Munida spinicruris, Ahyong & Poore, 2004

Ahyong, Shane T. & Poore, Gary C. B., 2004, Deep-water Galatheidae (Crustacea: Decapoda: Anomura) from southern and eastern Australia, Zootaxa 472 (1), pp. 1-76 : 42-45

Munida spinicruris n. sp. ( Fig. 8 )

Type material. HOLOTYPE: AM P67297, male (10.0 mm), Gascoyne Seamount, Tasman Sea , 36º43.11’S, 156º13.31’E, 143 m, sled, coral and sand with many large invertebrates, FR0589­4, J. Lowry et al., 1 May 1989 . PARATYPES: AM P67298, 5 males (6.8– 10.9 mm), 7 females (5 ovigerous) (8.3–13.0 mm), type locality .

Diagnosis. Carapace frontal margins oblique; transverse ridges mostly uninterrupted; with transverse row of 10–12 epigastric spines; with several spinules on lateral anterior quarter of carapace in addition to paired parahepatic, paired anterior branchial and paired postcervical spines. Rostrum spiniform. Supraocular spines subparallel. Margins of carapace with 5 spines posterior to cervical groove. Fourth to fifth sternites at most with 2 or 3 short striae; lateral portion of seventh sternite with coarse granules; ridges demarcating fourth to seventh sternites feebly granular. Second abdominal tergite with row of 6–8 spines on anterior border; third to sixth tergites unarmed; fourth tergite with 2 uninterrupted transverse striae. Eyes large, with maximum corneal diameter about one­third basal distance between anterolateral spines. Basal antennular segment elongate, slightly overreaching cornea; with 2 terminal spines, mesial longer. Basal segment of antennal peduncle with strong mesial spine; second segment with spine on mesial margin and mesial and lateral terminal spines, mesial overreaching distal segment of peduncle. Maxilliped 3 merus with distal and larger proximal spine, and 1 or 2 small intervening spines or acute tubercles on flexor margin; extensor margin with small distal spine. Cheliped about 1.5 times carapace length; pollex with row of ventral spines and small subdistal spine. Propodus of pereopods 2–3 with spines on extensor margin; dactylus with movable spines along entire flexor margin.

Description. Carapace: Transverse ridges mostly uninterrupted; cervical groove distinct; with transverse row of 10–12 epigastric spines, those behind supraocular spines largest; with several spinules on lateral anterior quarter of carapace in addition to paired parahepatic, paired anterior branchial and paired postcervical spines. Frontal margins oblique; rostrum spiniform, faintly sinuous, about twice as long as supraocular spines and about half remaining carapace length. Supraocular spines subparallel. Anterolateral spine well developed, situated at anterolateral angle, not extending to 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: Fourth to fifth sternites at most with 2 or 3 short striae; lateral portion of seventh sternite with coarse granules; ridges demarcating fourth to seventh sternites feebly granular.

Abdomen: Second tergite with row of 6–8 spines on anterior border. Third to sixth tergites without spines on anterior border. Second and third tergites with 3 and 2 or 3 uninterrupted transverse striae respectively. Fourth tergite with 2 uninterrupted transverse striae.

Eye: Large, with maximum corneal diameter about one­third basal distance between anterolateral spines.

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

Antenna: Basal segment of peduncle with strong mesial spine. Second segment with spine on mesial margin and mesial and lateral terminal spines, mesial overreaching distal segment of peduncle. Third and fourth segments of antennal peduncle unarmed.

Maxilliped 3: Ischium with strong distal flexor spine. Flexor margin of merus with distal and larger proximal spine, and 1 or 2 small intervening spines or acute tubercles; extensor margin with small distal spine.

Pereopod 1 (cheliped): Length about 1.5 times carapace length; squamous and setose, setae densest dorsally. Dactylus with 6–9 dorsal spines and small subdistal spine; occlusal margin denticulate. Propodus with palm about 2 times as long as high, shorter than dactylus, upper and outer margin irregularly spinose; pollex with row of ventral spines and small subdistal spine, occlusal margin denticulate. Dactylus and pollex with minor gape. Carpus and merus with irregularly distributed spines on lateral, dorsal and mesial surfaces; spines strongest distally.

Pereopod 2: Merus extensor margin with 8–10 spines; flexor margin with 2 spines. Carpus with 4 extensor and 1 flexor spine. Propodus extensor margin with 3 or 4 spines; flexor margin with 9–11 spines. Dactylus about 0.8 propodus length; with 8 or 9 movable spines along entire flexor margin.

Pereopod 3: Merus extensor margin with 5–7 spines; flexor margin with 2 spines. Carpus with 4 extensor and 1 flexor spine. Propodus extensor margin with 3 spines; flexor margin with 8–10 spines. Dactylus about 0.8 propodus length; with 8 or 9 movable spines along entire flexor margin.

Pereopod 4: Merus extensor margin with 2 or 3 small denticles proximally; flexor margin with 2 or 3 spines on distal third. Carpus extensor and flexor margins each with distal spine. Propodus extensor margin with 0–1 spines; flexor margin with 7 or 8 spines. Dactylus about 0.8 propodus length; with 8 or 9 movable spines along entire flexor margin.

Etymology. Derived from the Latin spina, meaning ‘thorn’, and cruris, meaning ‘leg’ or ‘limb’, in reference to the characteristic spination of the propodi of pereopods 2–3.

Remarks. Munida spinicruris n. sp. closely resembles M. limula Macpherson & Baba, 1993 from Madagascar and M. guttata Macpherson, 1994 from New Caledonia and the Loyalty Islands. The new species differs from M. limula and M. guttata in bearing spines on the extensor margin of the propodi of pereopods 2–3 and in bearing striae only on the fourth, instead of the fourth to sixth thoracic sternites. Munida spinicruris further differs from M. guttata in having a shorter mesial spine on the first antennal segment (not overreaching the peduncle), more spinous chelae and more elongate dactyli of pereopods 2–4, being more than three­quarters instead of about half the propodus length. Munida spinicruris further differs from M. limula in having a longer mesial spine on the first antennal segment (reaching to midlength instead of base of third antennal segment) and a longer mesial spine on the second antennal segment (distinctly overreaching distal peduncle segment). The smallest female of M. spinicruris examined (8.3 mm cl., 5.5 ocl.) is ovigerous suggesting that the species matures at a smaller size than M. guttata in which the smallest ovigerous females studied by Macpherson (1994) measured 8.3 mm ocl.

Distribution. Known only from the type locality at 143 m depth.

Figures

FIGURE 8. Munida spinicruris n. sp., holotype male (10.0 mm), AM P67297. A, dorsum. B, left basal antennular segment, ventral. C, left antennal peduncle, ventral. D, right third maxilliped, lateral. E, right cheliped. F–H, right pereopods 2–4, dorsal. I, sternum. Scale A, E–H = 2 mm, B–D, I = 1 mm.