Marine survey documents rare sea slugs off Vizhinjam

The findings were confirmed at the recently concluded World Congress of Malacology- 2016 held at Penang, Malaysia.

A marine biodiversity survey conducted by an independent group off the coast of Vizhinjam here has reported the presence of four species of sea slugs never before sighted in India.

The participatory survey carried out by the Thiruvananthapuram-based Friends of Marine Life, with the help of local traditional fishers in 2015, documented more than 100 species of marine molluscs along the rocky reefs of southern Kerala. The four new species of sea slugs, including Glossodoris rufomaculatus , Goniobranchus annulatus, Hypselodoris nigrostriata , and Hoplodoris flammea, were reported from the near-shore rocky reef areas between Kovalam and Mulloor in the Vizhinjam bay.

The findings were confirmed at the recently concluded World Congress of Malacology- 2016 held at Penang, Malaysia. A. Biju Kumar, Head, Department of Aquatic Biology and Fisheries, University of Kerala, who identified the specimens and presented the findings at the conference said: “The spotting of these rare sea creatures in the Vizhinjam area demands further studies and thorough documentation of the biodiversity of this region.”

Colourful marine animals

Known scientifically as opisthobranchs, sea slugs are the most colourful marine animals mostly found in reef-associated areas.

Unlike other organisms of their phylum Mollusca which possess a hard external skeleton, sea slugs have a rudimentary shell inside or none at all. Several novel medicines, including anticancer drugs have been developed from sea slugs.

Glossodoris rufomaculatus and Goniobranchus leopardus are sea slugs of the family Chromodorididae, earlier recorded only from Australia and the Philippines.

Another member of this family, Goniobranchus annulatus, earlier described from Zanzibar, is also a new addition to the Indian marine biodiversity database. Hoplodoris flammea of the family Discodorididae was recorded earlier from Bali, Indonesia.

The underwater survey documented around 300 marine species primarily from the rocky reef along the Thiruvananthapuram coast. FML chief coordinator Robert Panipilla fears that the unique ecosystem would be lost due to the reclamation of the seabed for the Vizhinjam seaport. He highlights the need to harness the traditional knowledge of fisherfolk for a major conservation programme.