Calappidae
Harlequin Shrimp
I'd thought I'd share my experience so far with harlequin shrimp. I feel they are an excellent specimen to have and many want them but are too worried about diet.. care.. tankmates.. etc.
What is a Harlequin shrimp?
First of all, if you never heard of these specimens, I should probably include what they are. Harlequin shrimp are small little shrimp that reach the size of around 1 1/2 to 2 inches in length. They appear as an odd, orchid mantis looking creature usually all white with several large blue, purple, pink, or red dots. They move around and preform a "Boxing" or "Dancing" motion as they hunt or scare off predators. They travel and form mated pairs for life. The most well know factor about these shrimp is the fact that they ONLY eat starfish... to be more specific, the tubefeet part of the starfish.
<iframe width="420" height="315" src="//www.youtube.com/embed/-DxKLIyZBKs" frameborder="0" allowfullscreen></iframe>
Video of a harlequin shrimp doing a defensive dance
Diet
As you read above... they ONLY will eat starfish.. this may come to surprise but believe it or not this is true. Harlequin shrimp also hunt and eat them in a very horrific way as well. First, they find their prey using scent. They will roam around searching for the starfish.. once they finally find the starfish, they will walk ontop of it to keep it scared and threatened.. thus immobilizing it. Harlequins will then attempt to flip over the starfish to expose it's tubefeet.. the only part of the star they eat. They will then drag it to their lair, and for 1 to 2 weeks, slowly pick off the tubefeet and eat... what's even more scary is the fact the harlequin may actually harvest the algae the star eats and force feed it to keep it alive! This is a very disturbing and often the reason why we frown apon this animals.
<iframe width="560" height="315" src="//www.youtube.com/embed/DAUlrIVp29g" frameborder="0" allowfullscreen></iframe>
A Harlequin attempting to flip over it's prey.
Naturally, first thought in your mind is these animals must have an alternative as that's a bit ridiculous... well, surprisingly there is no alternative.. there are ways to get past the whole live starfish, and the expense, but everything has to be starfish.. it is recommended to check and make sure you have an LFS (local fish store) that can easily get a supply of stars in stock at any given time as this can get really really expensive..
Methods of feeding
There are a few ways to feed them... some more humane and less expensive than others. While there are probably more out there, only 4 come to mind.
First, there is the basic method.. just feed it a live star..
Second, this is the most commonly use method. This method is mainly used for the lack of expense but is frowned apon. Setting up a starfish species aquarium, filling it up with several starfish (mainly chocolate chip), and because of their ability to regenerate lost limbs, cut a leg off of one and rotate the process cutting the leg off another star until the first one's leg has grown back. Each star also needs separated to prevent cannibalism.
The third method is the most difficult to pull off... and shouldn't be attempted even if there are millions of them. Asterina stars are a common hitchhiking pest starfish that breeds rapidly. Do note a harlequin could eat 15 in a day if it wanted to.. so a HUGE and controlled population in another species tank may work but its extremely hard to pull off.
The last and final method, which I prefer, is a frozen starfish diet. One can buy a live starfish (unless a LFS supplies them) and freeze them... the only problem with this method is the starfish rots very very quickly. Remember how I said the harlys eat a star sometimes for up to 2 weeks? They would be lucky to get 2 days out of a frozen star... feeding them smaller pieces in a daily or every other day basis is recommended to prevent too much rotting and wasting starfish.
Do note that whatever method you use to feed them.. they only eat the tubefeet part, not the actual starfish leg. The only way to tell when they are truly finished eating is if they are walking around hunting for more. Remains will have to be manually removed as most CUC (Clean-up-crews) will not bother to clean up dead rotting starfish.
Tank setup
Tank setups for harlequins are pretty simple, nothing special. One thing for sure is that they cannot tolerate moderate to high water flow... these animals are very frail and their limbs are almost like kites and will flow with the water flow sometimes. I lost 3 harlequins from the intakes of a fluval desktop filter and a 225 GPH undergravel filter powerhead. The current ones I have in my 10 gallon mini reef also struggle just from the power filter alone in there. A Protein skimmer is a very important piece of equipement as dead or rotting starfish will pollute the water quickly. They are consitured not reef safe for a few reasons.. 1. When feeding them, live stars such as chocolate chips are not reef safe.. and 2. As mentioned, they can pollute the water with their rotting starfish diet making skimmers a must have in reef setups with these. Other than those reasons, harlequins will not nip at or consume corals and are often consitured reef safe themselves.
Tank mates
Harlequin shrimp will only harass starfish, and ocassionally sea urchins. Fish such as wrasse, damsels, puffers, triggers, and invertebrates such as sally light foot crabs, arrow crabs, decorator crabs, and such are a no go with these shrimp.. Pretty much anything predatory or large should be avoided. Only one pair per tank... not only because they would need fed individually, but one of the pair's male for example might go for the other's female and they will begin fighting.
Sexing
Sexing or telling the difference between male and female is simple. Where the shrimp's pleopods are located (under the abdomen) the female will have purple large spots along the pleopods. Males will be clear and pure white under their abdomens.
This is all based off my experience.. There is a lot more valuable info that can be found here: http://www.chucksaddiction.com/harlequinshrimp.html
What is a Harlequin shrimp?
First of all, if you never heard of these specimens, I should probably include what they are. Harlequin shrimp are small little shrimp that reach the size of around 1 1/2 to 2 inches in length. They appear as an odd, orchid mantis looking creature usually all white with several large blue, purple, pink, or red dots. They move around and preform a "Boxing" or "Dancing" motion as they hunt or scare off predators. They travel and form mated pairs for life. The most well know factor about these shrimp is the fact that they ONLY eat starfish... to be more specific, the tubefeet part of the starfish.
<iframe width="420" height="315" src="//www.youtube.com/embed/-DxKLIyZBKs" frameborder="0" allowfullscreen></iframe>
Video of a harlequin shrimp doing a defensive dance
Diet
As you read above... they ONLY will eat starfish.. this may come to surprise but believe it or not this is true. Harlequin shrimp also hunt and eat them in a very horrific way as well. First, they find their prey using scent. They will roam around searching for the starfish.. once they finally find the starfish, they will walk ontop of it to keep it scared and threatened.. thus immobilizing it. Harlequins will then attempt to flip over the starfish to expose it's tubefeet.. the only part of the star they eat. They will then drag it to their lair, and for 1 to 2 weeks, slowly pick off the tubefeet and eat... what's even more scary is the fact the harlequin may actually harvest the algae the star eats and force feed it to keep it alive! This is a very disturbing and often the reason why we frown apon this animals.
<iframe width="560" height="315" src="//www.youtube.com/embed/DAUlrIVp29g" frameborder="0" allowfullscreen></iframe>
A Harlequin attempting to flip over it's prey.
Naturally, first thought in your mind is these animals must have an alternative as that's a bit ridiculous... well, surprisingly there is no alternative.. there are ways to get past the whole live starfish, and the expense, but everything has to be starfish.. it is recommended to check and make sure you have an LFS (local fish store) that can easily get a supply of stars in stock at any given time as this can get really really expensive..
Methods of feeding
There are a few ways to feed them... some more humane and less expensive than others. While there are probably more out there, only 4 come to mind.
First, there is the basic method.. just feed it a live star..
Second, this is the most commonly use method. This method is mainly used for the lack of expense but is frowned apon. Setting up a starfish species aquarium, filling it up with several starfish (mainly chocolate chip), and because of their ability to regenerate lost limbs, cut a leg off of one and rotate the process cutting the leg off another star until the first one's leg has grown back. Each star also needs separated to prevent cannibalism.
The third method is the most difficult to pull off... and shouldn't be attempted even if there are millions of them. Asterina stars are a common hitchhiking pest starfish that breeds rapidly. Do note a harlequin could eat 15 in a day if it wanted to.. so a HUGE and controlled population in another species tank may work but its extremely hard to pull off.
The last and final method, which I prefer, is a frozen starfish diet. One can buy a live starfish (unless a LFS supplies them) and freeze them... the only problem with this method is the starfish rots very very quickly. Remember how I said the harlys eat a star sometimes for up to 2 weeks? They would be lucky to get 2 days out of a frozen star... feeding them smaller pieces in a daily or every other day basis is recommended to prevent too much rotting and wasting starfish.
Do note that whatever method you use to feed them.. they only eat the tubefeet part, not the actual starfish leg. The only way to tell when they are truly finished eating is if they are walking around hunting for more. Remains will have to be manually removed as most CUC (Clean-up-crews) will not bother to clean up dead rotting starfish.
Tank setup
Tank setups for harlequins are pretty simple, nothing special. One thing for sure is that they cannot tolerate moderate to high water flow... these animals are very frail and their limbs are almost like kites and will flow with the water flow sometimes. I lost 3 harlequins from the intakes of a fluval desktop filter and a 225 GPH undergravel filter powerhead. The current ones I have in my 10 gallon mini reef also struggle just from the power filter alone in there. A Protein skimmer is a very important piece of equipement as dead or rotting starfish will pollute the water quickly. They are consitured not reef safe for a few reasons.. 1. When feeding them, live stars such as chocolate chips are not reef safe.. and 2. As mentioned, they can pollute the water with their rotting starfish diet making skimmers a must have in reef setups with these. Other than those reasons, harlequins will not nip at or consume corals and are often consitured reef safe themselves.
Tank mates
Harlequin shrimp will only harass starfish, and ocassionally sea urchins. Fish such as wrasse, damsels, puffers, triggers, and invertebrates such as sally light foot crabs, arrow crabs, decorator crabs, and such are a no go with these shrimp.. Pretty much anything predatory or large should be avoided. Only one pair per tank... not only because they would need fed individually, but one of the pair's male for example might go for the other's female and they will begin fighting.
Sexing
Sexing or telling the difference between male and female is simple. Where the shrimp's pleopods are located (under the abdomen) the female will have purple large spots along the pleopods. Males will be clear and pure white under their abdomens.
This is all based off my experience.. There is a lot more valuable info that can be found here: http://www.chucksaddiction.com/harlequinshrimp.html