Munidopsis aurantia, 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 : 52-55

publication ID	https://doi.org/ 10.5281/zenodo.208113
DOI	https://doi.org/10.5281/zenodo.6186585
persistent identifier	https://treatment.plazi.org/id/03E487D6-DE04-FFFD-FF5A-FF4EC83D84F2
treatment provided by	Plazi
scientific name	Munidopsis aurantia
status	sp. nov.

Treatment

Munidopsis aurantia sp. nov.

( Figs. 1–2 View FIGURE 1 View FIGURE 2 , 5A View FIGURE 5. A )

Material examined. Holotype, “ TAIWAN 2007”, stn PCP401, 22°21N, 120°07’E, 682–724 m, 0 7 Nov 2007, ♀ 15.7 mm cl ( NTOU A00468 View Materials ).

Paratype, “ TAIWAN 2010”, stn PCP460, 22°21N, 122°01’E, 889–964 m, 26 Jul 2010, carapace only 14.1 mm cl ( NTOU A00514 View Materials ).

Diagnosis. Carapace covered with short striae and short simple setae, without dorsal spines, antennal and epigastric spines absent, frontal margins transverse, outer orbital angle rounded, anterolateral spine strong, followed by 2–4 spines and with the posteriormost spine at the base of the branchial groove. Rostrum broadly triangular, apex pointed and with a pair of small subdistal teeth. Thoracic sternite 4 scattered with a few striae. Thoracic sternites 5–7 smooth. Abdominal tergites sparsely setose, unarmed; tergites 2–4 each with elevated anterior ridge followed by shallow transverse groove. Ocular peduncle slightly movable, unarmed. Basal antennular segment bearing 1 small distomesial spine and 2 distolateral spines; dorsal spine shorter than ventral spine. Pereopods lacking epipods. Cheliped 1.3 times as long as carapace length; pollex and dactylus with simple apices. Pereopod 2 extending to about midlength of cheliped dactylus. Pereopods 2–4 squamose, each bearing 2 distal spines on merus.

Description. Carapace: slightly longer than broad, dorsal surface with short striae, without dorsal spines and sparsely covered with simple setae, frontal margins oblique, outer orbital angle rounded, cervical groove distinct, anterolateral angle sharp to spine-like; antennal and epigastric spines absent; lateral margins broadly convex, widest at level of cardiac region, bearing 2–4 spines and with posteriormost spine at base of branchial groove. Rostrum broad, 0.4 times carapace length, width about 0.4 times as long as distance between anterolateral spines; apex pointed, carinate and slightly upward dorsally, with pair of small subdistal teeth, proximal parts convex laterally. Pterygostomian region scattered with striae, anterior margin angular.

Thoracic sternum: Sternum slightly wider than long, widest at sternite 7. Sternite 3 about half width of sternite 4, bilobate, separated by median notch. Sternite 4 scattered with few setose striae. Sternites 5–7 smooth.

Abdomen: Tergites densely covered with short setae, unarmed. Tergites 2–4 with elevated anterior ridge followed by shallow transverse groove, transverse groove shallowest at tergite 4. Tergite 5 without transverse groove. Tergite 6 with transverse posterior margin. Telson composed of 9 plates.

Eye: Slightly movable, unarmed, partially concealed by rostrum. Cornea globular, wider than peduncle.

Antennule: Basal segment with 1 small distomesial spine and 2 distolateral spines, dorsal spine longer than ventral spine, lateral surfaces with few striae.

Maxilliped 3: Dactylus, propodus and carpus unarmed. Merus squamous, with distal extensor spine, flexor margin with 2 proximal teeth and some denticles. Ischium with distal extensor spine

Pereopod 1 (cheliped): 1.3 times as long as carapace length; sparsely setose and rugose. Propodus with few striae, unarmed; palm about 1.5 times as long as high, dorsal margin shorter than dactylus. Pollex and dactylus with dentate occlusal margins, apices simple. Carpus with 4 distal spines, about 0.6 times palm length. Merus distally with dorsal, ventral and mesial spines, surfaces squamose.

Pereopods 2–4: Surfaces sparsely setose, with scattered striae. Pereopod 2 extending to about half length of cheliped dactylus. Meri extensor and flexor margins dentate, most prominent on anterior 2 pereopods, with distal spines. Carpi extensor margins each bearing 2 distal spines, with irregular dorsal and lateral carinae. Propodi unarmed, sparsely striated, length about 6 times of height, flexor margins each with a pair of small distal movable spines. Dactyli less than half propodi length, terminating in corneous unguis, flexor margins each with 7–9 movable spines.

Epipods: Epipods absent on all pereopods.

Coloration. Generally bright orange overall. Tips of rostral spines, uropods whitish. Dorsal carapace also with 4 white spots at cervical and cardiac grooves. Eyes pale pink.

Distribution. Taiwan at depths of 682– 964 m.

Etymology. The species is named after its bright orange color (the Latin aurantia for orange) which is uncommon in Munidopsis .

Remarks. Munidopsis aurantia sp. nov. belongs to the group of species having a trifid rostrum, unarmed abdominal somites, carapace dorsally unarmed or at most with pair of epigastric spines, and frontal margin of carapace transverse or slightly oblique. This group contains M. comarge Taylor, Ahyong & Andreakis, 2010 , M. serricornis ( Lovén, 1852) , M. ternaria Macpherson, 2007 and M. treis Ahyong & Poore, 2004 . Munidopsis serricornis was considered as widely distributed in the Atlantic and Indo-Pacific but specimens in the Indo-West Pacific show some differences from the topotypic material in the Atlantic in the shapes of the rostrum and pereopods, numbers of lateral spines on the carapace, and sometimes bearing epigastric spine (Baba & Poore 2002). Moreover, the M. serricornis -like forms in the Indo-West Pacific represent a species complex and some of them have already been recognized as distinct species, such as M. treis and M. comarge .

The “ M. serricornis ” reported from Taiwan before ( Osawa et al. 2008; Baba et al. 2009) is actually M. comarge ; it has a transverse row of epigastric scales on either side of the midline of the carapace and lacks distinct spines along the lateral carapace margin. Munidopsis aurantia differs from M. comarge in lacking the antennal spine and lacks epigastric spines or scales. Munidopsis aurantia sp. nov. is similar to the true M. serricornis in lacking epigastric spines but differs in lacking the antennal spine, chelipeds with fingers longer than palm and merus bearing distal spines but without row of dorsal spines. Munidopsis treis and M. ternaria both have epigastric spines as well as antennal spines.