Munidopsis norfanz, Ahyong, Shane T., 2007

Ahyong, Shane T., 2007, Decapod Crustacea collected by the NORFANZ Expedition: Galatheidae and Polychelidae, Zootaxa 1593, pp. 1-54 : 7-10

Munidopsis norfanz sp. nov.

( Fig. 3 B, 5)

Type material. Holotype: AM, male (13.1 mm), E of Ball’s Pyramid, Tasman Sea, 31°45.73’S, 159°20.93’E, 565–960 m, TAN0308/066 #020, 23 May 2003.

Diagnosis. Carapace with short striae, without dorsal spines; frontal margins oblique, outer orbital angle rounded; anterolateral spine stout; lateral margins unarmed. Rostrum width about one-third distance between anterolateral spines; exceeding one-third remaining carapace length; apex bluntly pointed; with pair of small subdistal teeth. Sternite 4 with few scattered striae. Sternites 5–7 smooth. Abdominal tergites sparsely setose, unarmed; tergites 2–4 with elevated anterior ridge and shallow transverse groove behind anterior ridge. Ocular peduncle movable, unarmed. Antennular basal segment with 2 distolateral spines, dorsal shorter; with short distomesial spine. Cheliped slightly longer than carapace; pollex and dactylus with simple apices. Pereopod 2 reaching to about proximal third of cheliped dactylus. Pereopods 2–4 with dentate extensor and flexor margins on merus, most prominent on anterior two pereopods. Pereopods without epipods.

Description. Carapace: 1.4 times as long as wide; moderately convex from side to side, sparsely covered with hooked, plumose setae; without dorsal spines; with short striae; cervical groove distinct; frontal margins oblique, outer orbital angle rounded; anterolateral spine short, stout. Lateral margins broadly convex, irregularly serrate but without teeth; widest at level of cardiac region. Rostrum broad, width about one-third distance between anterolateral spines; length exceeding one-third remaining carapace length; apex bluntly pointed, slightly inclined dorsally; with pair of small subdistal teeth; carinate dorsally; lateral proximal faintly convex, distally crenulate. Pterygostomian region with scattered striae; anterior apex acute.

Sternum: Sternum slightly wider than long; widest at sternite 7. Sternite 3 about one-third width of sternite 4; anterior margin medially emarginate, crenulate either side of midline. Sternite 4 with a few scattered setose striae. Sternites 5–7 smooth.

Abdomen: Tergites sparsely setose, unarmed. Tergites 2–4 with elevated anterior ridge and shallow transverse groove behind anterior ridge, shallowest of tergite 4; tergite 2 with few granules laterally. Tergite 5 without transverse groove. Tergite 6 with sinuous posterior margin. Telson composed of 9 plates.

Eye: Movable, non-setose, unarmed; partially concealed by rostrum. Cornea subglobular, slightly wider than peduncle.

Antennule: Basal segment with 2 distolateral spines, dorsal shorter; with short distomesial spine; ventrmesial surface crenulate; ventral and lateral surfaces with few striae.

Antenna: Basal segment with blunt mesial and lateral tooth. Segment 2 with stout distolateral spine; distomesial margin angular. Segments 3 and 4 unarmed. Flagellum extending beyond cheliped.

Maxilliped 3: Dactylus, propodus and carpus unarmed. Merus with distal extensor spine; flexor margin with 2 proximal teeth and several smaller denticles; crista dentata with 19 or 20 corneous denticles.

Pereopod 1 (cheliped): Slightly longer than carapace; sparsely setose and rugose. Propodus with sparse striae; unarmed; palm about 1.6 times as long as high; dorsal margin of palm shorter than dactylus. Pollex and dactylus with dentate occlusal margins; apices simple. Carpus unarmed, trigonal, about half palm length. Merus distally with stout dorsal (bifid on right side), ventral distal and mesial spine. Ischium with blunt dorsodistal tooth.

Pereopods 2–4: Slightly compressed, sparsely setose, with scattered striae. Pereopod 2 reaching to about proximal third of cheliped dactylus. Merus extensor and flexor margins dentate, most prominent on anterior 2 pereopods, with distal spines. Carpus extensor margin with irregular dorsal carina and distal spine; with low, irregular, lateral carina. Propodus unarmed, sparsely striated, length about 6 times height; flexor margin with pair of small, distal movable spines. Dactylus about half propodus length; terminating in corneous unguis; flexor margin with 8 or 9 movable spines.

Epipods: Pereopods without epipods.

Colour in life. Pale orange dorsally; off white ventrally.

Etymology. Named for the expedition that resulted in the present collection; used as a noun in apposition.

Remarks. Munidopsis norfanz sp. nov. closely resembles M. moresbyi Alcock & Anderson, 1899 , reported from the Arabian Sea and Indonesia ( Macpherson 2007), in the broad rostrum, absence of the outer orbital spine, absence of dorsal or lateral carapace spines (apart from anterolateral), and absence of pereopodal epipods. The new species is distinguished from M. moresbyi by the comparatively broader rostrum with a pair of small, subdistal marginal spines; shorter, less pronounced carapace striae (particularly on the gastric region); posteriorly sloping rather than transverse anterolateral carapace margins; and prominently dentate rather than relatively smooth flexor and extensor margins of the meri of the walking legs. Further, based on Macpherson’s (2007) account of Indonesian material tentatively identified as M. moresbyi , M. norfanz also differs in bearing a distal mesial tooth on the basal antennular segment, movable rather than fixed eyes, smooth rather granular sternites, and simple rather than spooned cheliped finger-tips (features neither mentioned nor figured by Alcock & Anderson (1899)). The Indonesian specimens, however, do not entirely agree with the type account: the rostrum is broader rostrum and the carapace striation resembles that of M. norfanz . As indicated by Macpherson (2007), the Indonesian material might represent a distinct species.

Distribution. Presently known only from east of Ball’s Pyramid, Tasman Sea; 565– 960 m.

Figures

FIGURE 3. A, Munidopsis bractea sp. nov. paratype female, 4.9 mm, TAN 0308 / 126 (NMNZ). B, Munidopsis norfanz sp. nov., holotype, TAN 0308 / 066 (AM). C, Munidopsis treis Ahyong & Poore, 2004, female, 10.7 mm, TAN 0308 / 154 (NMNZ).