PCB exposure and regeneration in crinoids (Echinodermata)

Echinoderm regeneration provides a convenient and tractable test to monitor the effects of persistent micropollutants on the developmental physiology of marine animals. Regeneration involves crucial and sensitive biological p rocesses (cell proliferation, morphogenesis, differentiation, tissue renewa l) that make it an ideal tool to assess micropollutants at the tissue and c ellular level. Our results provide evidence that the regenerative response in the crinoid Antedon mediterranea is especially sensitive to PCBs and tha t exposure to these chemicals induces significant variations in timing and modality of arm regeneration. Prolonged exposure to low concentrations of A roclor (R) 1260 (14 ng l(-1) of total PCBs), typical of moderately polluted coastal zones, results in abnormal arm growth in terms of both gross morph ology and microscopic anatomy. In terms of tissue/cellular aspects the main modifications are: accelerated growth of the regenerate; massive cell migr ation/proliferation; hypertrophic development of the coelomic canals; and, extensive rearrangement of differentiated tissues of the stump. The anomali es observed in the developmental regenerative processes appear to be compat ible with a pattern of pseudo-endocrine activities.