Rediscovery and range extension of Ciliopagurus liui Forest, 1995 and description of a new species of Pagurus Fabricius, 1775 (Crustacea: Decapoda: Anomura: Paguroidea) from the Kerala State, southwestern India Author Komai, Tomoyuki Author Reshmi, Rema Author Kumar, Appukuttan Nair Biju text Zootaxa 2013 3710 5 467 484 journal article 10.11646/zootaxa.3710.5.5 57d1ac72-6a0a-435d-b17e-a54ae4e9c7f7 1175-5326 221190 364284D2-63E4-4EC6-8363-31E9A46252F0 Ciliopagurus liui Forest, 1995 ( Figs 1–5 ) Ciliopagurus krempfi .—Miyake 1982: 104 (in part), pl. 35, fig. 2 left. Ciliopagurus liui Forest, 1995: 75 , figs. 12j, 15d, 17a, 33c.—McLaughlin et al. 2010: (list). Material examined . Kerala State, India , 08°11’N , 75°44’E to 08°15’N , 76°11’E , 25–30 m , 25 May 2011 , 2 males (sl 7.3, 7.6 mm ), 2 females (sl 6.4, 7.3 mm ), CBM-ZC 11806; same data, 2 females (sl 8.8, 9.0 mm), UOK/AQB/ AR/AN12–13. Description of Indian specimens . Cephalothorax ( Fig. 1 ) strongly depressed dorsoventrally. Shield ( Fig. 2 A) approximately as long as broad; anterior margin nearly transverse, with faint concavity either side of obsolete rostrum; anterolateral angle blunt, but distinctly delineated; lateral margins convex, with row of moderately long setae in anterior one-third; posterior margin narrow, roundly truncate; dorsal surface flat, with scattered shallow pits and few tufts of short setae laterally; Y-shaped groove present posteriorly, integument around the groove decalcified. Posterior carapace substantially widened. Ocular peduncles ( Fig. 2 A) equal in length, long and slender, about 0.8 times as long as shield and 5.5–6.0 times longer than corneal width, cylindrical, slightly inflated basally (slightly wider than cornea); cornea not dilated; dorsal surfaces with scattered very short setae. Ocular acicles narrowly triangular, mesial margins nearly straight, lateral margins sloping, terminating in simple or bifid spine; narrowly separated basally (distance between acicles less than half width of 1 acicle). Antennular peduncles ( Fig. 2 A) not reaching corneal bases. Ultimate segment about 0.4 times as long as shield and about 1.5 length of penultimate segment, dorsal surface glabrous. Penultimate segment with tuft of moderately short setae slightly proximal to midlength. Basal segment short; ventrodistal margin terminating in tiny spine; laterodistal margin with 3 or 4 spinules; lateral surface armed with 1 minute spine. Antennal peduncles ( Fig. 2 A) reaching distal one-third of ocular peduncles. Fifth segment slightly flattened dorsoventrally, with tuft of short setae at dorsolateral distal angle; lateral surface non-calcified. Fourth segment with simple or bifid spine on dorsodistal margin. Third segment with prominent spine at ventrodistal angle and few tufts of short setae. Second segment with dorsolateral distal angle produced, terminating in bifid spine, lateral margin with 1 or 2 small tubercles; dorsomesial distal angle with minute spinule, mesial margin with short stiff setae. First segment with ventrodistal margin with few minute spinules or tubercles lateral to antennal gland opening. Antennal acicle reaching midlength of fifth segment, terminating in acute, simple or bifid spine; mesial margin with 4 or 5 small spines, lateral margin with 2–4 small spines. Flagellum slightly shorter than carapace; each article with some minute setae (<0.2 length of one article) on distal margin. Maxillule with endopod bearing 2 bristles on moderately well developed internal lobe, external lobe well developed, slender, recurved ( Fig. 2 B). Third maxilliped with basis and ischium incompletely fused; basis with 1 or 2 minute corneous-tipped denticles ( Fig. 2 C); ischium with crista dentata well-developed, consisting of row of blunt or distally truncate corneous teeth, without accessory tooth ( Fig. 2 C); merus and carpus unarmed on dorsodistal margins; exopod broad (broadest at proximal two-fifths), uncalcified in lateral half, mesial surface with shallow concavity in distal half, accommodating proximal part of exopodal flagellum. FIGURE 1 . Ciliopagurus liui Forest, 1995 , male (sl 7.3 mm), CBM-ZC 11806, entire animal in dorsal view, showing coloration in life. Chelipeds short, fairly flattened dorsoventrally, subequal or slightly unequal, when unequal, left larger ( Fig. 1 ). Left cheliped ( Figs. 3 A–D, 4A–D) with dactylus subequal in length to palm; cutting edge with 2 obsolete calcareous teeth in proximal 0.6, distal 0.4 bordered by darkly pigmented corneous plate leading to tip; dorsomesial margin not delimited, dorsal and mesial surfaces with 7 shallow transverse furrows proximally bounded by low, setose ridges (3 furrows and striae in proximal half complete (extending to ventromesial margin of dactylus), others not complete); dorsal parts of ridges bearing minute corneous spinules; mesial surface ( Fig. 4 B) with transverse rows of corneous rods forming stridulating apparatus, these rods becoming shorter and fewer distally, distal ones corneous spine-like; ventral surface with a few tufts of stiff setae. Palm longer than carpus; dorsolateral or lateral margin not delimited, dorsomesial margin bluntly angular, surfaces each marked by shallow transverse furrows, each furrow bounded proximally by setose, microscopically denticulate to almost smooth ridges (main ridges 7 in number on dorsal surface, shorter additional striae interspersed by main ridges); 4 furrows on mesial surface, each continuous with dorsal furrows, each bounded proximally by low ridges bearing rows of corneous rods forming stridulating apparatus (for details, see below); ventral surface almost flat, laterally with 4 or 5 setose transverse ridges bordered by row of minute corneous spines and moderately long, stiff setae. Fixed finger with 4 furrows extending from dorsal to ventral surface, each proximally bounded by low ridges; on ventral surface, ridges bearing row of minute corneous spines; cutting edge with 2 low, blunt calcareous teeth in proximal three-fifths, distal twofifths bordered by darkly pigmented corneous plate extending to tip. Carpus about half length of merus, subtrapezoidal in dorsal view; dorsal, lateral and mesial surfaces each with shallow transverse furrows, and each furrow bounded proximally by low, smooth or minutely denticulate ridges (3 main ridges and 2 interspersing striae limited to dorsal surface); dorsodistal margin almost smooth, fringed with dense row of short setae becoming longer laterally, ventrodistal margin with less dense, longer stiff setae; dorsomesial distal angle with 1 small spine; ventral surface almost flat, mesially with 1 transverse ridge extending from mesial surface. Merus subrectangular in cross section, subtriangular in dorsal view; dorsal, lateral and to lesser extent mesial surfaces with 4 shallow transverse furrows, bounded proximally by low, smooth ridges, each ridge with dense short setae marginally; dorsal surface with additional setose striae interspersed by main ridges, dorsodistal margin unarmed, fringed with row of dense short stiff setae extending laterally and mesially; mesial surface nearly smooth except for transverse ridges or striae, ventromesial margin unarmed; ventrolateral distal margin with 1 or 2 tiny spines; ventral surface laterally with some transverse ridges extending from lateral surface and a few additional short striae, ventrodistal margin with row of stiff setae becoming longer laterally. Ischium with ventromesial margin smooth, terminating distally in blunt prominent tubercle; lateral surface with 1 transverse ridge. Right cheliped similar to left cheliped in armature and ornamentation. Stridulating apparatus on palm ( Fig. 4 C) consisting of 4 distal ridges bearing corneous rods and 2 proximal ridges with minute corneous teeth. First (distalmost) ridge broad, bearing about 10 long corneous rods equally spaced (rods nearly horizontal to oblique, each terminating in minute spine distally). Second ridge very short, limited to dorsal side, bearing 4 or 5 corneous rods. Third ridge as wide as second, but narrower than first ridge, with about 10 rods aligned with those on first ridge and extending over width of ridge, each rod terminating in minute spine distally. Fourth ridge slightly wider than third ridge, bearing about 10 corneous rods, these rods much shorter than those on distal ridges, ventral ones more strongly oblique. In total, about 40 corneous rods present. Ambulatory legs ( Figs. 1 , 5 A–F) moderately stout, second slightly overreaching tips of chelipeds; generally similar in armature and ornamentation, but dactyli of third distinctly longer than those of second. Dactyli about 1.4 (second) or 1.6 (third) times as long as propodi, terminating in strong terminal claws, in lateral view gently curved ventrally, in dorsal view nearly straight, bearing 8–10 transverse, occasionally squamiform ridges continuous on dorsal and ventral margins, 1 or 2 distalmost ridges interrupted on lateral or mesial surfaces; these ridges bearing dense stiff setae, becoming longer ventrally (ventral setae forming prominent tufts); ventral surfaces with row of 5– 12 slender corneous spines increasing in size distally (3 or 4 distalmost spines darkly pigmented). Propodi each with series of prominent ridges and rows of short stiff setae circumscribing segment (6 main ridges and a few interspersing, short striae limited to lateral or mesial faces); setae on transverse ridges becoming noticeably longer ventrally, forming prominent tufts. Carpi subtriangular in cross section with broad dorsal surface, each with 1 or 2 dorsodistal spines mesially; dorsal surfaces each with 5 transverse ridges bearing rows of short dense setae, of them 1 or 2 ridges extending onto ventral surfaces though sometimes interrupted medially. Meri trapezoidal in cross section with dorsal surfaces broader than ventral surfaces; dorsal surfaces each with 9 or 10 transverse ridges bearing row of dense setae, of them 7–9 extending onto lateral surfaces and 5 or 6 to mesial surfaces, all ridges interrupted on ventral surfaces; mesial faces slightly concave; ventral surfaces each with row of tufts of long stiff setae mesially. Ischium with 1 or 2 short transverse striae on dorsal surfaces, without conspicuous spines. Fourth pereopods ( Fig. 2 D) semichelate. Dactylus about twice as long as palm, slightly curved, overreaching tip of fixed finger by about 0.3 length, terminating in minute corneous claw, lateral surface with row of small corneous spines ventrally; preungual process absent; ventral (opposable) surface broad, nearly flat. Propodal rasp very well developed, encompassing half to two-thirds of lateral surface, consisting of numerous small corneous scales increasing in size distally. Carpus with dorsodistal spine. Merus with some short setose striae or tufts of setae on lateral surface. Tufts of long stiff setae present on dorsal surfaces of dactylus to merus and distal part of ventral surface of merus. Fifth pereopods chelate. FIGURE 2 . Ciliopagurus liui Forest, 1995 , male (sl 7.6 mm), CBM-ZC 11806. A, shield and cephalic appendages, dorsal view; B, endopod of maxillule, internal view; C, ischium of left third maxilliped, ventral view (setae omitted); D, left fourth pereopod (ischium broken); E, third to sevenths thoracic sternites, ventral view; F, sixth pleonite, dorsal view; G, telson, dorsal view. Scale bars: 2 mm for A, F, G; 1 mm for B–D, E. FIGURE 3 . Ciliopagurus liui Forest, 1995 , male (sl 7.6 mm), CBM-ZC 11806. A, left chela, dorsal view (setae omitted); B, carpus of left cheliped, dorsal view (setae omitted); C, left chela, ventral view; D, carpus of left cheliped, ventral view. Scale bar: 2 mm. Thoracic sternum ( Fig. 2 E) extremely broad, flattened plate-like. Sternite 3 fully visible, with anterior margin produced medially, divided by distinct median notch. Sternite 4 subtriangular, anteriorly with setose, submarginal transverse stria. Anterior and posterior lobes of sternite 6 (of third pereopods) rod-like, former slightly narrower than latter, with transverse submarginal row of setae; posterior lobe without median groove. Membranous part between calcified plates of sternites 7 and 8 broad, with prominent, subtriangular process on each lateral margin, each process bearing many long setae. Sternite 8 (of fifth pereopods) also very narrow, rod-like, slightly widened laterally, without conspicuous median groove. Males with 4 unpaired left pleopods (second to fifth pleopods; length: third = fourth> fifth> second); each exopod well developed, whereas endopods reduced, about half length of exopods, both rami multi-articulated. Female with 4 biramous unpaired pleopods (length: third = fourth = fifth> second), with both rami multiarticulated and well developed. Uropods asymmetrical. Pleonite 6 ( Fig. 2 F) divided into two parts by distinct transverse groove across at about posterior two-thirds; lateral indentations shallow; anterior margin oblique; posterior part with deep median longitudinal groove, posterolateral margins with few faint tubercles and tufts of setae. Telson ( Fig. 2 G) with distinct lateral indentations; anterior lobe slightly wider than posterior lobe; posterior lobes broadly and roundly subtriangular, slightly unequal (left slightly larger than right), with narrow, deep median cleft; terminal margins unarmed, but with row of moderately long stiff setae. FIGURE 4 . Ciliopagurus liui Forest, 1995 , male (sl 7.6 mm), CBM-ZC 11806. A, left cheliped, lateral view; B, same, dactylus, mesial view (setae omitted); C, same, palm, mesial view; D, same, carpus to ischium, mesial view (setae omitted). Scale bars: 2 mm. Coloration in life ( Fig. 1 ). Shield pale red, lateral parts yellowish. Posterior carapace translucent generally; posteromedian plate with red tinge medially. Ocular peduncle red, without conspicuous markings; cornea black. Antennular and antennal peduncles red, antennal flagellum uniformly light red. Palms of chelipeds generally orange-red, transverse ridges lined by red, transverse sulci whitish. Dactyli of ambulatory legs generally orangered, becoming slightly paler distally; propodi with distal parts cream or light yellow with tinge of red, followed by 7 or 8 alternate rings of red and white (white ring corresponding to furrows), proximally part whitish; carpi similarly annulated with 4 or 5 white and red rings, proximal part yellow or cream; meri also annulated with 7 or 8 alternated white and red rings (red rings broader than white rings, sometimes bicolored with red and orange), proximal parts yellow or cream; ischia generally red or orange, with few white rings or short striae. Pleon with numerous, short to long, red and white transverse or obliquely transverse stripes. Biocoenoses . The cone shell, Conus inscriptus Reeve (Gastropoda: Conidae ). Distribution . Tonkin Gulf in the South China Sea ( type locality), Japan , and now southern India . Remarks . Ciliopagurus liui was originally described on the basis of a single male specimen collected in the Tonkin Gulf, southern China , at a depth of 53 m (Forest 1995). In addition, Forest (1995) referred a specimen from Japan , identified as C. krempfi (Forest, 1952) by Miyake (1982: 104, pl. 55, fig. 2, left), to C. liui , though Forest did not personally examine the Japanese specimen. We tried to locate the Japanese specimen, but whereabouts of the specimen remains unknown. Since the original description, there have been no additional records of this species. The present specimens agree well with the type description of C. liui by Forest (1995) in every diagnostic aspect, including the terminally simple or at most bifid ocular acicles, the relatively long antennal acicle reaching to the midlength of the fifth segment of the antennal peduncle, the smooth transverse ridges on the chelae and the pattern of annulation on the ambulatory legs. The characteristic coloration in life also agrees well with that of the specimen reported from Japan (Miyake 1982: pl. 55, fig. 2; as C. krempfi ), particularly in the uniformly reddish ocular and antennal peduncles, chelipeds and ambulatory legs with alternated white and red bands, and the pleon with irregular pattern of short to long red and white transverse stripes. FIGURE 5 . Ciliopagurus liui Forest, 1995 , male (sl 7.6 mm), CBM-ZC 11806. A, right second pereopod, lateral view (setae omitted); B, same, mesial view; C, left third pereopod, lateral view; D, same, mesial view; E, same, dactylus, lateral view (perpendicular), showing setation; F, same, propodus, lateral view (perpendicular), showing setation). Scale bars: 2 mm. As Forest (1995) discussed, Ciliopagurus liui appears closest to C. macrolepis Forest, 1995 described on the basis of a single male specimen from the Banda Sea, Indonesia . He cited armature and shape of the antennal acicle, proportion of the dactyli of the ambulatory legs, and development of annulation of the ambulatory legs to differentiate the two species. We confirm that the armature of the antennal acicle and the development of transverse furrows of the ambulatory legs are reliable, but other characters might overlap between the two species. Mesial spines on the antennal acicle are less numerous in C. liui than in C. macrolepis (up to six versus eight or nine). As Forest (1995) noted, transverse furrows on the propodi and meri of the ambulatory legs are deeper in C. macrolepis than in C. liui . Ciliopagurus is currently represented by 19 extant and two fossil species (Forest 1995; Bakel et al. 2003; Poupin 2001; Poupin & Malay 2009; McLaughlin et al. 2010; Komai et al. 2012). All but C. caparti (Forest, 1952) occur in the Indo-West Pacific to Central Pacific. Ciliopagurus caparti is distributed in the tropical eastern Atlantic. From the Indian Ocean, the following seven species of the genus have been recorded: C. grandis Komai, Reshmi & Biju Kumar, 2012 , C. haigae Forest, 1995 , C. krempfi (Forest, 1952) , C. shebae (Lewinsohn, 1969) , C. strigatus (Herbst, 1804) , C. tenebrarum (Alcock, 1905) , and C. tricolor Forest, 1995 . Of them, C. grandis , C. strigatus and C. tenebrarum are known from India . The present study documents the occurrence of C. liui in the Indian Ocean.