Newbie question

Dear Ruben:

With your background as a reefkeeper, you certainly have the aquarium knowledge to be a very successful seahorse keeper, sir.

The aquarium parameters you outlined would be excellent for most any tropical seahorses, and Hippocampus will often thrive in a properly designed refugium with sufficient height. Whether or not your 10-gallon refuge fits the bill depends largely on how tall it is.

In my experience, most refugia lack sufficient height to be suitable for the greater seahorses. Seahorses need vertical swimming space in order to complete the copulatory rise and transfer of the eggs, and they are susceptible to depth-related conditions such as gas bubble syndrome (GBS), a potentially fatal affliction caused by gas emboli forming within the seahorse’s blood and tissue. The greater hydrostatic pressure at increased depth is known to protect seahorses against GBS, whereas the reduced hydrostatic pressure in shallow aquaria is known to be conducive to GBS. For this reason, tanks that are at least 20 inches tall (the taller the better) are preferred for a seahorse setup. Shallower aquaria may prevent successful breeding and result in chronic problems with subcutaneous emphysema, pouch emphysema, or other forms of GBS. Due to a lack of height, the typical refugium is simply not the best choice for the long-term health of large seahorses.

If you’re 10-gallon refuge has similar dimensions to a standard, off-the-shelf 10-gallon aquarium, that it would be only suitable for the smaller breeds of seahorses. For example, Ruben, if you could maintain an adequate feeding density of newly-hatched live brine shrimp (Artemia nauplii), your refuge is certainly spacious enough to house an entire colony of dwarf seahorses (Hippocampus zosterae). Several dozen dwarfs would happily coexist in a 10-gallon refugium with inadequate supply of bbs.

But I would not recommend keeping dwarf seahorses in the refugium of a reef tank because such a setup would have chronic problems with hydroids, which pose a great risk to these pint-size ponies. So I don’t think that’s a possibility in your case, sir.

If you could keep your refugium cool enough (72°F-75°F at all times), then your 10-gallon refugium would make a fine home for a pair of Zulu-lulus (H. capensis), but it sounds like your refuge maintains a water temperature of around 76°F, and Zulus are temperate seahorses that do best and somewhat cooler temps than that. They are very susceptible to heat stress and don’t do well in aquaria that run at water temperatures much above 75°F.

If your refuge could maintain a constant temperature of 76°F, with no temperature spikes above that temperature, then a pair of Zulus might do well for you. If you do a search on this forum for dwarf seahorses (Hippocampus zosterae) or for Zulus (Hippocampus capensis), you will find a great deal more information on these two small seahorse species.

If you’re 10-gallon refugium is close to 20-inches tall, then a pair of Mustangs or Sunbursts could thrive in it at a temperature of 76°F, Ruben. Mustangs or Sunbursts (Hippocampus erectus) would be a great choice for your first seahorses, but they wouldn’t do well over the long term in a refuge that was significantly shorter than 20 inches.

Another thing to keep in mind when adding seahorses to a refugium is that they can rapidly deplete the population of copepods and amphipods within such a confined space, which defeats one of the primary purposes of establishing a refugium. This can be counterproductive if the aquarist is relying on his refugium to seed the main tank with ‘pods or to provide larval Crustacea and zooplankton for their corals and reef invertebrates.

So, depending on how tall your ‘fuge is, Ruben, and the type of corals and inverts your reef system contains, a better option for you may be to seahorse proof your reef tank and keep your seahorses in the main tank instead. Seahorses typically thrive in the right type of reef system, which provides them with pristine water quality, plenty of roam to roam, assorted ‘pods to graze on between meals, and a colorful, natural setting that makes them feel right at home. The multicolored coral background will keep them looking their best and brightest, and nothing makes a more breathtaking exhibit than brilliant yellow and orange seahorses lazily gliding amidst the lovely corals, polyps and gorgonia in a well-established minireef, much like the butterflies adorning a beautiful flower garden.

If that’s something you may want to consider, Ruben, let me know what type of fish, corals, and inverts are in your reef system and I can give you a better idea if your reef tank might make a good home for seahorses.

Best wishes with all your fishes (and invertebrates), Ruben!

Happy Trails!
Pete Giwojna

Dear Ruben:

Okay, providing you target feed them, seahorses should do well with all of the fish and invertebrates in your reef system, with the possible exception of the clam and the bubble coral. I have had a few reports over the years from hobbyists that had Tridacna clams that clamped down on the tail of one of their seahorse. Such cases seem to be the exception rather than the rule, and the seahorses generally emerge unharmed after such an ordeal, but as you can imagine, such an experience could be quite stressful for the unlucky seahorse. I know a number of reefkeepers who keep clams and seahorses together without any such incidents or problems, but you should be aware that it’s a possibility.

Bubble coral is an LPS coral that has a pretty potent sting but its tentacles are normally only exposed after dark, when the bubblelike vesicles are deflated, whereas the seahorses are active by day, so if you observe the proper precautions, it may do well with seahorses that are reef specialists such as Hippocampus barbouri, which are said to be impervious to the stings of stony corals.

If you think that is something you might want to consider, please contact me off list and I will be happy to send you lots of detailed information on keeping seahorses in a reef system, which should explain everything you need to know in that regard. You can reach me at the following e-mail address: [email protected]

Best of luck with your reef tank, sir! It sounds like you have created a beautiful microcosm in your reef system.

Respectfully,
Pete Giwojna