The Hindu: New species of fishes found in Indian waters
The presence of a shark species new to science and 84 other deep-sea dwellers new to the Indian waters have been brought out by a stock assessment of deep sea fishes of the Indian Exclusive Economic Zone and the central Indian Ocean, according to researchers.
Mustelus manglorensis, a new gummy shark species, was discovered from a depth of 500 metres off the Mangalore coast. According to researchers, this is the second gummy shark that has been reported from the Indian Ocean against the 19 known worldwide.
Of the 84 species of fishes found in the Indian waters, 15 were shark varieties, including Baloon, Cat, Lantern and Gulpers. Researchers have also confirmed the presence of 10 species of eels belonging to Conger, Cusk and Snipe families from the study region. Most of the species were found inhabiting the sea at a depth beyond 500 metres, researchers said.
The assessment was carried out by a research team led by B. Madhusoodana Kurup, Director, School of Industrial Fisheries of the Cochin University of Science and Technology. The team included researchers M. Harikrishnan, S. Venu, Sharin Sonia, A.V. Deepu, Ginsen Joseph and Diana. The study was supported by the Centre for Marine Living Resources and Ecology of the Ministry of Earth Sciences.
The assessment also revealed that the Indian waters supported rich and diverse deep sea angler fish, which uses the fleshy lobe on its head to catch its prey. The presence of six new species coming under ‘smooth,' ‘double,' ‘dicerateid' and ‘blackmouth' angler fish categories was also recorded. Most of them were found occupying the ocean space between a depth of 500 and 800 metres.
The samples were collected from the exploratory deep sea fishery cruises on board the ocean research vessel Sagar Sampada. Fishing was carried out in depths between 200 and 1100 metres from the Wadge bank in the south and Ratnagiri in the north along the south west coast during the last 10 years. Fishing operations were carried out in 220 stations with high speed demersal fish and shrimp trawls, researchers said.
The analysis has revealed that the Kozhikode-Mangalore region was rich in deep sea fish biodiversity as 121 species were collected from there. This was followed by the Kochi-Kozhikode belt with the presence of 95 species. In the Kozhikode- Mangalore belt, the richest fish biodiversity was found at depths ranging between 500 and 800 metres, they said.
The morphological features of some of the species identified included transparent or black body, poorly developed muscles, absence of gas bladder and greatly reduced eyes. Some of the species possessed expandable stomachs. In some other fishes, jaws were either absent or present with huge hinged jaws with long and inward pointing teeth, they said.
The origin of many species could be tracked to the tropical regions of the Pacific and the Atlantic, especially to South African coast, Madagascar Bridge, Mozambique, Gulf of Aden, Canary Islands and the Mediterranean Sea. Many species were found sharing similar habitats with their counterparts in other oceans, they said.