Samples for molecular analysis
Haemolymph was withdrawn directly from the adductor muscle using a Hamilton microsyringe. Syringes were thoroughly cleaned with 10% hydrochloric acid and washed in 70% ethanol and deionized water between individuals to avoid contamination. Haemolymph volume varied between specimens with range of approximately 20 – 100 µl. Equivalent volume of absolute ethanol was added to each haemolymph sample. Foot muscle tissue was dissected from each individual and put into 200 µl of absolute ethanol. Both haemolymph and soft tissue samples were stored at -20°C until the time of transport to our partner laboratory (PNRI, Seattle, USA) where they were further processed for molecular analysis. Ethanol-fixed samples were transported in the time not exceeding two days via plane in room temperature and after arrival were stored at -20°C.