ICAR-Central Inland Fisheries Research Institute reported the availability of Octopus in Narmada estuary for the first time in Bag Net catch during the routine survey (3-5 December 2018) by the research team from ICAR-CIFRI, Vadodara. Cistopus indicus (Rapp, 1835), commonly known as old woman octopus, has been observed for the first time from the estuarine zone of Narmada river at Bhadbhut region (21°40’52”N, 72°50’42”E), which is about 35 km away from the sea.
Cistopus indicus caught from Narmada estuary through bag net
C. indicus comes under the Class Cephalopoda of Order Octopoda in the family Octopodidae. In an around 200 species of Octopidae are reported from world Oceans and 38 commercially important species reported from Indian seas. In India, octopuses are caught mainly as by-catch in trawl nets used for shrimp trawling, shore seines, boat seines, hooks and line and stake nets. Octopus contributed merely 0.72% of the total molluscan resource (61688 t) landed in Gujarat during 2017. The species is mostly distributed in the Indo-Pacific region mainly Philippines, China, Bangladesh, India and Pakistan. Other important species of Octopus occur in the West coast of India are Octopus dollfusi, Octopus membranaceus, Octopus lobensis and Octopus vulgaris.Octopus is a marine benthic species occurring up to the depth of 50 m, which used to inhabit the coastal sea waters, but rarely observed in the estuarine waters.
A total of 17 specimens with the total length ranging from 190-320 mm have been recorded from the catches. The maximum total length of the species was recorded as 325 mm with a weight of 56.2 gram.The maximum length of this species was reported as 600 mm from the Bay of Bengal. The presence of Octopus species has been monitored in the bag net (10 mm cod end mesh size) fish catch at Bhadbhut village in the month of December 2018.
The bag net is locally known as ‘Golava’ fishery usually commenced at the winter season (October to March) composed mainly with the marine fish species including juveniles of Hilsa, while the occurrence of Octopus in the catches is reported for the first time from this water.
The salinity of the Bhadbhut (21°40’52”N, 72°50’42”E) and the adjacent Mahegam region (21°40’26”N, 72°45’23”E) was in the range of 18-20 ppt during the month of December 2018 and the high salinity along with the flow of flood tide may be the reason for the ingress of true marine species like octopus into the estuary.
(Source: ICAR-Central Inland Fisheries Research Institute, Barrackpore)