Munida aequalis, 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 : 17-20

Munida aequalis n. sp. ( Fig. 2 )

Type material. HOLOTYPE: AM P42267, male (23.0 mm), NE of Tweed Heads , Queensland, 27º57’S, 154º03’E, 548 m, K78­23­09, 6 Nov 1978 . PARATYPES: AM P42271, 1 male (25.8 mm), SE of Cape Byron , New South Wales, 28º37’S, 153º50’E, 502 m, K78­ 17­21, 19 Aug 1978 ; AM P26574, 5 males (18.4–26.0 mm), 2 females (19.1–19.3 mm), E of Wooli , New South Wales, 29º52–51’S, 153º43’E, 503 m, K77­13­10, 23 Aug 1977 ; AM P31430, 1 female (23.0 mm) with bopyrid, SE of Byron Bay , New South Wales, 28º41– 44’S, 153º51’E, 153 m, K78­17­21, 18 Aug 1978 ; AM P26573, 1 female (22.3 mm), E of Wooli , New South Wales, 29º52–51’S, 153º43’E, 503 m, K77­13­10, 23 Aug 1977 ; AM P31488, 1 female (25.8 mm), E of Wooli , New South Wales, 29º55’S, 153º42’E, 225 m, K78­06­06, 26 Apr 1978 ; AM P31428, 4 males (14.0– 27.1 mm), 1 female (24.2 mm), NE of Wooli , New South Wales, 29º47–49’S, 153º44–43’E, 437 m, K78­16­07, 2 Aug 1978 ; AM P31431, 31 males (18.8–31.5 mm), 19 females (20.0– 28.5 mm), SE of Cape Byron , New South Wales, 150 m, 28º42’S, 153º51’E, K78­17­21, 18 Aug 1978 ; AM P42266, 13 males (25.0– 29.7 mm), 6 females (23.7–26.7 mm), SE of Yamba , New South Wales, 29º40’S, 153º47’E, 475 m, K78­23­15, 7 Nov 1978 .

Diagnosis. Carapace with numerous, closely spaced transverse striae; with transverse row of 8–10 epigastric spines; with paired parahepatic, paired anterior branchial and 1 or 2 pairs of postcervical spines; frontal margins transverse; lateral margins with 2 spines anterior to cervical groove and 5 spines posterior to cervical groove; rostrum spiniform, about twice as long as supraocular spines and about half remaining carapace length. Fourth to sixth thoracic sternites with short striae. Second abdominal tergite with row of 8–14 spines on anterior border. Third to sixth abdominal tergites unarmed. Eyes large, with maximum corneal diameter exceeding one­third basal distance between anterolateral spines. Basal segment of antennule with 2 terminal spines, lengths subequal. Basal segment of antennal peduncle with strong mesial spine. Second segment with mesial distal spine overreaching distal segment of peduncle. Maxilliped 3 ischium with strong distal flexor spine; merus flexor margin with small distal and larger proximal spine. Cheliped 2.5–3.0 times carapace length. Pereopod 2–3 merus with spinose extensor and flexor margins. Pereopod 4 merus with unarmed extensor margin. Pereopods 2–4 dactylus flexor margin with small movable spines along proximal two­thirds

Description. Carapace: Strongly convex; with numerous, closely spaced transverse striae, most of which are uninterrupted; cervical groove distinct; with transverse row of 8– 10 epigastric spines, those behind supraocular spines largest; rarely with pair of small protogastric spines; with paired parahepatic, paired anterior branchial and 1 or 2 pairs of postcervical spines. Intestinal region with interrupted striae or at most with a few scales. Frontal margins transverse; rostrum spiniform, faintly sinuous, about twice as long as supraocular spines and about half remaining carapace length. Supraocular spines subparallel or slightly divergent. Anterolateral spine well developed, situated at anterolateral angle, extending to or slightly beyond 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: Fourth to sixth sternites with short striae, only present laterally on sixth sternite; seventh sternite smooth; ridges demarcating fourth to seventh sternites granular.

Abdomen: Second tergite with row of 8–14 spines on anterior border. Third to sixth tergites unarmed. Second to sixth tergites with numerous, closely spaced, transverse striae.

Eye: Large, with maximum corneal diameter exceeding one­third basal distance between anterolateral spines; peduncle with dorsal striae and row of short distal setae (‘eyelashes’).

Antennule: Basal segment elongate, overreaching cornea; with 2 terminal spines, lengths equal or mesial minutely shorter than lateral; with two lateral spines, distal markedly longer than proximal.

Antenna: Basal segment of peduncle with strong mesial spine. Second segment with 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 small distal and larger proximal spine; extensor margin unarmed.

Pereopod 1 (cheliped): 2.5–3.0 times carapace length; squamous and setose, setae densest dorsally. Dactylus usually with 3–5 dorsal spines and small subdistal spine, spines obsolete in some large males; occlusal margin denticulate. Propodus with palm about 3 times as long as high, as long as or slightly 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 in large males. Carpus and merus with irregularly distributed spines on lateral, dorsal and mesial surfaces; spines strongest distally.

Pereopod 2: Merus extensor margin with 9–15 spines; flexor margin with 8–11 spines. Carpus with 2–4 extensor and 2 flexor spines. Propodus extensor margin unarmed; flexor margin with 8–12 spines. Dactylus about 0.8 propodus length; flexor margin with 6–12 movable spines; distal third unarmed.

Pereopod 3: Merus extensor margin with 9 or 10 spines; flexor margin with 6–9 spines. Carpus extensor and flexor margins each with 2 spines. Propodus extensor margin unarmed; flexor margin with 7–9 spines. Dactylus about 0.8 propodus length; flexor margin with 5 or 6 movable spines; distal third unarmed.

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 unarmed; flexor margin with 3–6 movable spines. Dactylus as long as propodus; with 4 or 5 flexor movable spines; distal third unarmed.

Etymology. Named aequalis, Latin , meaning ‘like’ or ‘same’, alluding to the similarly sized terminal spines of the basal antennular segment.

Remarks. Munida aequalis n. sp. closely resembles M. pagesi Macpherson, 1994 from New Caledonia and the Loyalty Islands in almost every respect, but differs in the following features: the mesial terminal spine of the basal antennular segment is subequal to, instead of distinctly shorter than, the lateral distal spine; the carapace bears very few scales, whereas numerous scales are present anterolaterally and on the intestinal region in M. pagesi ; and the sixth thoracic sternite bears striae on the lateral portions.

In general habitus, M. aequalis resembles M. haswelli Henderson, 1885 and M. chydaea n. sp., both known from off central and southern New South Wales. Munida haswelli and M. chydaea are both readily distinguished from M. aequalis by having the mesial terminal spine of the basal antennular segment distinctly longer than the outer terminal spine.

A female specimen (23 mm cl., AM P31430), is infected with a bopyrid isopod on its left side. The bopyrid is registered in the Australian Museum collection as P31432.

Distribution. Northeast of Tweed Heads, southern Queensland, to the vicinity of Wooli, New South Wales, at depths of 150– 548 m.

Figures

FIGURE 2. Munida aequalis n. sp. A–I, holotype male (23.0 mm), AM P42267. J, paratype female (25.8 mm) P31488. A, dorsum. B, left basal antennular segment, ventral. C, left antennal peduncle, ventral. D, left third maxilliped, lateral. E, right cheliped. F–H, right pereopods 2–4, dorsal. I, sternum. J, left basal antennular segment, ventral. Scale A, E–H = 5 mm, B–D, I, J = 2.5 mm.