Length-weight relationships and Fulton’s condition factors of two flatfishes, Cynoglossus cynoglossus and Cynoglossus lingua, from Cox’s Bazar coast, Bay of Bengal

Length-weight relationships (LWRs) and Fulton’s condition factor were estimated for two flatfishes, Cynoglossus lingua Hamilton, and Cynoglossus cynoglossus (Hamilton), from the Cox’s Bazar coast of Bangladesh. Sampling was done from September to November 2022 from the landing center of Bangladesh Fisheries Development Corporation. In this study, the maximum total length of C. cynoglossus (34.0 cm) is a new record for this species. The length-weight relationships for these two species were highly significant (P < 0.001) with adjusted r² values of 0.918 and 0.927 for C. lingua and C. cynoglossus, respectively. The calculated growth coefficient (b) for C. lingua and C. cynoglossus was 2.873 and 3.359, respectively. The estimated Fulton’s condition factor (Kn) was 0.42 ± 0.05 for C. lingua and 0.72 ± 0.11 for C. cynoglossus. No information about the population parameters of C. lingua from the Bay of Bengal has been reported previously in any scientific database. The maximum Kn value of C. lingua was observed in the 13.0–15.9 cm length class while that of C. cynoglossus was found in the 31.0–33.9 cm length class. Our estimated LWR and Fulton’s condition factor values for these two flatfishes can be useful for management and conservation.