Impiego di tecniche di induzione all'emissione dei gameti in Crassostrea gigas per l'esecuzione di test di embriotossicità.

• Autores: E. Turolla, F. Savorelli, D. Palazzi, Francesca Gelli
• Localización: Bollettino Malacologico, ISSN 0394-7149, Nº. 43, 1, 2007, págs. 73-77
• Idioma: italiano
• Texto completo no disponible (Saber más ...)
• Resumen

  • This work reports the results obtained studying spawning induction techniques in the Pacific oyster, Crassostrea gigas (Thunberg, 1793) to perform embryo toxicity bioassays.

    911 mature oysters were induced to spawn by adding hydrogen peroxide (5 mM): 342 in basic seawater (pH 9.1) and 299 in unaltered seawater. 270 oysters were the control group (no stimulations).

    The basic seawater method (pH 9.1) was more efficient (42.1% spawners) than the unaltered seawater method (29.4% spawners).

    No significant differences were observed in the spawned eggs/females ratio obtained by both methods.

    Fertilized eggs coming from stimulation trials were employed to carry out short-term static embryo toxicity tests performed in artificial seawater, using copper nitrate as reference toxicant.

    After 24 hours, the percentage of living larvae with completely developed shells in negative controls was 84 ± 7%. This value is greater than the test acceptability limit requested in embryo toxicity bioassays (70%). The average 24h-EC50, calculated by Trimmed Spearman-Karber statistical method, was 23.06 ± 5.21 µg/l Cu2+ as reported in the literature.

    The use of hydrogen peroxide to induce spawning in Pacific oyster is a simple, effective and inexpensive method to obtain good quality gametes for embryo toxicity bioassays.