IS THERE ANY RELATIONSHIP BETWEEN FLUCTUATING ASYMMETRY AND REPRODUCTIVE INVESTMENT IN GIANT FEATHERBACK (CHITALA LOPIS, NOTOPTERIDAE)

Abstract

Fluctuating asymmetry (FA) is often used as an indicator of perturbed development. As organisms placed under greater stress, less energy is available to buffer their development compared to unstressed individuals and increasing levels of asymmetry. Therefore, individual asymmetry scores within a population can be used as a measure of an organism’s ability to buffer its development and can be considered as an indirect measurement of individual fitness. In this study a test was conducted to know any correlation among FA and four fitness traits in giant featherback (Chitala lopis) inhabiting non acidified and acidified region along the Kampar River. Three bilateral meristic characters were counted on each side of the fish: number of gill rakers on the lower first branchial arch, eyes diameter, and number of pectoral-fin rays and four traits related to the fitness were measured: egg diameter, size of first maturity, gonad somatic index, and fecundity. Results show that FA (both number and magnitude) levels are differerent, giant featherback inhabiting more acidic station were slightly more asymmetric than those from less acidic one except to those inhabiting alkali station. However, the reproductive investment of giant featherback in the five sampling stations studied here gave no indication that the populations strongly affected by acidification. In this study it did not find any significant negative correlation between FA and any of the measured fitness traits. Therefore it can be concluded that FA is not a useful measure of fitness in this species.