a Successful Marking Method for the Saucer Scallop Amusium balloti (Bernardi)

Abstract

Wired-on Petersen discs, tags of monel metal, titanium and plastic attached with δ-cyanoacrylate adhesive, Epitar patches over plastic tags, and Epitar numbers were tested in the search for a suitable field method by which to mark the scallop A. balloti for growth and movement studies. A plastic tag stuck on with δ-cyanoacrylate, an adhesive which hardens in sea water, had the lowest mean probability of loss in recoveries up to 17 months after release. The other advantages of this method were: (1) there was no damage to the shell or organism, (2) the method was quick, which minimized exposure to air, (3) the colour range available in the tags enabled coding of release date and area and the option of either blending or contrasting with the scallop's natural shell colours, and (4) there was no need to record shell height at release (experiments 7-11). The short lifespan of this scallop (about 4 years) prevented the attainment of information over longer periods.