Reference

Abstract

There have been growing interests and practices in mandarin fish artificial enhancement for the high market value and effect in lake ecology system as a solution to the conflict between fishery development and water quality conservation in lakes along the middle and lower reaches of the Yangtze River. Coded mark-recapture techniques that identify individual animals offer a potential for the accurate estimation of those targets, provided that individual marks are retained and the marking process has no detrimental effects on the response variables of interest. Coded wire tag (CWT) has been effectively used in over 20 fish genera for its high retention rates and minimal biological impact on fish living, while serious effects on growth and survival have been reported with different species and tag placements. So it is important to estimate the effects of tagging placement on growth, survival, and tag retention to determine a suitable placement before a mandarin fish field CWT tagging investigation. CWT was injected into mandarin fish body at three locations: dorsal, abdomen, and caudal musculature. After 1-28 day, and 29-333 days experiment of injections, there was no significantly different effect on mortality rate, growth and tag retention in all treatments. CWT is suitable for juvenile mandarin fish tagging, and dorsal, abdomen and caudal musculatures are all proper tagging placements. Based on the high survival rate, high tag retention and operational facility, the dorsal musculature was the prior suitable side in three locations for the injection for juvenile mandarin fish. The results indicate that the mortality rate of mandarin fish injected the dorsal musculature from 1st to 28th day (28 days) was 8.3% and 0 from the 29th day to the 333th day (305 days), and the tag retention was 97.9% from the 1st to the 28th day and 100% from the 29th to the 333rd day. The practice of CWT operation in tagging procedure and the use of needle guard are very important for greatly increasing the survival rate and tag retention in experiment. For the high tagging speed of CWT, 500-600 inds/h, it is very efficient for tagging relatively large number of fish in short time for fisheries management and study. These results confirm that injection of CWT in the dorsal musculature is a reliable method for juveniles used for large size releasing and mark-recapture research in the future.

Tag

Coded Wire Tags (CWT)

Objective