Biometric analysis of rainbow sardine, Dussumieria acuta Valenciennes, 1847 from Andaman Waters

Abstract

The present study aimed to generate baseline biometric data of rainbow sardine Dussumieria acuta from the Andaman Islands. A total of 127 specimens were analysed to examine meristic and morphometric characters, while 939 specimens were used to assess sex ratio, length-weight relationship, and relative condition factor. Eight meristic and twenty-eight morphometric characters were recorded for the current study. Based on the current study of meristic characters, the fin formula for D. acuta can be represented as follows: B_14-15D_18-19P₁₄V₈A_14-15C₁₉G_{(10-11)+(21-22)}. The coefficient of correlation (r) ranged from 0.536 to 0.983 for total length against different morphometric characters and from 0.724 to 0.785 for head length against different morphometric characters. After applying a log transformation, the pairwise linear regression between total length and various morphometric variables indicated that most characters' 'b' value was close to unity. The male-to-female ratio in the above species showed no significance difference from the theoretical 1:1 ratio. The length-weight relationship for D. acuta was expressed as W = 0.0053L^3.1822 for pooled samples, W = 0.0049L^3.2109 for males, and W = 0.0063L^3.116 for females. The relative condition factor (K_n) was close to an ideal threshold value in both males and females and across all seasons.