Alain Manning, 1998

Ahyong, Shane T. & Ng, Peter K. L., 2008, Alain raymondi, a new species of deepwater pinnotherid crab (Crustacea: Decapoda: Brachyura) from the Philippines, commensal with holothurians, Zootaxa 1919, pp. 61-68 : 62

Alain Manning, 1998

Alain Manning, 1998: 358 [type species: Alain crosnieri Manning, 1998 , by original designation].

Diagnosis. Carapace with long, sparsely distributed simple dorsal setae and short, plumose setae lining margins. Pereopods covered with plumose setae. Carapace firm, subglobular, dorsal outline subcircular, widest near midlength. Maxilliped 3 palp 3-segmented, dactylus inserting proximal to midlength of lower margin of propodus; ischium and merus fused; exopod 3-segmented. Walking legs symmetrical from left to right; dactyli simple. Dactyli of P2–3 shorter than dactyli of P4–5. Abdomen comprising 7 free somites (including telson) in both sexes. Male abdomen hourglass-shaped, widest at somite 5; telson broader than long.

Composition. A. crosnieri Manning, 1998 ; A. raymondi sp. nov.

Remarks. Although Manning (1998) characterized Alain crosnieri as having a 6-segmented abdomen, reexamination of the type material in the MNHN confirmed that males possess a 7- rather than 6-segmented abdomen as originally diagnosed. Two factors probably contributed to the confusion over the male abdominal segmentation. First, abdominal somite 1 is usually partially concealed by the posterior margin of the carapace, and was probably overlooked as a result of the setose integument. Second, the bases of the gonopod of somite 2 (G2) and vestigial pleopods of somite 3 are more or less appressed owing to the arching of the abdomen. The G2 and pleopod 3 thus have the appearance of a common source, as would be expected if somites were fused. With corrected interpretation of male abdominal segmentation in Alain , Manning’s (1998) major distinguishing generic character is invalidated. Alain is in fact most similar to Nepinnotheres Manning, 1993 b, and Viridotheres Manning, 1996 , sharing a third maxilliped dactylus that is inserted at or slightly proximal to the propodal midlength, and walking legs that are left right symmetrical. Unfortunately, no single character or combination of characters will collectively distinguish both sexes of Alain from Nepinnotheres and Viridotheres . Males of Alain differ from male Nepinnotheres and Viridotheres by the hourglass-shaped abdomen, which is widest at somite 5, rather than triangular or linguiform with the widest point at somite 3. The P4–5 dactyli in female Alain are distinctly longer than those of P 2–3 in contrast to Nepinnotheres and Viridotheres in which the P2–3 dactyli are subequal to or longer than those of P4–5.