ANALISIS ISI LAMBUNG IKAN CAKALANG (Katsuwonus pelamis) DAN IKAN MADIDIHANG (Thunnus albacares) YANG DIDARATKAN DI BITUNG, SULAWESI UTARA

Abstract

Penelitian ini telah dilakukan terhadap isi lambung ikan cakalang (Katsuwonus pelamis) hasil tangkapan pole and line dan ikan madidihang (Thunnus albacares) hasil tangkapan hand line yang didaratkan di Bitung, Sulawesi Utara pada bulan Mei, Juli, dan September 2005. Penelitian ini bertujuan untuk mengetahui komposisi jenis makanan ikan cakalang (Katsuwonus pelamis) dan ikan madidihang (Thunnus albacares). Contoh ikan cakalang (Katsuwonus pelamis) berjumlah 69 ekor dan contoh ikan madidihang (Thunnus albacares) berjumlah 63 ekor. Pengambilan contoh dilakukan di perusahaan perikanan dan tempat pengasapan atau fufu cakalang. Pengamatan dilakukan secara visual dan gravimetrik kemudian dianalisis dengan metode indeks of preponderance. Hasil penelitian menunjukkan bahwa komposisi makanan ke-2 jenis ikan pelagis besar tersebut berubah-ubah dan memiliki kemiripan terhadap 1 jenis makanan yaitu ikan malalugis (Decapterus macarellus), yang merupakan makanan utama ikan cakalang (Katsuwonus pelamis) dan ikan madidihang (Thunnus albacares). Stomach content analysis of skipjack tuna (Katsuwonus pelamis) which was caught by pole and line and yellow fin tuna (Thunnus albacares) caught by hand line, landed in Bitung, North Sulawesi i May, July, and September 2005 were conducted. The objective of the experiment is to know dietary composition of skipjack tuna (Katsuwonus pelamis) and yellow fin tuna (Thunnus albacares). The number of specimen observed 69 of skipjack tunas (Katsuwonus pelamis) and 63 of yellow fin tunas (Thunnus albacares). Sampling site were located in fishery company and at a small scale fish smoked industry. Stomach content analysis of the two fishes were observed visually measured and gravimetrically. The stomach content analysis was analysed based on indeks of preponderance) method. Result shows, the stomach content of skipjack tuna (Katsuwonus pelamis) and yellow fin tuna (Thunnus albacares) related changes and similar among one species are scad mackerel fishes (Decapterus macarellus). Therefore, scad mackerel fishes (Decapterus macarellus) is the dominant food for both skipjack tuna (Katsuwonus pelamis) and yellow fin tuna (Thunnus albacares).