Comparison of amphipods Corophium insidiosum and C. orientale (Crustacea: Amphipoda) in sediment toxicity testing.

The aim of this study was to compare the sensitivity of two Corophidae: Corophium orientale a standardized species and Corophium insidiosum a species more available in the Ionian sea (Southern Italy), in order to evaluate the suitability and applicability of C. insidiosum to sediment toxicity test. The sensitivity of the 2 species was compared through simultaneous bioassays: the 96-h static water-only toxicity test and a 10-day static sediment toxicity test. Sediment samples were collected in the Livorno harbour (Ligurian Sea). Both amphipods showed high sensitivity to reference toxicant and no significant differences were found between the two Corophiidae (t test; p > 0.05). Numerical Sediment Quality Guidelines (SQGs) have been used to relate the chemical concentrations of sediment samples to biological effects. Both amphipod species indicated the same sediment samples as potentially toxic according to chemical data. The results indicate that Corophium insidiosum would be suitable as an alternative test species to the recommended species C. orientale, in the development of sediment toxicity test.