Induction of chromosomal aberrations, sterility and mortality in irradiated polychaete worms

Few studies concerning the effects of environmental pollutants on marine invertebrates have compared genotoxic effects with organismal effects such as reduced reproductive success and mortality. The authors have compared these endpoints using the marine polychaete Neanthes arenaceodentata exposed to acute doees of 662 keV gamma rays. Changes in mortality and fecundity were examined in adult and juvenile worms receiving 1 multiplied by 0 to 1000 Gy; chromosomal aberration frequencies were examined in juvenile worms that received doses of either 2 multiplied by 0, 4 multiplied by 0, 8 multiplied by 0 or 16 multiplied by 0 Gy and were sampled at 6h and 51 h. The group of adults and juveniles receiving 100 Gy had less than 15% mortality after 120 days whereas the group receiving 500 Gy had 50% mortality in adults after 73 days and in juveniles after 45 days. Development of discrete, postvitellogenic oocytes, which resulted in viable embryos, was completely inhibited in adult worms receiving 50 Gy of radiation. However, in juvenile worms receiving 50 Gy, oocyte development, spawning, and embryo development were all observed.