Assessment of T bar anchor tags for marking the Blue Swimmer Crab Portunus pelagicus (L.)

摘要

Tagging is a critical technique when studying the population dynamics of any organism, in crustaceans the occurrence of periodic molting further jeopardises the tagging process. When applied as tested the standard "T" bar anchor tag (Hallprint Australia TBA-1, TBA-2), similar to the Floy anchor tag, is not considered successful for tagging the Blue Swimmer Crab Portunus pelagicus. When assessed under laboratory conditions, the tag showed a 100% failure rate during molting. The use of this methodology for population studies on P. pelagicus is not supported by data gathered by these laboratory based observations. A modified "T" bar anchor tag, with the labelled barrel extending almost the complete length of the tag, has been developed and data are presented which show this tag to be superior for use with this animal. These results raise serious questions about data gathered by other studies utilising standard T bar anchor tags on P. pelagicus. The work also provides a better understanding of the mechanics of tag behaviour during both the act of tag application, and over the: molting process.