Indian Journal of Geo Marine Sciences Vol. 48 (03), March 2019, pp. 309-318 Food and feeding habits of oil sardine Sardinella longiceps from Ratnagiri coast off Maharashtra India Tasaduq H. Shah 1 *, S.K. Chakraborty 3 , Tarkeshwar Kumar 2 , R.K. Sadawarte 4 , & Sandhya K.M. 3 1 Faculty of Fisheries, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Kashmir (J&K) 2 Division of Livestock and Fisheries Management, ICAR-Research Complex for Eastern Region, Patna, Bihar, India 3 Central Institute of Fisheries Education, Versova, Andheri (West), Mumbai, Maharashtra, India 4 College of Fisheries, DBSK Krishi Vidyapeeth, Ratnagiri, Maharashtra, India * [E-mail: tasaduqs@gmail.com] Received 07 August 2017; revised 08 January 2018 The food of oil sardine, Sardinella longiceps caught off Ratnagiri, Maharashtra, was studied using 917 specimens obtained randomly from commercial catches. The fish was found to be predominantly a plankton feeder, consuming diatoms, dinoflagellates, zooplankton, blue-green algae, and unrecognizable matter. Diatoms formed the most important group followed by zooplankton and dinoflagellates. Unrecognizable matter comprising mud, fish scales and detritus were observed in the stomach contents throughout the year. [Keywords: Diatoms, Oil sardine, Sardinella longiceps, Ratnagiri, Index of relative importance] Introduction The oil sardine, Sardinella longiceps Valenciennes 1847 is by far the most important single-species fishery that contributes to the fisheries wealth of not only India but the entire Indian Ocean. It has traditionally played a crucial role in the marine fishery economics of India. It has a wide distribution along the coasts of Seychelles, Somalia, Africa, Gulf of Aden, Red Sea, Gulf of Oman, Persian Gulf, Sri Lanka, Malaysia, Vietnam, India, Pakistan, Indonesia, and Philippines 1 . In the Indian peninsula, the resource is predominant along the south-west coast between 8 0 N and 16 0 N latitudes, covering Kerala, Karnataka, Goa and southern part of Maharashtra, though stray catches of the species are landed along the coasts of Tamil Nadu, Andhra Pradesh, and even Orissa on the east coast as well 2 . Along the west coast, large shoals of oil sardine occur from Ratnagiri in the north to Quilon in the south. Materials and Methods For the present investigation, 917 fresh specimens of S. longiceps were collected at random from Mirkarwada Landing Centre of Ratnagiri Maharashtra, India, from October, 2010 to May, 2012. The specimens were brought in ice packs to the laboratory for further analysis. Prior to analysis, the specimens were cleaned and wiped properly. To examine the food, fish were dissected and the weight and length of the whole gut and the stomach were recorded after wiping off the moisture. The condition of the stomach with respect to the food was also noted. The stomach of all the specimens were cut open and the food was removed. The weight of the food was determined by the method given by Kagwade 3 . The stomach contents were made up to a known volume (10 cc) by adding 5% formaline and stored for analysis later. At the time of examination, 1 cc from this mixture was taken on a counting chamber and the various food items were examined and counted under a microscope. Each food item was identified to the genus level, and wherever possible, attempts were made to identify the food up to the species level. As the oil sardine is a plankton feeder, the points (volumetric) method 4 was followed in the present work. Each food item was allotted a certain number of points based on its volume. The occurrence method was also employed to indicate the relative importance of different food items. In this method, the number of stomachs containing a particular item of food is expressed as a percentage of the total number of guts examined 4 . Depending on the percentage of stomachs when a particular food item occurred in the diet of the fish, the different items were grouped into ‘very common’ (76-100%), ‘common’ (51-75%), ‘frequent’ (26-