Munida rubrimana, Ahyong, Shane T., 2007

Ahyong, Shane T., 2007, Decapod Crustacea collected by the NORFANZ Expedition: Galatheidae and Polychelidae, Zootaxa 1593, pp. 1-54 : 36-38

Munida rubrimana sp. nov.

( Fig. 14 D, 18)

Type material. Holotype: NMNZ, ovigerous female (15.0 mm), northern Norfolk Ridge, 26°25.94’S, 167°10.87’E, 750–774 m, TAN0308/043 #60, 18 May 2003.

Diagnosis. Carapace margins with 5 spines posterior to cervical groove; with 1 anterior branchial and 1 postcervical spine. Rostrum spiniform. Sternite 4 with anterior margin broadly convex; sternites 5–7 smooth. Abdominal tergite 2 with row of spines along anterior ridge; tergite 3 unarmed, with 1 transverse stria. Maximum corneal diameter almost half basal distance between anterolateral spines. Antennular basal segment with terminal spines equal. Antennal basal segment mesial spine reaching base of segment 3; segment 2 with distomesial spine reaching to about midlength of segment 4. Maxilliped 3 merus extensor margin unarmed. Cheliped about 1.5 times carapace length; pollex with strong spine on ventral proximal margin; carpus about twice as long as high. Pereopod 2–4 dactylus with distalmost flexor spine at base of unguis.

Description. Carapace: Transverse ridges well spaced, generally entire; gastric and branchial regions with several short striae; cervical groove distinct; with pair of distinct epigastric spines behind supraocular spines, flanked mesially and laterally by small spine; with 1 parahepatic, 1 anterior branchial and 1 postcervical spine. Frontal margins sloping posteriorly; rostrum spiniform, horizontal, about three times as long as supraocular spines and almost half remaining carapace length. Supraocular spines subparallel. Anterolateral spine situated at anterolateral angle, slightly divergent, extending to base of sinus between rostrum and supraocular spine. Margins of carapace anterior to cervical groove with 2 spines (including anterolateral); with 5 spines posterior to cervical groove.

Sternum: Sternite 3 broadly subquadrate; anterior margin sinuous. Sternite 4 with pair of short striae, otherwise smooth; anterior margin broadly convex. Sternites 5–7 smooth. Ridges demarcating sternites smooth.

Abdomen: Tergite 2 with 11 spines along anterior ridge; with 1 transverse stria and several short arcuate striae laterally. Tergite 3 unarmed, with 1 transverse stria. Tergite 4 with medially interrupted transverse stria. Tergite 5 with 2 striae.

Eye: Large, with maximum corneal diameter almost half basal distance between anterolateral spines; peduncle with few short, distal setae.

Antennule: Basal segment elongate, slightly overreaching cornea; terminal spines equal; with two lateral spines, distal markedly longer than proximal.

Antenna: Basal segment with strong mesial spine, apex almost reaching base of segment 3. Segment 2 with small spine on mesial and lateral margins; distomesial spine reaching to about midlength of segment 4, lateral reaching beyond midlength of segment 3. Segments 3 and 4 unarmed.

Maxilliped 3: Ischium with distal flexor spine. Merus shorter than ischium; flexor margin with strong distal and proximal spine; extensor margin unarmed.

Pereopod 1 (cheliped): About 1.5 times carapace length; with few rows of spines and few short squamae; sparsely setose. Dactylus longer than palm; unarmed dorsally; occlusal margin denticulate, without gape. Propodus palm twice as long as high, surface spinose; pollex with 2 subdistal spines and 1 strong spine on ventral proximal margin. Carpus less than 2.1 times long as high, shorter than palm; strongly spinose dorsally, surface with 2 rows of small spines. Merus with strong distal and dorsal spines, surface otherwise unarmed except for row of 3 small lateral spines; longest distal spine reaching to proximal third of carpus.

Pereopod 2: Merus with 8 extensor and 5 flexor spines. Carpus with 4 extensor and 2 flexor spines. Propodus 6.3 times as long as high; distal extensor margin unarmed; flexor margin with 10 small movable spines. Dactylus 0.7 propodus length; flexor margin with 9 movable spines, distalmost spine at base of unguis.

Pereopod 3: Merus with 10 extensor and 4 flexor spines. Carpus with 3 extensor and distal flexor spine. Propodus 6 times as long as high; extensor margin unarmed; flexor margin with 10 small movable spines. Dactylus 0.7 propodus length; flexor margin with 8 movable spines, distalmost spine at base of unguis.

Pereopod 4: Merus with 4 small, proximal extensor spines and distal flexor spine. Carpus with distal extensor and flexor spine. Propodus 4.9 times as long as high; extensor margin unarmed; flexor margin with 7 small movable spines. Dactylus 0.7 propodus length; flexor margin with 8 movable spines, distalmost spine at base of unguis.

Colour in life. Base colour translucent white. Carapace and abdomen pale, diffuse red-pink, darkest anteriorly and posterolaterally; anterolateral and gastric spines red. Chelipeds largely red with white fingers. Walking legs with red and white banding.

Etymology. From rubri and manus, Latin for red hand, alluding to the mostly red chelipeds of the new species.

Remarks. Munida rubrimana sp. nov. most closely resembles M. masoae Macpherson, 1996 , from Bayonnaise Bank, in sharing five branchial marginal spines on the carapace, a row of spines along the anterior ridge of abdominal tergite 2, subequal distal spines on the basal antennular segment, relatively short chelipeds with proximal and subterminal spines on the margin of the pollex, and absence of granular patches on sternite 7. The new species is readily distinguished from M. masoae by the presence of anterior branchial and postcervical spines on the carapace, one instead of two transverse striae on abdominal tergite 3, and in having the distalmost flexor spine on the walking leg dactyli inserting at the base of the unguis, rather than well proximal to the unguis. Of the species in the NORFANZ collection, M. rubrimana sp. nov. most closely resembles M. tangaroa sp. nov., M. collier and M. cerisa . Munida rubrimana is distinguished from M. tangaroa by the relative lengths of the distal spines on the basal antennular segment: subequal in the former, distolateral longer in the latter. Munida collier and M. cerisa are readily distinguished from M. rubrimana by the absence of a spine on the proximal margin of the cheliped pollex, and by the absence of anterior branchial and postcervical spines on the carapace.

Distribution. Presently known only from the northern Norfolk Ridge; 750– 774 m.

Figures

FIGURE 14. A, Munida exilis sp. nov., male paratype, 11.4 mm, TAN 0308 / 136 (NMNZ). B, Munida howensis sp. nov., male holotype, 19.2 mm, TAN 0308 / 066 (AM). C, Munida redacta sp. nov., male holotype, 9.4 mm, TAN 0308 / 020 (AM). D, Munida rubrimana sp. nov., ovigerous female holotype, 15.0 mm, TAN 0308 / 043 (NMNZ). E, Munida tangaroa sp. nov., ovigerous female paratype, 14.1 mm, TAN 0308 / 29 (NIWA 28070).