Cestopagurus hinepuia, Komai, Tomoyuki, Tsuchida, Shinji & Clark, Malcolm R., 2014

Komai, Tomoyuki, Tsuchida, Shinji & Clark, Malcolm R., 2014, First record of the hermit crab genus Cestopagurus Bouvier, 1897 (Crustacea: Decapoda: Anomura: Paguridae) from the South Pacific Ocean and description of a new species, Zootaxa 3860 (6), pp. 580-588 : 581-587

publication ID	https://doi.org/ 10.11646/zootaxa.3860.6.6
publication LSID	lsid:zoobank.org:pub:12D183AA-FE91-43EE-B019-2E09919C8450
DOI	https://doi.org/10.5281/zenodo.6129843
persistent identifier	https://treatment.plazi.org/id/0929235B-3FD3-4CAB-BA75-B01F4D2871A1
taxon LSID	lsid:zoobank.org:act:0929235B-3FD3-4CAB-BA75-B01F4D2871A1
treatment provided by	Plazi
scientific name	Cestopagurus hinepuia
status	sp. nov.

Treatment

Cestopagurus hinepuia n. sp.

( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Material examined. Holotype: RV “Yokosuka”, YK13-11 cruise, DSV “Shinkai 6500”, dive #1374, Hinepuia submarine volcano, Kermadec Arc, 26°24.125’S, 177°14.643’W, 499 m, 30 October 2013, slurp gun, coll. Cornel de Ronde (GNS, New Zealand), male (sl 1.6 mm), NIWA 90217.

Description. Eleven pairs of distally divided quadriserial gills.

Shield ( Fig. 1 View FIGURE 1 A) approximately as long as wide; anterior margin between rostrum and lateral projections slightly concave; anterolateral margins sloping; posterior margin truncate; dorsal surface slightly convex, with few tufts of short setae laterally, otherwise glabrous; paragastric grooves indistinct. Rostrum triangular, terminating in acute spine, distinctly overreaching lateral projections. Lateral projections rounded, each without marginal or submarginal spinule.

Ocular peduncles (including cornea) ( Fig. 1 View FIGURE 1 A) moderately stout, 0.7 length of shield; somewhat inflated basally; cornea not dilated, narrower than base of ocular peduncle; dorsal surface with 3 tufts of short to long stiff setae mesially (length of setae increasing distally). Ocular acicles subtriangular, separated basally by width of one acicle, with small submarginal spine directed slightly mesially against tip of acicle.

Antennular peduncles ( Fig. 1 View FIGURE 1 A), when fully extended, overreaching distal corneal margins by 0.8 length of ultimate segment. Ultimate segment elongate, exceeding twice length of penultimate segment, widened distally in lateral view, with subterminal tuft of long setae. Penultimate segment short, without setae. Basal segment with ventrodistal margin terminating in minute tooth, statocyst lobe weakly inflated, with prominent spine distolaterally.

Antennal peduncles ( Fig. 1 View FIGURE 1 A) slightly overreaching distal corneal margins by half length of fifth segment. Fourth and fifth segments with few setae distally. Third segment with spinule at ventromesial distal angle (not visible in dorsal view). Second segment with dorsolateral distal angle produced, reaching midlength of fourth segment, terminating in bifid, acute spine; dorsomesial distal angle with small spine; mesial and lateral faces with few setae. First segment with spinule on lateral face; ventromesial distal margin moderately produced anteriorly, with 1 small spine laterally. Antennal acicle slightly overreaching distal corneal margin, slightly arcuate, terminating in slender spine; dorsomesial margin with few short to long setae. Antennal flagellum exceeding 5 times length of shield; each article with 2–4 short setae on distal margin (setae at most 1.3 length of 1 article).

Mouthparts not dissected. Third maxilliped ( Fig. 1 View FIGURE 1 B) moderately stout; carpus unarmed on dorsodistal margin; merus unarmed on dorsodistal margin, but armed with small ventral spine subdistally; ischium with crista dentata consisting of narrowly spaced corneous teeth and with 1 accessory tooth located subdistally ( Fig. 1 View FIGURE 1 C); basisischium fusion incomplete; basis with few denticles on mesial margin; exopod reaching midlength of carpus.

Chelipeds distinctly unequal and dissimilar. Right cheliped ( Fig. 2 View FIGURE 2 A–D) stout, not particularly elongate. Chela subovate in dorsal view, about 1.7 times as long as wide (greatest width at about midlength of palm); narrow hiatus between fingers. Dactyl about 0.7 length of palm, very slightly curved ventrally, overlapped by fixed finger distally; surfaces without conspicuous spines, dorsomesial margin not delimited; longitudinal row of tufts of short setae on dorsal surface adjacent to cutting edge and scattered short individual or tufts of short setae on mesial surface; cutting edge with 3 calcareous teeth in proximal half (proximal-most tooth largest, rounded) and with row of small corneous teeth in distal 0.2, terminating in minute corneous claw. Palm subequal in length to carpus; dorsal surface gently convex, with scattered short setae and few low tubercles proximally, with row of tiny, low tubercles or granules on proximal half of midline, dorsomesial margin not delimited, dorsolateral margin slightly delimited by row of low, tiny tubercles extending onto fixed finger; lateral face almost smooth, with scattered very short setae; mesial face also smooth, with scattered short setae; ventral surface gently convex, smooth, with sparse short to long setae. Fixed finger slightly curving ventrally, with sparse tufts of short to moderately long setae; cutting edge with 1 calcareous tooth at midlength, terminating in minute corneous claw. Carpus widened distally, slightly longer than merus; dorsal surface with scattered small spines or spinulose tubercles laterally and mesially (median area smooth) and sparse short to long setae, dorsomesial and dorsolateral margins not clearly delimited; lateral surface smooth, almost glabrous; mesial surface almost smooth, shallowly concave, with sparse tufts of short to long setae; ventral surface gently convex transversely, with sparse long setae. Merus with few short setae on dorsal surface, dorsodistal margin unarmed; lateral and mesial faces almost glabrous, ventrolateral margin with row of 3 small spines followed by short, oblique, marginally denticulate ridges, ventromesial margin with 3 small, widely spaced spines and several long setae; ventral surface slightly concave, with some small tubercles proximally and with scattered long setae. Ischium with smooth ventromesial margin; surfaces with few short setae. Coxa unarmed.

Left cheliped ( Fig. 3 View FIGURE 3 A–C) moderately slender, slightly overreaching base of dactylus of right cheliped. Chela about 2.6 times longer than wide (greatest width at base of dactylus); no hiatus between fingers. Dactylus about 1.2 times longer than palm, almost straight, without conspicuous spines or tubercles on surfaces, with sparse tufts of short to moderately long setae, dorsomesial margin not delimited; cutting edge with row of small, slender corneous teeth, terminating in strong corneous claw. Palm about half length of carpus, with row of small spines on somewhat elevated midline, not extending onto fixed finger, and additional row of small tubercles lateral to midline; dorsolateral and dorsomesial margins not delimited; lateral and mesial faces almost smooth, with sparse short setae; ventral surface convex, with sparse tufts of long setae. Cutting edge of fixed finger with row of spaced minute corneous teeth, terminating in strong corneous claw. Carpus slightly longer than merus; dorsolateral margin with row of small spines decreasing in size proximally followed by some short transverse ridges and tufts of long setae; dorsomesial margin also with row of small spines extending beyond midlength; lateral face with scattered minute granules, ventrolateral distal angle with 3 tiny spines or tubercles; mesial face nearly smooth, with few tufts of long setae; ventral surface gently convex longitudinally, with numerous tufts of long setae. Merus with sparse short setae on dorsal margin; lateral face almost glabrous, with sparse granules ventrally, ventrolateral margin with row of small spines or tubercles; mesial face smooth, with long setae adjacent to ventral margin, ventromesial margin with row of small spines over entire length; ventral surface slightly concave, without distinct spines or tubercles, but with long stiff setae. Ischium unarmed, with few setae. Coxa unarmed.

Ambulatory legs ( Fig. 4 View FIGURE 4 A, C) moderately long and stout, right second pereopod slightly falling short of tip of extended right cheliped. Dactyli about 6.2–6.6 times longer than wide, in dorsal view straight, in lateral view slightly curving ventrally, about 1.1 times as long as propodi; dorsal margins with sparse setae; lateral faces flat; mesial faces also flat, unarmed (second; Fig. 4 View FIGURE 4 B) or armed with row of widely spaced corneous spinules adjacent to dorsal margin (third; Fig. 4 View FIGURE 4 D); ventral margins each with 11 moderately strong corneous spines decreasing in size proximally. Propodi distinctly longer than carpi; dorsal surfaces each with sparse moderately short to long stiff setae; lateral and mesial faces glabrous; ventral margins each with row of 4 widely spaced corneous spinules, ventrodistal margin each with 2 slender corneous spines. Carpi each with tiny dorsodistal spine; sparse stiff setae on dorsal surface; lateral faces glabrous. Meri each with sparse setae on dorsal and ventral margins (setae on ventral margin longer); lateral faces smooth, glabrous; ventral margins armed with spinule at distal one-fourth (second) or unarmed (third).

Fourth pereopods ( Fig. 1 View FIGURE 1 D) semichelate. Dactyli each with row of minute corneous teeth on ventral margin, terminating in small corneous claw; no preungual process. Propodal rasp consisting of single row of small corneous scales.

Fifth pereopods chelate. Coxae ( Fig. 1 View FIGURE 1 F) slightly unequal, dissimilar. Right coxa with sexual tube of medium length, gradually tapering distally, oriented towards left across ventral body surface, extending beyond lateral margin of left coxa, distal part strongly curved ventrally. Left coxa with very short, papilla-like sexual tube directed mesially.

Third thoracic sternite with obsolete denticle on either side of shallow median notch. Anterior lobe of sixth thoracic sternite ( Fig. 1 View FIGURE 1 E) roundly squarish, with moderately short setae on anterior surface. Eighth thoracic sternite compressed, ( Fig. 1 View FIGURE 1 F) divided into 2 subequal, non-setose lobes.

Pleon dextrally twisted. Male with 3 unpaired, very unequally biramous left pleopods (third to fifth pleopods). Uropods markedly asymmetrical; protopods unarmed.

Telson ( Fig. 1 View FIGURE 1 G) with distinct lateral indentations; posterior lobes slightly asymmetrical, rounded, terminal margins slightly oblique, each with row of 4 small spines, lateral margins not forming chitinous plate.

Coloration in life. Shield pale orange, with scattered darker dots. Ocular, antennular and antennal peduncles uniformly orange tone, without markings. Chelipeds and ambulatory legs generally reddish orange, without markings; dactylus of right cheliped whitish; distal parts of dactyli of ambulatory legs also whitish. See Fig. 5 View FIGURE 5 .

Distribution. Known only from the type locality, Hinepuia submarine volcano, Kermadec Arc, at a depth of 499 m.

Housing. Gastropod shell (probably Trochidae ). No association with cnidarians was seen.

Remarks. Cestopagurus hinepuia n. sp. appears closest to C. puniceus among the four known congeneric species. Shared characters include: antennular peduncle elongate, overreaching distal corneal margin by 0.8 length of ultimate segment; antennal acicle overreaching distal corneal margin; chela of right cheliped without conspicuous spines on dorsal surface; carpus of right cheliped concave on mesial surface; no hiatus between fingers of left chela; and meri of second pereopods unarmed on ventral margins. In addition, these two species occur in waters greater than 200 m deep, whereas the other three are found in intertidal to shallow subtidal depths down to 25 m. The new species has different armature of the right and left chelipeds in the male: the carpus of the right cheliped is armed with numerous scattered small spines or spinulose tubercles laterally in C. hinepuia n. sp., rather than unarmed in C. puniceus (cf. Komai & Takeda 2005: fig. 4C, D); the ventromesial margin of the merus of the right cheliped is armed with three widely spaced spines in the new species, but unarmed in C. puniceus (cf. Komai & Takeda 2005: fig. 4B); the ventromesial margin of the merus of the left cheliped is armed with a row of tiny spines in C. hinepuia n. sp., but unarmed in C. puniceus (cf. Komai & Takeda 2005: Fig. 5 View FIGURE 5 E).

Owing to the extensive work by de Saint Laurent & McLaughlin (2000), the pagurid fauna of waters around New Zealand was fairly well documented, and 34 species from 11 genera are now known. Nevertheless, the present species represents the first Cestopagurus occurring in the South Pacific Ocean, as well as New Zealand and its adjacent waters. Recent studies have revealed the existence of a rich pagurid fauna in the western Pacific, including species of small sizes in sublittoral to upper bathyal zones (e.g., McLaughlin 1997; Komai 2013a, 2013b; Komai & Rahayu 2013a, 2013b). There is no doubt that many unknown species still await discovery in large areas of the South Pacific Ocean.

Etymology. Named after the submarine volcano “ Hinepuia ”, which is the type locality of the new species. “ Hinepuia ” is a Maori god of geothermal activity. Used as a noun in apposition.