Variation in the Allometry of Morphometric Characteristics, Growth, and Condition Factors of Wild Bostrychus sinensis (Butidae) in Northern Vietnam
Variation in the Allometry of Morphometric Characteristics, Growth, and Condition Factors of Wild Bostrychus sinensis (Butidae) in Northern Vietnam
Nam Thanh Nguyen1,2,3, Linh Manh Ha4, Anh Thi Nguyen5, Nam Hoang Chu5, Hau Duc Tran5, Hung Phuc Nguyen5 and Thuy Thi Ta6*
ABSTRACT
The four-eyed sleeper (Bostrychus sinensis), found in the Indo-Pacific, is a commercial goby in Vietnam. Knowledge of the allometric growth patterns of morphometric characters, the length-weight relationship, and the conditions for assessing and managing the fish populations is unknown. The present study tested the intersex differences in growth of morphometric characters, sexual and seasonal change in length-weight relationship, and growth conditions for this species based on a year-round (2018‒2019) wild specimen collection in northern Vietnam. Four morphometric characteristics (standard length, pre-dorsal-fin length, body depth, body width) showed higher growth rates in males than in females, suggesting a morphometric sexual dimorphism. The growth pattern of males and females were similarly higher than the isometric value of three, showing positive allometric growth in favorable environmental conditions. The slope values were higher in the dry season than in the wet season, but this was only significant in females. The higher intra-seasonal variability in the slope values was evaluated, showing females undergoing gonad depletion of the two sexes during their spawning season. The condition factors of both sexes were higher in the wet season when water temperature and food availability are higher. Female fish seemed to be more sensitive to environmental changes. The high value of the condition factors was shown for fish 9.9‒12.8 cm in total length (slightly larger than the optimum size of 11.48). Based on these findings, for a sustainable exploitation plan, we suggest fishing B. sinensis from December to March, with a catch size of 9.9‒12.8 cm in total length.
To share on other social networks, click on any share button. What are these?
