Agononida procera, 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 : 10-13

Agononida procera n. sp. ( Fig. 1 )

Type material. HOLOTYPE: AM P25095, female (22.8 mm), E of Broken Bay , New South Wales, 33°32’S, 152°03’E, 823 m, K76­24­03, 20 Dec 1976 . PARATYPES: AM P42260, 1 male (22.1 mm), NE of Tweed Heads , Queensland, 28º03’S, 154º04’E, 731 m, K78­23­08, 6 Nov 1978 ; AM P42263, 1 female (27.3 mm), NE of Tweed Heads , Queensland, 28º03’S, 154º04’E, 731 m, K78­23­08, 6 Nov 1978 ; AM P20993, 1 female (20.3 mm), E of Broken Bay , New South Wales, 33°32–38’S, 152°00–04’E, 824 m, K75­05­05, 19 Aug 1975 ; AM P19382, 1 female (22.3 mm), E of Long Reef , New South Wales, 33°43’S, 151°55’E, 675 m, K72­06­04, 19 Oct 1972 ; AM P19383, 1 female (16.8 mm), E of Sydney , New South Wales, 33°51’S, 151°51’E, 675 m, K72­06­03, 19 Oct 1972 .

Diagnosis. Carapace transverse ridges mostly uninterrupted; cervical groove shallow; with pair of epigastric spines followed by pair of protogastric spines; with small hepatic spine lateral to epigastric and protogastric spines; with transverse row of 2–4 cardiac spines; with line of 2–4 branchiocardiac spines either side of cardiac spines; posterior margin with 4–13 antrorse spines; lateral margin of carapace anterior to cervical groove with 2 spines (including anterolateral) and 4 spines posterior to cervical groove. Fourth sternite with several short striae at most; remaining sternites smooth. Second and third abdominal tergites with row of 4 spines on anterior border; fourth tergite with row of 4 spines on anterior border and single spine on posterior border. Terminal spines of basal antennular segment subequal. Inner margin of basal antennal segment with stout triangular tooth, not exceeding second segment. Second segment with inner and outer distal spine, neither overreaching third segment. Cheliped slender, subcylindrical; propodus with palm 17–18 times as long as high, about twice as long as pollex. Walking legs with propodus 18–22 times as long as high; dactylus slightly exceeding one­third propodus length; extensor margin crenulate; flexor margin denticulate along distal three­quarters.

Description. Carapace: Transverse ridges mostly uninterrupted; cervical groove shallow; with pair of epigastric spines followed by pair of protogastric spines; with small hepatic spine lateral to epigastric and protogastric spines; with transverse row of 2–4 (usually 2) cardiac spines; with line of 2–4 (usually 4) branchiocardiac spines either side of cardiac spines. Posterior margin with 4–13 antrorse spines. Frontal margins transverse; rostrum slender, spiniform, about twice as long as supraocular spines. Supraocular spines subparallel. Anterolateral spine well developed, situated at anterolateral angle, extending to or slightly beyond sinus between rostrum and supraocular spine. Lateral margin of carapace anterior to cervical groove with 2 spines (including anterolateral) and 4 spines posterior to cervical groove.

Sternum: Fourth sternite with several short striae at most; remaining sternites smooth; ridges demarcating fourth to seventh sternites feebly granular.

Abdomen: Second and third tergites with row of 4 spines on anterior border. Fourth tergite with row of 4 spines on anterior border and single spine on posterior border.

Eye: Large, with maximum corneal diameter about one­third basal distance between anterolateral spines; with short distal setae on peduncle (‘eyelashes’).

Antennule: Basal segment slightly overreaching cornea; with 2 subequal terminal spines; outer margin strongly convex, with two lateral spines, proximal spine minute.

Antenna: Inner margin of basal segment with stout triangular tooth, not exceeding second segment. Second segment with inner and outer distal spine, neither overreaching third segment. Third and fourth segments unarmed.

Maxilliped 3: Ischium with strong distal flexor spine. Midflexor margin of merus with spine; extensor margin unarmed.

Pereopod 1 (cheliped): Slender, subcylindrical, about 3.0–3.5 times carapace length; sparsely squamous and setose. Dactylus unarmed dorsally; occlusal margin denticulate. Propodus upper and outer margin spinose; palm about 17–18 times as long as high, about twice as long as pollex; pollex with 2 terminal spines, ventrally unarmed, occlusal margin denticulate. Carpus and merus with irregularly distributed spines on lateral, dorsal and mesial surfaces; spines strongest distally.

Pereopod 2: Merus extensor margin with 10–12 spines; flexor margin with 6–8 spines. Carpus with 2 or 3 extensor and 1 distal flexor spine. Propodus flexor margin with 6 or 7 minute movable spines; 18–19 times as long as high. Dactylus slightly exceeding one­third propodus length; extensor margin crenulate; flexor margin denticulate along distal threequarters.

Pereopod 3: Merus extensor margin with 11–14 spines; flexor margin with 7–9 spines. Carpus with 2 extensor and 1 distal flexor spine. Propodus flexor margin with 5 or 6 minute movable spines; 18–20 times as long as high. Dactylus slightly exceeding one­third propodus length; extensor margin crenulate; flexor margin denticulate along distal threequarters.

Pereopod 4: Merus extensor margin with 10–14 spines; flexor margin with 6–9 spines. Carpus with 2–4 extensor and 1 distal flexor spine. Propodus with 5 or 6 minute movable flexor spines; 18–22 times as long as high. Dactylus slightly exceeding one­third propodus length; extensor margin crenulate; flexor margin denticulate along distal three­quarters.

Etymology. From the Latin procerus, slender, alluding to the very slender chelipeds that distinguish the species from A. soelae .

Remarks. It is with some hesitation that we assign the present specimens to a new species in view of their strong similarity to A. soelae Baba, 1986 . Agononida soelae was described from the Northwest Shelf but is also reported from Japan, Taiwan, New Caledonia, Indonesia and the Austral Islands, French Polynesia ( Baba et al. 1986, Wu et al. 1998, Macpherson 1994, 1997, and Poupin 1996, respectively). The characters by which the present specimens (of both sexes) differ from A. soelae are consistent, however, justifying recognition of the new species. Agononida procera n. sp. closely resembles A. soelae but differs in the relative slenderness of the cheliped, and in the relative length and ornamentation of the pereopodal dactyli. The palm of the cheliped in A. procera differs from that of A. soelae in measuring at least double instead of 1.6 times the length of the dactylus and pollex. The dactyli of pereopods 2–4 in A. procera differ from those of A. soelae in being less slender and minutely spinose on the flexor margin for the distal three­quarters instead of the median third.

The figures given by Baba et al. (1986) and Wu et al. (1998) for a specimen from Japan and Taiwan, respectively, agree well with A. soelae sensu stricto. Records of A. soelae , however, from New Caledonia, Indonesia and the Austral Islands require verification. Unfortunately, Macpherson (1994, 1997) did not remark on the chelipeds of his New Caledonian and Indonesian specimens referred to A. soelae . The specimen from the Austral Islands, French Polynesia, figured by Poupin (1996) (and more fully at his website http:// decapoda .ecole­navale.fr) differs in coloration from that figured by Wu et al. (1997) and appears not to be referable to A. soelae . Poupin’s specimen requires restudy; it might be referable to A. procera or an undescribed species.

Distribution. Known only from eastern Australia between southern Queensland and Broken Bay, New South Wales; 675–824 m depth.

Figures

FIGURE 1. Agononida procera n. sp., holotype female (22.8 mm), AM P25095. A, dorsum. B, left basal antennular segment, ventral. C, left antennal peduncle, ventral. D, right third maxilliped, lateral. E, sternum. F, right chela, lateral. Scale: A, F = 5 mm, B–D = 2.5 mm, E = 3.5 mm.