Adaptive hyperplasia of epidermal chloride-secreting cells in fry of mummichog, Fundulus heteroclitus L., incubated and reared in supranormal salinity

Abstract

Cells, structurally identical with branchial chloride-secreting cells, were observed to be broadly distributed in buccal and pharyngeal epithelia and various regions of the trunk epidermis, in early fry of the mummichog, Fundulus heteroclitus L., that had been incubated in embryonal and alevin stages in sea water concentrated by additional salts to 60‰ salinity, at 20 °C. Although there was some proliferation of these cells in the buccal and pharyngeal epithelia, such apparently adaptive hyperplasia and hypertrophy of these cells did not occur in early fry that had previous incubation and rearing in seawater concentrations of 30, 20, and 10‰ salinity (S), and in fresh water (< 0.5‰ S)