Aniptumnus Ng, 2002

Hari, P. Praved, Hershey, N. Regina & Mendoza, Jose Christopher E., 2022, On two species of Aniptumnus Ng, 2002 (Crustacea: Brachyura: Pilumnidae) from India, with a description of a new species from the coast of Kerala, Zootaxa 5214 (2), pp. 261-272 : 270-271

Key to the species of Aniptumnus Ng, 2002

1. External surface of major chela generally smooth or finely granular with few large round granules; fourth ambulatory leg (P5) with postero-distal margin of basis-ischium armed with spines or large conical tubercles; distal tip of G1 blunt, sometimes with distinct, scoop-shaped apical lobe........................................................................ 2

- External surface of major chela profusely covered with large, round granules; fourth ambulatory leg (P5) with postero-distal margin of basis-ischium unarmed, or if armed, only with relatively small conical tubercles; distal tip of G1 tapering to a slender tip................................................................................................. 4

2. Male thoracic sternite 8 completely or almost completely covered by wide (width-to-length ratio>4) pleonal somite 2; G1 with well defined, scoop-shaped apical lobe.................................................................... 3

- Male thoracic sternite 8 readily visible externally, pleonal somite 2 relatively narrower (width-to-length ratio <4); G1 distal tip bluntly round, without distinct, scoop-shaped apical lobe................................... A. neolaevis comb. nov.

3. Carapace anterolateral and posterolateral margins subequal in length; junction between supra- and infraorbital margins uninterrupted; male sternite 8 never visible externally; apical lobe of G1 narrow...................... A. bijoyi sp. nov.

– Carapace posterolateral margin distinctly longer than anterolateral margin; junction between supra- and infraorbital margins interrupted by a distinct notch; male sternite 8 sometimes visible externally; apical lobe of G1 broad..... A. quadridentatus

4. Anterior margin of merus of fourth ambulatory leg (P5) unarmed, posterior margin armed with conical tubercles and sharp granules until proximal half only; distal tip of G1 tightly recurved................................... A. vietnamicus

– Anterior and posterior margins of merus of fourth ambulatory leg (P5) armed with conical tubercles and sharp granules until nearly the distal end; distal tip of G1 slightly curved only............................................ A. nefissurus