This is a list of various species of marine invertebrates, animals without a backbone, that are commonly found in aquariums kept by hobby aquarists. Some species are intentionally collected for their desirable aesthetic characteristics. Others are kept to serve a functional role such as consuming algae in the aquarium. Some species are present only incidentally or are pest species.
This list is incomplete; you can help by . (February 2011)
Found living anchored in live coral colonies in nature. Each worm has two crowns, which come in a variety of different colors, and are spiraled in the shape of a Christmas tree.
This species grows in groups of up to 100 individual tube worms, living together in a single clump. The clusters of tubes adhere to a rocky substrate at a central point.[2]
A sedentary, tube dwelling worm with a fan-shaped crown (radiole) that projects from the end of the tube. This can be white, tan, orange, sometimes with striping. They build their tubes out of sand, mud, and bits of shell.
20 cm (7.9 in)
Arthropods[]
Cheliceratas[]
Common name
Image
Taxonomy
Reef safe
Care Level
Description
Max size
Atlantic horseshoe crab
Limulus polyphemus
Yes, with caution
Easy
A bottom dwelling animal that is actually more closely related to arachnids than to true crabs. Found burrowing in mud or sand flats in the wild, they need a deep sand bed in their aquarium.
Not collected for the aquarium trade, but occasionally seen on live rock and corals as a hitchiker. They can be pests in a reef tank, preying on soft coral, sponges and anemones.
A very rare species, it is generally not available to the average hobby aquarist due to its critically endangered status. It would make a good aquarium specimen, but can only be obtained with a special license.
This jellyfish actually ranges in color from white to dark purple to reddish brown. It has a dome-shaped bell which pulses at a quick, steady pace, making these jellyfish strong, active swimmers.
25 cm (9.8 in)
Moon jellyfish
Aurelia aurita
No
Moderate to Difficult
A whitish to clear jellyfish with a large dinner-plate shaped bell. They have a fringe of short tentacles around the edge of the bell, and four longer oral arms extending from around the mouth.
This jellyfish has a somewhat green or grayish blue coloration due to symbiotic algae living in its tissues. It resides on the bottom, exposing its tentacles (and the algae inside them) to the light.
A sacoglossan sea slug with folded parapodia (side appendages), that give it a lettuce-like appearance. They feed on algae, and incorporate algal chloroplasts into their cells. Color ranges from brownish to green, and can include blues, yellows, and pinks.
A common pest species in marine aquariums which spreads rapidly and harms corals and invertebrates with their sting. Can sting fish, but fatalities are rare. Notoriously difficult to eradicate, but a number of organisms can be used for control, including peppermint shrimp and Berghia verrucicornis.
Bubble-tip anemone
Entacmaea quadricolor
With caution
Moderate
A relatively easy to keep anemone species, it is very colorful, and has distinctive bubble-like swellings on the tips of its tentacles.
Common anemone species in the aquarium trade. The base color is usually brown to white, often with color on tentacle tips. Many color variations exist, including magenta, purple, yellow, and green.
Also known as the malu anemone or white sand anemone. Color tipped tentacles reach 4 cm in length. This anemone should not be placed on a rock, it prefers a sandy substrate to bury its base in.
Not a true anemone (actinarian), but a member of the order Ceriantharia. Can make a very colorful aquarium specimen, colored with pinks, purples and sometimes shades of fluorescent green.
Alderton, David (2005). Encyclopedia of Aquarium and Pond Fish (Second ed.). DK Publishing, Inc. pp. 286–297. ISBN9780756636784.
Lougher, Tristan (2008) [First Published 2007]. What Invertebrates?: A Buyer's Guide for Marine Aquariums. What Pet? Books Series. Barron's Educational Series, Inc. ISBN978-0-7641-3741-9. LCCN 2006933016.
