Length at maturity and relationship between weight and total length of five deep-sea fishes from the, Andaman and Nicobar Islands of India, North-eastern Indian Ocean

Abstract

AbstractWe have estimated the length at maturity and length-weight relationships for five fish species inhabiting the deep-sea from the Andaman and Nicobar Islands off the Indian coast between 295–650 m deep in a trawl survey carried out in March–April 2017. Hauls were carried out by a high-speed Demersal Trawl Crustacean Version trawl net and analysis was performed for a total of 832 specimens. Length at first maturity of the five deep-sea fish species ranged from 14.28–105.73 cm while length at 90% maturity was in the range 17.87–159.83 cm. The length at maturity of the fish are Alepocephalus bicolor (male = 66.09, female = 105.73), Bathyclupea hoskynii (m = 15.14, f = 14.15), Chlorophthalmus corniger (m = 17.54, f = 15.31), Neoepinnula orientalis (m = 20.76, f = 16.76), and Neoscopelus microchir (m = 14.28, f = 15.40). The b value in the length-weight relationship ranged from 0.69–2.60, i.e. Alepocephalus bicolor (m = 1.93, f = 1.62), Bathyclupea hoskynii (m = 3.5, f = 1.66), Chlorophthalmus corniger (m = 2.07, f = 1.56), Neoepinnula orientalis (m = 2.86, f = 2.46) and Neoscopelus microchir (m = 0.89, f = 0.49). Based on these results, the b value showed an allometric relationship with length for all species studied, because these species have a similar morphometry, i.e. a flattened back. Since they are primary or secondary consumers at the bottom of consumer food webs, their roles are as predators of small–medium prey and as prey of top predators of food web chains.