On a shoal of Javanese cow-nose ray from Palk Bay

The occurrence of violated shoals of Javanese cow-nose ray (Rhinoptera javanica) has been reported on a few occasions from the south east coast of India. One such shoal was operated at a depth of 10 m and netted the fish at an average rate of 350 kg per boat. The rays had a disc width ranging from 100 -165 cm and a weight from 16 - 57 kg. The rays landed were processed by pit curing method

Sex change in hound shark, along Madras coast

The big eye hound shark, logo omanensis has been recorded from the continental shelf off Bombay and Kutch region along the west coast and the Gulf of Mannar in the east coast

Some observations on the rare bow-mouth guitar fish Rhina ancylostoma

The present record of a female bow-mouth guitar fish Rhina ancylostoma specimen of 2,360 mm in total length is the largest size recorded from our coast. The morphometric measurements are give

Length weight relationship and relative condition of Leiognathus brevirostris (Valenciennes) from the Palk Bay

The length -weight relationship of Leiognathus brevlrostris which supports a commercial fishery in the Palk Bay at Mandapam is found to be logarithmic, expressed by the formula : Log W s=—4.8512 + 3.004 Log L indicating an isomometric growth pattern of the fish in its natural habitat. The mean relative condition of the species is 0.996 which denotes the normal well being of the fish in this region

Rare occurrence of diamond back squid Thysanoteuthis rhombus (Troschel, 1867) off Chennai coast

A single female specimen of diamond back squid Thysanoteuthis rhombus (Troschel, 1857) locally called 'thalan kadama' was recorded for the first time in the landings of Kasimedu Fishing Harbour on 9.7.2008. The squid was caught in the drift gill net operated off north Chennai at a depth of around 100 m

Report on a sperm whale Physeter macrocephalus (Linnaeus) caught at Chennai coast

In Indian Ocean, sperm whales are distributed in substantial numbers near Madagascar, Mahe banks. East and West coast of India and off Sri Lanka. Instances of sperm whales caught / stranded / sighted are reported from Mahabalipuram, Madras, Tranquebar, Nagapattinam, Pondicherry, Pamban, Manauli Island, Krusadai Island, Quilon, Karwar, Mangalore and Kalpen

Landing of giant devil rays at Chennai Fisheries Harbour

Three numbers of giant devil rays, Manta birostris (Fig. 1), locally called as “kombu thirukkai” along with the lesser devil ray, Mobula diabolus (Fig. 2) were landed by mechanised gillnet at Chennai Fisheries Harbour on 04-06-201

Ray fishery by trawlers off Chennai and some aspects of biology of the scaly whipray Himantura imbricata (Bloch & Schneider, 1801)

Rays are important components in the elasmobranch landings by different gears at Chennai fisheries harbour, contributing about 75.4% to the annual average elasmobranch landings. The annual average catch of rays during 2002-‘07 was 588.3 t and the maximum catch of 1297.4 t was recorded in the year 2002. Eleven species contributed a major portion to the landings of rays by trawlers at Chennai, among which Himantura jenkinsii dominated the catch, forming 38.6% and H. imbricata, 8.0%. The disc width (DW) range of H. imbricata in the landings was 110-229 mm and 130-289 mm for males and females, respectively. The annual average mean size was greater in females. The annual average sex ratio (M:F) was 1:1.11. The disc width-weight relationships were W = 0.00022DW2.676 and W = 0.00005DW2.965 for male and female, respectively. Analysis of covariance showed that the slopes differed significantly, at 5% level, between the sexes. More than 95% of fishes sampled were in wellfed condition. Analysis of gut contents revealed H. imbricata to be a benthic carnivore feeding mostly on small crustaceans, cephalochordates, molluscs, polychaetes and small fishes

First report on the philopatric migration of bull shark, Carcharhinus leucas in the Pulicut lagoon

Bull sharks Carcharhinus leucas were captured by a modified gillnet, made of cotton twine from Pulicat lagoon during 2005-06. The bull sharks exhibit unique philopatric behaviour in the lagoon for parturition. The four specimens caught were all pregnant. The value of the sharks ranged from Rs. 20000-22000

Status of Elasmobranchs Fishery in Chennai, India

Catches of elasmobranchs in India showed an increasing trend from 27.4 thousand t in 1961 to 49 thousand t in 2006. During 2006, among the total elasmobranch catches throughout India, Tamil Nadu contributed substantially with 10.8 thousand tonnes. Observations on elasmobranchs fishery in Chennai for a period of 5 years from 2002–2006 was carried out. In Chennai fisheries harbor, annual elasmobranch catches varied from 489 t to 1735 t for the trawlnets and 194 t to 519 t for mechanized gillnets. In the same harbor, maximum catch of 2074 t of elasmobranchs was recorded in 2002. The contribution of elasmobranch i.e. 4.0 %, 16.0 % & 2.0 % to the trawl, gillnet, and hooks and line (H&L), respectively, with the CPUE of 24.4, 136.7, and 1.3 kg in the respective gears were observed. Trawlers landed heavy catch of more than 100 t of elasmobranchs during June and July with the catch per hour (cph) of 1.4–1.6 kg. Gillnet catches were better during June-September, where monthly catch was above 35 t with CPUE of 203-287 kg. H&L landed good catch during February and March, where the catch was above 1 t with the CPUE of 3.3-4.0 kg