Re:New to seahorses

Dear Karl:

As an experienced reefkeeper, I’m sure you will do very well with seahorses, sir, and I would be happy to help you get started off on the right foot.

When it comes to the type of environment that’s best for Hippocampus, a certain amount of complexity is desirable in a seahorse setup. For example, a tank with too few attachment sites and hitching posts is a stressful environment for seahorses, as is a sparsely decorated aquarium that leaves these secretive animals feeling vulnerable and exposed. Such sterile environments are commonplace when seahorses are being maintained under laboratory conditions. A Spartan setup facilitates feeding, water changes and maintenance, in general, but it can adversely affect the behavior of the inhabitants and may even prevent captive seahorses from breeding.

Hippocampus relies on camouflage and remaining hidden for its very survival. Seahorses can thus become distressed and agitated if their tank is too barren to provide adequate cover. This is particularly true during courtship and mating when the increased activity level and heightened coloration make them highly conspicuous and vulnerable, and breeding may be severely inhibited under these conditions.

A recent research project that studied the behavior of captive Cape seahorses (Hippocampus capensis) recently confirmed the need for a certain level of complexity in any setup for seahorses (Topps, 1999). The study found that seahorses display more "natural" behavior when they are provided with an elaborate, structured environment that includes a number of different microhabitats (Topps, 1999). These findings are another indication that a sparse setup with inadequate shelter can inhibit the behavior of captive seahorses.

As we’ve been discussing, your seahorse setup should therefore include plenty of hiding places and sight barriers such as live rock, real or artificial corals, and macroalgae. A well-planted tank with lush beds of colorful macroalgae simulates the natural seagrass habitat of many seahorses quite nicely, but they will do equally well in a coral reef biotope consisting of seahorse-safe live corals. Given your background as a reefer, I would suggest setting up a modified reef tank for your seahorses, Karl. For best results, you would need to limit yourself to live corals that don’t require high intensity lighting and that can be do well with relatively moderate water movement. Many of the soft corals, along with certain SPS corals, fit the bill nicely.

If you are going to do a modified reef tank with seahorse-safe corals, then the aquascaping can be much the same as in most any reef system, minus the LPS corals and decorative clams that should be avoided with seahorses. If you contact me off list ([email protected]), I can send you detailed information explaining how to seahorse-proof a reef tank and adjust the lighting and water circulation, along with lists of compatible corals, corals that can be considered under the right circumstances (proceed with caution), and corals and invertebrates that should be avoided altogether.

However, Karl, you must take care when feeding seahorses in such an elaborate setup, as I have discussed on this forum many times. Whether it is a live rock tank, a modified minireef, a seagrass system or a mangrove biotype, a well-designed seahorse setup is an elaborate environment. A certain level of complexity is necessary in order to assure that our seahorses behave naturally (Topps, 1999) and to provide our ponies with plenty of hitching posts and shelter, and enough sight barriers to assure them a little privacy when they feel the need to be alone.

Their homemade habitat may thus take the form of a labyrinth of live rock, an intricate arrangement of corals and gorgonians, a well-planted bed of seagrass or macroalgae, or a full-fledged reef face. When feeding seahorses in such intricate surroundings, the worst thing you can do is to scatter a handful of frozen Mysis throughout the tank to be dispersed by the currents and hope that the hungry horses can track it all down. Inevitably some of the frozen food will be swept away and lodge in isolated nooks and crannies where the seahorses cannot get it. There it will begin to decompose and impair your water quality, which is why ammonia spikes are common after a heavy feeding. Or it may be wafted out into the open again later on and eaten after it has gone bad, where a hungry seahorse may discover it and scarf up the bacteria-laden Mysis. Either outcome can lead to dire problems.

Using a feeding station or target feeding your seahorses, and diligently cleaning up any leftovers afterwards can avoid this. That is absolutely imperative when maintaining seahorses in an appropriately elaborate environment. An efficient team of aquarium janitors and scavengers can also be a big help with the tidying up.

The best way to avoid such problems is to target feed your seahorses or set up a feeding station for them. See my online article in Conscientious Aquarist for a detailed discussion explaining exactly how to set up a feeding station and train your seahorses to use it:

Click here: Seahorse Feeders
http://www.wetwebmedia.com/ca/volume_2/cav2i5/seahorse_feeders/seahorse_feeders.htm

But I prefer to target feed my seahorses instead. The individual personalities of seahorses naturally extend to their feeding habits. Some are aggressive feeders that will boldly snatch food from your fingers, while some are shy and secretive, feeding only when they think they’re not being observed. Some like to slurp up Mysis while it’s swirling through the water column, and some will only take Mysis off the bottom of the tank. Some are voracious pigs that greedily scarf up everything in sight, and some are slow, deliberate feeders that painstakingly examine every morsel of Mysis before they accept or reject it. Some eat like horses and some eat like birds. So how does the seahorse keeper make sure all his charges are getting enough to eat at mealtime? How does the hobbyist keep the aggressive eaters from gobbling up all the mouth-watering Mysis before the slower feeders get their fair share? And how can you keep active fishes and inverts with seahorses without the faster fishes gobbling up all the goodies before the slowpoke seahorses can grab a mouthful (Giwojna, unpublished)?

Target feeding is the answer. Target feeding just means offering a single piece of Mysis to one particular seahorse, and then watching to see whether or not the ‘horse you targeted actually eats the shrimp. Feeding each of your seahorses in turn that way makes it easy to keep track of exactly how much each of your specimens is eating (Giwojna, unpublished).

There are many different ways to target feed seahorses. Most methods involve using a long utensil of some sort to wave the Mysis temptingly in front of the chosen seahorse; once you’re sure this has attracted his interest, the Mysis is released so it drifts down enticingly right before the seahorse’s snout. Most of the time, the seahorse will snatch it up as it drifts by or snap it up as soon as it hits the bottom (Giwojna, unpublished).

A great number of utensils work well for target feeding. I’ve seen hobbyists use everything from chopsticks to extra long tweezers and hemostats or forceps to homemade pipettes fashioned from a length of rigid plastic tubing. As for myself, I prefer handfeeding when I target feed a particular seahorse (Giwojna, unpublished).

But no doubt the all-time favorite implement for target feeding seahorses is the old-fashioned turkey baster. The old-fashioned ones with the glass barrels work best because the seahorses can see the Mysis inside the baster all the way as it moves down the barrel and out the tip. By exerting just the right amount of pressure on the bulb, great precision is possible when target feeding with a turkey baster. By squeezing and releasing the bulb ever so slightly, a skillful target feeder can keep a piece of Mysis dancing at the very tip of the baster indefinitely, and hold the tempting morsel right in front of the seahorse’s mouth as long as necessary. Or if the seahorse rejects the Mysis the first time it drifts by, a baster makes it easy to deftly suck up the shrimp from the bottom so it can be offered to the target again. In the same way, the baster makes it a simple matter to clean any remaining leftovers after a feeding session (Giwojna, unpublished). (You’ll quickly discover the feeding tube is also indispensable for tapping away pesky fish and invertebrates that threaten to steal the tempting tidbit before an indecisive seahorse can snatch it up.)

In short, target feeding allows the hobbyist to assure that each of his seahorses gets enough to eat without overfeeding or underfeeding the tank. And it makes it possible to keep seahorses in a community tank with more active fishes and invertebrates that would ordinarily out-compete them for food, since the aquarist can personally deliver each mouthful to the seahorses while keeping more aggressive specimens at bay (Giwojna, unpublished).

The key to keeping active specimens like firefish or cleaner shrimp successfully with seahorses is to feed the other fish and inverts with standard, off-the-shelf aquarium foods first, and once they’ve had their fill, then target feed the seahorses.

A good protein skimmer is an optional piece of equipment for a seahorse system, rather than a prerequisite, Karl, but I highly recommend them in most cases. As long as you can maintain good water quality without a protein skimmer, then excluding one is not a big deal at all. But if you do without a protein skimmer, then you should be prepared to carry out an accelerated maintenance schedule with more frequent partial water changes in order to assure that the water chemistry stays right where you want it and that you can keep the nitrates below 20 ppm.

There is a fairly simple way to roughly determine whether or not the water movement and circulation in your seahorse tank is adequate, under circulated or too overpowering. As a general rule of thumb, if your filter and power heads are not turning over the entire volume of your seahorse tank at least 3-5 times per hour, then the aquarium is under circulated. So just total up the number of gallons per hour that your filter and powerheads pump out and divide that number by the capacity of your aquarium (its volume in gallons), and you can get a rough gauge of where things stand. Ideally, that calculation will come out to be around 5; if it’s lower than that, you can probably stand to increase the water flow a bit, and if the figure works out to be less than three, then you definitely need to step up the circulation. Likewise, if the number comes out to be considerably greater than 5, then you probably need to tone down the water movement somewhat. However, that being said, you can achieve much higher turnover rates in a tall seahorse tank without generating too much turbulence or producing water currents that are too strong if you use a spray bar return or waterfall return to attenuate the discharge from the filter. Remember, adequate surface agitation to promote efficient oxygenation and gas exchange at the air/water interface is just as important as the overall water movement.

Here’s what I normally advise hobbyists with regard to the water movement in their seahorse tanks, Karl:

<Open quote>
Water Circulation

Time and time again I find that home hobby tanks have far too little water movement. In my experience, most seahorse setups are chronically undercirculated, a serious mistake for small, closed-systems aquaria, and our pampered pets often suffer as a result. Many hobbyists are overly conscious of the seahorse’s inactive life style and limited swimming ability, and have adjusted their flow rates accordingly, resulting in less water movement than desirable. In actuality, seahorses prefer moderate water movement, including some areas of brisk current, providing there are also sheltered spots and some areas of relatively slack water they can move to when desired. Slack water means comparatively low flow, NOT stagnant conditions! Avoid dead spots and stagnant areas at all costs.

I have often discussed this matter with professional divers and collectors who regularly encounter seahorses in the ocean, and they report that the horses are often found where you would least expect them — well offshore and thriving in areas with powerful currents. For example, here is how Paul Baldassano, a commercial diver in New York who makes his living collecting sea urchins, describes the behavior of his local seahorses:

"In regard to seahorses in the wild, I occasionally see Hippocampus erectus in the wild while SCUBA diving but never in the places where they are supposed to be. I see them in the open sea far from shore and also in areas with large rocks and very strong currents. The last one I saw was in a channel off the south shore of Long Island New York in water about 12 feet deep. The current was so strong that I had to hold on to the rocks so as not to be swept away. This Hippocampus erectus was having no trouble staying there munching on the abundant plankton. Apparently they find places near the rocks where there is no current because as you know they are lousy swimmers. There is also a large population of seahorses in a similar area in another part of the New York shore, but I think it is best not to divulge that location for obvious reasons (Baldassano, pers. com.)."

Neil Garrick-Maidment, a very successful seahorse breeder in the UK, reports much the same thing:

"Whenever I have dived on Seahorse sites I have always been amazed by the currents and tides that this very fragile looking Seahorse lives in. We often find Seahorses in flat muddy/silt areas nowhere near rocks or weed. These areas are often scoured by strong currents and the Seahorses do well in them and seem completely unperturbed by the current. In setting up a tank for them I try to remember the feeling I had in those areas and replicate them. (Garrick-Maidment, Jun. 2002)."

Likewise, David Warland, a fish farmer and commercial seahorse breeder in Port Lincoln, Australia, reports he often finds Hippocampus abdominalis perching on the tuna net enclosures at the farm in deep water:

"The Horses that are around the farms have traveled vast distances over plain sand/mud to get to the farms, which are in at least 20 meters of water, and are miles from the nearest land or shallow water (Warland, pers. com.)."

And Jorge Gomezjurado, the Senior Aquarist at the National Aquarium in Baltimore, recommends the following when it comes to water movement:

"I personally believe that current and water dynamics are very important for Syngnathids. In nature they live in areas with active water movement.(i.e., tides in mangrove lagoons and estuaries, coral reefs, kelp forests, etc.). Why don’t give them the same environmental conditions in captivity? Our small tanks (90 gallons) also have large turnovers on an average of 5 gpm (or 300 gph). It is very important that the current is steady and directional constant, which allows the animals to find a good spot to hold and they will not be pulling in different directions all the time."

The point is that, as long as slack-water retreats are available, the greater seahorses can tolerate far more current than most folks suspect and good circulation is as important for a seahorse setup as any other aquarium. I cannot emphasize that enough.

For example, in addition to an external power filter, my SHOWLR system also has a 200 gph powerhead with a sponge pre-filter positioned right near the top for surface agitation and extra water movement, with additional small powerheads used as needed to eliminate any dead spots along the substrate or behind the rockwork. I like to give my seahorses as much current as they can handle without getting blown around.

In short, if your filtration is not turning over the entire volume of the aquarium a MINIMUM of 5 times per hour, your seahorse setup is probably undercirculated. With a spray bar return raised above the surface of the water to diffuse the outflow, you can achieve turnover rates of several times that much without producing too much turbulence or current for seahorses. A waterfall return is another good way to diffuse the output from your filter, and also works well for seahorses. There will be an area of relatively vigorous water movement at one end of the aquarium underneath and nearby the waterfall, while the other end of the tank is a relatively low flow area.

But as with anything, too much of even a good thing can be undesirable, and too much current can overwhelm the limited swimming ability of Hippocampus. One indication that you may have too much water movement in your seahorse tank is if the seahorses are getting buffeted around by the currents, and whisked away uncontrollably when they tire of fighting the current. Or alternatively, they may stay perched in one place all the time and refuse to swim around and explore their tank for fear of getting swept away by the current if they relax their grip on their hitching posts. So you can get a pretty good gauge of how well the seahorses are able to cope with the water movement than their tank by observing how the current affects the swimming ability.

Likewise, if a mated pair of seahorses is consistently spilling eggs during the copulatory rise, that’s another pretty good indication that there may be too much turbulence or water movement in the upper reaches of their aquarium.

If the seahorses are having difficulty tracking their prey and eating because the current whisks the frozen Mysis past them too quickly to target it accurately and slurp it up, that’s another red flag. Often that situation can be corrected simply by adjusting the output from your filter to reduce the current during feeding time or turning it off altogether while a seahorses are eating.

But as long as your seahorses aren’t getting buffeted around, aren’t routinely dropping eggs during disrupted mating attempts, and aren’t having difficulty targeting their prey and eating, there’s really no such thing as too much water movement. In general, the stronger the water flow, the more important it is to keep the water currents steady and unvarying so the seahorses can establish holding areas in the sheltered spots and low-flow zones downcurrent without getting blindsided by unpredictable currents. Just make sure your seahorses are not getting trapped against overflows and be sure to screen off the intakes for any powerheads. Powerheads can be switched off at feeding time, if necessary.

Best of luck with the new seahorse system you and your wife are planning, Karl! Contact me off list and I will provide you with a lot more information in that regard, sir. In the meantime, just let us know if you have any further questions.

Happy Trails!
Pete Giwojna