5 Inverts Saltwater Beginners Should AVOID [2021]!

by George Mavrakis on December 08, 2021

People love getting invertebrates for their saltwater aquariums because they can make great additions to a cleanup crew, but many people simply get them because of how cool these alien creatures can be. For this reason, people make impulse invertebrate purchases all the time without realizing the potential consequences.

Stay tuned for five inverts that beginners should totally avoid when first getting into the saltwater aquarium hobby.


 1. Starfish 

Starfish have an over 90% mortality rate in captive systems and will usually die anywhere within a week to a year. Now occasionally this can be due to shipping damage, but most often it’s because starfish react badly to changes in water quality. You shouldn't try to introduce them to a tank that isn't stable or hasn't been running for quite some time. Starfish don't have brains, so the reason they have such a hard time going from a tank in the store to your tank and surviving is because they can't think or understand how to adapt to the new conditions. Again, they're very sensitive to any minuscule changes in your water (specifically salinity and pH).

Now, if you're just dying to have a starfish as a beginner, I would stick with a serpent star. These are the hardiest and will make a great addition to a cleanup crew by eating all the leftover food that you're feeding your fish. The only challenges with these are that they can get pretty big, and the green ones will sometimes go after small and slow-moving fish. (And they’re pretty creepy looking!)


 2. Harlequin shrimp 

These may be the most unique looking shrimp in the aquarium hobby. However, the issue with the harlequin shrimp is that it only eats starfish. They’re great if you have those little asterina pest starfish and you need to get rid of them, but once you run out of starfish, this shrimp will starve to death. If you're a beginner and you don't have a lot of starfish on hand, it's essentially a waste of money. I would avoid them unless you want to devote a small tank to them.


 3. Sea apples and sea cucumbers 

Brilliant coloration makes these guys coveted by beginners, which is an issue because they can poison your entire tank if they get stressed out or die, killing everything in your system. This happens if your tank parameters fluctuate too quickly or if your temperature skyrockets. It's also very common for these guys to get sucked into your overflow or power head intake. When stressed out, they'll either shrivel down or blow up and inflate to the size of a basketball. Now, these aren't impossible to keep, but no beginners should risk the possibility of nuking their first tank!


 4. Nudibranch/sea slugs 

I'll always advise against the purchase of a sea slug, specifically nudibranchs (also called nudies and nudes). First, it's really hard to differentiate the good ones from the bad ones, and even under the best conditions they usually don't live past seven months in reef aquariums. They're delicate and have very specific dietary needs, and it doesn't help that there's not a whole lot of information out there for aquarists on most types of nudibranchs. Despite the fact that there's so many beautiful types of sea slugs out there, unless you know exactly what you're getting and its specific feeding requirements, I would totally avoid sea slugs altogether. The only ones that seem to do well are the ones that will feed off of your corals!


 5. Flame scallops 

Flame scallops are really hard to feed because they're not photosynthetic, so additional feedings of plankton need to be provided. They don't always accept the food though, so the harsh reality is that most specimens starve to death in a few months of captivity. Another issue is that they can move by clapping their shells open and closed, so oftentimes you'll find them wandering into regions of the tank that are hard to see and reach, further complicating feeding. Despite their gorgeous looks and usually modest price tag, flame scallops should be left to very dedicated, expert hobbyists.


 6. Anemones 

I know everybody wants an anemone, but if you're a beginner, please wait six months to a year after your tank is established before getting an anemone. They're maintainable with strong lighting and good water parameters, but most only live under a beginner's care for a few weeks to a few months because they're sold to unsuspecting newbies who don't really understand their full dietary needs. (Anemones like to eat!) The hardest ones to take care of are the carpet anemones and tube anemones, but I also want to recommend you stay away from any white-looking anemones like seabae anemones. Sometimes they can be bleached, which makes them look especially pretty and tempting to buy, but a white anemone means it is sick!


To learn more about the top inverts to avoid when starting out in the saltwater aquarium hobby, check out this video!