J. Exp. Zool. India Vol. 22, No. 1, pp. 609-613, 2019 www.connectjournals.com/jez ISSN 0972-0030 FEEDING BIOLOGY AND LENGTH-WEIGHT RELATIONSHIP OF INDIAN ( DUVAUCELI) IN COASTAL WATERS OF GUJARAT

Panja Tehseen*, A. Y. Desai, Jyoti Saroj and Joshi Arti College of Fisheries, Junagadh Agricultural University, Veraval - 362 265, India. *e-mail: [email protected] (Accepted 27 August 2018)

ABSTRACT : are exclusively marine molluscs and there are about 600 species in the world oceans and of these less than a hundred species are of commercial importance. Indian squid (Uroteuthis duvauceli) is the commercially important species of Veraval. The marine fish landing during the year 2013 of the country has been estimated as 3.78 million tonnes. Marine squid landings in India during the year 2013 was 100014 tonnes (CMFRI, 2013). The present study gives a brief information about the feeding biology of . Gujarat is one of the most important maritime state of the nation contributing to the nation’s economy. Cephalopods including squids are one of the most important export commodity from the state. The length-weight relationship study would help to analyse the status of squid fishery off Gujarat mainland and the study about the feeding biology using monthly stomach content data of squid will help to know about the feeding intensity in different seasons and their diet composition. The maximum Dorso–Mantle length encountered during the study was 205 mm, where as the minimum was 56 mm. The food of U. duvaucelli appears to consist of fish, crustaceans and cephalopods. The detailed results of studies on feeding biological aspects such as length composition, length-weight relationship, feeding intensity are presented here in this paper. Key words : Uroteuthis duvauceli, , biology, feeding intensity, FPI.

INTRODUCTION as Tamil Nadu, Gujarat, Kerala and Maharashtra. They Cephalopods are exclusively marine molluscs and constitute 4-5% of the total marine fish production in there are about 600 species in the world oceans, which India. Among the molluscan Cephalopods, squid has been et al are diverse in form, size and nature. Of these less than a catch in high quantity (Meiyappan , 2000). (Write hundred species are of commercial importance (Mohamed, new data regarding production of cepahlopods). 2012). The life expectancy of cephalopods is about one Cephalopods represent one of the most important to two years in most forms, but larger species of squids exploited marine fishery resources of Veraval. Cephalopod and octopus, live for several years. Many species are landings formed 56,092 tonnes 7.95% of the total marine known to die after spawning (Anusha et al, 2014). production in Gujarat, with contribution of 52% landings Among the diversity of Intertidal area, the molluscs of squids (CMFRI, 2013). Cephalopod landing was 1.73 are highly successful group in terms of ecological lakh tonnes in 2014 and in that the total squid landing adaptation and they are found in nearly all habitats ranging was 83223 tonnes (CMFRI, 2014). Cephalopods were from deepest ocean trenches to the intertidal zone, one of the major fish resources landed at various landing freshwater and land where they occupy a wide range of centers in India and the state, which contributed the habitats (Vaghela and Kundu, 2011). are very maximum in cephalopod landing was Gujarat with 33% abundant and form an important link in the food chains of the total landing in year 2014 (CMFRI, 2014). (Vaghela et al, 2013). Kore and Joshi (1975) studied that squid is Cephalopods, which have gained great grandness in carnivorous, cannibalistic and shows seasonal variation recent years due to the increasing, demand in the export in the intensity of feeding; they also reported in trade. It is mainly due to their abundance and high L.duvauceli an increase in cannibalism and decrease in et al nutritional quality. Bulk amount of cephalopods were crustacean feeding for larger squid. Silas (1985) exploited in India, mainly in the four maritime states such also reported that Prawns and fishes form the chief item of food of this species. Other items like crabs, stomatopods