Let's talk about all things Shrimp. I'm going to cover some of the main Shrimp you'll find in your Local Fish Shop, what they are and what they do. Not all Shrimp are equal and by the end of this Blog you'll know the difference between your Skunk Cleaners and your Harlequins!
Invertebrates in the Reef tank are generally speaking one my of favourite things about having a Reef. Yes you can get shrimp for tropical tanks and if you really wanted to you could keep crayfish in cold water setups but its only in the Marine side of the Aquatic hobby that you get such a wide range of Invertebrates and the opportunity to keep a lot of these with each other, with fish and with Coral. Shrimp are a great part of that Invertebrate family, they are great to watch in the Reef but they also provide useful services such as being part of the clean up crew or pest control.
I'm going to kick this off with some of the most common Shrimp you're likely to come across and then make my way onto some of the less well known characters of the Reef. So without further ado, here are the first two!
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On the left we have arguably the most common and well known of the Reef Shrimp and that is the Cleaner Shrimp, aka Scarlett Cleaner Shrimp, aka Skunk Cleaner Shrimp. This Shrimp gets its name from one of the functions it performs on the Reef and that is cleaning fish of their parasites. They establish cleaning stations where fish will come by and wait to be cleaned. There are some great clips of on some well known nature documentaries of fish that would otherwise be predators to small shrimp and such, stopping by at the cleaning station and opening their mouths for the shrimp to clean. What the shrimp is doing though is an invaluable service for the fish, it's picking off parasites and dead flesh. The shrimp gets a meal and the fish gets a marine spa treatment keeping it pest free and healthy, another great example of symbiotic relationships on the Reef. We keep them in our reef tanks for much the same reason, they form a great part of the clean up crew, eating left over food and sometimes they even clean our fish as well. This is the main reason I keep one, I hope that if any of my fish did somehow gain a parasite or need a bit of TLC, that the Cleaner Shrimp would look after them, plus I can't really imagine a reef tank without one. They have great little characters and can be very tame. If you put your hand in the water near them they will learn to trust you and will jump on your hand to clean you! Free manicure!
On the right we have the Peppermint Shrimp. The Peppermint Shrimp is often bought in the Reef trade to control Aiptasia which it does however they tend to do better in groups as they are generally very shy. In a group they have the confidence to move about the Reef tank and find Aiptasia and generally to be an active member of the Reef tank, let's face it, you don't really keep fish and critters just for them to vanish and only be seen once in a blue moon. That's the main drawback to Peppermints, they aren't extremely active compared to the Cleaner Shrimp, although that being said, they come into their own in say a Nano tank. The other problem with Peppermint shrimp is that they are often confused with the likes of Camel Shrimp which will potentially nip at corals. There are subtle differences between the two but ultimately, make sure you trust your LFS that you're getting the right ones. At Rock N Critters only Peppermint Shrimp are actively stocked, if you really want a Camel Shrimp then they can be easily sourced.
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On the left we have the Fire Shrimp aka Blood Shrimp. This is quite a popular Shrimp in the US and whilst it's available in the UK I would say that the Cleaner Shrimp is the more popular of the two here. The Fire Shrimp is also regarded as a cleaner shrimp as it will pick at pests on fish and will clean up left over food in the reef tank although they have been known to potentially nip at corals, this is the same as all shrimp though however. They tend to be a little bulkier than the Cleaner Shrimp but get to roughly the same size overall. It's really down to personal choice whether you want a Cleaner Shrimp or a Fire Shrimp. I'm not saying you have to or should have one but most Reef tanks tend to have one or the other.
On the right we have the Boxer Shrimp aka Coral Banded Shrimp. It is called the Boxer Shrimp because it holds its two pincer claws out in front of its body like a boxing stance. It's always nice to see these shrimp because they're not as popular as the others so they add something different to the reef tank. The problem with these shrimp is that they can be territorial so can only be kept singularly or as a mated pair. They may also fight other shrimp, crabs and snails. They are naturally found in caves and overhangs so need a live rock scape in order to feel comfortable in the aquarium.
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On the left we have the Harlequin Shrimp which is arguably one of the coolest shrimp out there (apart from maybe the last shrimp... I'm saving the best till last!). The Harlequin not only looks really cool but also provides a great service to the reef tank, it will eat asternia starfish which are a nuisance hitch hiker. If you leave asterinas to get out of control they will take over a reef tank and potentially eat coral like Zoanthids. The only problem is though that Harlequins only eat starfish so once they've eaten all the starfish in your reef they will need to be fed other starfish. They can take down starfish much larger then themselves too so if you've got a sand sifting starfish or another large starfish don't fall into the trap of thinking it's safe, the Harlequin will take it down. If you've got a large enough reef, enough asterinas and are willing to feed them starfish once all the asterinas have been eaten you could keep a pair of harlequins. They will form a mated pair and 'dance' with one another which is fascinating to watch.
On the right we have the Pistol Shrimp. These little shrimp look more like lobsters but they are definitely shrimp. They get their name from the loud popping/cracking noise they make to ward of any fish or critters that get too close to their burrow. One of their claws are significantly larger than the other, its this larger claw that they use to pinch shut quickly which forces water out making the loud pop/crack noise like a gun shot. These guys often get a bad reputation for causing aquariums to smash when they 'pop' their claw but this isn't true. They cannot crack aquariums with their claw. What more often happens is as these shrimp burrow in the sand under the rock scape they cause the rock scape to collapse or to fall onto the glass causing it to crack. This is why it is really important to place your rock work directly onto the glass bottom of your aquarium and then fill in sand around the rock scape, that way when the shrimp moves the sand about it wont impact the support of the rock work in any way. Back to what's really great about the Pistol Shrimp, you can pair it with a small goby like the Watchman Goby or the Sulphur Goby. They form a symbiotic relationship where the shrimp maintains the burrow and does the housekeeping whilst the Goby acts as a lookout for threats. When the Goby sees a threat it darts back into the burrow alerting the shrimp who has bad eye-sight and cant see threats coming as well. The Shrimp then also darts into the burrow and into safety. This Shrimp & Goby pair are a great addition in a nano tank because there's always the risk of them disappearing into the rock scape of a larger reef tank only to be seen occasionally. Don't let this put you off though, I have a pair in my 4ft reef and yes they are burrowed on the back of a rock island but I can still see them and now that they've settled in and are familiar with the other fish and critters they come out a lot and are really active.
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I said I'm saving the best till last and I think you'll agree this guy is pretty cool. The Mantis Shrimp. The name Mantis Shrimp comes from the spear like claws that some of the species have to spear prey. Others of the species have calcified clubs that they use to strike their prey, killing, stunning and breaking shells in order to get their meal. There are a number of things that make this Shrimp really cool, firstly are their eyes. They are understood to be the most complex eyes in the animal kingdom. Put it this way, human eyes have three types of photoreceptors whereas the Mantis Shrimp has between 12 and 16 types. On top of this, they can tune their eyes to the wavelength of light in their environment which is known as spectral tuning. Ultimately, they can see more of the spectrum of light than we can, they can see and process what we see and UV light. Plus, they have been neurologically streamlined to be able to process and analyse what they see extremely quickly, this is necessary as they hunt fast moving prey and are constantly in conflict with other critters who might stray into their territory. It's possible that the Mantis Shrimp's eyes may hold the answers for how we advance optical technology. On top of all this, the eyes are mounted on stalks and can move independently from one another allowing the Shrimp to observe its environment unlike other critters in the reef and indeed nature as a whole.
That's only the first thing! The next cool thing are their club claws. The club claws can move so quickly that the friction they cause at a molecular level as they move through the water cause the water in the immediate vicinity boil. Yes, they move so fast that they cause the water around them to boil! The clubs move so fast that they create a shockwave in the water so the prey will get hit twice from the one attack plus, even if the clubs physically miss the prey, the shockwave will often be enough to stun or kill the prey in itself. The clubs are used to not only stun and kill prey but to smash through shells in order to get at their prey. They are a pretty formidable predator!
Thirdly, they are really quite intelligent. They are able to recognise, remember and communicate with other Mantis Shrimps whose territories border its own. They have even developed complex social behaviour to preserve their territory and relationships. Female Mantis Shrimp will become fertile at certain times of the Lunar cycle so it is assessed that combined with their vision, they have the ability to interpret the Lunar Cycle to determine an appropriate mating time.
So yeah, they're pretty cool aren't they. On top of this, they look really cool especially the Peacock Mantis variants. There was one in the shop until recently and it was hands down my favourite thing in the shop. There is a small green Mantis in so if you're popping in, have a look and see if you can see the independent eyes and clubs! You can keep these Shrimp at home however they will need their own species specific aquarium. This should also be made out of acrylic rather than glass because unlike the Pistol Shrimp, there is a risk that when the Mantis strikes its prey it will inadvertently smash a glass aquarium. If you want to keep a Mantis at home then make sure you do plenty of research and pop in to the shop to have a chat about what they need.
That sums up the Reef Shrimp blog, it is definitely not an exhaustive list though. There are plenty of other shrimp you can add to your reef, these are just the more popular options out there. Make sure you do plenty of research on any prospective additions and make sure they're compatible with your stocking list. Fish such as Eels, Lionfish and Triggers wont think twice about having your new Shrimp for lunch so just make sure everything is compatible. The other thing to be conscious of is that all Invertebrates including Shrimp are sensitive to copper so if you have inverts, you can't be using copper treatments in the aquarium with them.
That really does sum up the blog, if you're near by to the shop pop in and have a look at all the inverts for yourself! Nothing beats seeing everything in person!