Karakteristik Morfologi dan Morfometrik Otolith Ikan Beles (Barbonymus schwanefeldii Bleeker, 1854) di Bendungan Kamijoro Kabupaten Kulon Progo

Navida Vinca Hanif, Prof. Dr. Ir. Djumanto, M.Sc.

2026 | Skripsi | MANAJ. SUMBER DAYA PERIKANAN

Ikan beles (Barbonymus schwanefeldii) merupakan ikan air tawar dari famili Cyprinidae yang banyak ditemukan di perairan Asia Tenggara, termasuk di kawasan perairan Bendungan Kamijoro, Yogyakarta. Penelitian ini bertujuan menganalisis karakteristik morfologi dan morfometrik otolith ikan beles berdasarkan variasi ukuran ikan. Penelitian ini dilaksanakan pada bulan Oktober hingga Desember 2025. Sebanyak 267 sampel ikan beles yang digunakan lalu  dikelompokkan menjadi tiga kelas ukuran, yaitu kecil (8,5-14,9 cm), sedang (15,0-18,9 cm), dan besar (19,0-29,0 cm). Otolith yang digunakan yaitu otolith jenis sagitta, kemudian diukur parameter panjang, lebar, luas, keliling, berat serta enam indeks bentuk otolith. Hasil yang diperoleh otolith ikan beles berbentuk asimetris eliptik dengan tipe sulcus heterosulcoid. Semua parameter morfometrik otolith yang dianalisis menunjukkan peningkatan signifikan seiring bertambahnya ukuran tubuh ikan (p < 0,001). Hubungan panjang ikan dengan parameter otolith bersifat positif dengan nilai koefisien determinasi 0,50707 hingga 0,81368 yang sifatnya cenderung kuat hingga sangat kuat. Indeks bentuk otolith mencerminkan perubahan ontogenetik, yaitu penurunan nilai roundness, form factor, dan rectangularity serta peningkatan nilai circularity, aspect ratio, dan ellipticity, menunjukkan perubahan bentuk dari bulat transparan menjadi lebih memanjang,padat, dan kompleks.

The beles fish (Barbonymus schwanefeldii) is a freshwater fish of the Cyprinidae family commonly found in the waters of Southeast Asia, including the waters of the Kamijoro Dam in Yogyakarta. This study aims to analyze the morphological and morphometric characteristics of beles fish otoliths based on fish size variation. The study was conducted from October to December 2025. A total of 267 beles fish samples were collected and grouped into three size classes: small (8.5-14.9 cm), medium (15.0-18.9 cm), and large (19.0-29.0 cm). The otoliths used were of the sagitta type, and the following parameters were measured: length, width, area, perimeter, weight, and six otolith shape indices. The result showed that beles fish otoliths are asymmetrically elliptical in shape with a heterosulcoid sulcus type. All analyzed otolith morphometric parameters showed a significant increase with increasing fish body size ( p <0.001). The relationship between fish length and otoltih parameters was positive, with coefficient of determination value ranging from 0.50707 to 0.81368, indicating a strong to very strong correlation. The otolith shape indices reflect ontogenetic changes, namely a decrease in roundness, form factor, and rectangularity, as well as an increase in circularity, ascpect ratio, and ellipticity, indicating a change in shape from transparent, round form to a more elongated, compact, and complex one.

Kata Kunci : Indeks bentuk, Perairan, Populasi, dan Tengadak.