Reference

Morgan, C. E. and M. A. Farooqi. 1995. A preliminary investigation of Elastomer Visible Implant (VIE) tag retention rates and the effect of tagging on the growth and survival of barbel (Barbus barbus L.). National Rivers Authority, North West Region, P.O. Box 12, Warrington, United Kingdom WA4 1HG.

Abstract

The Elastomer Visual Implant system (VIE) is a relatively new technique for batch marking fish. The aim of this study was to assess retention rates and the possible effects of tagging on the growth and mortality of barbell, Barbus barbus, (81-197mm, fork length) over approximately 2 months using a syringe injection system.

Sixty-nine fish were tagged and 66 were used as a control. Four tagging sites were selected for evaluation. The following retention rates were obtained; 91.3% for the base of the caudal fin, 82.6% for the base of the anal fin and 47.8% for the post-orbital adipose tissue. It was not possible to investigate the relationship between tag retention and fish length because of the small sample size and the narrow length range of the fish.

The quality of retained tags, expressed as a percentage of the total number of tags applied, was subjectively classified on a scale ranging from good to very poor. Tag quality was highest (i.e. those classed as good) for the caudal (53.6%) and head (50.7%) locations.

Although tag retention was highest for the caudal site, it was very difficult to tag in this region, thus the head location may be the most practical site for tag application with the syringe injection system.

There was no significant difference between the growth of the tagged and control fish. No mortalities were recorded during the experiment.

Tag

Visible Implant Elastomer (VIE)

Objective

Evaluate tags