Length-Weight Relationship and Condition Factor of Sumera Fish (Tor tambroides) in the Waters of Aek Sibundong, North Sumatra

Hubungan Panjang Bobot dan Faktor Kondisi Ikan Sumera (Tor tambroides) di Perairan Aek Sibundong, Sumatera Utara

Abstract

Sumera fish (Tor tambroides) is a commercially and culturally valuable food fish whose populations are threatened by overfishing and habitat degradation. Data on the growth pattern of this species in the Aek Sibundong waters, Central Tapanuli Regency, remain limited. This study aimed to describe the length distribution of the sample, test the hypothesis of isometric growth (H0: b = 3) in the length-weight relationship of male and female fish, and compare their condition factors (H0: male K = female K). The study was conducted in December 2025. Samples were obtained from fishermen’s catches using purposive sampling, totaling 30 individuals (15 males and 15 females). The length-weight relationship was analyzed using the equation W = aL^b, the growth pattern was tested using a t-test, and the condition factor was calculated using Fulton’s equation (K) and relative condition factor (Kn). The total length of the captured fish ranged from 156 to 303; 7 of 15 males were in the 256–305 mm class, whereas 9 of 15 females were ≤205 mm. The b value was 2.6888 for males (r = 0.86) and 2.5434 for females (r = 0.76); the t-test showed that both values were not significantly different from 3 (t-calculated 0.714 and 0.765 < t-table 2.160), so isometric growth could not be rejected (low-power test; 95% CI of b: males 1.75–3.63, females 1.25–3.83), although both b values were numerically < 3. The mean condition factor was 0.966 for males and 1.422 for females; the higher value in females was possibly influenced by one extreme individual (K = 6.106), and without this individual the female mean was 1.087,only slightly different from that of males (Welch test: p = 0.21 with all data and p = 0.23 without the extreme individual). K values ranged around 1.