Munida howensis, Ahyong, Shane T., 2007

Ahyong, Shane T., 2007, Decapod Crustacea collected by the NORFANZ Expedition: Galatheidae and Polychelidae, Zootaxa 1593, pp. 1-54 : 28-31

Munida howensis sp. nov.

( Fig. 14 B, 15)

Type material. Holotype: AM, male (19.2 mm), Lord Howe Rise, E of Ball’s Pyramid, 31°45.73’S, 159°20.93’E, 565–960 m, TAN0308/066 #023, 23 May 2003.

Diagnosis. Carapace densely striated; margins with 5 spines posterior to cervical groove; posterior half of the carapace surface with rows of secondary striae; with 1 anterior branchial and 1 postcervical spine. Rostrum spiniform. Sternites without posterolateral granular patches; sternite 4 with broadly convex anterior margin. Abdominal tergite 2 with row of spines along anterior ridge; tergite 3 unarmed. Maximum corneal diameter slightly exceeding one-third basal distance between anterolateral spines. Antennular basal segment with distomesial spine shorter than distolateral spine. Antennal basal segment mesial spine reaching to distal two-thirds of segment 3; segment 2 with distomesial spine overreaching segment 4. Maxilliped 3 merus extensor margin with minute distal tooth; flexor margin with 3 spines. Cheliped pollex with 2 stout spines along proximal ventral margin; carpus less than twice as long as high. Pereopod 2–4 propodus about 5–6 times as long as high; dactylus flexor margin with terminal fifth unarmed.

Description. Carapace: Densely striated; striae generally entire; gastric, hepatic and branchial regions with several short striae; cervical groove distinct; with pair of distinct epigastric spines behind supraocular spines, flanked mesially by 1 smaller spine, and laterally by 4 or 5 smaller spines; with 1 parahepatic, 1 anterior branchial and 1 postcervical spine. Frontal margins slightly sinuous, almost transverse; rostrum spiniform, horizontal, about twice as long as supraocular spines and exceeding one-third remaining carapace length. Supraocular spines subparallel. Anterolateral spines well-developed, situated at anterolateral angle, parallel, extending slightly beyond base of sinus between rostrum and supraocular spine. Margins of carapace anterior to cervical groove with 2 or 3 spines (including anterolateral); with 5 spines posterior to cervical groove.

Sternum: Sternite 3 bilobed; anterior margin biconcave. Sternite 4 with 5 pairs of striae, otherwise smooth; anterior margin broadly convex. Sternites 5–7 smooth. Ridges demarcating sternites smooth.

Abdomen: Tergite 2 with 9 spines along anterior ridge; with 2 transverse striae, 2 rows of secondary striae and several short arcuate striae laterally. Tergite 3 unarmed, with 2 entire transverse striae, 1 subdivided transverse striae, and several short striae laterally. Tergite 4 with 1 medially interrupted and 1 entire transverse stria, and several short striae laterally. Tergite 5 with 2 entire transverse striae in addition to short lateral striae.

Eye: Moderate, with maximum corneal diameter slightly exceeding one-third basal distance between anterolateral spines; peduncle with numerous short distal setae.

Antennule: Basal segment elongate, slightly overreaching cornea; distomesial spine shorter than lateral terminal spine; with 2 lateral spines, distal markedly longer than proximal.

Antenna: Basal segment with strong mesial spine, apex reaching to distal two-thirds of segment 3. Segment 2 with small spine on mesial margin; distomesial spine overreaching segment 4, lateral not overreaching third segment. Segments 3 and 4 unarmed.

Maxilliped 3: Ischium with small distal flexor spines. Merus shorter than ischium; flexor margin with strong distal, proximal and median spine; extensor margin with minute distal tooth.

Pereopod 1 (cheliped): About 1.7 times carapace length; sparsely granulate and setose. Dactylus longer than palm; with small proximal spine only; occlusal margin denticulate, without gape. Propodus palm 1.7 times as long as high; with row of dorsal, lateral and ventral spines; pollex with 2 subdistal spines and 2 stout spines along proximal margin. Carpus 1.8 times as long as high, subequal to palm length; strongly spinose dorsally, surface with 2 rows of small spines. Merus with strong distal and dorsal spines, longest reaching proximal third of carpus; surface with 2 rows of small spines.

Pereopod 2: Merus with 12–14 extensor and 5 or 6 flexor spines. Carpus with 3 extensor spines and distal flexor spine. Propodus 5.6 times as long as high; extensor margin unarmed; flexor margin with 10–14 small movable spines. Dactylus 0.7 propodus length; flexor margin with 10–14 movable spines; terminal fifth of flexor margin unarmed.

Pereopod 3: Merus with 8 or 9 extensor and 5 flexor spines. Carpus with 5 extensor spines (distal 2 longest, proximal 3 minute) and distal flexor spine. Propodus 5.3 times as long as high; extensor margin unarmed; flexor margin with 13–15 small movable spines. Dactylus 0.7 propodus length; flexor margin with 11 or 12 movable spines; terminal fifth of flexor margin unarmed.

Pereopod 4: Merus with distal extensor and 4 or 5 flexor spines. Carpus with distal extensor and flexor spine. Propodus 4.6 times as long as high; extensor margin unarmed; flexor margin with 10 small movable spines. Dactylus 0.7 propodus length; flexor margin with 9 or 10 movable spines; terminal fifth of flexor margin unarmed.

Colour in life. Dusky overall. Anterior spines and rostrum of carapace dull red. Cheliped fingers with dull pink distal half.

Etymology. Derived from the Lord Howe Rise, from which the holotype was collected.

Remarks. Munida howensis sp. nov. is morphologically closest to M. eclepsis Macpherson, 1994 , from New Caledonia: both species have a spinose ventral margin of the cheliped pollex, five spines on the branchial carapace margins, parahepatic, anterior branchial and postcervical carapace spines, a row spines along the anterior ridge of abdominal tergites 2 and 3, and a short distomesial spine on the basal antennular segment.

Munida howensis sp. nov., however, is readily separated from M. eclepsis by the presence of rows of secondary striae on the posterior half of the carapace surface, in the shorter lateral spine of antennal peduncular segment 2 (which does not overreach segment 3), and in the tri- rather than bispinose flexor margin of maxilliped 3 merus.

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