NANFA-- Sacrificing or immobilizing fish

Scott Davis (
Mon, 29 Jul 2002 11:03:15 -0500

I'm way out of my league in asking about this, but Martin's observation in
his darterfest account that

*after speaking with these darter folks I see the necessity of
killing/preserving fish to identify what they are. it's to hard to count
rays and scales on moving fish!*

is something I'm sure that resonates with a number of amateurs.

While looking for something else in the introduction to the Medakafish
I noticed that in a section on Anesthesia there were several anesthetics
which could be used for sexing, observing or operating (!) on medaka.

Tokio Yamamoto suggested that

*For this fish, however, phenylurethane is the best. Phenylurethane of 0.015
percent may be used satisfactorily to immobilize the fish...*

and advised against immobilizing any fish more than once a day.

It may be that those anesthetics are prohibitively expensive, or
unrealistic/unwise, to work with, for any of several other reasons.

Is it feasible to do fish IDs with an anesthetic or is this just fuzzy
minded fish hugging?

Thanks and all the best!

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