Ancylomenes kuboi, Bruce, 2010

Bruce, A. J., 2010, Ancylomenes kuboi and A. okunoi spp. nov. (Decapoda: Pontoniinae), from the Australian Northwest Shelf, Vietnam and the Philippines *, Zootaxa 2372 (1), pp. 169-176 : 170-171

publication ID	https://doi.org/ 10.11646/zootaxa.2372.1.17
DOI	https://doi.org/10.5281/zenodo.5312944
persistent identifier	https://treatment.plazi.org/id/C37F879E-8457-5676-FF64-FF6D566B9115
treatment provided by	Felipe
scientific name	Ancylomenes kuboi
status	sp. nov.

Treatment

Ancylomenes kuboi View in CoL sp. nov.

( Figs. 1–2 View FIGURE 1 View FIGURE 2 )

Material examined. (i) 1 holotype female, 1 male paratype, 1 sex unknown, CLs 3.0, 3.5 mm, FRV Soela, stn NWS–17, B4, Northwest Shelf , Western Australia, 19°05.3’S, 118°53.8’E, 80 m, beam trawl, 26 April 1983, NTM Cr015049; (ii) GoogleMaps 1 female paratype, CL 2.2 mm, FRV Soela, stn NWS–15, B4, Northwest Shelf , Western Australia, 19°05.4’S, 118°53.3’E, 80 m, epibenthic sledge, 27 April 1983, NTM Cr015054 GoogleMaps .

Additional, non-type material examined: (iii) 1 male, CL 2.2 mm; 1 female, CL 3.7 mm, FRV Soela , stn NWS-23, B4, Northwest Shelf, Western Australia, 19°03.5’S 119°03.1’E, 82 m, epibenthic sledge, 28 April 1983, NTM GoogleMaps Cr.015047; (iv) 1 ov. female, CL 2.8 mm, FRV Soela , stn BT–10, Northwest Shelf, Western Australia, 19°04.6’S, 118°57.9’E, 81 m, beam trawl, 30 June 1983, NTM GoogleMaps Cr 015052; (v) 3 males, 1 ov. female, CL 2.7, 2.4, 2.0; 3.3 mm, Nha Trang Bay, Vietnam, scuba, 9.2 m, 5 September 2008, leg. Z. Ď uriš & I. Horká, #122A, on Actinodendron sp. , QM W28917 .

Diagnosis. A species of Ancylomenes closely resemblin g A. tosaensis ( Kubo, 1951) . R, 1+6–8/1; third abdominal tergite posteriorly feebly produced, bluntly subcarinate; with small angular interocular process; second pereiopod with fingers completely edentate, without proximal diastema, sparsely setose, subequal to palm length, carpus longer than palm; ambulatory propodi with slender simple dactyli, about 0.3 of propodus length, 9.5 times longer than basal width, propodus with single short terminal distoventral spine about 0.05 of dactylus length.

Description. A typical member of the genus Ancylomenes Okuno & Bruce, 2009 .

Rostrum ( Figs. 1A–B View FIGURE 1 ) reaching to about distal margin of proximal segment of antennular peduncle, about 0.68 of CL, slightly arched, at about 8° to longitudinal carapace axis, dorsal carina well developed, convex, extending onto anterior carapace, with 7–9 small acute teeth, posterior tooth on carina, posterior to orbital margin, well separated from second tooth, more anterior teeth closer, ventral margin feebly concave, densely setose, with small acute preterminal tooth; inferior orbital angle acutely produced, with well developed ventral flange, antennal spine marginal, well below inferior orbital angle level, hepatic spine lower still, anterior to level of epigastric spine; third abdominal tergite posterodorsally produced, bluntly carinate, rounded or slightly angular in profile, second pereiopod ( Fig. 1C View FIGURE 1 ) exceeding antennular peduncle by carpus and chela, chela ( Fig. 1D View FIGURE 1 ) about 0.85 of CL, palm oval in section, about 3.2 times longer than depth, fingers ( Fig. 1E View FIGURE 1 ) subequal to palm length, dactylus slender, about 6.3 times longer than proximal depth, with strongly hooked tip, cutting edge laminar, without teeth, fixed finger similar, carpus about 1.5 times palm length, merus subequal to carpal length, ischium 1.25 times carpal length; third pereiopod with dactylus ( Fig. 1G View FIGURE 1 ) about 0.38 of propodus length, slender, 9.5 times longer than basal width, unguis about 0.3 of corpus length, corpus without distal accessory tooth, propodus ( Fig. 1F View FIGURE 1 ) about 0.75 of CL, feebly bowed, about 17.0 times longer than depth, sparsely setose, with single, very small, distoventral spine ( Fig. 1H View FIGURE 1 ) only, length about 0.5 of the distal propodus width.

Measurements (mm). Holotype female, postorbital carapace length, 3.6; carapace and rostrum, 6.0; total body length, (approx.) 21.0; second pereiopod chela, 3.0.

Systematic position. Most closely related to A. tosaensis ( Kubo, 1951) , and A. okunoi sp. nov., the only other Indo-West Pacific species of the genus Ancylomenes group known to have simple ambulatory dactyli. All other species of this group have biunguiculate dactyli, although in some species the accessory tooth may be relatively small. Ancylomenes kuboi sp. nov. is readily distinguished from both these species by the very short distoventral spines on the ambulatory propodi.

Host. The specimens from Vietnam were found in association with Actinodendron sp. [Actiniaria].

Colouration. The colouration of the Vietnamese specimens is illustrated in Fig. 2 View FIGURE 2 . Field notes for specimen (i) are: third abdominal segment with submedian red dorsal spots outlined in white on the anterior portion, posterior region with carina white with red apical spot; rostrum transparent; second pereiopods with palm with distal two thirds yellow, proximal third whitish, fingers deep purple, carpus with distal third whitish, proximal two thirds ventrolaterally purple.

Etymology. The specimen is named in honour of Prof. Itsuo Kubo (1909-1968), of the Tokyo University of Fisheries, Japan, in recognition of his studies on pontoniine shrimp, including the original description of Periclimenes tosaensis .

Remarks. A full illustrated description is not provided as this species conforms so closely to A. tosaensis and the other species of Ancylomenes . The salient features outlined above should enable it to be readily recognised.

The Northwest Shelf specimens are not in good condition. All specimens except one have intact rostra. The female holotype specimen (i) and the paratype (ii) each have a single second pereiopod. The third specimen lacks much of the abdomen. The holotype and (ii) also lack the posterior half of the telson. Only the female (iv), CL 2.8 mm, is ovigerous, with ova of normal length, about 0.5 mm. The Vietnamese specimens are in good condition with intact rostra, the female, CL 3.3, has a dentition of 1+7/1 and the males, CLs 2.7, 2.4 and 2.0, have 1 +6/1, the female and two males have both second pereiopods.