Get Out of My Tank! Fish Removal Tips & Tricks

Republished with permission from Reef Keeping, written by Steven Pro

Removing fish from a fully decorated display is a common headache for some and a nightmare for others.

The typical scenario involves removing every piece of live rock and coral, followed by tediously chasing the fish until it succumbs to exhaustion and is finally removed. At this point, the aquarist is left with the ominous task of replacing all the live rock and corals to their exact previous locations because the display just looked so good before. Inevitably, all of the pieces don’t fit back together just right – things don’t end up looking the same.

A lot of dirt and detritus get kicked up in the process, and the fish suffer a tremendous amount of stress from the ordeal. Well, fear not, fellow fish geeks! I am going to provide a variety of tips and tricks to help even the most novice net wielders successfully remove their targeted fish safely and efficiently.

Helping my Friend, Scott Fellman

I recently visited some marine aquarist clubs on the west coast. The first club I visited was the Marine Aquarium Society of Los Angeles County (MASLAC). My host for the weekend was fellow fish geek and friend, Scott Fellman. He had the makings of a rather beautiful display at his home. The aquascaping was original and interesting, and he had an unusual and eclectic group of fishes. The only thing lacking was enough time to permit the corals to grow into the display. While I was commenting on his fish selection, I remarked that he should get a partner for his black and white clownfish (Amphiprion ocellaris). Scott said that he had a second clownfish that he had already removed to the sump, and he actually had been working on catching the second one for several weeks. It turns out that this particular pair was aggressive and had been harassing some of his other smaller fishes. After numerous failed attempts to remove them, he had become somewhat discouraged and remarked that this one, in particular, was tricky. I assured him, “Don’t worry, we will get that fish out of there this weekend.” I could read the look in Scott’s eyes. It was a combination of, “Please don’t wreck my display. It took me weeks to get everything just the way I want,” and, “Yeah, right! There is no way on God’s green earth that you are going to be able to get that fish.”

Later that same evening, I was relaxing while watching TV and checking out the fish tank. Scott and his wife had gone off to the kitchen to get more drinks and snacks. While they were gone, the lights on the display began turning off, which caught my attention. I looked up and noticed that while most of the fish had gone into hiding, that lone troublesome clownfish was front and center. You see, the rest of the room’s lights were on, leaving the living room fairly bright. This fish was orienting itself to the room lights. Being a long time fish geek and student of fish behavior, I quickly realized that this was a golden opportunity to catch this fish. Based upon this short observation and my experience, I was fairly confident that this fish would stay along the front glass, keeping toward the light, and this would make for an easy removal. I called to Scott in the kitchen and asked him where his fish net was. He seemed a bit reluctant to get it for me, but also seemed to want to humor me. We opened up the top canopy, and I made my attempt at removing the fish. Although somewhat disappointed in myself, it took me two swoops with the net and almost 30 seconds to catch and remove that fish. I must be getting a little old and rusty! Back when I was catching fish day in and day out at the local fish store, that little clownfish never would have escaped my first swoop. But, out he went nonetheless, leaving Scott both a bit baffled and amazed at the same time.

The point of this story should be obvious. First, it is possible to remove fish from fully decorated and stocked displays. Second, the easiest method of accomplishing this feat is to get me or some other experienced fish geek to come to your house and do it for you. I am a friendly fellow and get around to a lot of local fish clubs – “Have net, will travel.” All kidding aside, there are some things to be learned from this experience. Foremost, know your fish. Know when and where they hide at night and know how they behave in general. Knowing where the fish are going keeps you one step ahead of them and enables you to cut them off and scoop them out.

Gone Fish’n

Using a rod, reel and baited hook is probably the most intimidating method of fish removal for aquarists, but it is proven to work and, in contrast to how it might appear, it does no real harm. This method is best used on belligerent fish or aggressive eaters. This is no way to catch a sick or passive fish that is being bullied in the display. For those instances, pick another method. But to remove a fish that has outgrown its current quarters or has become too territorial and is hording all the offered foods, this might be the best and easiest technique.

Pick an appropriately sized hook. Any store that carries sporting goods should also carry a variety of hooks of most any size, even some that are very small. Crimp down or file the barb off to make removing the hook easier. Then, simply bait it with the targeted fish’s favorite food and wait for the strike. Try to keep the line taut, so that the hook is not swallowed. Once the bait is taken and the fish is hooked, pull the fish out and remove the hook as soon and as cleanly as possible.

One last caveat – because this method requires the aquarist to handle the fish to remove the hook, it is not a good method for venomous fishes such as lionfish or rabbitfish. Also, be careful in general when handling any fish. Surgeonfish, for example, can certainly hurt an aquarist if they are allowed to thrash about. Gloves would be a good idea to protect both the aquarist and the fish. They protect the hands while also providing a level of self-assurance in handling the fish gently, yet firmly.

Joe Yaiullo’s Light Trick

Joe Yaiullo of the Atlantis Aquarium passed along this tidbit of information when he was discussing removing fish from his 20,000 gallon reef display. The key is to make the tank as dark as possible. Turn off all the lights at night, including any moonlights or ambient room light. Sometimes it’s necessary to cover the tank with a blanket, depending on the situation, to make the display dark enough. Then, sneak back in the middle of the night after the tank has been in complete darkness for several hours. At that time, abruptly turn on all the lights in the room and on the tank. This temporarily disorients the fish. For the next several minutes, any fish can be removed very easily. If it is known where the particular target fish “sleeps” at night, this same method can be used on a smaller scale by simply startling the fish at night with a flashlight.

Hunting at Night

Sometimes, aquarists can even catch fish at night without going through the trouble of startling them with abrupt lighting. In many instances, when you know where the fish rests in the evening, you can simply place a net in front of its abode and goose it from behind with a prod of some sort and drive it right into the net. This method works best on medium to larger fish, as it is a bit difficult to correctly “shoo” a small fish in the right direction. But this technique works well for surgeonfish, angelfish and others of similar size and behavior.

Leaving Them High and Dry

This is another method that astounds aquarists, but I assure my fellow aquarists that it is perfectly safe. All that is needed are some large barrels for holding and mixing saltwater; a large, submersible pump and a few lengths of vinyl tubing. Wave all the corals’ polyps so they retract; turn off the pumps, heater and lights; and then drain the display’s water into the barrel(s), leaving behind only a shallow puddle at the bottom. The fish will all make their way to the deepest section of water. Once there, they are easily removed. All that is needed at this point is to pump the water back into the display. Think of this as nothing more than a short low tide period. This is a good method if the tank’s water volume is not too large.

Trapping

A variety of commercial traps are available (Link 1, 2, 3) that run the gamut from targeting bristle worms and mantis shrimp to full-fledged fish traps. But the design I wish to talk about is the soda bottle (or pop bottle, for my fellow Pittsburghers) do-it-yourself trap. These are simple to build. Just take a rinsed-out soda bottle and cut off its top. Invert the top, slide it back inside the base, adhere it in place with some tape or super glue, and you are done. All that is left to do is to bait and place the trap. These work well for smaller fish or crustaceans.

The downside to this method is that these traps will first capture every single hermit crab and ornamental shrimp in the aquarium before the target animal is finally caught. It might be necessary to temporarily relocate these captured animals to a quarantine tank until the desired specimen is finally seized.

Some Final Thoughts

I have one last word of advice. Remember that we are just talking about removing a fish from an aquarium. These are animals with a brain anywhere from the size of a BB to a pea. Allowing one to outsmart you is a disgrace to the human species.

When making the first removal attempt, it is sometimes helpful to play Wagner’s “Ride of the Valkyries” in the background, a la Robert Duvall’s Lieutenant Colonel Bill Kilgore’s character from Apocalypse Now. It lets the fish know who the boss is. I love the smell of fish water in the morning. Da dadada da, da dadada da, da dadada da, da dada daaa…