International Journal of Scientific & Engineering Research Volume 11, Issue 8, August-2020 104 ISSN 2229-5518 IJSER © 2020 http://www.ijser.org Gut content analysis and Feeding Habits of the Indian Mackerel, Rastrelliger kanagurta (Cuvier) at Ratnagiri Madhura Mukadam Abstract— In the current research, some feeding habits and diet composition of Indian Mackerel, Rastrelliger kanagurta were investigated by regular monthly collection over the period of 13 months from April 2014 to April 2015. A total of 350 specimens of Rastrelliger kanagurta were evaluated. The highest and lowest fork length and body weight were 25cm -16.7 cm and 141.23 g - 60.94 g respectively. Studies have shown that this fish having the relative length of Gut RLG = 0.78± 0.004, is mainly carnivorous (meat-eater) since zooplankton (21.4%) and fish body parts in the form of Semi digested matter (3.54%) were observed in the gut. Coscinodis- cus sp. was found to be the most preferable food of plant origin constituting 32.43% by number followed by Dinophysis miles which constituted 11.97% by number repectively. Among zooplankton, Tintinnids (7.89%) were the most dominant items followed by Calanus copepod (5.65%).contributing The CV = 53% indicates the middle alimentary of this fish. The feeding intensity was higher during October to January and during April to July which coincided with the period of gonadal maturation. The fullness index (FI) increased in January and July before spawning and decreased in March and September during spawning. Index Terms— copepod, GaSI, gut content, Indian mackerel, Rastrelliger kanagurta, Ratnagiri, stomach emptiness index, ——————————  —————————— 1 Introduction As food intake is the major factor controlling fish pro- duction, studies of food intake and growth of the vari- ous species is expected to yield valuable information for assessing the role of the particular species in the marine food web [1-2] . Diets of fish correspond to a combination of many important ecological compo- nents that include behavior, condition, habitat use, en- ergy intake and inter/intraspecific interactions. An ac- curate description of diets and feeding habits provides the basis for understanding the trophic interactions in aquatic food webs [3] . The diet of fishes changes with a number of factors which are extrinsic (biotope, region) or intrinsic (species, size, behaviour) and thus infor- mation on the diet of fishes is important to know the basic functioning of fish assemblages which are im- portant for developing Ecosystem-Based Fisheries Management (EBFM) models [4-5] . The Indian mackerel, Rastrelliger kanagurta is an im- portant fishery resource in the Indian EEZ especially along the southwest coast of India as well as an im- portant forage item for the highly prized food fishes such as seer fishes and tunas occupy higher trophic levels [6] . The Indian mackerel, Rastrelliger kana- gurta [7] is a pelagic shoaling fish that form commercial fisheries along the coasts of the countries bordering the Red Sea, Oman Sea, Arabian Gulf, Pakistan, India, Sri Lanka, Bangladesh, Myanmar, Thailand and Ma- laysia [8] . Studying the feeding habit of fishes does have great importance both in Fisheries and Aquacul- ture. In Fisheries, it provides information on distribu- IJSER