Microcheus, Souza-Filho, 2011

Souza-Filho, Jesser F., 2011, First record of the family Cheidae (Amphipoda, Gammaridea) from the Brazilian coast, with description of two new genera and new species, Journal of Natural History 45 (5 - 6), pp. 327-346 : 329

Microcheus gen. nov.

Etymology

Compound name, formed by Latin suffix micro plus the genus Cheus , in allusion to the relatively small body size of the species compared with others species within the family Cheidae . Gender masculine.

Type species

Microcheus nortoni sp. nov. (monotypic).

Diagnosis

Eyes poorly developed. Antenna 1 article 2 subequal to article 3. Antenna 2 article 1 with posterodistal corner rounded and produced (ensiform). Mandible molar non-triturative; left mandible with large lacinia mobilis, and strongly dentate; right mandible with lacinia mobilis reduced, undentate. Maxilla 1 inner plate with three distal setae; outer plate with seven robust setae; palp 2-articulate. Coxae 1–4 long. Uropod 2 biramous.

Generic remarks

Microcheus gen. nov. differs from both Cheus and Ruffosius gen. nov. by the following combination of characters: poorly developed eyes, antenna 2 article 1 with posterodistal corner rounded and produced (ensiform), 2-articulate palp of maxilla 1, presence of lacinia mobilis on right mandible, and uropod 2 biramous. Moreover, Microcheus gen. nov. shares with Cheus the biramous uropod 2, while in Ruffosius gen. nov. it is uniramous. Microcheus gen. nov. and Ruffosius gen. nov. bear a lacinia mobilis on right mandible whereas it is absent in Cheus .