Electronic Theses and Dissertation

Penelitian ini dilakukan untuk mengkaji kebiasaan makan dan pola pertumbuhan ikan Rasbora sp. yang ditemukan di perairan Danau Aneuk Laot, Kota Sabang. Penelitian dilaksanakan pada bulan Oktober 2024 hingga Maret 2025. Sampel diambil sebanyak 2 kali pada musim penghujan yaitu dibulan November dan Desember 2024, menggunakan alat tangkap berupa bubu payung dengan metode purposive sampling dan dianalisis di Laboratorium Biologi Laut, Fakultas Kelautan dan Perikanan, Universitas Syiah Kuala. Parameter yang diamati meliputi jenis makanan, indeks kelimpahan makanan (index of preponderance), luas relung makanan, panjang usus relatif (Relative Gut Length), hubungan panjang-berat, dan faktor kondisi. Hasil analisis kebiasaan makan menunjukkan bahwa ikan Rasbora sp. jantan dan betina didominasi oleh konsumsi fitoplankton spesies Cosmarium obsoletum. Pada ikan betina ditemukan 14 jenis makanan, sedangkan pada ikan jantan ditemukan 8 jenis. Berdasarkan analisis indeks of preponderance dan panjang usus relatif kedua jenis kelamin ikan tergolong dalam kelompok omnivora. Luas relung ikan betina menunjukkan karakteristik generalis, sementara ikan jantan termasuk kategori intermediate atau moderat. Aspek pertumbuhan, hubungan panjang-berat dianalisis menggunakan metode Linear Allometric Model (LAM). Nilai koefisien b untuk kedua jenis kelamin ikan Rasbora sp. berada di bawah angka 3, menandakan pola pertumbuhan allometrik negatif. Hal ini mengindikasikan bahwa pertambahan panjang tubuh lebih cepat dibandingkan pertambahan bobot. Faktor kondisi ikan betina dan jantan menunjukkan nilai >1, menandakan kondisi fisiologis ikan dalam keadaan baik dan mendukung pertumbuhan optimal.

Kata kunci: Rasbora sp., kebiasaan makan, panjang usus relatif, pertumbuhan, allometrik, faktor kondisi, Danau Aneuk Laot.

This research was conducted to examine the feeding habits and growth patterns of Rasbora sp. found in the waters of Lake Aneuk Laot, Sabang City. The study was carried out from October 2024 to March 2025. Samples were collected twice during the rainy season, in November and December 2024, using umbrella traps and a purposive sampling method. Analysis was conducted at the Marine Biology Laboratory, Faculty of Marine and Fisheries, Syiah Kuala University. The observed parameters included food types, index of preponderance, food niche breadth, Relative Gut Length (RGL), length-weight relationship, and condition factor. The analysis of feeding habits showed that both male and female Rasbora sp. predominantly consumed phytoplankton of the species Cosmarium obsoletum. Fourteen food types were identified in females, while eight types were found in males. Based on the index of preponderance and relative gut length, both sexes were categorized as omnivores. The food niche breadth of females indicated generalist characteristics, whereas males fell into the intermediate or moderate category. Growth aspects, including length-weight relationships, were analyzed using the Linear Allometric Model (LAM). The b coefficient values for both sexes of Rasbora sp. were below 3, indicating a negative allometric growth pattern. This suggests that body length increases faster than body weight. The condition factor values for both male and female fish were above 1, indicating that their physiological condition was good and supportive of optimal growth Keywords: Rasbora sp., feeding habits, relative gut length, growth, allometric, condition factor, Aneuk Laot Lake.