PRELIMINARY-RESULTS OF A FIELD-STUDY ON SOME STRESS-RELATED PARAMETERS IN TAPES-PHILIPPINARUM NATURALLY INFECTED BY THE PROTOZOAN PERKINSUSSP

The aim of the present work Mas to investigate the possible use of the clam Tapes philippinarum-a filter-feeding bivalve living on soft bott oms-in the monitoring of sediment pollution in the Lagoon of Venice (N orth-East Italy). Ib this end two clam populations, exposed to differe nt environmental conditions (a relative clean site and an industrial p olluted area), have been monitored for the prevalence of the protozoan parasite Perkinsus sp. as well as for several biological parameters c ommonly used as determinants of contaminants exposure. First results s howed a low prevalence, higher in the clean site, but a very diffuse d istribution of the parasite throughout the two populations. Neverthele ss, greater digestive cells height and longer lysosomal latency time w ere observed in clams from the clean area. As for the physiological st ress-related parameters, even if clearance rates were always higher in these clams, scope for growth values indicated a more complicated bio logical response. (C) 1998 Elsevier Science Ltd. All rights reserved.