Catapaguroides longior, Komai, Tomoyuki, Yamada, Yusuke & Shirakawa, Naoki, 2010

Komai, Tomoyuki, Yamada, Yusuke & Shirakawa, Naoki, 2010, A new hermit crab species of the genus Catapaguroides A. Milne-Edwards & Bouvier (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, Japan, and additional record of C. foresti McLaughlin, Zootaxa 2690, pp. 32-42 : 33-38

publication ID	https://doi.org/ 10.5281/zenodo.199548
DOI	https://doi.org/10.5281/zenodo.3507122
persistent identifier	https://treatment.plazi.org/id/03D23E41-FFB7-AA5B-C9D6-FE15FD0EFA2C
treatment provided by	Plazi
scientific name	Catapaguroides longior
status	sp. nov.

Treatment

Catapaguroides longior View in CoL n. sp.

[New Japanese name: Manza-gama-hime-yadokari] ( Figs. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 , 5A View FIGURE 5. A )

Material examined. Holotype: male (sl 2.1 mm), Apo-gama Cave, Onna Village, Okinawa Island, Ryukyu Islands, 30 m deep, 10 m from entrance of cave, 18 January 2010, SCUBA diving, coll. Y. Yamada and N. Shirakawa, CBM-ZC 9977.

Description of holotype. Ten pairs of biserial, phyllobranchiate gills; arthrobranchiae on third maxilliped and cheliped very small, poorly lamellate; no pleurobranch on wall of seventh thoracic somite.

Shield ( Fig. 1 View FIGURE 1 A, B) slightly broader than long; anterior margins between rostral lobe and lateral projections concave; anterolateral margins sloping, posterior margin roundly truncate; dorsal surface almost naked, with iridescent sheen. Rostral lobe rounded. Lateral projections obtusely triangular, falling short of level of rostral lobe; each with submarginal spinule.

Ocular peduncles ( Fig. 1 View FIGURE 1 A) about 0.6 length of shield, moderately stout, slightly tapering distally, with 2 tufts of setae adjacent to base of cornea (setae of mesial tuft much longer than those of lateral tuft) and 2 tufts of moderately short setae dorsomesially; cornea rather small, narrower than ocular peduncle, but not conical in shape, corneal width about 0.2 of peduncular length. Ocular acicles ( Fig. 1 View FIGURE 1 B) moderately small, narrowly triangular, terminating in acute marginal spine, separated basally by more than basal width of one acicle. Interocular lobe ( Fig. 1 View FIGURE 1 B) visible in dorsal view.

Antennular peduncles ( Fig. 1 View FIGURE 1 A, C), when fully extended, overreaching ocular peduncles by half length of penultimate segment. Basal segment with spinule at distolateral portion of statocyst lobe; lateral margin distal to statocyst lobe concave. Ultimate segment about 1.9 times longer than penultimate segment, broadened distally in lateral view, with 1 long, setulose seta (slightly shorter than dorsal flagellum) and 1 simple seta on dorsolateral distal portion. Dorsal flagellum with distal portion distinctly longer than proximal, aesthetascbearing portion.

Antennal peduncles ( Fig. 1 View FIGURE 1 A) overreaching distal corneal margins by full length of fifth segments. Fifth segment with few setae distally. Fourth segment with few, very short setae. Third segment with 1 prominent spine at ventrodistal angle. Second segment with dorsolateral distal angle produced into bifid spine not reaching midlength of fourth segment; dorsomesial distal angle with prominent spine. First segment unarmed. Antennal acicle elongate, slightly curved only at base, overreaching distal corneal margin by half-length and reaching to distal margin of fifth peduncular segment, terminating in sharp spine, with prominent tuft of long setae distally and few much shorter setae dorsomesially in distal half. Antennal flagellum long, about 5.0 times longer than shield; articles each with 3–5 short to long setae distally ( Fig. 1 View FIGURE 1 D).

Third maxilliped ( Fig. 1 View FIGURE 1 E) relatively long and moderately stout. Crista dentata on ischium consisting of 7 corneous-tipped teeth; accessory tooth absent ( Fig. 1 View FIGURE 1 F). Merus with small dorsodistal spine. Carpus unarmed.

Chelipeds markedly unequal. Right cheliped ( Fig. 2 View FIGURE 2 A–D) large, massive. Right chela subrectangular in dorsal view, about 2.0 times longer than broad; palm-carpal articulation rotated clockwise about 15° from perpendicular. Dactylus about 0.8 times as long as palm, somewhat curved ventrally; dorsal surface slightly elevated and broadly rounded proximally, dorsomesial margin not delimited, with 1 tiny tubercle proximally; cutting edge with 3 bluntly triangular calcareous teeth, terminating in small calcareous claw; scattered tufts of short to moderately long setae on surfaces. Palm longer than carpus; dorsal surface transversely convex, unarmed, bearing tuft of short to long setae arranged in irregular longitudinal rows; dorsolateral and dorsomesial margins not delimited; lateral and mesial faces nearly smooth, also with tufts of setae; ventral surface also smooth, with scattered tufts of long setae. Fixed finger with 2 large triangular teeth on cutting edge, terminating in small calcareous claw. Carpus subequal in length to merus, markedly broadened distally (width subequal to length); dorsal surface with 2 small spines on midline (first spine subdistal, second spine located at about midlength), and with some tufts of short to moderately long setae; dorsomesial and dorsolateral margins not delimited; lateral surface with few tufts of setae, ventrolateral margin convex, unarmed; mesial face also with some tufts of long setae, produced distal angle bearing 1 moderately strong spine; ventral surface convex, with tufts of long setae. Merus with few tufts of setae on dorsal surface in distal half; lateral face smooth, ventrolateral margin slightly concave in distal half, gently convex in proximal half, with 1 prominent spine distally; mesial face also smooth, with few tufts of setae, ventromesial distal angle with 2 small spines; ventral surface with few long setae. Ischium with tufts of stiff setae.

Left cheliped ( Fig. 3 View FIGURE 3 A–C) moderately slender, reaching beyond proximal margin of dactylus of right cheliped, palm-carpal articulation with about 45° counterclockwise rotation from perpendicular. Chela about 3.6 times longer than broad. Dactylus and fixed finger slightly curved ventrally, without hiatus, cutting edges each with row of minute corneous teeth in distal half; dactylus about 1.1 times as long as palm, unarmed, but with scattered tufts of long setae; dorsolateral margin not delimited. Palm 0.6 length of carpus; dorsal surface slightly convex, unarmed; surfaces with scattered short to long setae. Carpus widened distally, length about 3.2 of distal width; dorsal surface with 1 small spine mesially slightly proximal to midlength and 1 spine at dorsomesial distal angle, also with tufts of long setae; dorsodistal margin with 1 small spine in middle; lateral and mesial faces with few tufts of short to moderately long setae, ventrolateral and ventromesial margins unarmed; ventral surface with scattered tufts of long setae. Merus with row of tufts of short setae on dorsal margin; lateral face smooth; ventrolateral margin gently convex, with 2 small spines in distal 0.3; mesial face also smooth; ventromesial margin with 1 small distal spine. Ischium unarmed, but with long, setae.

Ambulatory legs ( Fig. 4 View FIGURE 4 A, C) moderately slender for genus, overreaching right cheliped by about half lengths of dactyli. Dactyli ( Fig. 4 View FIGURE 4 B, D) 1.4–1.6 times longer than propodi, straight in dorsal view, slightly curved ventrally in lateral view, terminating in long, slender corneous claws; dorsal margins each with row of moderately long stiff setae (setae on distal one-third to half bristle-like), ventral margins each with 6–8 widely-spaced slender corneous spines. Propodi of second pereopods each with 4 short-to-long, basally articulated, bristles on ventrodistal margin; propodi of third pereopods each with ventrodistal margin unarmed or armed with small corneous spine; dorsal and ventral surfaces all with sparse long setae. Carpi unarmed, with some long setae on dorsal surfaces. Meri each with tiny subdistal spine on ventrolateral margin (second) or unarmed (third), with some long setae on dorsal and ventral surfaces. Ischia each with tuft of long setae on ventrodistal portion.

Fourth pereopods ( Fig. 1 View FIGURE 1 G) semichelate; dactyli each with row of minute corneous denticles on ventral margin; propodal rasp consisting of single row of corneous scales. Fifth pereopods semichelate.

Anterior lobe of sixth thoracic sternite ( Fig. 1 View FIGURE 1 H) broadly subsemicircular, with moderately short to long setae on anterior margin.

Male with long sexual tube extending from coxa of right fifth pereopod ( Fig. 1 View FIGURE 1 I), directed from right to left across ventral body surface and then strongly curved anteriorly, gradually tapering distally; left coxa with short sexual tube directed anteromesially, obscured by tufts of dense setae on anterior margin of eighth thoracic sternite. Eighth thoracic sternite ( Fig. 1 View FIGURE 1 I) consisting of single, broadly rounded lobe.

Telson ( Fig. 1 View FIGURE 1 J) with asymmetrical posterior lobes separated by shallow median cleft; terminal margins strongly oblique, left with 4 tiny spinules increasing in size laterally, right with smaller spinules also increasing in size laterally.

Coloration in life. See Fig. 5A View FIGURE 5. A . Shield white; posterior carapace translucent. Ocular peduncles with 3 orange-red spots on white background (1 laterodistal and 2 dorsomesial); cornea gray. Ultimate segment of antennular peduncle with alternating bands of white and orange-red. Antennal peduncle and acicle also banded with white and orange-red. Chelipeds with orange-red markings on white background. Ambulatory legs banded with white and orange-red.

Distribution and habitat. Known only from the type locality. The holotype was collected from inside of the cave about 10 m from the entrance. It remains unknown if this new species is a cave endemic.

Remarks. Catapaguroides longior sp. nov. most closely resembles C. inermis , sharing with it the small corneas, the antennal peduncles distinctly overreaching the distal corneal margins, the subrectangular right chela unarmed on the dorsal surface, and the presence of spines on the carpus of the right cheliped. The prominently elongate antennal acicle immediately distinguishes the new species from C. inermis . The distomesial angle of the carpus of the right cheliped is armed with one prominent spine in C. longior , rather than unarmed in C. inermis . Furthermore, the length of the carpus is subequal to the distal width in C. longior n. sp., but is about 1.9 in C. inermis .

Etymology. The name is derived from the comparative of the Latin adjective “longus” and reflects the elongate antennal acicles bearing long setae.