Pilumnopeus africanus ( De Man, 1902 )

Fahimi, Neda & Naderloo, Reza, 2023, Pilumnidae Samouelle, 1819 (Crustacea: Decapoda: Brachyura: Pilumnidae) of the Persian Gulf and Gulf of Oman, with a note on their phylogeny, Zootaxa 5264 (2), pp. 256-274 : 264-268

Pilumnopeus africanus ( De Man, 1902)

( Fig. 3 )

Heteropanope africanus De Man, 1902: 255 , 256.

Heteropanope (Pilumnopeus) africanus .—Monod 1956: 270, figs. 319–325.

Pilumnopeus africanus .—Uschakov 1970: 455 (listed).—Manning & Holthuis 1981: 151.

Material examined. 1 male, CL 8.23 mm, CW 12. 21, 5 females, CL 11.23–16.13 mm, CW 14.13–18.17 ( ZUTC 5748 ), Ramchah , Qeshm I., Persian Gulf, 26°53′N, 56°09′E, cobble bed with scattered corals, coll. N. Fahimi, 11.02.2017 .

Diagnosis. Carapace broader than long, carapace oval, moderately convex ( Fig. 2A ); dorsal surface smooth, regions moderately defined; hepatic region more or less granulated; mesogastric region limited by shallow transverse portion of cervical groove; front bilobed with deep notch, each lobe more or less convex; frontal and epigastric regions with rows of setae; anterolateral margins with three stout triangular teeth, nearly in equal size, first anterolateral teeth absolutely separated from the exorbital angle ( Fig. 2A ); distinct lobe between frontal lobe and inner orbital angle, supraorbital region with two faint fissures, outer orbital angle without tooth ( Fig.2A ). Third maxillipeds completely covering buccal cavern when closed; ischium rectangular; merus quadrate, about 1.2 times as long as broad; merus and ischium with some small granules and setae ( Fig. 2E ); palp (carpus, propodus and dactylus) short, stout ( Fig. 2E ); exopod stout, inner margin moderately denticulate, with setae.

Adult male and female chelipeds unequal ( Fig. 2C, D ); ischium short, upper margin with some denticles, outer surface of right carpus with stout rounded teeth ( Fig. 2F ), upper and lower surfaces of right palms and dactylus smooth, without any setae or granules ( Fig. 2C ). Ambulatory legs with anterior margins sparsely lined with soft setae ( Fig. 2G ).

Remarks. De Man (1902) initially described Heteropanope africanus from the Ivory Coast. Further studies and comparisons between Heteropanope and Pilumnopeus showed that this species really belongs to the genus Pilumnopeus (Davie 1989) . Manning & Holthuis (1981) pointed out that Pilumnopeus africanus is restricted to West Africa ( Guinea to Cameroon), where it occupies estuaries and lagoons. This is the first record of Pilumnopeus africanus from the Persian Gulf, and the first record well outside of its normal distribution.

Distribution. Northwestern Indian Ocean: Persian Gulf, West Africa.

Figures

FIGURE 2. Glabropilumnus levimanus, male CL 4.30 mm, CW 7.23 mm (ZUTC 5769). (A) carapace; (B) abdomen; (C) palm of right cheliped (outer face); (D) palm of left cheliped (outer face); (E) merus of right cheliped (outer face); (F) Carpus of left cheliped (inner face); (G) fourth walking leg; (H) third maxillipeds

FIGURE 3. Pilumnopeus africanus, female CL 11.13 mm, CW 15. 41 (ZUTC 5748). (A) carapace; (B) third maxillipeds; (C) palm of right cheliped (outer face); (D) palm of left cheliped (outer face); (E) carpus of right cheliped (outer face); (F) fourth walking leg.