Effects of triphenyltin on fish early life stages

Using a static-renewal procedure, effects of triphenyltin chloride (TPT) on hatching, survival, and morphology were assessed in early life stages of European minnows Phoxinus phoxinus. Embryonic-larval exposure at 16 and 21 degrees C, and larval exposure at 16 degrees C were compared. In the embryonic-larval exposure at 16 degrees C, hatching was delayed and hatching success decreased at 15.9 micrograms/L. Mortality increased at > or = 3.9 micrograms/L TPT, and complete mortality occurred after 7 and 9 days at 15.9 and 5.1 micrograms/L, respectively. Mortality was higher at 21 degrees C that at 16 degrees C. Triphenyltin was more toxic to fish in larval stages. The induced effects were dose related, mortality increased at 1.8 microgram/L after 3 days, and was total after 5 days at 10.6 micrograms/L. In all high TPT exposures, larvae developed skeletal malformations (bent tails), showed impaired swimming behavior or paralysis, and eyes became opaque. Marked histopathological alterations were found. Degenerative hydropic vacuolation of the cytoplasm were evident in skeletal muscles, skin, kidneys, corneal epithelium, lens, pigment layer of the retina and choroid, retina, and CNS including spinal cord. In severe cases, nuclear changes including pycnosis and karyorrhexis occurred. The observed toxicity of TPT was similar to that of tributyltin, but TPT acted more selectively on the lens and CNS, whereas other tissues were less affected. The study indicates that Phoxinus phoxinus larvae are negatively affected at peak TPT concentrations found in polluted environments.