Morphometric characteristics and meristic counts of greenback grey mullet (Liza subviridis) population from the Khulna district

Abstract

A study was conducted in four different regions of Khulna district, to describe the morphometric and meristic characteristics of greenback grey mullet (Liza subviridis) populations. The comparison was based on data collected over three months in 2023, from June to August. A total of one hundred specimens with total body weights (TBW) ranging from 10.05 to 16.25 g and total body lengths (TBL) ranging from 13.8 to 14.65 cm were used in the morphometric and meristic analyses. When compared to the other four populations, the Mongla River population exhibited higher averages for total body length, standard length, post-orbital length, eye diameter, length of pre-dorsal fin, and length of anal fin. Every biological trait differed significantly (p < 0.05) between the Gajirhat beel and Mongla population. The average meristic features of the anal, pelvic, and dorsal fin spines did not vary among the four populations (p > 0.05). However, the number of pectoral fin rays in the Rupsha and Gajirhat beel was significantly (P<0.05) higher than in other regions. Additionally, there were more dorsal and caudal fin rays in the Mongla River. Compared to other populations, the Paikgacha population had more scales on its lateral line. Four different body proportions showed significant differences at the 5% level: Head length: pre-orbital, head length: post-orbital, head length: eye diameter, head length: body depth, and head length: standard lengths. Overfishing, pollution, environmental degradation, disease transmission, the introduction of alien species, and inadequate management, all contribute to population loss, according to the research. The investigation also advocated for the protection of the Liza subviridis population in the Khulna division and neighboring areas.