the re-accuring theme: tank mates

Dear Greg:

Yes, that sounds like a wonderful seahorse setup you are planning, sir! However, for the substrate, I would avoid the use of crushed coral. It tends to get compacted and welded together in a concrete like mass over time in a marine aquarium. I would stick with a fine-grained oolitic sand for the main tank. If you want to use a deep live sand bed, that’s best installed in the sump rather than the main tank.

I really like the way you are planning to arrange your rockwork, but I just wanted to remind you that 1-2 pounds of live rock per gallon is generally considered adequate for carrying out all of the nitrification and denitrification your aquarium will require. In other words, you don’t need to pack the tank with 3-4 pounds of live rock per gallon for the sake of the biofiltration — that’s about twice as much as you will need in that regard — unless you want to add more live rock for aesthetic purposes in order to create overhanging ledges, caves, and arches.

Two other things to bear in mind with the intricate rockwork structures you have in mind, Greg: (1) it’s very important to anchor the rockwork securely in place to avoid collapses or slipping rocks that could injure the aquarium inhabitants or scratch acrylic and possibly even break the glass; and (2) it’s equally important to avoid broadcast feeding in a complex environment such as you’re planning.

Feeding Seahorses

When keeping seahorses in an appropriately elaborate environment, it is imperative that you feed them properly! Domesticated seahorses thrive on enriched frozen Mysis as their staple, everyday diet. But the worst thing you can do when feeding the seahorses in a intricate reef or live rock environment 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 (Giwojna, 2005). There it will begin to decompose and degrade the 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 begun to spoil. Either outcome can have dire consequences (Giwojna, 2005).

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

Personally, 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 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 and occelaris clownfish 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 (Giwojna, unpublished).

When it comes to compatible tankmates and stocking your aquarium, Leslie is right on the button. Banggai Cardinalfish and Amphiprion occelaris or A. percula clownfish (sans anemone) will do fine with your seahorses as long as you feed them properly, as discussed above. Neon gobies are quite territorial and antagonistic towards one another, so a single individual or mated pair would probably be best. You can try a Mandarin goby and if it learns to take frozen Mysis, as I’ve found they sometimes do when they are maintained with seahorses, it may also do well. Or you can supplement the pod population periodically, just as Kris suggested. And a royal gramma would be a much better choice than the marine betta considering the assortment of small fish you are considering.

I have found that the royal gramma (Gramma loretto) does great with seahorses. Royal grammas are highly territorial and very quarrelsome amongst themselves, but for all practical intents and purposes, it’s been my experience that they utterly ignore seahorses (and vice versa). They have brilliant colors, a docile disposition towards seahorses, and are deliberate feeders that won’t outcompete the ponies at mealtime. As long as you are willing to limit yourself to just one Royal Gramma and quarantine it before you introduce it to the main tank, I’m quite confident it will make a wonderful addition to your seahorse tank. A Gramma would thrive amidst all the rockwork in your tank, Greg — they love to dart in and out of the holes and caves in the rocks and hole up under overhanging ledges.

Bob is basically correct too when he states that it’s usually best to avoid otherwise docile tankmates for seahorses tankmate for seahorses if they are aggressive feeders that could out-compete them for food. However, I find that such concerns are generally unwarranted when it comes to farm-raised seahorses that eat frozen foods. In the bad old days of seahorse keeping, it was indeed absolutely imperative to avoid keeping active fishes that were greedy eaters with wild-caught seahorses that were dependent on live foods. It was difficult enough to come up with sufficient live food for the seahorses in the first place, and active fishes would greedily dart around the tank and busily scarf up all the live food before the horses got much more than a taste. But that is no longer the case with Ocean Rider seahorses, and the feeding habits of potential tankmates need no longer be an overriding concern (Delbeek, Oct. 2001).

Although competition for food is always an issue with seahorses, it is no longer sufficient reason to automatically exclude entire categories of fishes as potential tankmates. There’s no denying that Longnose Hawkfish (Oxycirrhites typus), for example, are active feeders; they will definitely love the taste of frozen mysis and can complicate feeding your seahorses. Same with your clownfish and Cardinalfish. But there are ways around that…

For instance, the same thing is true with regard to pipefish and decorative shrimp, yet no one disputes that they make splendid companions for seahorses. Nowadays, almost every seahorse setup includes a few Peppermint Shrimp (Lysmata wurdemanni), Scarlet Cleaner Shrimp (Lysmata amboinensis), or Fire Shrimp (Lysmata debelius). They are popular additions to a seahorse tank because hobbyists like to use them to augment their cleanup crews and add a splash of color and activity to their tanks. Aside from their utility as attractive scavengers, they often perform a useful service by grooming the seahorses, which is fascinating to watch, and regularly reproduce, releasing swarms of nauplii many seahorses love to eat. Peppermint Shrimp are especially popular because they are natural predators of Aiptasia rock anemones and do a wonderful job of eradicating these pests from the aquarium.

Yet once established in the aquarium, those beautiful red shrimp species are much more active feeders than seahorses. They’ll come flying across the tank the moment that enticing scent of frozen mysids hits the water, raiding the feeding station and snatching mysis right out of the ‘horse’s snouts. Does that mean they’re incompatible with seahorses? Heck no, you just shoo the pesky shrimp out of the way at dinnertime and target feed the seahorses, making sure each of them gets its fill. Well, a Longnose Hawk is no more of an aggressive feeder than the ever-popular cleaner shrimp are, and no more difficult to deal with than the mischievous shrimp at feeding time.

For captive-bred seahorses, which eat enriched frozen mysis as their staple diet, it is customary to feed the more active fish and inverts their fill of standard aquarium foods first, and then target feed the seahorses with frozen mysis, using the feeding wand or baster to discourage any fishes that might try to steal a bite while the seahorses are eating (Delbeek, Oct. 2001). This works quite well providing the fishes are suitable tankmates for seahorses.

That’s SOP for many seahorse keepers and is not much different than the situation in a species tank when one of your seahorses is an aggressive eater with an insatiable appetite that tends to monopolize the feeding station, and one of your other seahorses is a deliberate feeder that has to examine every morsel of mysis forever before he finally eats it. Hardly an insurmountable problem. Just remember the following when you’re stocking your new aquarium, Greg:

All fishes that are intended as tankmates for seahorses MUST be quarantined first without exception. For the same reasons we discussed earlier with regard to wild-caught seahorses, any fish you bring home from your LFS is a potential disease vector for all manner of nasty pathogens and parasites, and you need to take every possible precaution to prevent these from being introduced to your display tank.

Best of luck with your new aquarium, Greg!

Happy Trails!
Pete Giwojna