ZSI researchers identify new species of parasitic isopod in Bay of Bengal

Kolkata: A novel species of parasitic isopod, designated ‘Lobothorax bharat’ (L.bharat) has been identified in the Bay of Bengal by researchers from the Zoological Survey of India (ZSI).

The discovery — a result of collaborative research between the Estuarine Biology Regional Centre, ZSI, Gopalpur-on-Sea and Berhampur University — contributes to the existing knowledge of marine biodiversity and fish parasitology.

The newly-identified species belongs to the genus Lobothorax, a group of isopods known to parasitise the buccal cavity of marine fish. These parasites survive by feeding on the blood and mucus of their hosts, often leading to anaemia in affected fish populations. Six specimens of L. bharat were collected from the mouths of the ribbonfish, Trichiurus lepturus Linnaeus 1758, at the Bahabalpur fish landing centre in Balasore district and the Gopalpur fish landing centre in Ganjam district, Odisha. The isopod, approximately 3 cm in length and creamy white in colour, is characterised by seven pereonites and five pleonites. It employs seven pairs of legs, each equipped with hook-shaped dactyli, to firmly attach itself to the fish’s oral cavity.

“This discovery is significant because it not only adds to the known diversity of Lobothorax isopods but also highlights the complex ecological relationships within the Bay of Bengal,” said Dhriti Banerjee, director, ZSI. The research team from ZSI was led by Jaya Kishore Seth, Anil Mohapatra and Basudev Tripathy and comprised Sandeep Kumar Mohapatra, Sanmitra Roy. Prior to this discovery, the genus Lobothorax comprised only three known species. The addition brings the total number to four.

The research, which began in 2023, emphasises the importance of continued exploration and study of marine ecosystems to uncover and understand the intricate lives of marine organisms.