抄録
Rust was used to mark the shells of short necked clam Ruditapes philippinarum. Marking was achieved by placing the clams on a rusted testing sieve. Total iron (Fe) on marked clam shells reached more than 300 μg Fe/cm2 after 17 days of treatment, and the marked clams could be distinguished from unmarked clams with the naked eye. The survival rate of the marked clams in3 marking trials ranged from 73-93%, and was not significantly different from untreated controls. Fe thickness on the marked clam shell was approximately 16 μm. Retention rate of the rust mark was 83.7% at 270 days after spread to tideland, and the clams could be distinguished from non-marked clams. The rust marking can be used to investigate clam populations, since it has a long retention period, high survival, and no adverse effect on the growth of clams. Additionally, this method has practical advantages of a simple procedure and regardless of clam size.
