Morphological description and molecular characterisation of a new species of Anilocra Leach, 1818 (Crustacea: Isopoda: Cymothoidae) from India

Abstract

A fish parasitic isopod recently reported from India as Anilocra leptosoma Bleeker, 1857, was re-examined and morphologically compared to five closely related species: A. capensis Leach, 1818, A. clupei Williams and Bunkley-Williams, 1986, A. leptosoma Bleeker, 1857, A. paulsikkeli Welicky and Smit, 2019 and A. pilchardi Bariche and Trilles, 2006. This species was sequenced and compared to other known Anilocra species based on mitochondrial cytochrome c oxidase subunit I (COI) gene fragments. Both morphological and molecular data corroborate that the Anilocra species parasitising the clupeid fish Tenualosa toli (Valenciennes, 1847) from India should be recognised as a new species, and we describe Anilocra grandmaae n. sp. based on the holotype and paratype females. The key characters of A. grandmaae n. sp. include the body being less than 4.0 times as long as wide; antennula article 3 anterodistal margin expanded, 1.2–1.4 times as wide as long; pleonite 1 concealed by pereonite 7 and lateral margin posteriorly produced; pereopods 1–4 with three nodules on dactylus; endopod of pleopods 3–5 with a proximomedial lobe and folding; and pleotelson ovate, with lateral margins converging smoothly to a caudomedial point.

Keywords

• Marine fish parasites
• Anilocra grandmaae
• Tenualosa toli
• Anilocra leptosoma
• Kerala