Redescription of Nerocila exocoeti Pillai, 1954 (Crustacea: Isopoda: Cymothoidae) parasitic on beloniform (Exocoetidae and Hemiramphidae) hosts with Nerocila madrasensis Ramakrishna Ramaniah, 1978 placed into synonymy.

Nerocila exocoeti Pillai, 1954 is re-described based on the neotype and additional material from exocoetid hosts. Nerocila madrasensis Ramakrishna Ramaniah, 1978 (from Madras) is placed into synonymy with N. exocoeti. Nerocila exocoeti is characterized by the presence of short coxae, postero-lateral angles of the first five pereonites not backwardly produced, pereonites 6-7 are reduced, cephalon sub-quadrate with anterior border straight; first antenna composed of eight articles and endopod of uropod half the size of exopod. Nerocila exocoeti is only known from beloniform hosts; Parexocoetus brachypterus and Exocoetus volitans (Exocoetidae); Hemiramphus sp. and Rhynchorhamphus malabaricus (Hemiramphidae) are the identified hosts for the species.