Uroptychus bardi, Mccallum, Anna W. & Poore, Gary C. B., 2013

Mccallum, Anna W. & Poore, Gary C. B., 2013, Chirostylidae of Australia’s western continental margin (Crustacea: Decapoda: Anomura), with the description of five new species, Zootaxa 3664 (2), pp. 149-175 : 158-160

Uroptychus bardi sp. nov.

( Fig. 4 )

Type material. Holotype: Male (cl 18.8 mm),Western Australia, off Cape Leveque (14°33.43'S, 121°20.38'E – 14°32.76'S, 121°19.65'E), 924–1101 m, 4 Jul 2007 (stn SS05/2007 156), CSIRO acquisition number 0 12, NMV J63754 . Paratype: Collected with holotype, female (cl 15.7 mm), NMV J59083 .

Diagnosis. Carapace excluding rostrum as long as broad; width between anterolateral margins 0.6 times that of broadest carapace width at posterior 0.75; lateral margins of carapace convex with irregular tubercles along margin; anterolateral spine prominent with small accessory spine; dorsum with scattered tubercles but unarmed. Rostrum narrowly triangular; almost horizontal but gently directed dorsally at tip; length 0.4 that of remaining carapace. Sternite 3 anterior margin deeply concave, with pair of submedian spines separated by narrow U-shaped notch. Sternite 4 surface with one continuous transverse row of sharp setose tubercles and additional short rows of tubercles, mostly in pairs. Antennal peduncle ultimate and penultimate articles unarmed; ultimate article 2.6 times length of penultimate; antennal scale extending to distal end of peduncle. Pereopod 1 carpus, merus and ischium with sharp tubercles on inner margin. Pereopods 2–4 propodi with 7–9 movable spines on distal flexor margin, distalmost paired; dactyli with 11–14 obliquely directed spines on flexor margin, ultimate spine significantly broader than penultimate. Pereopod 2 slightly longer than pereopod 3; length of pereopod 3 merus 0.9 that of pereopod 2 merus. Pereopod 4 shorter than pereopod 3; length of pereopod 4 merus about 0.8 that of pereopod 3 merus.

Description. Carapace: Carapace excluding rostrum as long as broad; width between anterolateral margins 0.6 times that of broadest carapace width; lateral margins convex, broadest at posterior 0.75, with sharp tubercles, especially behind base of cervical groove. Rostrum narrowly triangular, 1.8 times as long as broad; almost horizontal but directed dorsally at tip; length 0.4 that of remaining carapace. Anterolateral spine prominent with small accessory spine. Lateral orbital margin angular but without distinct spine. Dorsal surface with shallow depression between indistinct gastric and cardiac regions; gastric region with feebly granulate epigastric ridges posterior to ocular peduncles and scattered tubercles on lateral surface; branchial region with a short row of tubercles behind base of cervical groove. Dorsum smooth without setae. Pterygostomian flap with row of tubercles on dorsal margin and scattered tubercles anteriorly, anterior margin with spine.

Sternum: Sternal plastron 1.2 times as long as broad, slightly widening posteriorly. Sternite 3 anterior margin deeply concave, with pair of submedian spines separated by narrow U-shaped notch; lateral margin with short irregular teeth. Sternite 4 with blunt anterolateral teeth extending anteriorly beyond level of the sternite 3 median spines; surface with one continuous transverse row of sharp setose tubercles and additional short rows of tubercles, mostly in pairs.

Abdomen: Somites glabrous. Telson 0.45 times as long as broad; distal portion posteriorly emarginate, about twice length of proximal portion.

Eyes: Cornea as wide as peduncle, slightly shorter than length of peduncle; reaching to midlength of rostrum.

Antenna: Peduncle extending to distal third of rostrum. Article 2 with outer spine; ultimate and penultimate articles unarmed; ultimate article 2.6 times length of penultimate. Antennal scale 1.75 times broader than ultimate peduncle article, extending to distal end peduncle.

Maxilliped 3: Dactylus, propodus, carpus and merus unarmed. Crista dentata distinctly serrate with 30 denticles. Basis with 9 denticles on mesial ridge.

Pereopod 1 (cheliped): Pereopod 1 3.8 times carapace length; glabrous dorsally with sparse setae on fingers. Propodus expanded; palm 2.5 times as long as high, 1.5 times as long as pollex. Fingers crossing, occlusal margins finely dentate; occlusal margin of dactylus with bilobed process proximally; occlusal margin of pollex excavated on proximal half with low prominence at midlength. Carpus 1.4 times as long as merus and 1.2 times propodal palm. Carpus, merus and ischium with sharp tubercles on inner margin, sometimes occurring in close-set pairs; ischium with low triangular spine on outer margin.

Pereopods 2–4: Sparsely setose, setae on dactyli, carpi and meri very long. Propodi slightly broadened distally, flexor margin ending in pair of robust spines preceded by 9 (on pereopod 2 and 3), and 7 (on pereopod 4) movable spines on distal three-quarters. Dactyli with 11 (on pereopod 2), 12 (on pereopod 3) and 14 (on pereopod 4) fixed, obliquely directed triangular spines on flexor margin, ultimate significantly broader than penultimate spine. Pereopods 2 and 3 similar; carpus and merus unarmed; carpus 0.5 merus length, 0.7 propodus length. Pereopod 2 slightly longer than pereopod 3; length of pereopod 3 merus 0.9 length of that of pereopod 2. Pereopod 4 shorter than pereopod 3; merus 0.8 that of pereopod 3; carpus 0.6 propodus length.

Etymology. After the indigenous Bardi ‘sea people’ of the Dampier Peninsula (noun in apposition).

Distribution. North-western Australia, off Cape Leveque, 924–1101 m.

Remarks. Uroptychus bardi is similar to U. litosus Ahyong & Poore, 2004 , U. occidentalis Faxon, 1893 , U. empheres Ahyong & Poore, 2004 and U. taylorae sp. nov. (see below), in general carapace shape, the armature of pereopods 2–4, and the length of the antennal scale. Both U. empheres and U. bardi can be distinguished from U. occidentalis , U. litosus , and U. taylorae by the presence of a field of granules on the surface of sternite 4, where the latter species have a single row of granules. U. bardi can be distinguished from U. empheres by the following: in U. empheres the merus of pereopod 4 is about half the length of the merus of pereopod 3, while in U. bardi the merus of the pereopod 4 is 0.8 times the merus of the pereopod 3; U. empheres has a narrower carapace which is slightly longer than broad (excluding the rostrum), while in U. bardi the carapace is as long as broad; U. bardi has a prominent anterolateral spine which distinctly overreaches the outer orbital angle, while in U. empheres the anterolateral spine does not extend beyond the orbital angle.

Figures

FIGURE 4. Uroptychus bardi sp. nov., male (8.8 mm), NMV J 63754. A, carapace and abdomen, dorsal. B, carapace, lateral. C, sternum. D, telson. E, left antenna, ventral. E, maxilliped 3, basis and ischium, right, ventral. G, pereopod 1, right. H, pereopod 1, mesial, distal part. I, pereopod 1, merus and ischium, lateral. J, P 2. K – L, pereopods 3 – 4, setae omitted. Scales: A, B, C, G, H, J – L = 5 mm, D – F = 1 mm.