Seahorses come in different types and they are all endearing, interesting and super to keep. In the wild they are, unfortunately, under intense pressure from collection. They are gathered by the millions; some are for the aquarium hobby but most are for alleged medicinal purposes or dried souvenirs.
It isn’t all bad news though, I’m pleased to say. There have been a lot of successes with breeding seahorses, and quite a number for sale are from these efforts. Anyone contemplating keeping the creatures should attempt to source these home-bred or commercial versions.
A mixed reef aquarium, that is one containing fish and corals, is going to be competitive at feeding time. Once the food goes into the water the fish are at it with gusto. Seahorses are not quick enough to compete and will not get enough of the food. They particularly like frozen brine shrimp, or better live. So do the fish of course so it is going to be gone before the seahorses have eaten. Seahorses like food that is close at hand so they can eat easily, they’re not going to get that opportunity with other competitive fish present. The only fish that seahorses should be housed with are pipefish, which are not so competitive that the seahorses lose their chance to eat.
So a standard reef aquarium is unsuitable. Perhaps a seahorse can be placed in a coral only reef. In view of the lack of fish and what has already been said, this would seem to be fine. Unfortunately once again, it isn’t. Seahorses are slow, and they cannot deal with strong and swirling seawater currents. What is one of the important needs in a coral reef aquarium? That’s right, strong and swirling seawater currents. These currents are needed for the sake of the corals to keep them healthy. Some corals need less than others, but the need is still there. The currents will also most likely move the food around too rapidly for the seahorses. So, despite the lack of fish, the coral only reef is not a good home for the seahorse.
So where can seahorses be kept? The answer is in a species aquarium, where the seahorses can be accompanied by pipefish if desired and the habitat can be tailored to them. The aquarium need not be large. Seahorses often occupy ‘grassy’ areas and this can be duplicated. Live rock can be placed in the aquarium with a decorative sand bed to create a pleasing picture, and the macro algae Caulerpa can be grown. The Caulerpa will need sufficient lighting which can be provided, if the aquarium is not too deep, by white and actinic fluorescents, the actinic blue being mainly for a ‘dawn/dusk’ cycle. If the Caulerpa growth is successful it will need to be carefully harvested from time to time.
Having live rock in the aquarium will provide bio-filtration, and the bio-load will not be large. Having Caulerpa in the aquarium will have the same effect as an aquarist with a standard reef placing it in a sump: nitrates and phosphates will be used by the algae as nutrients.
Seawater movement should be gentle. A small powerhead or two can be placed in the rear corners of the aquarium, and there should be enough current to make the Caulerpa sway about very gently, like long grass in a light summer breeze.
Feeding can be by frozen shrimp, brine and mysis. Live brine shrimp can be used if available and from a good source. The food will be available to the seahorses without undue competition.
Seawater quality needs to be tested routinely as in a normal marine system and routine seawater changes undertaken.
In a tailored system such as this, the seahorses should be happy and healthy, not being faced with excessive competition and seawater currents, just eating the available food with their tails wrapped around a strand of Caulerpa.
Who knows, all things being equal the aquarist may have the good fortune to see baby seahorses, this time born from the father.