Macrobrachium olfersii (Wiegmann, 1836)

Macrobrachium olfersii (Wiegmann, 1836) View in CoL

( Fig. 6A–D View Figure 6 )

Material examined. Brazil, Piauí: Portinho Lagoon , 25.iv.2013, 46 specimens [ CZDP ( F2 ) 0050]. Idem, 19.vii.2013, 38 specimens [ CZDP ( F2 ) 0051]. Idem, 20.ii.2014, 10 specimens [ CZDP ( F2 ) 0052]. Idem, 04.viii.2013, 46 specimens [ CZDP ( F2 ) 0053]. Idem, 19.vii.2013, 2 females ( LSZ 075 ) .

Distribution. In Brazil, this species has been recorded in the states of Amapá, Piauí, Ceará, Rio Grande do Norte, Alagoas, Sergipe, Bahia, Minas Gerais, Espírito Santo, São Paulo and Santa Catarina ( Barros and Braun, 1997; Müller et al., 1999; Melo, 2003; Pimentel and Magalhães, 2014; present work).

Remarks. This is the first record of M. olfersii in the lower Parnaíba River basin, although Ferreira et al. (2010) mentioned the occurrence of this species in Piauí when discussing an indeterminate specimen from the Piauí River without a precise locality [material deposited at the Museu Nacional (MNRJ 2574)]. Macrobrachium olfersii can be easily differentiated through its almost straight and relatively short rostrum, and the strong second pair of pereopods with chelae of unequal sizes and gaping fingers and a dense pubescence on the palm and cutting edges.