Heat-induced germ cell deficiency in the teleosts Odontesthes bonariensis and Patagonina hatcheri.

Pathological or experimental elevation of testicular temperature is known to trigger degeneration and disappearance of germ cells in scrotal mammals. In contrast, there are no reports of heat-induced germ cell deficiency in males of non-scrotal mammals and other vertebrate taxa, nor in females of any species. This study describes the induction of germ cell deficiency up to complete sterility in the teleosts Patagonina hatcheri and Odontesthes bonariensis by rearing larvae and juveniles for prolonged periods at incipient lethal, high temperatures (27-28.5 and 29 degrees C, respectively). It was shown that female germ cells are also heat-sensitive and disappear under high temperatures. The potential implications of these findings for physiological, ecological, and environmental studies and the usefulness of heat-induced germ cell-deficient fish in research and animal production are discussed.