Re: NANFA-- Sacrificing or immobilizing fish

Bruce Stallsmith (
Mon, 29 Jul 2002 13:08:08 -0400

Scott, there are a variety of options for safely anesthetizing fish. One
available pharmaceutical is called MS-222, available from Argent Chemical
Labs among others (a.k.a. Finquel). It's a fine white powder chemically
related to novocaine, so I'd advise against international travel with it...
people have been arrested with it in the Mexico City airport but that's
another story(!).

Clove oil is something that can also work in small amounts. In an emergency
you could blow lots of air through a straw into a small amount of water and
the elevated CO2 levels can knock out a fish temporarily. But MS-222 is
probably the best thing for most fish, most of the time.

--Bruce Stallsmith
Huntsville, AL, US of A

>From: "Scott Davis" <>
>To: <>
>Subject: NANFA-- Sacrificing or immobilizing fish
>Date: 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
>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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