Journal of the Marine Biological Association of India

Biometric characteristics of Megalaspis cordyla (Linnaeus, 1758) in the Chennai coastal waters, India

Volume 68 Issue 1

K. Silambarasan, R. John Peter, A. Tiburtius, Y. Tharumar and K. R. Sreenath

doi:10.6024/jmbai.2026.68.1.2643-13

Abstract

The biometric characteristics of the horse mackerel, Megalaspis cordyla (Linnaeus, 1758) from the Chennai coastal waters, Southeastern India, were investigated to examine morphometric variation and to provide baseline biometric information for the species. A total of 411 specimens, ranging in total length from 16.6 to 43.6 cm and in weight from 42.0 to 630.0 g, were collected monthly between April 2023 and March 2024. Fifteen morphometric and seven meristic characters were measured and analysed using standard statistical methods. The coefficients of variation for morphometric traits ranged from 9.51% to 21.64%, while those for meristic traits ranged from 4.76% to 16.11%. Highly significant positive correlations (p < 0.01) were observed among key morphometric traits, particularly between total length and fork length, standard length, and snout to pelvic distance. In contrast, post-orbital length, snout length, and eye diameter exhibited relatively slower growth. The fin formula was observed to be: D1 VII-VIII, D2 I + 10–11, followed by 6–9 dorsal finlets; P 10-22, V I + 4–5, A I + 6-17, followed by 6–8 ventral finlets. Principal component analysis (PCA) was conducted on 15 allometrically size-corrected morphometric variables to identify the major contributors to morphological variation in M. cordyla. The first principal component (PC1) explained 29.53% of the total variance, with the highest loadings observed for TL, FL, and interdorsal space. The relatively narrow variation and strong interrelationships among morphometric characters indicated limited morphological variability among the sampled specimens. These findings provide baseline morphometric and meristic data for future comparative studies and may support further investigation on population structure and stock assessment of the species.

Keywords

Morphometry, meristics, stock structure, fishery management, Chennai coast

Date : 26-05-2026