Uroptychus longvae, Ahyong & Poore, 2004

Ahyong, Shane T. & Poore, Gary C. B., 2004, The Chirostylidae of southern Australia (Crustacea: Decapoda: Anomura), Zootaxa 436 (1), pp. 1-88 : 58-60

Uroptychus longvae n. sp. ( Fig. 16 )

Type material. HOLOTYPE: SAM C6064 , ovigerous female (13.7 mm), 342 km west of Cape Wiles, Great Australian Bight , South Australia, 34°56’S, 133°20’E, 805–816 m, FV Longva III, K. Gowlett­Holmes, 10 Nov 1989.

Diagnosis. Carapace excluding rostrum distinctly broader than long; lateral margins smooth, distinctly convex, broadest posterior to midlength; with distinct anterolateral spine; outer orbital angle rounded, unarmed; dorsum unarmed. Rostrum sharply triangular, slightly shorter than half­length of remaining carapace, margins unarmed. Sternite 3 anterior margin with deep V­shaped emargination. Basal antennal segment without outer spine; ultimate and penultimate segments unarmed. Antennal scale extending about to midlength of ultimate peduncle segment. Cheliped about 3 times carapace length; propodus palm about 2.5 times dactylus length. Pereopods 2–4 similar, propodi not broadened distally, unarmed; dactyli with 18–20 small, slender teeth on flexor margin.

Description. Carapace: Carapace excluding rostrum distinctly broader than long. Lateral margins slightly irregular, distinctly convex, broadest posterior to midlength; with distinct, anterolateral spine; posterior fifth with low, indistinct ridge. Rostrum sharply triangular, slightly less than half­length of remaining carapace, margins unarmed but sparsely setose. Outer orbital angle rounded, unarmed. Dorsum minutely punctate, finely but sparsely­setose, unarmed. Pterygostomian flap without anterior spine.

Sternum: Plastron broader than long, slightly widening posteriorly. Sternite 3 (at base of maxilliped 3) not depressed, anterior margin with deep V­shaped emargination; outer lobes of emargination obtusely angled. Sternite 4 (at base of pereopod 1) with blunt anterolateral margins, extending anteriorly to about midlength of emargination of sternite 3.

Abdomen: Segments glabrous. Telson about half as long as broad; distal portion posteriorly emarginate, about 1.5 times length of proximal portion.

Eye: Eyestalks not reaching to proximal half of rostrum; cornea not dilated, about onethird length of remaining stalk.

Antenna: Basal antennal segment unarmed. Peduncle extending to distal third of rostrum. Flagellum about 1.5 times as long as peduncle. Ultimate and penultimate segments unarmed; ultimate segment about 1.5 times length of penultimate segment. Antennal scale wider than opposite peduncular segments, extending about to midlength of ultimate peduncle segment.

Maxilliped 3: Dactylus, propodus, carpus and merus unarmed. Crista dentata distinctly serrate on proximal half of ischium, not extending onto basis.

Pereopod 1 (cheliped): Slender, subcylindrical to ovate in cross­section; about 3 times carapace length; rugose, sparsely setose. Propodus palm about 3.5 times as long as high, about 2.5 times as long as dactylus; lower distal margin slightly concave. Fingers crossing, occlusal margins finely dentate; occlusal margin of dactylus with obtuse process proximally; occlusal margin of pollex with low prominence distal to midlength. Carpus longer than merus and shorter than propodal palm; ischium with low triangular projection on outer margin.

Pereopods 2–4: Sparsely setose, similar, becoming shorter distally; propodus, carpus and merus unarmed. Propodi not broadened distally, unarmed, but setose distally. Dactyli lined with 17–20 small, slender teeth on flexor margin, but obscured by dense setae. Pereopods 2–3 carpus about half merus and propodus length. Pereopod 4 carpus about 0.7 merus length, about 0.5 propodus length.

Ovum: Diameter 1.2 mm.

Etymology. Named after the vessel from which the holotype was collected, FV Longva III.

Remarks. Uroptychus longvae n. sp. most closely resembles U. patulus n. sp., but also resembles U. onychodactylus Tirmizi, 1964 , from the Maldives and U. setosidigitalis Baba, 1977 , from Midway Island in the broad carapace, broad V­shaped anterior emargination of sternite 3, and elongate, curved, setose dactyli of pereopods 2–4. Uroptychus longvae resembles U. patulus and differs from U. onychodactylus and U. setosidigitalis in having a rounded instead of acute outer orbital margin. Uroptychus longvae n. sp differs from U. patulus in the relative length and proportions of the cheliped segments and in the spination of the dactyli of the walking legs. In U. longvae , the cheliped is about three instead of two times as long as the carapace, the dorsal margin of the cheliped palm is about 2.5 instead of less than twice as long as the dactylus, and the teeth lining the inner margin of the dactyli of the walking legs are slender and longer than wide instead of being about as long as wide.

Distribution. Known only from the type locality, 342 km west of Cape Wiles, Great Australian Bight, South Australia; 805– 816 m.

Figures

FIGURE 16. Uroptychus longvae n. sp., holotype female, 13.7 mm, SAM C6064. A, dorsum. B, anterior carapace, right lateral. C, telson. D, sternum. E, maxilliped 3, right lateral. F, crista dentata, right. G, antenna, right ventral. A–B = 4 mm, C–E = 2 mm, F–G = 1.3 mm.