Preferensi Pakan Ikan Belida (Notopterus notopterus Pallas, 1769) di Rawa Pening Kabupaten Semarang

FIKI NAFIDZA, Dr. Ir. Djumanto, M. Sc.

2019 | Skripsi | S1 MANAJEMEN SUMBERDAYA AKUATIK

Preferensi pakan adalah derajat kesukaan pada makanan tertentu yang dipilih dan dimakan. Penelitian ini bertujuan untuk mengetahui jenis pakan dan kesukaan makan ikan belida (Notopterus notopterus) di Rawa Pening Kabupaten Semarang. Pengambilan sampel ikan dilakukan setiap bulan dari bulan Oktober 2018 sampai Maret 2019. Setiap sampel diukur panjang total dan berat individu. Sampel ikan dibedah di bagian perut kemudian diambil saluran pencernaannya untuk diukur panjang dan dianalisis isi saluran pencernaannya. Data yang dianalisis meliputi distribusi frekuensi panjang dan berat ikan, panjang usus relatif, komposisi makanan, frekuensi kejadian, indeks bagian terbesar, luas relung makanan, tumpang tindih, dan tingkat trofik ikan. Hasil penelitian menunjukkan bahwa panjang usus relatif ikan belida berkisar antara 0,13-0,7 sehingga diklasifikasikan sebagai ikan karnivora. Makanan ikan belida terbanyak adalah udang (31%), sedangkan makanan lainnya yaitu ikan (26%), insekta (22%), detritus (12%), tumbuhan (8%), dan keong (1%). Frekuensi kejadian makanan tertinggi yaitu udang 72,58%. Makanan utama ikan belida muda (<20 cm) dan ikan belida tua (>20 cm) yaitu udang, sedangkan makanan utama ikan belida dewasa (20-25 cm) yaitu ikan. Luas relung berkisar antara 2,06-2,95 dengan nilai standarisasi 0,21-0,39. Persaingan paling tinggi dalam mendapatkan makanan terdapat pada ikan belida muda (<20 cm) dengan ikan belida tua (>25 cm). Status tingkat trofik ikan belida di Rawa Pening termasuk ikan karnivora dengan nilai tingkat trofik 3,41-3,59.

Food preference is a degree of choice for certain foods that chosen to be eaten. This research aims to determine the type of food and food preferences of featherback fish (Notopterus notopterus) in Lake Rawa Pening, Semarang Regency. Sampling was conducted monthly from October 2018 until March 2019. Each featherback sample was measured for total length and individual weight. Fish samples were dissected in the abdomen, and then the digestive tract was taken. Furthermore, the digestive tract was measured in length and analyzed the contents of the gastrointestinal tract. Data were analyzed descriptively in term of the length and weight distribution, relative gut length, food composition, occurance frequency, preponderance index, niche breadth, food overlapping, and thropic level. The result showed that relative gut length was 0.13-0.7, classified as a carnivorous fish. The most feed of featherback fish was shrimp with a composition of 31%, and other feeds were fish (26%), insects (22%), detritus (12%), plants (8%), and snail (1%). The highest frequency of food occurrence was shrimp 72.58%. The main food for young featherback fish (<20 cm) and old featherback fish (>20 cm) are shrimp, while the main food for adults (20-25 cm) is fish. The niche breadth ranged from 2.06-2.95 with a standardization value of 0.21-0.39. The highest competition in the struggle for feed was young featherback fish (<20 cm) with old featherback fish (>25 cm). Featherback fish in Rawa Pening include predatory fish with a trophic level value of 3.41-3.59.

Kata Kunci : belida, ikan, karnivora, makanan, udang/ carnivore, featherback, fish, food, shrimp.