Amblycephalon Pillai, 1954

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 : 10

Genus Amblycephalon Pillai, 1954

Amblycephalon Pillai, 1954: 13 ; 1963: 66.— Bruce, 1987b: 361.

Type species. Amblycephalon indicus Pillai, 1954 by original designation ( Pillai 1954).

Diagnosis of female. Body generally similar that of Anilocra Leach, 1818 , peraeon relaxed, with the posterolateral corners of segments not produced; coxal plates except the last not reaching beyond the posterior border of the respective segments. Cephalon is highly flattened and considerably expanded, almost squarish, posterior margin trilobed as in Nerocila Leach, 1818 . Eye small, dorsal. Pleon narrower than peraeon, not immerse. Peduncle of the uropod is massive, produced internally; exopcd is long and uniformly broad throughout, apically rounded and curved slightly inwards, one and a half times as long as the endopod; endopod is broad, apically bifid.

Remarks. In the triloped anterior border of the first pereon segment and in the shape of the telson Amblycephalon resembles with Nerocila . The pereon segments and the coxal plates are like those of Anilocra . The highly expanded cephalon and the apically forked endopod of the uropod distinguish Amblycephalon from all the known genera. A remote resemblance to Olencira Leach, 1818 is evident but in Olencira the cephalon is broadest at the base and the pereopod 7 is abruptly longer than the pereopod 6. In Amblycephalon the cephalon is proximally narrower and the pereopod 7 is subequal the pereopod 6. The generic name refers to the highly flattened and expanded cephalon.

Nerocila schadleri Nierstrasz, 1915 agrees well with Pillai’s (1963) diagnosis and transferred to Amblycephalon by Bruce (1987b). Both A. indicus and A. schadleri are in need of redescription before their status can be ascertained.