best tank mates for siamese fighting fishThus they without problems augment the awareness of that neurohormone on the synapses of serotonergic neuron endings thus increasing the action of that indolamine and suppressing the aggressive activities . So far there were few investigations about the dependence among aggression and 5 HT concentration in aquatic animals. Perreault et al. determined the effect of 5 HT on the aggression of bluehead wrasse Thalassoma bifasciatum a fish of the coral reef. After a long software of SSRIs males of that species showed a cut back of aggression in opposition t the intruder. Also the period of latency until the first attack became longer as in comparison with the control males.