Q. I have become very interested in sea horses. I have decided that I would like to keep some sea horses in an aquarium. Are they tough to keep alive? Can they be kept in an established reef aquarium with other fish species? What type of aquarium set-up do sea horses require?
A. Sea horses (Hippocampus spp.) are very interesting creatures and many aquarists, at some point or another, get the desire to keep them. In the past, the vast majority of sea horses offered for sale were wild caught. These sea horses typically would not eat anything in the aquarium and perish shortly after they were purchased. Today, captive breeding programs have been successful in producing sea horses that are tremendously hardy and do quite well in the aquarium. The first step to ensuring success would be to acquire captive bred sea horses. Believe it or not, there are still wild caught sea horses on the market even though their record for success is dismal at best.
There are a variety of Hippocampus species available for purchase. I have had the best success (both breeding and in general ease of keeping), with Hippocampus erectus, commonly known as the Weedy Sea Horse. I had several breeding pairs and they all fared very well in a 20 to 30 gallon aquarium. Sea horses are not fit for reef aquariums that contain other fish. Even a fish as passive as a False Percula Clownfish is enough to stress a sea horse and cause them to stop feeding. Keeping sea horses with corals and anemones also poses a tremendous risk because the corals or anemones can sting the sea horse if they try to anchor to it.
A sea horse aquarium is different from your average tank. I recommend a 30 gallon long aquarium for one or two pairs. An aragonite sand bottom works well and a normal output 10,000k fluorescent light. In my experience sea horses are not big fans of high output lighting. Filtration in a sea horse tank can be accomplished rather easily with a strong power filter or canister. Typically the output from this filtration will also be enough to create all the flow necessary to keep these unique creatures. I add several hermit crabs and snails to the tank to add movement and clean up any of the uneaten food left behind by the sea horses. I don’t add any corals to the tank and make sure to add several “anchor posts.” Sea horses will stay anchored to areas at the bottom of the aquarium. I have found that artificial marine plants that are soft work very well as sea horse anchor posts.
A heater will be necessary. I have had the best success with temperatures of 72 to 75 degrees Fahrenheit and a density of 1.027. In all honesty, a sea horse aquarium, given some careful shopping, can be set-up and implemented rather cheaply. Captive raised sea horse pairs however, are often very expensive. The other area of expense is feeding. Sea horses typically will only accept frozen mysis or brine shrimp in the aquarium. When we consider that the proper feeding regimen is three times per day keeping these animal’s stomachs full is not a cheap proposition.
It’s hard to believe that at one time sea horses where considered underwater insects. We now know that sea horses are in fact, biologically, a fish species and a tremendously unique and intelligent one.
With captive breeding techniques you can not only successfully keep sea horses alive but breed them as well. Hippocampus erectus, when paired, is often a very active breeder and the excitement of having your own baby sea horses is often enough to give aquarists a lifelong enjoyment of these amazing animals.