Effects of thyroxine administration on plasma thyroxine levels in the goldfish, Carassius auratus L.

Abstract

Pellet implantation, immersion, or feeding of thyroxine (T4) raised plasma T4 levels above values of control fish (usually less than 1 .mu.g/100 mg). Values for treated fish in the lower dosage groups generally fell between 1-5 .mu.g/100 ml, while in the higher dosage groups plasma T4 levels ranged from 5-16 .mu.g/100 ml.