Vitellogenin induction in the clam, Ruditapes philippinarum, and the crab, Carcinus aestuarii, from the Lagoon of Venice: a comparative study

In the present study, potential exposure to xenoestrogens was evaluated in the clam Ruditapes philippinarum and the crab Carcinus aestuarii, both from the Lagoon of Venice. Animals were collected in 4 sites (Ca' Roman, Valle di Brenta, Marghera, and Palude del Monte), differently influenced by anthropogenic impact and natural conditions. Vitellogenin (Vg)-like protein levels were measured in digestive gland and haemolymph. The survival-inair test was also performed on clams, since it is useful in detecting general stress conditions in bivalves. Clams from Palude del Monte had higher Vg levels in haemolymph than those from Valle di Brenta and Ca’ Roman. In digestive gland, statistically significant differences in Vg levels were detected in clams from Marghera with respect to those from Valle di Brenta. In crabs, statistically significant higher Vg levels were observed in haemolymph of animals from Palude del Monte, with respect to crabs from Ca’ Roman. No statistically significant differences were recorded in crab digestive gland. Significantly increased resistance to air exposure was observed in clams from Palude del Monte, compared with that of clams from the other sites. LT50 values fell from 11 days in clams from Palude del Monte to 5 days in ones from Ca’ Roman. The present study demonstrates that measurement of Vg levels is a valuable biomarker in biomonitoring estuarine environments, highlighting a similar pattern of variation in both species. Although the animals used have different habits, the two-species approach identified a peculiar condition for Palude del Monte, a licensed area for clam culture.