Fishery of sciaenids off Veraval with special reference to growth, mortality and stock assessment of Otolithes cuvieri (Trewavas, 1974)

Sciaenids form an important demersal finfish resource off Veraval and contribute about 12 % to the total marine landings. They are exploited mainly by trawls and gillnets with an annual average landing of 9086 t and 323 t respectively during 1986-95. Nearly 16 species contribute to the sciaenid fishery of which, Otolithes cuvieri and Johnius glaucus contributed 52.6% and 13.8 % respectively. In gill net seven species contribute to the landings, dominated by Otolithes cuvieri and Protonibea diacanthus. The peak landing of sciaenids was noticed in September and January. Studies on O. cuvieri revealed that there was no significant difference in the length weight relationship between the sexes, and hence a common regression was fitted as Log W = -4.4632 + 2.9701 Log L (r=0.9036). The asymptotic length (L ) and growth coefficient (K) were estimated as 382 mm and 0.89 y-1 respectively. O. cuvieri grows to 225, 317, 354, 371 and 382 mm at the end of 1st, 2nd, 3 rd, 4th and 5th years. The fishery mainly consisted of 0 and 1 year classes. The average instantaneous rates of total, natural and fishing mortalities were 2.86 y-1, 0.81 y-1 and 2.05 y-1 respectively. The length at first capture was 148 mm at which the age works out to be 0.5 year. The exploitation ratio is higher than the Emax estimated indicating that the resource is overexploited. In view of the heavy fishing pressure, there is a need for reducing the fishing effort to sustain the fishery

Sighting of a rare whale

Indopacetus pacificus (Longman, 1926), Longman’s beaked whale (also known as Indo-pacific beaked whale or tropical bottlenose whale) is a rare ziphid restricted to tropical waters of Indian and Pacific Ocean

Fishery, biology and stock assessment of Cynoglossus macrostomus (Norman) off Malabar coast

Cynoglossus macrostomus formed 93 % of the annual average landings of flatfishes (3951 t) during 1993-2004 at Calicut. The fishery showed annual fluctuations. Peak landings were recorded during December-April. Growth parameters of this species were L! = 164.5 mm y-1 and K = 0.70y-1. The fish grows to 83, 124 and 146 mm at the end of 1-3 years. The total and natural mortality were 3.01 y-1 and 0.91 y-1 respectively. The length-weight relationship shows that the growth is isometric and there is no significant variation between sexes. The spawning is prolonged with two peaks. The length at first maturity is 102 mm. Females dominated the fishery. The stock is exploited marginally below the optimum level at present. The total and standing stock of this species along the Calicut coast is estimated as 5430 t and 1720 t respectively

Rare landing of devil ray, Manta birostris, at Calicut

A female devil ray, Manta birostris, measuring 342 cm length and 594 cm breadth, weighing approximately 1400 kg, was caught by a trawler at Beypor

An account on the smallest whale shark, Rhincodon typus (Smith 1828) landed at Calicut

Whale shark landings in India are mainly due to incidental catches and mostly discarded. This report gives details on the smallest whale shark, that landed at Calicut

Fishery of threadfin breams with some aspects on the biology and stock assessment of Nemipterus mesoprion (Bleeker, 1853) off Malabar coast

The average annual catch of threadfin breams along the Malabar coast was 16,754 t during 1998-2005. The fishery was constituted by Nemipterus japonicus (46.8 %) and N. mesoprion (53.2 %). Peak landings were noticed during August- September. Studies on N. mesoprion revealed that there is no significant difference in the length weight relationship between sexes, and hence a common equation was fitted as Log W = -3.9620+2.8298 Log L. The asymptotic length (L ) and growth coefficient (K) were estimated as 299 mm and 0.79 y-1 respectively. N. mesoprion grows to 164, 238, 271 and 287 mm at the end of first, second, third and fourth years. The total mortality, fishing mortality and natural mortality were 4.93 y-1, 3.41 y-1 and 1.52 y-1 respectively. The length at first capture was 105.4 mm. The resource is over exploited, and hence there is a need for reducing the fishing pressure to sustain the fishery

Food and feeding habits of Decapterus russelli (Ruppell, 1830) along the Malabar coast

Study on the food and feeding habits of Decapterus russelli showed that it is a carnivore, subsisting mainly on crustaceans, fishes, polychaetes, salps, molluscs and miscellaneous items. Crustaceans were the most dominant item in different size groups. The fish showed preference to other food fishes as they grew. The intensity of feeding was high during most of the months. Feeding intensity was high in juveniles followed by immature, maturing and spent fishes

Maturation and spawning of Decapterus russelli (Ruppell, 1830) along the Malabar Coast

The spawning period of the Indian scad Decapterus russelli, as indicated by ova diameter frequencies is prolonged, extending from March to December with peak in April-May and September. Fishes with mature, ripe and spent gonads were noticed from March to December. The relative condition factor(Kn) and gonadosomatic index (GSI) values ranged between 0.93-0.98 and 0.75-3.85 respectively, with peaks in March-May

First record of hound shark, Mustelus mosis from Calicut

Occurrence of a houndshark, Mustelus mosis, was noticed during the last week of May, 2010 in the landings of multi-day trawlers operating from at Beypore. Musteus mosis, belongs to the family Triakidae, inhabiting the continental shelves of western Indian ocean at depths ranging between 200 and 250 m

Fishery of sciaenids with some observations on the biology and stock assessment of Johnieops sina (Cuvier, 1830) exploited along the Malabar coast

Sciaenids form an important demersal finfish resource exploited off Malabar coast. They are caught by trawls, gillnets and ringseines and are landed throughout the year. The average annual catch was 2452 t during 2001-2008. The landings fluctuated but showed a decline. Though several species supported the sciaenid fishery, Johnieops sina was the dominant species contributing more than 58% to the catch. In the fishery, the length of J. sina ranged from 62 to 229 mm. The length at first maturity was 114 mm for males and 122 mm for females. The spawning period is prolonged with two peaks, one in September-November and another in February-April. The male – female sex ratio was almost equal in the catch. The length-weight relationship was estimated as W=0.000046658 L 2.8313. The estimated asymptotic length (L∞) and annual growth coefficient (K) of J. sina were 268 mm and 0.45, respectively. The respective annual total, natural and fishing mortalities were 3.63, 1.10 and 2.31. The spawning stock biomass is more than 30% of the stock at its unexploited level