گوارامی سه خال

Levonorgestrel is considered as an effective compound in contraceptive pills and a lipophilic-hydrophobic substance with the ability to bind to suspended organic matters.In this study,the inclusion effects of levels of levonorgestrel at 0 (control), 0.7, 7, 70, 100 and 150 ng/g of diet and a control-solvent treatment were evaluated on growth indices of gourami (Trichopodus trichopterus) during 45 days.Females (n=210;initial weight and length of 4.6 g and 63.2 mm, respectively) were randomly distributed in 21 aquariums with density of ten fish per aquarium;and fed daily at the rate of 3% of body weight.Results showed that body height, condition factor and survival rate of females were not affected by levonorgestrel levels.Females fed with levonorgestrel showed significant differences in terms of final weight and length, increment percentage in weight and body length, weight and length specific growth rate compared to the control(and control-solvent treatment). Nevertheless, the growth indices and maximum abdominal diameter of females fed with 150 ng/g showed no significant differences with lower levels (up to 7 ng/g) (P>0.05). Based on the results, it can be concluded that the addition of levonorgestrel in the diet of gourami females led to developmental disorders, especially at a level higher than 7 ng/g. Due to the binding ability of levonorgestrel to organic substances and the possibility of accidental feeding of these particles in the natural diet of fish, growth disorders and changes in the population dynamic of this species and probably other groups of aquatic animals can be expected in natural environments.