Ceratothoa trigonocephala ( Leach, 1818 )

Ravichandran, S., Vigneshwaran, P. & Rameshkumar, G., 2019, A taxonomic review of the fish parasitic isopod family Cymothoidae Leach, 1818 (Crustacea: Isopoda: Cymothooidea) of India, Zootaxa 4622 (1), pp. 1-99 : 78

Ceratothoa trigonocephala ( Leach, 1818)

Restricted synonymy:

Ceratothoa trigonocephala .— Martin, Bruce & Nowak, 2015a: 283–284.

Type and type locality. The lectotype (female specimen; NHMUK 2013.1013) and paralectotype (female specimens; BMNH 1979.404.2) were designated by Hadfield et al. (2014a) and are held at the Natural History Museum, London, both specimens collected by W. E. Leach (White’s MS Cat no. 404 a, b) from an unknown host and locality.

Remarks. Hadfield et al. (2014a) provided a detailed diagnosis and description of the type material. Ceratothoa trigonocephala has a triangular cephalon, for which it is named, and arched carinae on the last pair of pereopods. It is identified by the subequal pereonites 1–4; mid-dorsal protrusion on pereonite 1; short and bluntly rounded anterolateral margins of pereonite 1; and uropods which do not extend past the pleotelson posterior margin.

Pillai (1954) recorded the Codonophilus imbricatus from Parexocoetus brachypterus (Richardson, 1846) , India. Recently, Codonophilus imbricatus was synonymized with C. trigonocephala by Martin et al. (2015a). No Indian specimens were found, fresh or from museum collections, that could be identified as C. trigonocephala , and the species is here excluded from the Indian fauna.

Distribution. Most records of C. trigonocephala are now regarded as uncertain ( Hadfield et al. 2014a; Martin et al. 2015a) and the distribution of this species remains unknown.

Hosts. There are currently no confirmed hosts for this species ( Hadfield et al. 2014a; Martin et al. 2015a).