Molting, Feeding, and Fluoride Concentration of the Antarctic Krill Euphausia Superba Dana

Abstract

A series of experiments was carried out to examine the relationship between feeding, molting, and fluoride content in Antarctic krill (Euphausia superba). Starvation increased the intermolt period in krill, but had no effect on the fluoride concentration of the molts produced. Addition of excess fluoride to the sea water had no direct effect on the intermolt period, the molt weight, or molt size. Additions of 6 .mu.g l-1 and 10 .mu.g l-1 fluoride raised the fluoride concentrations of the molts produced and of the whole animals. The whole body fluoride content varied cyclically during the molt cycle, reaching a peak 6 days following ecdysis. Fluoride loss at ecdysis could largely be explained by the amount of this ion shed in the molt.