Research Article: Metals mixture effects on growth performance and their bioaccumulation in fish

A study was conducted to determine the growth performance and bioaccumulation and tolerance of metal mixture toxins in five fish species including Labeo rohita, Catla catla, Cirrhina mrigala, Hypophthalmichthys molitrix and Ctenopharyngodon idella separately, under chronic exposure of metal mixture (Fe + Zn + Pb) at sub-lethal concentrations (۱/۳ of LC۵۰) for ۱۲ weeks period. Moreover, response of different body organs of fish towards bioaccumulation of metals under metals mixture stress was also determined. It was found that the relationships among growth parameters of metals mixture stressed as well as unstressed (control) fish were significantly different. Results showed that, the sub-lethal exposure of metals mixture induced substantial impacts on the wet weight gain (g) and length (mm) of fish species, with following trend; C. catla> C. idella> C. mrigala> L. rohita >H. molitrix. However, growth rate of fish under control treatment (no stress) was significantly higher compared to the fish exposed to metals mixture. It was also observed that the condition factor was positively correlated with fish growth and expressed the extent of fish well-beings. The bioaccumulation pattern in the body organs was observed with the following trend: liver> kidney> gills> skin> fins > muscles> bones. This study concluded that metal mixtures seriously affect the growth and development of aquatic organisms.

Keywords:

Fish , Heavy metals , Chronic toxicity , Sub-lethal metal concentration , Growth response , Fe + Zn + Pb mixture