Uroptychus calcar, 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 : 28-31

Uroptychus calcar n. sp. ( Fig. 6 )

Type material. HOLOTYPE: AM P65829, male (11.8 mm), E of Sydney, New South Wales, 33°42’S, 151°52’E, 380–390 m, Boris box trawl, K96­47­02, 17 Sep 1996.

PARATYPES: AM P66000, 1 male (8.5 mm), 6 females (6.5–11.3 mm), E of Broken Bay , New South Wales, 403 m, K80­11­01, 15 Jul 1980 ; AM P26551, 8 males (8.2–11.7 mm), 4 females (10.0– 11.2 mm), NE of Broken Bay , New South Wales, 33°25–27’S, 152°04– 06’E, 329 m, on seapen Anthoptilium, K 77­14­03, 13 Sep 1977 ; AM P28809, 1 male (10.2 mm), 2 females (8.4–9.6 mm), E of Norah Head , New South Wales, 33°24’S, 152°07’E, 366 m, K79­08­04, 18 Jul 1979 ; AM P28806, 8 males (3.4–11.7 mm), 6 females (8.2–11.6 mm), E of Broken Bay , New South Wales, 33°30’S, 152°02’E, 366 m, K79­08­05, 18 Jul 1979 ; AM P25123, 1 male (8.5 mm), E of Broken Bay , New South Wales, 33°30’S, 152°01’E, 458–461 m, K76­24­06, 21 Dec 1976 ; AM P25035, 3 males (7.7–9.3 mm), 4 females (9.1–11.1 mm), SE of Broken Bay , New South Wales, 33°26–43’S, 151°50– 152°06’E, 329 m, K76­15­01/02/03, 5 Oct 1976 ; AM P26552, 5 males (9.1–9.5 mm), 5 females (9.4–10.5 mm), SE of Broken Bay , New South Wales, 33°39–41’S, 151°51–53’E, 329 m, K77­06­01, 7 Jun 1977 ; AM P31509, 2 males (10.0– 10.5 mm), 4 females (8.5–11.8 mm), E of Broken Bay , New South Wales, 33°40’S, 151°53’E, 450 m, on hydroid, K77­ 09­01, 4 Jul 1977 ; AM P24476, 1 male (10.2 mm), E of Sydney , New South Wales, 33°36’S, 151°57’E, 202 m, K76­07­06, 27 May 1976 ; AM P65999, 1 male (7.6 mm), 1 ovigerous female (9.0 mm), off Sydney , New South Wales, 33°37–40’S, 151°53–55’E, 326–331 m, K96­18­04, 24 Sep 1996 ; AM P18009, 3 males (9.6–10.9 mm), 1 female (9.5 mm), SE of Port Hacking , New South Wales, 34°12’S, 151°28’E, 357–366 m, K71­10­03, 28 Jun 1971 .

Other material examined. NEW SOUTH WALES: AM P21769, 2 males (7.4–8.7 mm), 1 female (8.7 mm), SE of Clarence River , 29°32’S, 153°47’E, 406–414 m, K75­09­ 04, 10 Oct 1975 ; AM P20800, 1 male (9.4 mm), 2 females (10.3–12.8 mm), E of Brush Island , 34°32’S, 150°45’E, 393–439 m, K75­03­01, 10 Jul 1975 ; AM P24398, 1 ovigerous female (9.2 mm), NE of Brush Island , 35°32’S, 150°46’E, 329 m, K76­08­01, 8 Jun 1976 ; AM P20807, 1 male (9.8 mm), 1 female (11.6 mm), SE of Gabo Island , 37°38’S, 150°16’E, 403–439 m, K75­03­02, 10 Jul 1975 .

VICTORIA: AM P31506, 5 males (8.3–11.0 mm), 5 females (7.3–10.8 mm), S of Gabo Island , 38°00–02’S, 150°02–04’E, 384 m, K80­07­11, 14 Jun 1980 ; AM P31508, 1 male (8.0 mm), eastern Bass Strait , 38°08’S, 149°49’E, 347 m, K80­07­09, 14 Jun 1980 ; NMV J17068 , 1 ovigerous female (7.9 mm), Lakes Entrance, 38°34.25’S, 148°32.25’E, 384– 378 m, Marine Science Laboratories , 24 Aug 1982 .

Diagnosis. Carapace excluding rostrum longer than broad; lateral margins with anterolateral spine and 7–12 lateral spines; dorsum smooth, with cluster of 3 or 4 small epigastric spines on each side. Rostrum sharply triangular, about half to two­thirds as long as remaining carapace (usually about half). Sternite 3 anterior margin deeply concave with narrow V­shaped median notch. Sternite 4 with anterolateral margins not produced beyond base of sternite 3. Antennal basal segment with outer spine; penultimate segment with distal spine. Antennal scale extending about to distal half of ultimate segment. Pereopods 2–4 merus and carpus unarmed; propodus not broadened distally, with pair of movable spines on distal flexor margin; dactylus with 4–7 strong, widely spaced, perpendicularly (or near perpendicularly) directed corneous teeth on flexor margin.

Description. Carapace: Longer than broad. Lateral margins divergent; with strong anteriorly directed anterolateral spine and 7–12 lateral spines. Anterior 2 lateral spines small, third spine large, stout, at base of indistinct cervical groove, remainder stout, closely spaced, decreasing in size posteriorly. Rostrum sharply triangular, about half to two­thirds as long as remaining carapace (usually about half), lateral margins smooth. Outer orbital angle produced to small acute spine. Dorsum smooth, with cluster of 3 or 4 small epigastric spines on each side. Pterygostomian flap with strong anterior spine and small spinules on proximal surface.

Sternum: Plastron about as long as wide, slightly widening posteriorly. Sternite 3 (at base of maxilliped 3) depressed, anterior margin deeply concave with narrow V­shaped median notch, anterolateral angle blunt. Sternite 4 (at base of pereopod 1) with anterolateral margins not produced beyong base of sternite 3.

Abdomen: Segments glabrous. Telson about half as long as broad; distal portion posteriorly emarginate, longer than proximal portion.

Eye: Cornea not dilated, about half­length of peduncle; not reaching beyond midlength of rostrum.

Antenna: Basal segment with outer spine. Peduncle extending beyond distal half of rostrum. Ultimate segment about as long as penultimate segment, penultimate with distal spine. Antennal scale wider than opposite peduncular segments, extending about to distal half of ultimate segment.

Maxilliped 3: Dactylus, propodus, carpus and merus unarmed. Crista dentata finely denticulate proximally, becoming smooth on distal half of ischium.

Pereopod 1 (cheliped): About 3 times carapace length; all segments glabrous, sparsely setose. Propodus with palm 3–4 times as long as high, about twice as long as pollex. Fingers crossing, occlusal margins dentate and each with low process proximally. Carpus and merus with or without small spinules on distal margin. Ischium with triangular distolateral spine.

Pereopods 2–4: Similar, slightly decreasing in length posteriorly. Meri and carpi glabrous, unarmed, sparsely setose. Propodi over twice length of carpus, not broadened distally, with pair of movable spines on distal flexor margin. Dactyli with 4–7 strong, widely spaced, perpendicularly (or near so) directed corneous teeth on flexor margin.

Ovum : 1.0 mm diameter.

Etymology. Named calcar , from the Latin for ‘spur’, alluding to the distinctive arrangement of teeth on the dactyli of the walking legs that distinguish the present new species from other Australian species.

Remarks. In bearing lateral and dorsal spines on the carapace, U. calcar n. sp. resembles U. zeidleri n. sp., U. cardus n. sp. and U. nanophyes McArdle, 1901 , in the spinose lateral margins and epigastric spines on the carapace. Uroptychus calcar differs from each of the aforementioned species in lacking a distal spine on the ultimate segment of the antennal peduncle and in the arrangement of spines on the inner margin of the dactyli and propodus of pereopods 2–4. In U. calcar , the pereopods 2–4 propodi bear a pair instead of a row of movable spines on the distal flexor margin, and the dactylar spines are widely spaced and orientated perpendicularly instead of being widely spaced and oblique.

In the juvenile male (cl. 3.4 mm), the lateral carapace spines are less pronounced, and the epigastric spines on the carapace are undeveloped.

Distribution. Vicinity of Clarence River, northern New South Wales, south to eastern Bass Strait, Victoria, at 326–461 m depth.

Figures

FIGURE 6. Uroptychus calcar n. sp., holotype male, 11.8 mm, AM P65829. A, dorsum. B, anterior carapace, right lateral. C, telson. D, sternum. E, maxilliped 3, right lateral. F, crista dentata, right. G, antenna, right ventral. Scale A–B = 4 mm, C–E = 2 mm, F–G = 1 mm.