How to catch a fish without removing 400 pounds of rock. (Anesthesia)

[tatuvaaj]

Thank you for the update!

Something that would allow easy and (relatively) stress free removal of fish from reef aquarium would, in my opinion, be very desirable. Taking down a full reef just to catch a few fish is very stressful not only to fishes but all organisms living in the aquarium.

On the other hand, the fact that they are so difficult to catch makes hobbyists think hard about all fish purchases

[JHemdal]

I ran an extended series of trials using metomidate on fishes back about fifteen years ago. I don't know if it was just due to familiarity with MS-222, but I did not find it as easy to use. Induction was not as smooth, and some fish had odd reactions to it. It also had an odd side effect, virtually all fish exposed to it would void feces. I used that to my advantage in collecting fecal samples for parasite analysis (grin). IIRC, it was stored by our veterinarians and doled out to me in small quantities, so it must be more of a controlled substance than MS-222 (but I don't know what class it is).
All of my paper files from that project are archived in big boxes, so I can't access them now - but the conclusion of it all is I stuck with using MS-222.

FWIW: If I can't bait a fish to the surface with food and net it, I'll use ice-fishing hooks with the barbs crimped down. Size 26 works well for anthias.


Jay

[tatuvaaj]

Jay,

Very nice to hear from a professional with extensive experience!

Have you tried clove oil or other anesthetics besides the two you mentioned? Have you used anesthetics together with invertebrates?

Thank you in advance!

[thanhjenn]

Not sure it you would want to risk the rest of your tank just to take out one fish. With all medications there will be side effects. Just like one of the earlier post. Strength of certain med will be ok for one fish, how will you know how will it effect the other smaller or larger fish. I work at a pharmacy. Medication dosing is very much weight dependent. Sure it will take you a lot of work to remove the rocks to take out one fish, but it is safe. If you dose and things don't go as plan, it would be too late. IMO

[tatuvaaj]

Originally Posted by thanhjenn

Sure it will take you a lot of work to remove the rocks to take out one fish, but it is safe.

I disagree. If you have established reef tank that has been working well for sometime, taking down the reef will almost certainly kill a lot of life that has grown on the rocks according to available light and water flow.

At minimum you would have a nutrient spike together with "mini cycle" and at worst some nasty sponge colony dies and poisons the whole tank.

The ice-fishing idea is interesting but how safe it is?

[JHemdal]

Tatu,

Sorry - I've only used those two anesthetics on aquarium fish, and never with invertebrates in the tanks.

I think the ultimate problem here is that no anesthetic can be used and then just left in the tank...invertebrates or not. When I've used MS-222 to capture a fish from a tank (rarely), I always end up doing a 100% water change to remove it. To find an anesthetic that will allow one fish to be removed, and then for the anesthetic to remain in the water is not likely in my opinion.....

Some time ago, there were some people here on RC that said what they do is wait until 3am, then suddenly turn on the aquarium lights. As the fish bump blindly around the tank in shock, they just net the ones they want removed. Crazy I think, but they were seriously in support of that idea....

Jay

[lostintheocean]

build a fish trap with a port for food ther are some threads about it. feed and wait. Eventually the fish you want will enter, pull the string to close the door and you have your fish. I built one to catch a damsel, ofcourse he was the last to go into the trap, it took about 5 days witht he trap in the tank and trying to get him to go in there but he eventually went in.

[tatuvaaj]

Jay,

Originally Posted by JHemdal

I think the ultimate problem here is that no anesthetic can be used and then just left in the tank...invertebrates or not. When I've used MS-222 to capture a fish from a tank (rarely), I always end up doing a 100% water change to remove it. To find an anesthetic that will allow one fish to be removed, and then for the anesthetic to remain in the water is not likely in my opinion.....

That's a good point

Maybe an anesthetic dosed together with food would work better in that respect but I realize my dream might be an impossible one at least for now.

The reason for my keen interest in this is the four Pomacentrus simils in my tank... They won't go into the traditional fish trap and sleep inside coral branches or caves.

[billsreef]

Originally Posted by JHemdal

To find an anesthetic that will allow one fish to be removed, and then for the anesthetic to remain in the water is not likely in my opinion.....

I agree. Any anesthetic dosed to the display tank would need to be promptly removed. Dosages with MS-222 are time dependent as well as concentration dependent. I would expect much of the same with any other anesthetic.

Some time ago, there were some people here on RC that said what they do is wait until 3am, then suddenly turn on the aquarium lights. As the fish bump blindly around the tank in shock, they just net the ones they want removed. Crazy I think, but they were seriously in support of that idea....

Jay

That's along the lines of what Joe Yaiullo does at Atlantis when he needs to get a fish out of the 20,000 gallon reef tank. Though, he just uses a bright flashlight to stun the target fish vs. turning on all the lights.