Morphological variations in marine pufferfish and porcupinefish (Teleostei: Tetraodontiformes) from Tamil Nadu, southeastern coast of India

In the present study, morphological variations in 14 species of two families, Tetraodontidae and Diodontidae, were examined for individuals collected from five different centres in Tamil Nadu in the southeastern coast of India. Twenty-seven morphological measurements and four meristic characters were taken and used for multivariate analyses such as discriminant function analysis (DFA) & MANOVA. DFA revealed that the first two functions accounted for more than 75% variation between the species. Negative allometric values were observed on head length (HL), orbital length (OL), pupil diameter (PD), interorbital length (IOL), pectoral-fin length (PEL), caudal peduncle depth (CPD), dorsal to pectoral fin distance (DPFD), caudal peduncle length (CPL) and post-pectoral-fin length (POPFL) measurements. Also, MANOVA supported the DFA results. Additions, allometric relationships, and meristic variations were observed for most of these species. Moreover, this is the first attempt to describe a greater number of morphological features of the species belonging to the order Tetraodontiformes.