Comparative analysis of length-weight relationships and condition factors of two congeneric rockcod species from the shores of King George Island, Antarctica

Length-weight relationships (LWR) and Fulton’s condition factors ( K ) of two notothenioid species, Notothenia rossii and Notothenia coriiceps , were assessed using 295 and 148 specimens, respectively. Fish samples were collected from two different locations: the wharf of the King Sejong Station and Chotdaebawi in Maxwell Bay, King George Island, from January to February 2023. The coefficient of determination ( R 2 ) of linear regressions on LWR ranged from 0.935 to 0.970, and the b values ranged from 3.05 to 3.27. Only N. coriiceps caught in the wharf exhibited positive allometric growth, while N. coriiceps from Chotdaebawi and N. rossii from both locations demonstrated isometric growth. The estimated condition factors ( K ) indicated that all groups of N. rossii and N. coriiceps exhibited favorable growth conditions in their respective biotopes. These findings enhance our understanding of the similarities and differences in fundamental biological characteristics, ecological aspects, and growth conditions of two important congeneric Antarctic fish species.