Uroptychus toka, Schnabel, 2009

Schnabel, Kareen E., 2009, A review of the New Zealand Chirostylidae (Anomura: Galatheoidea) with description of six new species from the Kermadec Islands, Zoological Journal of the Linnean Society 155 (3), pp. 542-582 : 568-570

publication ID	https://doi.org/ 10.1111/j.1096-3642.2008.00449.x
persistent identifier	https://treatment.plazi.org/id/03E487F2-FFC8-3C51-3189-1AAC0DAFF2B3
treatment provided by	Felipe
scientific name	Uroptychus toka
status	sp. nov.

Treatment

UROPTYCHUS TOKA View in CoL SP. NOV. ( FIG. 14 View Figure 14 )

Type material: HOLOTYPE: ♀ ovig. (5.3 mm), L’Esperance Rock, Kermadec Ridge, 33° 02.59′S, 179° 34.60′W, 350–490 m, 18.vii.1974, stn NZOI K795 View Materials ( NMNZ Cr. 012090). GoogleMaps

Diagnosis: Carapace approximately as wide as long; lateral margin without distinct spine but irregular, with large serrated process on anterior branchial region. Dorsal surface of carapace with cluster of small spines and granules on lateral hepatic and epigastric region, otherwise smooth. Lateral carapace margins convexly divergent posteriorly. Sternal plastron slightly wider than long along midlength. Basal antennal article with blunt triangular distolateral spine; penultimate antennal article with stout distal spine, ultimate unarmed; scale stout and rounded, not reaching midlength of ultimate article. Maxilliped 3 spineless. Pterygostomian flap surface covered with spines (anterior spines bifurcated). Sternal plastron anterior margin rounded with shallow concavity bearing U-shaped notch flanked by minute pair of submedian spines. Pereopod 1 (cheliped) with small distodorsal spine on ischium only. Pereopods 2–4 dorsal margin of meri and carpi smooth; propodi with pair of distal spines on flexor margin only; dactyli straight, longer than half length of propodi, with seven sharp triangular spines (excluding distal spine), loosely arranged and perpendicular to flexor margin, penultimate larger than antepenultimate.

Description of holotype: Carapace: 1.1 times as long as broad (0.8 without rostrum), moderately convex from side to side. Dorsal surface sparsely setose (transverse row of small spines in epigastric and hepatic region); cervical groove not deep but distinct, epigastric and hepatic region covered with small spines, hepatic region with a small spine posterior to anterolateral spine and covered with small spines (in posterior portion), carapace otherwise unarmed. Frontal margin deeply excavate; outer orbital angle produced into small spine, anterior to anterolateral spine. Anterolateral margin rounded, with small spine dorsomesial to margin, lateral margin convexly divergent posteriorly, with seven to nine small irregular spines posterior to anterolateral spine, distinct serrated process at anterior branchial margin. Posterior margin unarmed. Rostrum triangular, slightly deflected ventrally, 0.2 times length of remaining carapace; dorsal surface strongly excavate; lateral margins smooth. Pterygostomian flap lateral surface covered with small spines, anterior margin produced into a spine.

Sternum: sternal plastron 1.3 times as wide as long, lateral extremities subparallel between sternites 5–7. Sternite 3 anterior margin rounded, with median notch flanked by small submedian spines, lateral margins rounded. Surface smooth. Sternite 4 0.5 times as wide as sternite 3, anterior midline grooved; anterolateral margin rounded with blunt terminus.

Abdomen: tergites smooth and unarmed, without transverse ridges or grooves. Pleural margins of segments 2 to 4 rounded (tergite 2 slightly concave). Telson and tergite 6 two times as broad as long; posterior portions 0.8 times length of anterior portion.

Eyes: cornea subglobular, 0.4 times length of ocular peduncle, nearly reaching end of rostrum.

Antennal peduncle: article 2 with blunt and triangular outer spine. Penultimate article with stout distal spine. Ultimate article unarmed, 1.1–1.2 times as long as penultimate. Antennal scale not reaching midlength of ultimate article; two times as long as wide.

Maxilliped 3: surface smooth, ischium without distal spines, a few scattered small spines, basis smooth. Merus extensor margin without spine; flexor margin without spine. Carpus, propodus, and dactylus unarmed.

Pereopod 1: slender, 3.9–4.0 times as long as carapace, surface moderately setose. Ischium with distodorsal spine. Merus and carpus, surface unarmed; carpus as long as palm. Propodus with palm 3.5–3.6 times as long as high, unarmed. Length of dactylus 0.4 times as long as propodus, occlusal margins not gaping, denticulate.

Pereopods 2–4: similar; surfaces setose and unarmed. Merus 1.0–0.7 times as long as propodus (P2 merus slightly longer, P3–4 meri subequal). Propodus 1.7–2.0 times as long as dactylus (propodus increasing in length from P2–4), extensor margin smooth. Flexor margin with only distal pair of spines. Dactylus straight; flexor margin with eight spines, ultimate slender, penultimate prominent, other spines sharp triangular, loosely arranged and perpendicular to margin, diminishing proximally.

Ovum : 1.0– 1.1 mm.

Remarks: Uroptychus toka sp. nov. is most similar to Uroptychus rutua sp. nov. but differs with respect to dorsal carapace armature; specifically, the presence of a spine behind the anterolateral spine and a distinct process on the anterior margin of the branchial lateral region (both absent in Uroptychus rutua ) and the absence of broad paired inflations in the epigastric region.

See similarities to other congeners under Uroptychus rutua .

Distribution: L’Esperance Rock, Kermadec Ridge, 350–490 m ( Fig. 7 View Figure 7 ).

Etymology: Toka is the Māori word for rock, with reference to the type locality (L’Esperance Rock).