Uroptychus multispinosus, 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 : 60-63

Uroptychus multispinosus n. sp. ( Fig. 17 )

Type material. HOLOTYPE: AM P31415, female (5.2 mm), E of Southport , Queensland, 27°55–58’S, 153°55’E, 318 m, demersal trawl, K78­09­06, 2 Jun 1978 . PARATYPES: AM P31413, 1 male (4.4 mm rostrum), 1 female (4.9 mm), NE of Tweed Heads , 28°02– 05’S, 153°57’E, 364 m, demersal trawl, K78­09­03, 1 Jun 1978 ; AM P31414, 2 females (4.6–4.7 mm), NE of Tweed Heads , 28°02–05’S, 153°57’E, 364 m, demersal trawl, K78­ 09­03, 1 Jun 1978 .

Diagnosis. Carapace excluding rostrum longer than broad; broadest posterior to midlength; lateral margins divergent; with anterolateral spine and 5–7 small spines lateral spines; outer orbital angle produced to small spine; dorsum unarmed. Rostrum narrow, about half as long as remaining carapace, usually with trifid apex, dorsally with shallow concavity. Sternite 3 slightly depressed, anterior margin shallowly concave, with U­shaped median notch. Basal antennal segment with distinct outer spine; ultimate and penultimate segments with distal spine. Antennal scale extending well beyond apex of ultimate peduncle segment. Pereopods 2–4 propodi not broadened distally, with 6–8 movable spines on distal flexor margin; dactyli with 6 or 7 strong, widely spaced, obliquely directed, corneous teeth on flexor margin.

Description. Carapace: Length (excluding rostrum) greater than breadth; broadest posterior to midlength. Lateral margins divergent, with slender anteriorly directed anterolateral spine and 5–7 small spines lateral spines. Rostrum elongate, narrow, about half as long as remaining carapace, usually with trifid apex, dorsally with shallow concavity. Outer orbital angle produced to small spine, not extending anteriorly beyond apices of anterolateral spines. Dorsum sparsely setose, unarmed. Pterygostomian flap with small anterior spine and scattered spinules over lateral surface.

Sternum: Plastron slightly broader than long, widening posteriorly. Sternite 3 (at base of maxilliped 3) slightly depressed, anterior margin shallowly concave, with U­shaped median notch, anterolateral angle usually bifid, flanked laterally by short tooth. Sternite 4 (at base of pereopod 1) with lateral margins produced, angular, extending anteriorly to or slightly beyond U­shaped notch of sternite 3.

Abdomen: Segments sparsely setose. Telson less than half as long as broad; distal portion faintly emarginate, slightly longer than proximal portion.

Eye: Cornea not dilated, about one­third length of peduncle; extending beyond midlength of rostrum.

Antenna: Basal segment with distinct outer spine. Peduncle extending beyond midlength of rostrum. Flagellum almost 2 times as long as peduncle. Ultimate segment about as long as penultimate segment, both with distal spine. Antennal scale wider than opposite peduncular segments, extending well beyond apex of ultimate peduncle segment

Maxilliped 3: Dactylus and propodus unarmed. Carpus with 2 distal extensor spines. Merus with 2 distal flexor spines and 1 distal flexor spine. Crista dentata denticulate for three­quarters ischium length, not extending onto basis.

Pereopod 1 (cheliped): Stout, subcylindrical, with setose scales, about 3 times carapace length. Propodus palm 3 times as long as high, about twice as long as pollex. Fingers crossing, occlusal margins dentate, sinuous. Carpus longer than merus, as long as propodal palm. Merus with setose scales and acute tubercles on inner margin. Ischium with triangular distolateral spine.

Pereopods 2–4: Setose, similar, slightly decreasing in length posteriorly. Propodi not broadened distally, with 6–8 movable spines on distal flexor margin, distalmost paired. Dactyli with 6 or 7 fixed, strong, widely spaced, obliquely directed, corneous teeth on flexor margin. Pereopods 2–3 carpus about 0.6 merus and propodus length. Pereopod 4 carpus about 0.6 merus length, 0.5 propodus length.

Etymology. The specific epithet is derived from the Latin multi, meaning ‘many’, and spinosus, meaning ‘thorny’, alluding to the large number of lateral carapace spines in comparison to the very similar species U. joloensis Van Dam, 1939 .

Remarks. Uroptychus multispinosus n. sp. most closely resembles U. joloensis Van Dam, 1939 , from Indonesia, sharing the trifid rostral apex, similar carapace outline with small lateral spines, elongate ocular peduncles, and U­shaped median notch in the anterior margin of sternite 3. Uroptychus multispinosus differs from U. joloensis in the following features: the lateral carapace margins bear 6 or 7 instead of 2 spines, the antennal scale is longer than instead of distinctly shorter than the antennal peduncle, the chelipeds are shorter and more robust, and the spines on the inner margins of the dactyli walking legs are directed obliquely instead of perpendicular to the dactylar margin. The rostrum in one specimen is not trifid ( Fig. 17H ), but appears to be regenerating from damage.

Distribution. Presently known only from southern Queensland between Southport and Tweed Heads at 318– 364 m.

Figures

FIGURE 17. Uroptychus multispinosus n. sp., A–G, holotype female, 5.2 mm, AM P31415. H, paratype female, 4.6 mm, AM P31414. A, dorsum. B, anterior carapace, right lateral. C, sternum. D, telson, E, maxilliped 3, right lateral. F, antenna, right ventral. G, crista dentata, right. H, anterior, dorsal. A–B, H = 2 mm, C–F = 1 mm, G = 0.5 mm.