Home > Tips & Tricks > Sexy Shrimp Care & Info | The Dancing Anemone Shrimp

Sexy Shrimp Care & Info | The Dancing Anemone Shrimp

Looking for a fun invertebrate to add to your marine aquarium? We love all shrimp here at FantaSEA Aquariums, but we’re particularly fond of this tiny but unusual species: the sexy shrimp (Thor amboinensis). Perfect for nano reefs, this one’s fascinating to see but still easy enough to keep.

Below, find out everything you need to know about the sexy shrimp, including where it got its name, where it came from, what it eats, and much more.

Name (Common, Scientific)Sexy shrimp, squat anemone shrimp, bold-spotted anemone shrimp, Thor amboinensis
Min. tank size5 gallons
Min. group size2
Temperature73-81 °F
Salinity1.023-1.025
pH8.1-8.4
Difficulty levelEasy

Sexy shrimp description & natural habitat

Description

We’ve seen many wacky shrimp here on the FantaSEA blog—harlequin shrimp, anyone?!—but the sexy shrimp, Thor amboinensis, stands out as one of the oddest. Formerly classified in the family Hippolytidae, it now has its own taxonomic family named after it: Thoridae, also known as the anemone shrimp.

The first thing about this tiny shrimp (max. 0.8″) that catches the eye is its pattern. The species sports large white blotches on an orange-brown body, as well as white eyes. The spots are sometimes outlined in bright blue. This offers excellent camouflage in the wild, making sexy shrimp pretty hard to spot even for experienced divers.

Next, there’s that strange body shape. Sexy shrimp always have their booty in the air, and they tend to shake it as well, hence the common name. Whatever they’re doing, their upturned abdomen usually sways back and forth in a sort of dance!

Check it out:

Sexy Shrimp dancing

Tip: Telling the boys from the girls is easy enough. First off, female sexy shrimp are larger than the males. Additionally, the stripe running across the side of their back hump is usually broken and can even consist of two separate circles, rather than a continued line.

Natural habitat

Although this species’ scientific name (T. amboinensis) refers to one of the Indonesian Moluccas islands, Ambon, the sexy shrimp has a much wider distribution than just Southeast Asia. It’s considered pantropical, meaning it inhabits tropical waters around the world.

You can come across sexy shrimp in the Indo-Pacific, Red Sea, Caribbean and Gulf of Mexico, and the Eastern Atlantic all the way from South Africa to the Canary Islands and Madeira. Quite an impressive range, although it must be said that some scientists think the shrimp we know as Thor amboinensis is actually at least five distinct species.

Indeed, as of 2021, the sexy shrimp in the Caribbean Sea have been elevated to a separate species. They’re called Thor dicaprio (yes, named for the actor) and can be told apart from T. amboinensis by their stripey antennae.

Let’s stay tuned and see if any more changes are to come!

Shrimp ♥ anemone

The sexy shrimp is an anemone shrimp. In its natural habitat, it’s found on reefs at a maximum depth of around 200ft, where it maintains a fascinating symbiotic relationship with anemones or sometimes mushroom corals.

Like the Nemos of the shrimp world, sexy shrimp live on their host’s tentacles in a manner that’s referred to as commensal symbiosis. This means the shrimp benefits from getting to live on its host (for safety, camouflage, and food), while the anemone neither benefits from it (that would be called mutualism) nor is damaged by it (parasitism).

Which anemone or coral a sexy shrimp chooses to live with depends mostly just on what’s available at a given location. This is referred to as a generalist symbiont. Common hosts include:

  • Bubble tip anemone (Entacmaea quadricolor)
  • Mini-maxi carpet anemone (Stichodactyla tapetum)
  • Haddon’s sea anemone (Stichodactyla haddoni)
  • Long-tentacle plate coral (Heliofungia actiniformis)
  • Club-tipped anemone (Telmatactis cricoids)
  • Branching anemone (Lebrunia danae)

And many, many more! Sexy shrimp are usually found less than an inch away from their anemone or right on top of it.

These shrimp have been found on their anemones with roommates of different species. A study in the Bahamas, for example, revealed sexy shrimp to live on branching anemones with other shrimp (like the Pederson shrimp), crabs, a fish, and a species of brittle star. That’s quite a crowd!

Did you know? Sexy shrimp don’t tend to use their eyes much when they search for a suitable anemone. They rely on chemical cues to locate their host; only when they’ve reached it, they begin to look at it, touch it, and even taste it in order to confirm all is in order.

Host selection by shrimps symbiotic with sea anemones: A field survey and experimental laboratory analysis (1996)
Close-up of sexy shrimp in the aquarium sitting on a coral.

Sexy shrimp aquarium

Sexy shrimp are a pretty common sight in the saltwater hobby, and it’s not just because of their funny looks. What’s really great about them is that they stay so small, meaning they’re suitable for even the smallest tanks. Whether you’re setting up a 5-gallon reef bowl or a 1000-gallon monster, sexy shrimp will do well in there if you provide the right conditions.

The right conditions, in this case, mean normal saltwater water parameters and plenty of hiding places. That’s really all these shrimp ask for! Try to keep the flow levels on the low to medium side, or at least provide spots where they can escape the “waves”.

Tip: if you don’t want to give your sexy shrimp an anemone to live on—they can be challenging to care for, after all—you can opt for something like green star coral instead. As we’ve discussed, these guys aren’t that picky about their hosts.

Sexy shrimp compatibility

If you’re looking for an absolutely, 100% peaceful addition to your tank, this is it. Sexy shrimp won’t bother their tankmates at all; it’s more likely to be the other way round, which is why some aquarists opt to keep them in single-species tanks.

You should only combine sexy shrimp with peaceful fish that aren’t large enough to fit them into their mouths. The same goes for inverts: avoid bullies and go for friendly tankmates like hermit crabs, snails, other shrimp, and small crabs like the pom-pom crab.

As for their own species, sexy shrimp in the wild generally live in small groups. This probably functions as a form of safety in numbers, but also, there are only so many anemones to go around—having to share is unavoidable. There doesn’t appear to be any kind of social structure.

In the aquarium, your shrimp probably appreciate the presence of their own kind to help them feel safe.

Are sexy shrimp reef safe?

No easy answer for this one! They’re technically considered reef-safe and don’t feed on corals in the wild. However, some aquarists do report their sexy shrimp misbehaving.

Keep an eye on these shrimp during the first few weeks to make sure they don’t have a taste for your reef. Also make sure they’ve got plenty to eat—see below for more.

Thor amboinensis or sexy shrimp in the aquarium

Sexy shrimp diet

In the wild, sexy shrimp tend to find their meals on their anemones. They “borrow” some of their hosts’ meals by picking small particles and invertebrates they’ve caught off their tentacles. If there’s not much to go around, they’ll even munch on the tentacles or the mucus that covers them.

In the aquarium, like other marine shrimp, sexy shrimp can help play the role of janitor and clean up leftover bits. This being said, remember you’re still the one in charge of cleaning the tank in the end. And your shrimp do likely need supplemental feeding if you don’t want them to start picking at your corals!

Sexy shrimp are omnivores that lean towards carnivory, so they like a bit of protein in their diet. Sinking pellets and flakes, as well as a variety of frozen or even live foods, should work well.

Breeding sexy shrimp

We love captive breeding projects here at FantaSEA Aquariums, so we’re sad to see that sexy shrimp are still mostly wild-caught. Breeding them isn’t easy, but it’s definitely possible. Hopefully tank-bred shrimp will be available everywhere soon.

Want to do your part? Sexy shrimp breeding is similar to getting other marine shrimp to reproduce, as they pass through a larval stage, but there are some special challenges.

Notably, you need to use a kreisel system for a rearing tank. This is basically a small, cylinder-shaped tank that constantly gently circulates the water so the larvae wil never touch the walls. Sounds complicated, but a simple cylindrical vase with a very gentle air stone actually works.

Here’s how it works:

  • If your shrimp are healthy, mating will usually occur after the female molts. Within a few days, she should be carrying a batch of eggs in her back legs (pleopods).
  • The eggs take 2-3 weeks to hatch. You can set up your rearing tank at this point. No décor please, and certainly no anemone, as it can eat the larvae!
  • When the eggs are mostly transparent and quite large, you can move mom to the rearing tank so she can spawn there. Move her back to the main tank after.
  • The fry can eat newly hatched baby brine shrimp from the start, which they should receive twice a day. You can also feed decapsulated brine shrimp eggs.
  • Keep the water clean. Two water changes a day would be a good idea.

Don’t worry if you lose the first few batches. This is finicky stuff, but you’ll get the hang of it! Remember that sometimes the number of molts that larvae undergo before metamorphosing can vary. There are eight general stages and it normally takes around 28 days, but you’ll notice that some will take longer to reach maturity than others.

Did you know? Many marine shrimp species, including this one, are protandrous hermaphrodites. They start out their lives as males, but turn into females as they mature. This is because a larger body is better adapted to the energy-consuming task of producing eggs.

Conclusion

The booty-shaking sexy shrimp is a popular choice for nano and pico reefs, but actually makes a great addition to a wide range of aquariums. Those funny looks and swaying dance moves never fail to put a smile on your face!

Want your own saltwater aquarium filled with fascinating creatures like sexy shrimp, but not sure where to start? FantaSEA Aquariums can design, set up, and maintain your tank for you so all you have to do is enjoy it. Contact us with your ideas today.

Sources & further reading

Anker, A., & Baeza, J. A. (2021). Thor dicaprio sp. nov., a new, conspicuously coloured shrimp from the tropical western Atlantic, with taxonomic remarks on the T. amboinensis (De Man, 1888) complex (Decapoda: Caridea: Thoridae). Zootaxa5039(4), 495-517.

Bartilotti, C., Salabert, J., & Dos Santos, A. (2016). Complete larval development of Thor amboinensis (De Man, 1888) Decapoda: Thoridae) described from laboratory-reared material and identified by DNA barcoding. Zootaxa, 4066(4), 399-420.

Baeza, J. A., & Piantoni, C. (2010). Sexual system, sex ratio, and group living in the shrimp Thor amboinensis (De Man): relevance to resource-monopolization and sex-allocation theories. The Biological Bulletin219(2), 151-165.

Bos, A. R., & Hoeksema, B. W. (2015). Cryptobenthic fishes and co-inhabiting shrimps associated with the mushroom coral Heliofungia actiniformis (Fungiidae) in the Davao Gulf, Philippines. Environmental Biology of Fishes98, 1479-1489.

Guo, C. C., Hwang, J. S., & Fautin, D. G. (1996). Host selection by shrimps symbiotic with sea anemones: a field survey and experimental laboratory analysis. Journal of Experimental Marine Biology and Ecology202(2), 165-176.

Herrnkind, W., Stanton, G., & Conklin, E. (1976). Initial characterization of the commensal complex associated with the anemone, Lebrunia danae, at Grand Bahama. Bulletin of Marine Science26(1), 65-71.

Titus, B. M., Daly, M., Hamilton, N., Berumen, M. L., & Baeza, J. A. (2018). Global species delimitation and phylogeography of the circumtropical ‘sexy shrimp’ Thor amboinensis reveals a cryptic species complex and secondary contact in the Indo‐West Pacific. Journal of Biogeography45(6), 1275-1287.

Wirtz, P. (1997). Crustacean symbionts of the sea anemone Telmatactis cricoides at Madeira and the Canary Islands. J. Zool, Lond242, 799-811.

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Marijke Puts

Hey! I'm Marijke, FantaSEA's resident blog writer. I'm a full-time pop science author, part-time PADI diver and snorkeler, and have been keeping fish since I was a kid. When I'm not writing fish care guides, you can usually find me underwater or trying to figure out how to fit more tanks into my house.

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