Munidopsis laevisquama, Lin, Chia-Wei & Chan, Tin-Yam, 2011

Lin, Chia-Wei & Chan, Tin-Yam, 2011, Two new deep-sea squat lobsters of the genus Munidopsis Whiteaves, 1874 (Crustacea: Decapoda: Munidopsidae) from Taiwan, Zootaxa 2754, pp. 51-59 : 55-58

publication ID	https://doi.org/ 10.5281/zenodo.208113
DOI	https://doi.org/10.5281/zenodo.6186588
persistent identifier	https://treatment.plazi.org/id/03E487D6-DE01-FFFE-FF5A-FE05CFAA83C0
treatment provided by	Plazi
scientific name	Munidopsis laevisquama
status	sp. nov.

Treatment

Munidopsis laevisquama sp. nov.

( Figs. 3–4 View FIGURE 3 View FIGURE 4 , 5 View FIGURE 5. A B)

Material examined. Holotype, “ TAIWAN 2001”, stn CP115, 24°54’N, 122°02’E, 381–440 m, 21 May 2001, 3 8.4 mm cl ( NTOU A00561 View Materials ).

Diagnosis. Carapace densely covered with squamae and tubercles; cervical groove distinct; regions well defined; gastric region without spines or processes; anterolateral margin with distinct, blunt process; lateral margin with 3 small, blunt processes; posterior margin with small tubercles. Antennular basal segment with a distal tubercular process on lateral margin. Abdominal tergites unarmed. Telson composed of 8 plates. Eyestalk immovable. Pereopods 1–3 (cheliped and first 2 walking legs) with epipod. Cheliped elongate, 2.3 times longer than carapace length; palm about 2 times as long as high. Walking legs coarsely tuberculate; carpus extensor margin with row of tubercles; dactylus with 8–12 small movable spines on the flexor margin.

Description. Carapace: Moderately convex from side to side, 1.2 times as long as wide; dorsal surfaces densely covered with squamae and tubercles; some squamae even crenulated; regions well defined; gastric region covered with small tubercles, no spine or sharp process present; cervical groove distinct. Anterolateral margins slightly oblique; anterolateral angle squamose, with short, blunt tooth; outer orbital angle blunt, margins serrated. Lateral margins subparallel, broadly convex, with 3 or 4 small and blunt processes, without distinct spine. Posterior margin bearing numerous tubercles. Rostrum with anterior part broken and lost, covered with tubercles, dorsal surface with low median carina, basal part relatively more slender. Pterygostomian region squamose, anterior margin bluntly angular, not acute.

Thoracic sternum: Slightly longer than wide; widest at sternite 7. Sternite 3 about 0.3 width of sternite 4, bilobed, separated by notch; lateral margin of each lobe convex. Sternite 4 with sinuous anterior margin. Sternites 5–7 smooth.

Abdomen: Integument irregularly dimpled, pleura scattered with low granules. Tergites 2–4 unarmed, with 2 elevated ridges separated by median transverse groove. Tergites 4–6 smooth. Telson slightly broader than long; composed of 8 plates.

Eyes: Immovable, non-setose, unarmed. Cornea subglobular, wider than peduncle.

Antennule: Basal segment with short distomesial spine and larger multispinose distodorsal process, ventromesial surface serrated, anterolateral surface with a row of tubercles, distolateral process distally crenulate.

Antenna: Basal segment of peduncle with blunt disolateral and slender distomesial processes. Second segment with blunt distomesial and distolateral teeth. Remaining segments unarmed.

Maxilliped 3: Surface squamose. Carpus extensor margin bearing low teeth. Merus extensor margin with 3 or 4 small teeth, flexor margin with 2 broad, irregular teeth.

Pereopod 1 (cheliped): Elongate, equal, 2.3 times carapace length; surfaces rugose, densely covered with small squamae. Ischium with 1 distodorsal spine. Merus twice as long as carpus. Propodal palm longer than dactylus, length about 2.0 times height. Dactylus with occlusal margins dentate. Fingers without gape, apices slightly hollowed and bidentate.

Pereopods 2–4: Similar, surfaces squamose, pereopods 2–4 decreasing in length posteriorly. Pereopod 2 not reaching cheliped carpus. Meri extensor and flexor margins with rows of rugose, small squamae. Carpi extensor margins each with two rows of tubercles, flexor margins unarmed. Propodi about 5 times as long as high, surfaces sharply squamose; extensor margins irregularly tuberculate, each bearing a minute but movable distal flexor spine. Dactyli about half length of propodi, flexor margins with 8–12 movable spines on proximal half, unguis corneous.

Epipods: Epipod present at pereopods 1–3.

Coloration. Body generally pale orange except abdominal somite 5 to tailfan whitish. Eyes pale yellow. Distribution. Taiwan, at depths of 381– 440 m.

Etymology. The combination of the Latin “ laevis ” (smooth) and “ squama ” (scales) refers to the many squamae but no spines on the dorsal surface of the carapace in this species.

Remarks. Munidopsis laevisquama sp. nov. differs from most species of Munidopsis in having the dorsal carapace entirely covered with squamae. The squamose carapace is only known in a few species such as M. bractea Ahyong, 2007 , M. ceres Macpherson, 2007 , M. papanui Schnabel & Bruce 2006 , M. proales Ahyong & Poore, 2004 , M. sonne Baba, 1995 , M. tasmaniae Ahyong & Poore, 2004 and M. taurulus Ortmann, 1892 . Nevertheless, the present new species can be readily distinguished from M. bractea , M. papanui , M. proales , M. tasmaniae and M. taurulus by the eyes lacking a papillate or similar process. On the other hand, M. laevisquama sp. nov. differs from M. sonne in having a globular cornea (versus corneal region narrowed distally in M. sonne ), the merus and carpus of the cheliped lacking distinct distal spine (versus with strong distomesial spine in M. sonne ), and without spines on the dorsal surfaces of the carapace and abdomen (versus body bearing numerous spines in M. sonne ).

Munidopsis laevisquama sp. nov. is most similar to M. ceres from the New Caledonia, but can be separated by: 1) pair of epigastric spines present in M. ceres , but absent in the new species; 2) basal antennular segment with a strong distolateral spine in M. ceres , but with a larger multispinose distodorsal process in the new species; 3) extensor margin of maxilliped 3 merus produced in M. ceres , but with 3 or 4 small spines in the new species; 4) ventral margins of the dactyli of pereopods 2–4 armed with 16 minute spines in M. ceres , but only 8–12 in the new species.