Redescription of the freshwater shrimp Macrobrachium jelskii (Miers, 1877) (Caridea, Palaemonidae) Author Vera, Ana Luiza Author Carvalho, Fabrício Lopes Author Mantelatto, Fernando Luis text Zootaxa 2017 4269 1 journal volume 33013 10.11646/zootaxa.4269.1.2 59664c93-3249-42ea-a642-923c44a238b3 1175-5326 581285 7774D8D9-800E-4B81-AFB9-81F8B63623CE Key to differentiate Macrobrachium jelskii , M. amazonicum and M. acanthurus 1 Distal enlargement of the carpus of the second pereiopod gradual ( Figure 6 a); rostrum distinctly surpasses the scaphocerite; rostrum has an evident portion without teeth ( Figure 7 a); internal pair of posterior spine of the telson at most 2 times longer than the median apex in small individuals; internal pair of posterior spine of the telson does not reach the median apex in adults ( Figure 8 a).............................................................................. M. amazonicum - Rostrum reach or slightly overreach end of the scaphocerite; rostrum does not have an evident portion without teeth ( Figures 7 b and 7c); internal pair of posterior spine of the telson surpasses the median apex and is more than 2 times longer ( Figures 8 b and 8c)............................................................................................. 2 2 Carpus of the second pereiopod similar to the chela length, chela longer than half of the carapace length, distal enlargement of the carpus gradual ( Figure 6 b)............................................................... M. acanthurus - Carpus of the second pereiopod noticeably longer than the chela, distal enlargement of the carpus abrupt ( Figure 6 c)..................................................................................................... M. jelskii