Note: Please see Part I of this article, New Facts on Vision, Florescence and Movement, for natural history and other general information.
Mantis shrimp engender strong feelings among marine aquarists – to many, they are highly valued pets – responsive, complex and long-lived. However, small specimens sometimes arrive unnoticed among live rock and make themselves unwelcome by devouring expensive fish and other creatures. Either way, these alert predators are among the most interesting marine invertebrates available in the pet trade.
Mantis shrimp mannerisms, in my opinion, inspire one to wonder about their intelligence – they definitely seem to peer at their owners, and are very aware of all that goes on around them (see Part I of this article). The various species exhibit a startling array of neon-like colors, and even the drabber temperate types are often interestingly patterned in tans and browns.
Aquarium Size and Physical Set Up
Although water quality is more easily managed in large aquariums, small mantis shrimp do quite well in 10 gallon aquariums. Individuals longer than 8 inches or so do best in a tank of 20 gallons or larger.
A secure retreat, preferably a burrow below the substrate, is essential. Despite their fearless attitude, mantis shrimp will languish and die if forced to remain in the open. Providing a proper home will result in your seeing your pet more, not less, as it will feel secure enough to behave normally. Artificial rocks work well. Mantis shrimp will also explore rock and coral mounds, move incredibly large amounts of sand and gravel from one place to another, and sometimes manage to create quite stable burrows of their own.
Temperature and Water Quality
Most species thrive at temperatures of 74-80 F, and at salinities of 1.020-1.022. However, various species range from temperate to tropical waters, so please research the natural habitats of those you keep. Setting a light timer to mimic their natural cycle (i.e. varying the cycle for temperate species) will likely benefit their over-all health.
Filtration can be quite simple for small aquariums, (i.e. an under-gravel filter). Larger aquariums will require a suitably powerful canister or other filter. Mantis shrimp are reasonably hardy as concerns water quality but are, like many aquatic invertebrates, quite sensitive to air-borne chemicals. Fumes from cleaning products, paints, floor waxes and such may be introduced into even covered aquariums by the filtration system, and can be toxic to mantis shrimp. Unexplained aquarium deaths can often be attributed to chemical poisoning.
Depending upon the species, mantis shrimp catch their food using either of two distinct methods. Those which “club” their food and shatter the shell or carapace (see Part I) can take small crabs, crayfish, snails, mussels and other invertebrates. Those that grab or spear their prey are best fed shrimp, fish and aquatic worms (the “prey bashers” will accept these as well).
Mantis shrimp can be quite choosy when it comes to feeding – sometimes killing a live food item, seemingly as a territorial defense, but not consuming it. Most will, however, adjust to unfamiliar foods over time. They will, if you work carefully, usually accept dead food from a forceps (do not use your fingers, as serious injury can result). This takes time and experimentation – actually, it is quite comical to see them grab an unfamiliar food, retreat into their den, and then contemptuously toss it out as unpalatable!
Tong-feeding will allow you to provide them with a more varied diet than if you relied solely upon live food. Frozen mussels, clams, prawn, scallops, crab, squid and various fishes are all readily accepted. Seafood (human) markets and bait stores are also excellent sources of unique food items (different shrimp, fish, snail and abalone species, for example) – including such in your pet’s diet will go a long way in promoting good health.
Mantis shrimp have lived for over 20 years in captivity.
Mantis shrimp strike out viciously with their second pair of appendages (maxillipeds) when threatened, and can cause severe injuries requiring stitches (shrimpers and divers call them “thumb splitters”). The speed of this movement has been calculated at over 20 miles per second, and likened to the force of a small caliber bullet. Indeed, mantis shrimp have broken aquarium glass (this is not at all common, but watch them at feeding time).
They also have a strong feeding and burrow defense response, and so may attack fingers moved in their vicinity. Always use a tongs or other similar tool when working in the tank, and use a net if handling is necessary.
Social Groups and Breeding
It is almost impossible to house more than 1 mantis shrimp in an aquarium, unless it is very large and complex in its set up. That being said, their breeding behavior is fascinating (please see Part I) – pairs may remain together for 20 years and care for their eggs and each other. It would be well worthwhile to attempt to house a pair together, just be sure to have a spare tank set up in advance.
Males may be distinguished by the presence of organs known as penes. Used to transfer sperm, these slender structures are at the base of the last pair of walking limbs. Males of many species are also larger than females.
Mantis shrimp larvae are planktonic in nature, and thus not likely to survive in the aquarium, but a mated pair would be most interesting to study none the less.
Thanks for your interest – we have a lot to learn about these creatures, so please pass along your observations and questions. Until next time, Frank.
Photos of a variety of mantis shrimp species are posted at:
I have a mantis shrimp which had been eating well at the pet store but has stopped since I moved him into my tank. I have experience with other marine invertebrates, the water chemistry nad temperature is ideal. His hiding place is a plastic tube, partly covered but partly exposed, could this be the reason, he moves around a lot, in and out of tube, more than when he was at the store. Also he is alone in the tank, it is a 20 gallon and filtered with an undergravel only damsels were in the tank earlier, so bacteria should be established – is this ok, most books are now saying undergravel alone is not good
Hi Hye Jeong, thanks for your comment. Undergravel is outdated technology, but if maintained properly it can be ok. The problem is that the maintenance is more difficult because sludge builds up under the filter and can cause issues ir it is not regularly sucked out. That will involve removing all of the gravel probably to get to the grime beneath. The hang on power filters or canisters are much easier to maintain and do a nice job filtering. As long as the chemistry is checking out at ideal levels, it may just be that he is adjusting to his new home, and will not eat until he is a little more settled. He could be eating small bits of food in the tank that you may not see, and he should be fine for some time without food too, so I wouldn’t worry too much. Has he molted recently? Make sure there are adequate iodine levels in the tank, as he may be ready to molt and it may affect his appetite too. Try feeding him different foods too, maybe a shelled mussel or clam, he may just want something new!
Hello, I fond out about these very recently, and I would absolutely LOVE getting one of the smaller varieties. I am a semi-experienced aquarist, and I was wondering which would be good, or if I should wait. I am going to be emptying a 10 x 10, 17 inch tall tank, which currently houses freshwater fish – a loach and 2 gouramis. I have kept fish for, oh….. 8 years, and was wondering if you could help out. Like do I need sand or gravel? What decor do they prefer? How long do they live? Thanks!
Hi Max, Mantis shrimp are truly interesting creatures. There are about 400 known species of Mantis shrimp world wide, and of those there are only a handful that are commonly offered in the aquarium trade. The most common ones seen are the “Peacock Mantis”, cherished for their color and their personality. Others find there way into retail tanks too, sometimes just as hitchhikers in rock and coral. The challenge is finding one that will stay small enough to be housed in the aquarium you mentioned, a challengg compounded by the difficulty of positively identifying the oddballs that you may come across. I might recommend that if you have your heart set on a mantis that you consider a slightly larger set-up, at least 30-40 gallons to house a single shrimp, and preferably a tank that is wide and shallow like a breeder tank so the occupant will have room to explore. They are active predators, they like a nice selection of rubble and rock, coral skeletons and shells that they use to create a well-furnished cave dwelling. I would recommend a sand or crushed coral substrate as well. Most that we receive are maybe 3-7 inches when they arrive, and growth rate will depend on how much/often they are fed and how well the tank is kept. Take the time to establish the saltwater tank you plan on housing the ship in so it has a stable environment. There are accounts of these shrimp living for 15 to 20 years, though that too depends on conditions and the species you choose. Please let us know if you need more info.
It has been a life long dream of mine to have a mantis sshrimp. Im not set up for one yet but want to thank you for the great info.
Am lucky to be picking up a mantis shrimp tomorrow. Is it essential to have him in salt water? Have done a lot of reading but still need more reading. The local aqua shop has one in a very small talk with one rock. Seems too small. How often would you feed? Anything you think I might need to know? Thank you. Am excited
Hi Nicke, YES, it would need to be in saltwater! They will die quickly if put into freshwater or into a tank that hasn’t been setup and established yet. I would certainly recommend researching the species of mantis shrimp you are getting and making sure that you have the tank set up and established before bringing it home. They would need the correct water parameters, filtration, salt level temperature and tank setup for the type you are getting. The best size and setup would depend on the type and size of the mantis shrimp.
I got a pretty large tank I would say it is 30 gallons. I was going to put fresh water fish in it but am deciding to get a peacock mantis shrimp. What should I buy to get it all started?
Hi Ty, You can check out the Article Archive on our website for more beginners articles like Saltwater Aquarium Basics, Aquarium Setup Checklist and more. https://www.thatpetplace.com/article-archive