Macrobrachium ferreirai Kensley & Walker, 1982

Santos, Maria Aparecida Laurindo dos, Castro, Patrícia Madedo de & Magalhães, Célio, 2018, Freshwater shrimps (Crustacea, Decapoda, Caridea, Dendrobranchiata) from Roraima, Brazil: species composition, distribution, and new records, Check List (Washington, D. C.: 1974) 14 (1), pp. 21-35 : 27

Macrobrachium ferreirai Kensley & Walker, 1982 ( Figs 3H–K, 8)

Previous records. Melo (2003, in list and map).

Identification characters ( Fig. 3H–K). Rostrum straight, short, slightly directed downwards, reaching (or failing short of reaching) distal margin of scaphocerite; rostral formula: 9–10(2–3 post-orbital teeth)/1–2. Carapace with antennal and hepatic teeth present, anterolateral portion smooth; abdomen smooth, pleura of second somite enlarged and overlapping pleuron of first and third somites. Telson with posterior margin distinct, ending in a small acute point, usually overreached by inner pair of posterolateral spines. P2 (larger cheliped) similar in shape, slightly unequal in size, larger than entire body in full grown adults; palm subcylindrical in cross-section, fingers a little less than half the length of palm, cutting edges without tubercles.

Material examined. 3 spec. ( INPA 2332), Caracaraí, igarapé Corredeira, tributary of igarapé Leite, tributary of lago Aliança, lower rio Branco basin, 01°28ʹ55ʺ N, 061°14ʹ12ʺ W, 29-IX-2006, coll. L.H. Rapp Py-Daniel.

Distribution. Colombia, Brazil (Amazonas, Mato Grosso, Rondônia, Roraima) (see Pileggi et al. 2013 for references; present study). The distribution in Roraima is depicted in Figure 8.

Remarks. The morphology of our few specimens agrees very well with the description provided by Kensley and Walker (1992). Macrobrachium ferreirai closely resembles M. brasiliense and their juveniles and subadult specimens are almost impossible to distinguish. Adult specimens can be identified by the morphology of the second pair of chelipeds, especially the spinulation (fewer and longer spinules in M. brasiliense ; denser and smaller in M. ferreirai ) and the presence (in M. brasiliense ) or absence (in M. ferreirai ) of tubercles in the cutting edges of the fingers.

Ramos-Porto and Coelho (1998) and Melo (2003) listed M. ferreirai as occurring in the state of Roraima, but did not specify the localities or document the record with voucher specimens. Pileggi et al. (2013) discussed that the occurrence of the species in the state was probable since M. ferreirai is present in the Negro River basin and the Branco River is its main tributary. The records presented here confirm its occurrence in Roraima ( Fig. 8).