fish anesthetization-In the Aquarium

[davidharvey]

Dear Forum Mates,

I have done a fair amount of research on the anesthetization of fish. I give anesthesia (human) for a living so I understand the chemistry and pharmacology of the agents available.

I need to get a Magnificent Foxface Rabbitfish out of my 300 g. saltwater aquarium. I, and my wife, and my son (who works for the LFS) have tried many times to to capture this fish, I have tried to use the bottle trap a number of times... suffice to say that because of the design of the tank and the layout of the live rock (many, many, many hiding places) I have decided to begin researching anesthetizing, or at least sedating the fish just enough so that I can net it, and get it back to the LFS.

They pointed me to MS-222, and I have done further research into tertiary amyl alcohol and other agents also including Carbon Dioxide.

All the info I have found so far describes the use of the agent with the fish already in an isolated container. Obviously if I had the fish in an isolated container, I wouldn't have a problem, so what I would like is your view of using some type of agent in the aquarium itself. I realize that this will affect the other fish (One 10" Naso Tang, one 5" Bangai Cardinal, one 3" Lawnmower Blenny, one 3" Blue Spotted Jawfish, one 2" Hector's Goby), the 5 serpent stars and about 30 corals to some degree or another.

Any thoughts, or suggestions you may have would be greatly appreciated.

Thanks in advance,

Dave Harvey
Mason, MI

 

[waymack97]

did you try using a barbless hook? pull up the couch, and do some couch fishing.
_________________
bank bailout

 

[davidharvey]

I'm not familiar with what this is, or how it works, or where to get one, or how to use it.

Any further info would be greatly appreciated.

Thanks!!

Dave Harvey
Mason, MI

 

[davidharvey]

I'm not familiar with what this is, or how it works, or where to get one, or how to use it.

Any further info would be greatly appreciated.

Thanks!!

Dave Harvey
Mason, MI

 

[Anonymous]

Anesthesizing the entire tank sounds like a very bad idea. In addition to affecting all of the larger inhabitants, all of the microfauna would also be affected. It would be very difficult to predict what would happen to the tank as a whole.

Waymack suggested using a barbless hook. This is a very small fishing hook, about 1 cm in length, which has had the barb filed off.

Another option is to place a net in the tank and leave it there. Evertime you feed the fish, put the food into the net. (Never move the net.) After a day or two (or 4) the fish will get used to the net and venture in.

 

[Anonymous]

I have used micro hooks (fly fishing hooks) to catch a few fish in my tanks before. If you cant find barb less hooks you will need to file the barb off of the hook. Bait the hook with the fished fav food and drop the line in the tank. As soon as it nibbles the food set the hook so it does not have a chance to be swallowed. The fishes lip will heal very quickly.

A Foxface might be hard to hook with such a small mouth. Also be careful the other fish don't take the bait.


The Foxfaces I have had in the past would try to lodge themselves against the rock and hide - this made it rather easy to place the net over them and scrape them off the rock.


I would not dose the tank.

 

[Anonymous]

You will at the very least croak your jawfish if you try this. The lower the water temperature, the more sluggish the fish become, but I would be reluctant even to try that.

By the way, I thought anesthesia was kind of a medical mystery. I have no idea how it works.

I was able to catch my tanks recently be feeding them out of a net for a few days and then when they weren't suspecting foul play, I netted each of them.

It sucks to have a 500 neuron ganglion. But you have a several billion-fold advantage over that fish.

 

[Anonymous]

Don't forget that the Rabbit fish has venomous fins.

Louey

 

[ChrisRD]

Another method that sometimes works - try turning the lights on very early in the AM or the middle of the night to catch the fish "sleeping". Often they're a bit dazed for the first few seconds making it easier to net them.

Personally I would definitely NOT dose the tank...

 

[Anonymous]

CO2, for example, can affect the pH of the entire tank, and you may lose some of the fish and invert as a result. Too risky. You may do more harm than good. Why it need to get to the LFS? For a refund?

The fishing method is one of the better method, IMHO.

 

[davidharvey]

Thanks for the responses!

1. I give anesthesia for a living (human) so it is not quite the mystery to me as it may be to you.

2. Why do you say the Jawfish is particularly susceptible?

Unfortunately quite awhile back I had a precipitous drop in Oxygen in the tank- I lost 17 fish (sump pump was off while changing out a leaky sump tank), but the Jawfish and the Bangai Cardinal did not seem affected at all. The foxface was really sluggish and struggling at the top of the tank- YES, I know! I should have taken him out then.-

I'm reasonably sure that smaller fish have
as high or higher a liver clearance rate as the larger fish- just interested that you speciffically picked out the Jawfish.

A lady I have met during this discussion (also an aquarist and anesthesia provider) and obviously quite experienced at this sort of thing has suggested midazolam- I might try that after more research- it should only sedate the fish, which is all I really need.

3. The foxface already badgered a cross-hatch trigger to death, and is repeatedly eating one of my pacific rose brain corals.

4. If you saw how many hiding places this tank has, you would realize that scraping just isn't going to work.

Will continue to consider suggestions and go from there.

Thanks so much again.

Dave Harvey

 

[Anonymous]

1. I am a chemist and a biochemist, so I am curious how anesthesia works, not in whether you understand something that I don't.

2. I was thinking absorption through its skin.

Why not find out what marine collectors use (other than cyanide)?

 

[davidharvey]

Hey,

I'm sorry, I meant no offense. We think, and you're right we don't know absolutely for sure, that general anesthesia whether by Intravenous injected drugs, or by administration of a volatile agent (gas) depresses the reticular activating system in the brain. We do know that is the center responsible for our sleep cycles.

As far as Narcotics (Morphine, Heroin, Dilaudid, Demerol, Fentanyl- just to name a few) and Tranquilizers (midazolam, diazepam, lorazepam, etc.) actually occupy receptor sites in the brain and the spinal cord.

Gases are metabolized very little in the kidney, and or liver (although agents of a previous time were moreso). They are taken up by the lung, are quite insoluble in the blood and reach a clinically active concentration in the brain very quickly. Because of their low blood/gas solubility; when the gas is turned off, the lungs offload the agent quickly and the brain concentration drops to allow emergence. Injectable agents are on the other hand mostly metabolized and eliminated by the kidney and liver.
Other factors include Hoffman elimination and pseudocholinesterase activity.


This is, of course being quite simplistic, but the above is a very general overview. The administration of such is in many ways more an art than a science, and no one who does it would claim the science part is in any way exact.

As far as I am able to find out so far, volatile anesthetics may be bubbled into the water and indeed effect action via the fish's respiratory apparatus. Salt water fish drink and breathe the water they swim in so the GI tract also plays a part. I'm not sure about the skin absorption issue because most fish have a mucous layer that at the very least may delay uptake. I know that MS-222 is basically an ester type local anesthetic, and as nerve bundles are bathed, central and afferent and efferent pathways are blocked; this provides both motionlessness and analgesia.

I have indeed been researching what other aquarists have done and are doing, in fact I have been in contact with another anesthetist who is also an aquarist and obviously quite experienced with fish anesthesia and we are currently kicking around an idea that would allow just minimal sedation of the fish ( which is all I need)

I too, am hesitant to anesthetize, or sedate the whole tank, and I am hoping to gather more information on what exactly, if anything may happen to the corals- I also have a large entacmaea quadricolor anemone and as you might imagine- I'm worried about what effect my mad scientist approach might exact upon it.

I don't know about the hook Idea, this fish's mouth is not very big, and the Naso Tang will be all over any hook I might introduce into the tank.

At any rate, I really do appreciate everyone's ideas, contributions, criticism and questions, I'll keep researching and go from there.

Again, please don't take any offense at my previous response- I am truly interested in any views you may have.

Thanks again,

Dave Harvey

 

[Anonymous]

Dave, funny you are having trouble catching your foxface in a trap, I have found that when I needed to trap a fish my foxface was a nuisance for hanging out in the trap eating all the bait.

But anyway, we have a hippo tang that we needed to catch and remove, and he would not go in the trap for anything. Over time he was trained to eat with a large net held under him.

My husband would feed the tang nori strips by hand. He started leaving a large net clipped to the side of the tank and fed the fish closer and closer to it. As it became more comfortable, he would hold the net in one hand while he fed. Over time he was able to hold the net under the fish as he fed it, and one day the time was right to scoop him up.

Yes, this took several weeks, but, I would have never been able to catch my hippo in a trap he is far too skittish.

One word of advice, a foxface caught in a net thrashes something terrible. I did have mine get caught up in a net so badly once during a tank move that my only option was to set the tangled fish in a bucket of water and cut the net away from the net frame.

So, if you leave the fish trap in your tank for a week, only putting food in the trap, your foxface won't go in?

 

[Anonymous]

No offense, I am just genuinely curious (and being a med school dropout probably doesn't help). Is there a food (apart from that coral) that the foxface will eat that others don't? Maybe you could drug it.

I seem to remember something odd about jawfish and lack of a mucous layer but I want to double check before I say anything else.

 

[Anonymous]

diazepam

I was actually thinking valium in the fish food.

 

[Anonymous]

diazepam

I was actually thinking valium in the fish food.

You are over thinking this, man. The fish is an herbivore so feed it a little herb, man...

 

[Anonymous]

You are over thinking this, man. The fish is an herbivore so feed it a little herb, man...

Nooo! You want to get the poor fishy all paranoid? He will never come out then! :lol:

 

[Anonymous]

:lol:


He will get the munchies, bad - then it will be easy to get him to take the hook. 8)

 

[Anonymous]

Dave, funny you are having trouble catching your foxface in a trap, I have found that when I needed to trap a fish my foxface was a nuisance for hanging out in the trap eating all the bait.

Same here.