Hubungan panjang-berat dan faktor kondisi sangat penting dalam studi biologi perikanan, karena memberikan informasi tentang pertumbuhan ikan, kesejahteraannya secara umum, dan kesehatannya di habitat perairan. Penelitian ini dilakukan untuk mengetahui hubungan panjang-berat dan faktor kondisi ikan Tawes (B. gonionotus). Ikan ini merupakan salah satu ikan yang bernilai ekonomis di Sungai Luweng, Kecamatan Mentarang, Kabupaten Malinau. Sampel ikan ditangkap dengan jaring insang. Pengambilan sampel dilakukan pada bulan Oktober hingga November 2021. Sebanyak 30 spesimen diperiksa. Hubungan panjang-berat dianalisis menggunakan persamaan W = a.L . Faktor kondisi jenis ikan ditentukan dengan menggunakan persamaan CF = W/aLb. Hubungan panjangberat menunjukkan pertumbuhan alometrik negatif (b = 2,73). Faktor kondisi berkisar antara 0,81 dan 1,25, rata-rata 1,01. 50% spesimen memiliki berat normal, yang menunjukkan bahwa ketersediaan makanan yang cukup bagi spesies ini di lingkungannya, sehingga kondisinya dapat dikatakan baik.


Kata kunci: Hubungan panjang-berat, ikan Tawes, faktor kondisi.

Length-weight relationships (LWR) and condition factor are of great omportance in fishery assessment studies since it provides information about the growth of the fish, its general wellbeing, and fitness in an aquatic habitat. This study was conducted to examine LWR and the condition factor of silver bard (Barbonymus sp). This fish is one the economically valuabe fish in the Luweng river. A fish samples were taken from gill net. Sampling was conducted in October to November 2021. 30 specimens examined. Length-weight relationship was analysed using the equation W = a.Lb. The condition factor of the fish species was determide using the equation, CF = W/aLb. A LWR showed a negative allometric growth (b = 2.73). The condition factor range between 0.81 and 1.25, average 1.01. 50% of specimen were normal weight, indicating this species were well-being in their environmental. Keywords : Length-weight relationship, condition factors, Barbonymus sp.