. brevipes n. sp. , paratype male (7.6 × 5.9 mm) (ZRC 2016.0574), Taiwan. A, C, D, F, ventral view; B, E, dorsal view. Scales = 0.5 mm. Fig. 23. Lamoha longirostris ( Chen, 1986 ) carrying an unidentified sea anemone in vicinity of Mariana Island group at a depth of 1212 m on 13 August 2016. Photographs courtesy of the U.S. National Oceanographic and Atmospheric Administration Office of Ocean Exploration and Research. Fig. 24. Colour in life, A–H from South China Sea; I, J from Papua New Guinea and Bismarck Sea. A, Lamoha longirostris ( Chen, 1986 ) , female (24.9 × 20.3 mm) (ZRC 2016.0555); B, Lamoha murotoensis ( Sakai, 1979 ) , male (20.8 × 18.4 mm) (ZRC 2016.0200); C, Paromola macrochira Sakai, 1961 , female (16.5 × 11.4 mm) (ZRC 2016.0560); D, Paromola macrochira Sakai, 1961 , female (16.3 × 11.1 mm) (ZRC 2016.0562); E, Moloha majora ( Kubo, 1936 ) , male (54.8 × 47.8 mm) (ZRC 2016.0197); F, Homolochunia gadaletae Guinot & Richer de Forges, 1995 , ovigerous female (34.1 × 26.4 mm) (ZRC 2016.0198); G, Homolomania sibogae Ihle, 1912 , male (15.4 × 11.3 mm) (ZRC 2016.0199); H, Paromolopsis boasi Wood-Mason , in Wood-Mason & Alcock, 1891 , male (20.1 × 17.7 mm) (ZRC 2016.0565); I, Homologenus malayensis Ihle, 1912 , ovigerous female (16.0 × 13.9 mm) (MNHN-IU-2015-80); J, Homologenus malayensis Ihle, 1912 , ovigerous female (14.9 × 9.9 mm) (MNHN-IU-2014-8052). Etymology. The name alludes to the relatively shorter ambulatory legs of this species when compared to those of the allied new species, H. exilis . Used as a noun in apposition. Colour. The specimen illustrated in colour by Ahyong et al. (2009: 86 , fig. 54) is the present holotype of H. brevipes . In life, the carapace is dirty white overall with the anterior part of the carapace pink. Remarks. As discussed earlier, there are several differences between H. brevipes n. sp. and H. malayensis Ihle, 1912 . The most significant is in the ventral margin of the P4 merus in H. brevipes n. sp. possessing two spines ( Fig. 19K, O ) (margin unarmed in H. malayensis , Figs. 8B , 12G, K ). In addition, the rostrum of H. brevipes is relatively shorter ( Fig. 16 , 17B , 18G–I ) (rostrum distinctly longer in H. malayensis , Figs. 8A, F , 9 , 10 , 11B , 18A, B ); and the pseudorostral spines are almost straight and directed anterolaterally ( Figs. 17B , 18G–I ) (gently curving laterally in H. malayensis , Figs. 8A, F , 9 , 10 , 11B , 18A, B ). In addition to the difference in carapace shape and armature of the P4 merus discussed above, male H. brevipes can be separated from H. donghaiensis (known only from one male ) in having the spines on the dorsal margin of P2–P4 straight ( Fig. 19I–K, M–O ) (spines are curved backwards in H. donghaiensis , Fig. 13A–C ); the male has only five spines on the dorsal margin of the P2 merus ( Figs. 16A , 19I, M ) (with only 3 or 4 spines in male H. donghaiensis , Fig. 13A, B ); the spines on pleonal somites 2 and 3 are low but distinct ( Fig. 17F ) (very short or not visible in H. donghaiensis , Ng & Chen, 1999 : fig. 3g ); and the dactylus of P5 reaches to the subproximal spine of the propodus ( Fig. 20F–H ) (P5 dactylus relatively shorter, not reaching the subproximal propodal spine in H. donghaiensis , Fig. 13A, B ; Ng & Chen, 1999 : fig. 3e). The female specimen reported and figured as “ H. malayensis ” in Ho et al. (2004 : fig. 1A) from southern Taiwan could not be examined but the colour figure leaves no doubt it is conspecific with H. brevipes .