This study was conducted in the coastal estuaries of Thanh Hoa Province from 2022 to 2025 to assess the diversity of species in the family Sciaenidae. Among the recorded species, the distribution of the grey-finned croaker Pennahia aneus (Bloch, 1793) was identified. This paper analyzes the morphological characteristics and the correlations between body parts, standard length, and head length of P. aneus. The results indicate a strong correlation between standard length and the pre-dorsal, pre-pectoral, pre-pelvic, and pre-anal distances (with correlation coefficients R ranging from 0.91 to 0.93). The head-related measurements are moderately correlated with head length (R ranging from 0.52 to 0.63).