Latopilumnus malardi ( De Man, 1914 ) Ng & Clark, 2008

Ng, Peter K. L. & Clark, Paul F., 2008, A revision of Latopilumnus Türkay & Schuhmacher, 1985, and Aniptumnus Ng, 2002 (Crustacea: Decapoda: Brachyura: Pilumnidae) with larval comparisons, Journal of Natural History 42 (9 - 12), pp. 885-912 : 887-893

publication ID	https://doi.org/ 10.1080/00222930701869422
persistent identifier	https://treatment.plazi.org/id/7B088796-FFD2-FFED-FED6-DE82FCFBA090
treatment provided by	Felipe
scientific name	Latopilumnus malardi ( De Man, 1914 )
status	comb. nov.

Treatment

Latopilumnus malardi ( De Man, 1914) View in CoL new combination

( Figures 2–5 View Figure 2 View Figure 3 View Figure 4 View Figure 5 )

Pilumnus malardi De Man, 1914: 330-343 View in CoL , Figs 1a–f View Figure 1 .

Material examined

Madagascar, in Balanus barnacle clumps, coll. L. M. Malard. Lectotype, „ (7.8× 5.8 mm), ZMA De 102.879a. Paralectotypes 1 „ (6.9× 4.7 mm), 4 ♀♀ (10.1× 6.2 mm, 8.9× 6.3 mm, 7.0× 4.8 mm, 6.7× 4.4 mm), ZMA De 102.879b; 1 ♀ (7.2× 5.2 mm), RMNH 2187 View Materials .

Description of male lectotype

Carapace transversely hexagonal, broader than long, regions not distinct, defined by shallow grooves, surface with relatively dense patches of small rounded granules on frontal, gastric and branchial regions, most of surface visible, not covered by setae; anterior half of carapace, especially along margins, covered with scattered plumose setae of varying lengths, never completely obscuring surface, mostly aggregated around granules. Frontal margin distinctly bilobed, separated by U-shaped notch medially, margin gently convex, lined with numerous small granules; lateral frontal lobe low but discernible, separated from median frontal lobe shallow concavity or notch, separated from supraorbital margin by very shallow notch. Supraorbital margin granulated, entire. Anterolateral margin granulated, external orbital angle low, hardly separated from low first anterolateral tooth; second anterolateral tooth distinct, anterior margin slightly shorter than posterior margin or subequal in length; third anterolateral tooth smaller than second tooth, triangular. Posterolateral margin slightly convex, converging towards weakly convex posterior carapace margin. Basal antennal segment subrectangular, filling orbital hiatus. Orbits transverse; eyes filling orbital space; distal part of ocular peduncle covered with small granules. Infraorbital margin distinctly granulated, submedian part projecting anteriorly as low triangular tooth, visible from dorsal view. Suborbital, sub-branchial and pterygostomial regions granular. Merus of third maxilliped squarish, anterolateral angle not prominently produced, surface granular, especially marginally, inner margin granular; ischium subrectangular, with shallow submedian sulcus; exopod stout, distal edge almost reaching anterior edge of merus, inner subdistal tooth low, with long flagellum.

Chelipeds subequal, right larger. Inner margin of fused basis-ichium granular. Inner margin of merus with numerous small granules. Outer surface of carpus with numerous rounded granules, with scattered setae, inner distal angle produced as distinct tooth, lined with small granules. Outer surface of larger palm evenly covered with small rounded granules, covered with scattered longer and numerous short setae, obscuring most of surface; fingers distinctly shorter than palm; outer surface of pollex with distinct longitudinal groove on subventral surface, lined with distinct longitudinal row of granules; cutting edges with basal teeth proportionately larger but not molariform. Outer surface of smaller chela covered with small rounded granules, dense short setae obscuring most of surface; fingers shorter than palm; outer surface of pollex with deep submedian longitudinal groove lined with distinct longitudinal row of granules; cutting edges with several distinct teeth.

Ambulatory legs covered with scattered setae, especially on carpus and propodus, never obscuring surface or margin; second leg longest. Distal margin of basis-ischium of all legs almost smooth or with scattered small rounded granules, not comb-like. Dorsal margin of first to third meri weakly serrated, that of fourth merus uneven or weakly serrated; proximal part of ventral margins with scattered small rounded granules. Carpus with low submarginal ridge, outer margin covered with scattered small granules, otherwise unarmed. Dactylus gently curved with tapering tip.

Surfaces of anterior thoracic sternites relatively smooth, covered with short pubescence. Sternites 2 and 3 separated by almost straight groove; sternites 3 and 4 fused, demarcated only by lateral grooves, medially completely fused. Male abdomen with all segments freely articulating, surfaces almost smooth. Telson triangular with tip rounded. G1 sinuous, median part almost straight, distal part distinctly recurved from ventral view, appearing hooked. G2 very short, sigmoid. Remarks

In its external morphology, L. malardi , new combination, is close to the new Latopilumnus species from Hong Kong, but can be distinguished by its larger size and differently shaped G1 (see latter species for discussion).

Latopilumnus malardi , new combination, also superficially resembles Aniptumnus nefissurus in the general carapace form but the frontal margin of the latter species has no trace of a lateral lobule, which is small but still discernible in L. malardi , new combination. More significantly, the structures of the ambulatory merus and G1 (see earlier) are different. In addition, the pollex of the chela of A. nefissurus does not have the strong longitudinal row of granules adjacent to the cutting edge distinct in L. malardi ; and the outer surfaces of the ambulatory carpus and propodus of L. malardi are not prominently granulated like in A. nefissurus .

The largest male in the type series, 7.8× 5.8 mm ( ZMA De 102.879a) is here designated as the lectotype of the species ( Figures 2–4 View Figure 2 View Figure 3 View Figure 4 ) .