Leptuca cumulanta (Crane, 1943)

Masunari, Setuko, Martins, Salise Brandt & Anacleto, Andre Fernando Miyadi, 2020, An illustrated key to the fiddler crabs (Crustacea, Decapoda, Ocypodidae) from the Atlantic coast of Brazil, ZooKeys 943, pp. 1-20 : 1

Leptuca cumulanta (Crane, 1943) Figures 9B , 10A, B

Recognition characters.

Carapace semi-cylindrical, width ca. 1.6 times the length; strongly arched and dorsal surface without pile; lateral margins almost parallel (Fig. 10A ). Dorso-lateral margins well marked and strongly converging posteriorly; single pair of postero-lateral striae clearly visible (Fig. 10A , seta). The discrete pile on the carapace described by von Hagen (1987) was not observed in the specimens examined in the present study. Front triangular and moderately wide measuring from 25% to 29% of the front-orbital breadth. Manus of male major claw with dorso-lateral surface covered by tubercles except along the strong dorsal groove (mostly filled with dirt); smooth surface in the submarginal longitudinal area; dorsal surface with sparse tubercles while dorso-lateral one with small and dense tubercles; fingers ca. 1.7 times the manus length; pollex almost straight but dactyl strongly arched ending in a curved downward tip, forming a very wide gap (Fig. 10B ). Ambulatory legs without pile. Male abdomen somites distinct (Fig. 9B ). Small crabs, males’ CW up to 12.5 mm in a population from Caeté mangrove, Pará state, northern Brazil ( Koch et al. 2005).

Biological notes.

The species reproduces year-round in populations of northern Brazil and the crabs reach the largest CW among all other populations ( Koch et al. 2005). In the impacted mangroves, L. cumulanta is the fourth most abundant fiddler crab species, but crabs’ CW is the smallest among these populations ( Bedê et al. 2008). The species prefers muddy substrates ( Thurman et al. 2013). Hoods at the entrance of male burrows were observed in some populations in Venezuela and Curaçao, but there is no such record from populations of the Brazilian coast ( Crane 1975).

Remarks.

In sympatric area of Brazilian coast L. cumulanta can be confused with L. leptodactyla (from Pará to Rio de Janeiro) and L. uruguayensis (Rio de Janeiro state): they are similar in size and the major male claw is provided with a very curved dactyl forming a wide gap with the pollex. The best ways to distinguish these three species is described when referring to L. leptodactyla and L. uruguayensis (see below).

Figures

Figure 9. Abdomen of male, ventral view. A Leptuca leptodactyla, middle somites fused B Leptuca cumulanta, all somites distinct.

Figure 10. Leptuca cumulanta. A carapace with a pair of postero-lateral striae (seta), dorsal view B male major claw, frontal view.