standardization of records keeping in indian zoos - Central Zoo ...

8. MARKING OF FISHES FOR IDENTIFICATION
For the purpose of identifying individual fishes in a public aquarium, the
following list of criteria should be considered ideal and will help with the selection of
an appropriate technique (Allen Marshall 2004):
A. uniquely identifies each individual fish
B. remains unaltered on an individual throughout its lifetime
C. has no effect on growth, behaviour, mortality, or vulnerability to predators
D. nontoxic and nonirritating
E. is easy and fast to apply, without anesthetic, and with minimal stress to the fish
F. is not obvious to the public, while still unmistakable to curatorial staff and
G. is inexpensive, easily obtained and requires little or no specialized equipment.
It is impossible to meet with all the criteria cited above. Thus while marking animals
one has to choose from a variety of methods that meet one or more of these criteria.
Instead of depending solely on one method for identification of individual animal two
or more methods may be employed.
8.1 VI (Visual Implant) Alpha Tags
Picture 31: VI Alpha in ambient light.
Picture 32: VI Alpha in UV Light
The VI Alpha tag is a small fluorescent tag with an
alphanumeric code designed to identify individual
specimens. VI Alpha tags are implanted internally
but remain externally visible for easy recovery.
The tags are implanted with syringe-like injectors,
and are available in several colors (black letters on a
red, orange, or yellow fluorescent background or the
reverse), and in two sizes: standard - 1.0 x 2.5 mm
and large 1.5 x 3.5 mm. Because the tags are made
from a biocompatible medical grade elastomer, they
do not irritate the tissue at the implant site and seem
to have little negative effect on the host animal when
properly used.
Although many fish have transparent tissue (adipose
eyelids, fin membranes, clear boney tissue, etc.), tag retention varies by species. For
example, the adipose eyelids of salmonids have generally proven to be suitable
locations for these VI Alpha tags, but implants into larger masses of similar appearing
tissue in mullet (Mugulidae) have been rapidly shed,. Size of the tagged specimens is
also important. Shedding rates from adipose eyelids of salmonids less than 150 mm
total length have been excessive while retention in larger fish often exceeds 90%
Tagging sites in other body locations may also be used successfully. Various
sites on the head appear to be particularly useful ( e.g., mandible in walleye
Stizostedion vitreum (Larscheid 1995), and elsewhere on heads as reported by
Buckley 1994). Dorsal, anal, and adipose fins also provide potential targets (Crook
and White 1995, Blankenship and Tipping 1993, Wenburg and George 1995).
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