Uroptychus thermalis Baba & de Saint Laurent, 1992

Ahyong, Shane T. & Poore, Gary C. B., 2004, The Chirostylidae of southern Australia (Crustacea: Decapoda: Anomura), Zootaxa 436 (1), pp. 1-88 : 77-79

Uroptychus thermalis Baba & de Saint Laurent, 1992 ( Fig. 24 )

Uroptychus thermalis Baba & de Saint Laurent, 1992: 324–326 , fig. 2 [type locality: North Fiji Basin].

Material examined. QUEENSLAND: AM P64922, 1 male (14.5 mm), Argo Bank, 23°22.34’S, 159°38.73’E, 1497 m, soft sandy limestone, FR0888­D4 , RV Franklin, 9 Oct 1988 .

Diagnosis. Carapace excluding rostrum longer than wide, widest posterior to midlength; with distinct anterolateral spine; lateral margins irregular but unarmed; dorsum without spines but with scattered scales and rugosities. Anterior margin of sternite 3 with broad concavity and narrow median notch; laterally with distinct tooth. Eyes with cornea dilated. Basal antennal segment with outer spine; ultimate and penultimate peduncle segments unarmed distally. Maxilliped 3 with segments unarmed. Cheliped slender, subcylindrical; about 5 times carapace length; with scattered scales or tubercles. Pereopods 2–4 similar, slender, relative lengths 2>3>4; dactylus with 2 distal spines; propodi widened on medial flexor margin bearing group 4 or 5 spines and single distal spine.

Remarks. The present specimen represents the first record of the species since it was described from from the North Fiji Basin. The Australian specimen differs from the type description in having larger anterolateral projections on the third and fourth sternites, slightly longer anterolateral spines on the carapace, in having a distal spine on the carpus of the cheliped, and two instead of one distal spines on the merus of the cheliped. The differences between the two specimens (11.6 mm cl. for the holotype vs. 14.5 mm in the Australian specimen) appear to be size related;.

The holotype was collected from the vicinity of an active hydrothermal vent at 2000 m depth.

Distribution. Fiji and now from eastern Australia at depths of 1497–2000 m.

Figures

FIGURE 24. Uroptychus thermalis Baba & de Saint Laurent, 1992, male, 14.5 mm, Argo Bank, Queensland, AM P64922. A, dorsum. B, anterior carapace, right lateral. C, cheliped, proximal right lateral. D, sternum. E, telson. F, maxilliped 3, right lateral. G, crista dentata, right. H, antenna, right ventral. Scale A–C = 5 mm, D–H = 2.5 mm.