Pituitary control of pigmentation in xanthic, moor, and white Carassius auratus L

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Abstract
After hypophysectomy some of the melanophores in moor fantail goldfish underwent lysis and the remaining cells showed melanin aggregation. The orange color in xanthic, moor and white fantail varieties of goldfish pales after hypophysectomy. Homogenates of whole pituitary, pars distalis or neurointermediate lobe tissue given as i.p. injections effected a marked increase in the melanophore index in hypophysectomized moor fantails and intensified the orange color in hypophysectomized moor and xanthic fantails. Ovine prolactin, ovine thyrotropin (TSH), ovine somatotropin (STH), and a combination of ovine luteinizing hormone (LH) and porcine follicle-stimulating hormone (FSH) were effective in increasing the melanophore index in hypophysectomized moor fantails. Of these 4 preparations the LH-FSH combination was the most potent. Saline and thyroxine were without effect. Ovine prolactin, ovine STH, and a combination of ovine LH and porcine FSH restored the orange color of hypophysectomized xanthic and moor fantails. Of these 3 preparations the LH-FSH was most potent. Saline, ovine TSH and thyroxine were without effect. Differences were found in the apparent activity of prolactin, thyrotroph, gonadotroph and putative melanocyte-stimulating hormone (MSH) cells in the pituitaries of the 3 varieties of goldfish but these could not be directly correlated with pigmentation differences between the groups.