A new species of Prionodiaptomus (Copepoda: Diatomidae) from the Manu River, Peru

A new species which is proposed for inclusion in the monotypic genus Prionodiaptomus Light, 1939, from the Manu River, Peru, is described and illustrated in detail. The new species, Prionodiaptomus incarum, is defined by the structure of left leg 5 of the male, mainly in the pear-shaped basipodite with a prominent projection of the posterior inner corner and the 2nd exopod segment with a distal process, which is rounded but not digitiform. The spinulose seta of other Neotropical species is represented by a subapical triangular projection with a toothed inner margin. Prionodiaptomus incarum sp. nov. shares certain characters with the type species, P. colombiensis (Thiébaud, 1912), in particular, right leg 5 of the male, which has a narrow and evenly curved claw, and a lateral spine which is denticulate and inserted in the middle of the segment. Females of both species have a narrow and elongate leg 5 and a semicircular fold on the ventroposterior region of the genital double-somite. http://www.sinica.eud.tw/zool/zoolstud/43.2/425.pdf