Uroptychus taylorae, 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 : 167-169

Uroptychus taylorae sp. nov.

( Figs. 9 , 12 G)

Uroptychus gracilimanus .— Poore et al., 2008: 17.

Type material. Holotype: Female, ovigerous (cl 9.2 mm), Western Australia, south-western Australia, off Bunbury (33°0.58'S, 114°34.2'E – 32°59.62'S, 114°34.92'E), 423– 397 m, 20 Nov 2005 (stn SS10-2005 067), CSIRO acquisition number 0 38, NMV 63755.

Paratypes: Collected with holotype, 2 males (cl 8.6, 6.6 mm), 3 females (2 ovigerous) (cl 7.3–8.8 mm), NMV J55001 ; 2 males (cl 7.8, 8.3 mm), 2 juveniles (cl 5 mm), off Bunbury (33°0.5'S, 114°34.27'E – 33°0.12'S, 114°34.5'E), 421– 414 m, 29 Nov 2005 (stn SS10-2005 013), CSIRO acquisition number 0 34, NMV J55000 .

Diagnosis. Carapace excluding rostrum as long as broad; width between anterolateral margins 0.7 times that of broadest carapace width; lateral margins evenly convex, without granules, with anterolateral spine; outer orbital angle produced to small spine; dorsum smooth and without setae. Rostrum sharp triangular, horizontal, about half the length of remaining carapace. Sternite 3 anterior margin concave, with pair of submedian spines separated by narrow notch. Sternite 4 surface with a transverse row of tubercles and setae. Antennal peduncle ultimate and penultimate articles unarmed; ultimate article 2.7 times the length of penultimate article; antennal scale extending slightly beyond midlength of ultimate peduncle article. Pereopod 1 slender, 3 times carapace length; merus and ischium smooth on inner proximal margin. Pereopods 2–4 propodi not broadened distally, with 7–10 movable spines on distal flexor margin, distalmost paired; dactyli with 7–8 obliquely directed spines on flexor margin, unguis distinctly more slender than ultimate spine. Pereopod 2 slightly longer than pereopod 3; pereopod 3 merus length 0.8 that of pereopod 2 merus. Pereopod 4 shorter than pereopod 3; pereopod 4 merus length about 0.8 that of pereopod 3 merus.

Description. Carapace: Carapace excluding rostrum as long as broad; width between anterolateral margins 0.7 times that of broadest carapace width; lateral margins evenly convex without granules; dorsal surface with shallow depression between indistinct gastric and cardiac regions; gastric region without epigastric spines or granulate epigastric ridges; lateral orbital angle angular with small spine; anterolateral spines overreaching outer orbital spine; dorsum smooth and without setae. Rostrum sharp triangular, 1.7 times as long as broad; ventrally directed; length 0.6 that of remaining carapace. Pterygostomian flap smooth, anterior margin rounded, with small spine.

Sternum: Sternal plastron slightly longer than broad, slightly widening posteriorly. Sternite 3 anterior margin concave, with pair of submedian spines separated by narrow notch. Sternite 4 with blunt anterolateral tooth extending anteriorly to apex of median spines of sternite 3; surface with a transverse row of tubercles and setae.

Abdomen: Somites glabrous. Telson length about 0.5 breadth; distal portion posteriorly emarginate, about twice length of proximal portion.

Eyes: Cornea as wide as peduncle, slightly shorter than length of peduncle; reaching just beyond anterolateral margin of carapace.

Antenna: Peduncle extending to distal third of rostrum. Article 2 with outer spine; ultimate and penultimate articles unarmed; ultimate article 2.7 times length of penultimate article. Antennal scale 2.5 times broader than article 5, reaching the second article of flagellum.

Maxilliped 3: Dactylus, propodus, carpus and merus unarmed. Crista dentata distinctly serrate with 26 denticles. Basis with 4 denticles on mesial ridge.

Pereopod 1 (cheliped): Chelipeds slender, 3 times carapace length, glabrous dorsally and sparsely setose. Propodus palm 4.5 times as long as high, 1.9 times as long as pollex. Fingers crossing, occlusal margins finely dentate; occlusal margin of dactylus with 2 obtuse processes proximally; occlusal margin of pollex with low prominence proximal to midlength. Carpus 1.1 times longer than merus and 1.2 times propodal palm, with few setae. Merus and ischium smooth on inner proximal margin; ischium with curved spine on outer dorsal margin.

Pereopods 2–4: Sparsely setose, setae on propodi and distal parts of carpi very long. Propodi not broadened distally, flexor margin ending in pair of spines preceded by 6–9 movable spines on distal three-quarters. Dactyli with 7–8 fixed, obliquely directed triangular spines on flexor margin, unguis distinctly more slender than ultimate spine. Pereopods 2–3 similar; carpus and merus unarmed; carpus 0.4 merus length, 0.7 propodus length. Pereopod 2 slightly longer than pereopod 3; pereopod 3 merus length 0.8 that of pereopod 2 merus. Pereopod 4 shorter than pereopod 3; pereopod 4 merus length 0.9 that of pereopod 3 merus; carpus 0.5 propodus length.

Colour. Pale pink with fine speckled orange dots. Red intestinal tract observable through carapace.

Etymology. Named in honour of Joanne Taylor for her contribution to the crustacean collections at Museum Victoria, and her support with this research.

Distribution. South-western Australia, off Bunbury, 414– 424 m.

Remarks. This material was originally reported as Uroptychus gracilimanus (Henderson, 1885) by Poore et al. (2008), based on its carapace shape and slender chelipeds. However, a number of characters distinguish this new species from U. gracilimanus including the paired distal flexor spines of the propodus; the long antennal scale which over-reaches the ultimate peduncle article; and the absence of epigastric spines. It is more similar to U. bardi sp. nov., U. litosus , U. occidentalis and U. empheres in possessing an antennal scale which almost reaches or overreaches the peduncle, and paired spines on the distal margin of the propodal flexor margin. Characters distinguishing U. taylorae sp. nov. from U. empheres and U. bardi are outlined under the remarks for U. bardi . The robust chelipeds of U. litosus as well as the divergent carapace margins (see ratios in key) distinguish U. litosus from U. taylorae . Uroptychus occidentalis from the eastern Pacific can be distinguished from the new species by subtle differences. In U. occidentalis the antennal scale overreaches the distal three-fourths and never reaches the distal end of the ultimate article (Baba & Lin, 2008). In all specimens here, the antennal scale distinctly overreaches the peduncle.

Figures

FIGURE 9. Uroptychus taylorae sp. nov., female (9.2 mm), NMV 63755. A, carapace and abdomen, dorsal. B, carapace, lateral. C, sternum. D, telson. E, left antenna, ventral. F, maxilliped 3 basis and ischium, right, ventral. G, pereopod 1, right. H, pereopod 1, left, distal part. I, pereopod 2. J – K, pereopods 3 – 4, setae omitted. Scales A, B, G – K = 5 mm, C – F = 1 mm.

FIGURE 12. A, Uroptychus spinirostris (Ahyong and Poore, 2004), NMV J 61768. B, Uroptychus ciliatus (Van Dam, 1933), NMV J 55998. C, Uroptychus flindersi Ahyong & Poore, 2004, NMV J 54995. D, Uroptychus joloensis Van Dam, 1939, NMV J 57247. E, Uropychus nigricapillis Alcock, 1901, NMV J 57245. F, Uroptychus scandens Bendedict, 1902, NMV J 57249. G, Uroptychus taylorae sp. nov. NMV J 55000. H, Uroptychus vandamae Baba, 1988, NMV J 57248. I, Uroptychus worrorra sp. nov., NMV J 56119.