Neural and hormonal regulation of melanophores in fish, Puntius species (Ham.) melanophores

Abstract

The present study was carried out to investigate the neural and hormonal regulation in fish species of Puntius. To understand the neural and hormonal regulation in fish, we analyzed chromatic and transparency effect of neuron and hormonal agent on melanophore in fish. The white-adapted fishes when placed on a black background attained darkening and the black-adapted fish when subjected to a white background, attained a paling. The response is biphasic i.e., it was rapid initially and thereafter it was slow and gradual, suggesting to be co-ordinated both by nervous and endocrine or hormonal systems. Two peptide hormones, melanin-concentrating hormone and melanocyte stimulating hormone, having opposing actions, is associated with the color changes of fish. The observations pertaining to the effects of blinding and the effects of melatonin (a hormone from the pineal gland), do indicate that the gland functions as an extra-optic receptor for the colour changes of fish.