Environmental Influences on Thyroid Function in Teleost Fish

SYNOPSIS. A brief account of some of the influences that environmentalfactors, such as the lunar cycle, daylength and temperature,may have on thyroid activity in certain salmonids and the killifish,Fundulus heteroclitus, is presented. The rapid and immediatecharacterof temperature effects is discussed and a role for central neuroendocrinecontrolin mediating the effects of photoperiod and lunar phenomenainvolvement is suggested.