PREFERENSI PAKAN MUJAIR (Oreochromis mossambicus Peters, 1852) DI PERAIRAN RAWA PENING KABUPATEN SEMARANG

KURNIA CAHYA SAFITRI, Dr. Ir. Djumanto, M.Sc.

2021 | Skripsi | S1 MANAJEMEN SUMBERDAYA AKUATIK

Informasi pakan kesukaan dan kebiasaan makan ikan sangat penting sebagai dasar penetapan kebijakan pengelolaan stok ikan. Penelitian ini bertujuan untuk mengetahui kesukaan pakan dan kebiasaan makan mujair (Oreochromis mossambicus) di Rawa Pening, Kabupaten Semarang. Sampel ikan diambil setiap bulan dari bulan Oktober sampai Desember 2020 sebanyak 60 ekor. Sampel ikan diukur panjang, berat, dan ditentukan jenis kelaminnya. Sampel ikan dibedah bagian perut untuk dikeluarkan saluran pencernaannya, kemudian diidentifikasi jenis pakan dan dianalisis isinya. Data yang dikumpulkan adalah panjang dan berat, panjang saluran pencernaan, jenis dan jumlah serta volume pakan. Data dianalisis secara deskriptif antara lain, distribusi frekuensi panjang dan berat, panjang usus relatif, komposisi pakan, frekuensi kejadian, Index of preponderance (indeks bagian terbesar), tingkat trofik, luas relung makanan, dan tumpang tindih makanan (kompetisi makanan). Hasil perbandingan panjang usus terhadap panjang total ikan berkisar antara 9,94-11,17. Komposisi pakan ikan mujair terdiri dari fitoplankton (32,47%), zooplankton (27,27%), makrofita (7,79%), dan detritus (32.47%). Jumlah lambung yang berisi jenis makanan tertinggi yaitu fitoplankton (100%) dan detritus (100%). Pakan utama ikan mujair adalah fitoplankton. Status tingkat trofik ikan mujair termasuk ikan herbivora dengan nilai tingkat trofik sebesar 2,003-2,005. Dari hasil panjang usus relatif, komposisi makanan, frekuensi kejadian, pakan utama, dan status tingkat trofik ikan mujair dikategorikan sebagai ikan herbivora. Luas relung makanan berkisar antara 1,198-1,343 dengan nilai standarisasi antara 0,066-0,114. Kompetisi makanan paling tinggi terjadi pada ikan mujair ukuran 16-21 cm dengan >21 cm.

Information on food and feeding habits is essential an a basis for determining fish shock management policies. This study aims to assess tilapia's (Oreochromis mossambicus) food and feeding habits in Rawa Pening, Semarang Regency. Fish samples were collected every month from October to December 2020 as much as 60 tails. Fish samples were measured for length, weight, and sex. The fish sample was dissected in the stomach to remove its digestive tract, then identified the type of feed and analyzed its contents. The data collected were fish length and weight, digestive tract length, type and amount, and feed volume. The data were analyzed descriptively, including the distribution of length and weight frequency, relative intestinal length, feed composition, frequency of occurrence, index of preponderance, thropic level, food niche area, and food competition (food overlap). The result of comparison intestinal length relative to the total size of fish ranged from 9,94-11,17. The composition of tilapia fish feed consists of phytoplankton (32,47%), zooplankton (27,27%), macrophites (7,79%), and detritus (32,47%). The highest frequency of food occurrence was phytoplankton (100%) and detritus (100%). The main food for tilapia fish is phytoplankton. The trophic level status of tilapia fish is herbivorous with trophic level values of 2,003-2,005. From the results of relative intestinal lenght, feed composition, frequency of occurrence, index of preponderance, thropic level, Tilapia are categorized as herbivorous fish. The area of the food niches ranged from 1,198-1,343 with standardized value between 0,066-0,114. The highest overlap of feed occurred in tilapia fish measuring 16-21 cm with >21 cm.

Kata Kunci : fitoplankton, herbivora, ikan, mujair, pakan