Population structure of tropical eel ( Anguilla bicolor bicolor ) in Cikaso River, West Java

A. bicolor bicolor is a tropical eel subspecies that dominate catches in the coastal areas of West Java, and its conservation status is near threatened. Cikaso River, West Java, becomes eel migration path, while unfortunately, information concerning the stock of eel in this river is still inadequate. The objective of this study was to determine the population structure (size distribution, length-weight relationship, and condition factor) of A. bicolor bicolor in the Cikaso River. The research was carried out in the main streams of the Cikaso River and the coastal marsh of Ciroyom from January to December 2020. Eel samples were collected using lift-net, fishhook, and traps. The number of eels caught is counted, then the total length and weight are measured. We collected nine elvers and 89 yellow eels, but no silver eel was caught during the study. The elver's total length (TL) ranged from 10.2 to 20 cm, and the TL of yellow eel ranged from 20.1 to 42.2 cm. The catch of eel is dominated by the size of 25-30 cm. The growth pattern of eel in the Cikaso River is positive allometric, with the condition factor of eel ranging from 0.450 to 1.917 (1.160±0.3096).