Minuca victoriana (von Hagen, 1987)

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

Minuca victoriana (von Hagen, 1987) Figure 5A-C

Recognition characters.

Carapace pentagonal moderately arched and provided with few tubercles on the surface of antero-lateral corners and on mesogastric area (Fig. 5A ). Dorso-lateral margins well marked and strongly convergent posteriorly; major and minor pairs of postero-lateral striae clearly visible (Fig. 5B ). 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 large making up ca. 22 % of front-orbital breath (Fig. 5A , seta). Male major claw with manus covered with tubercles and provided with strong groove on dorsal margin filled with pile; fingers thick and slightly flattened; dactyl ca. 1.8 times longer than manus; pollex and dactyl strongly curved forming a large gap; a short and straight depression filled with pile at the base of pollex (Fig. 5C , seta). Scant pile on dorsal surface of carpus and manus of the first three pair of ambulatory legs. Male abdomen somites not fused. Medium-sized species and one of the smallest in the genus; males’ carapace width (CW) up to 19.1 mm in a population from Vitória, Espírito Santo state, southeastern Brazil ( von Hagen 1987).

Biological notes.

Although with a wide geographical distribution, the species forms sparse populations constituted by small individuals in impacted mangroves of southeastern Brazil ( Bedê et al. 2008). In tropical mangroves, these crabs form relatively dense populations, reaching larger CW than in southern population and preferring muddy substrates. The recruitment of juveniles occurs continuously; however, the reproductive period of the species is still unknown ( Castiglioni et al. 2010).

Remarks.

The easiest way to recognize this species is to examine the presence of a short and straight depression filled with a pile at the pollex base in the male major claw (Fig. 5C , seta). This character is unique among Brazilian fiddler crabs. Otherwise, the general shape of carapace of M. victoriana is similar to M. rapax , M. burgersi and M. mordax .

Figures

Figure 5. Minuca victoriana. A carapace with moderately large front, frontal view B carapace with two pairs of postero-lateral striae, dorsal view C male major claw with a short depression at the base of pollex (seta), frontal view.