Basic Advice

The Ten Worst Fish for Your Saltwater Aquarium

Aquarium enthusiasts have hundreds of species to choose from, but not all are created equal. These 10 saltwater fish are most definitely not a good idea:

orange spot fish

1.The Orange Spot File Fish

Cool looking, isn’t it? Would love to have one for your aquarium?

Well you won’t get it from us! This is one fish that simply should not be imported or collected. It has a diet that no aquarist will ever be able to replicate, thus if it can’t eat, it’s not going to be a very long lasting fish now, is it?


2. Seahorses

Don’t get me wrong, these are fascinating animals that are now being bred in captivity more than they are being collected in the wild, which is great. However, seahorses take a notoriously long time to hunt and eat their food, so you can’t keep them with other fish that are likely to eat all the food before they get a chance to. That means they can only be kept alone, in a tank of seahorses that camouflage themselves and don’t move around a whole lot. Boring!

marine betta

3. The Marine Betta

Named after the popular Siamese fighting fish, Betta, this is a fish that is really neat looking but the drawback is that you’ll never, ever see it. Shy would be the understatement of the year in describing this fish.

coral catfish

4. Coral Cat Fish

Problem: see Marine Beta. However, at least this fish is also ugly. “Look at that ugly fish hide….Awesome!!”

mantis shrimp

5. Mantis Shrimp

Yes, I know that a shrimp is not a fish, but this is another popular aquarium addition I’ve never understood. Again, an incredible animal, but one you will likely never see. It also has the ability to crack aquarium glass with its claws, and will eat anything and everything it comes near. So it has that going for it…

undulated triggerfish

6. Undulated Triggerfish

That is a pretty neat looking fish, no?. Too bad all it really wants to do is kill everything. Literally. If aquariums had prisons, these fish would fill them all.


7. The Octopus

Don’t get me wrong, the octopus is one of the coolest animals you will ever see, and watching them eat is creepy as can be. However, you can’t keep any other animals with them, and the tank needs to be locked down like Fort Knox or the octopi will escape. Oh, and lastly, you will never see him – maybe a couple times a week if you’re lucky.


8. Jellyfish

An incredible animal. Indescribably beautiful, really, but in terms of keeping and caring for them, you’re better off just getting artificial, plastic ones. “But they look so neat at the Shedd Aquarium,” you might say. Yes, the Shedd Aquarium has an army of interns to look after them. You most likely do not.

chain link eel

9. Chain Link Eel

The thing about the undulated trigger is it looks just like a normal, happy go lucky fish. The chain link eel, on the other hand, looks like it wants to attack you as soon as you see it. Why are you so angry, eel? In the aquarium prison, these guys would be in solitary confinement.

ribbon eel

10. Ribbon Eels

Just like the orange spotted filefish, there is no way to recreate this animal’s diet in captivity, so we do not support collecting. It’s a shame, because its neon color and tame nature would make in an incredible fish for any saltwater aquarium.

About Jon Wolf

Servicing Illinois, Wisconsin, Indiana & Michigan, Blue Planet Aquarium Services has been the most trusted name in aquarium design, installation and maintenance since 1999. A company large enough to be dependable but small enough to still watch out for your best interests, Blue Planet is the only company to call if you are planning to install an aquarium or have one maintained.