EVALUATION OF SUBCUTANEOUSLY IMPLANTED VISUAL IMPLANT TAGS AND CODED WIRE TAGS FOR MARKING AND BENIGN RECOVERY IN A SMALL SCALELESS FISH, GALAXIAS-TRUTTACEUS (PISCES, GALAXIIDAE)

Visual implant (VI) tags and coded wire tags (CWTs) were tested as met hods for marking a small galaxiid fish, Galaxias truttaceus, in such a way as to allow benign information recovery. VI tags were implanted b eneath the skin of the preoperculum and CWTs were implanted between ca udal fin rays. Both types of tag were easily implanted into fish >90 m m total length (4-5 g). Retention rates of both tag types were evaluat ed under field conditions. Retention of VI tags implanted in the preop erculum was estimated at 100% after 14 days and 92% after 131 days. Th ere was a loss of 8-18% of CWTs within the first four weeks after tagg ing. Tag loss continued more gradually thereafter and retention was es timated at 71% after 131 days. It was demonstrated that both types of tags could be applied successfully to four other species of Galaxias.