I am pleased to hear that your husband enjoyed the tour of the Ocean Rider aquaculture facility and seahorse farm during his visit to Hawaii — that is an experience that anyone with an interest in seahorses would find thrilling and thoroughly fascinating (the spectacular seadragons alone are worth the price of admission)!
When considering whether or not your particular community tank would be suitable for a pair of large seahorses, Debi, the two primary concerns we must examine our behavioral issues and feeding issues. Physically, the actual setup of your marine aquarium is excellent for seahorses. It has the superior height that is so important for seahorses as well as plenty of water volume for the community of fish you are keeping, meaning that there should be plenty of room to accommodate a pair of seahorses as far as the carrying capacity of your aquarium goes, and my preferred setup for seahorses is a FOWLR supplemented with a good protein skimmer, so I foresee no problems in that regard.
Regarding the specimens you are keeping, soft corals in general, Scarlet reef hermit crabs (Paguristes cadenati), cleaner shrimp (Lysmata amboinensis), and gobies in general make fine tank mates for large seahorses. And "Nemo clownfish" — percula clowns (Amphiprion Percula) and false percula clowns (Amphiprion occelaris) — are the ONLY clownfish that I recommend keeping with seahorses. Behaviorally, I agree with your assessment — the six line wrasse, Foxface rabbitfish, and lyretail Anthias will most likely simply ignore the seahorses, rather than reacting to them territorially or aggressively. The seahorses are so different in appearance and behavior that they are unlikely to be regarded as unwelcome competitors or unwanted intruders.
So in terms of the other inhabitants behavior, I believe that a large pair of seahorses such as Mustangs or Sunbursts (Hippocampus erectus) could do well in a tank like yours. I am a little leery of the pinkie-finger sized cleaner crabs simply because I don’t know which type of crabs you actually have, and crustaceans in general are not trustworthy with seahorses once they grow to a certain size. It would be helpful to know what species your cleaner crabs are, Debi, so that I will have an idea what size they may grow to. (Crabs and crustaceans in general are opportunistic predators that are likely to attack anything they can overpower. They may be entirely peaceful and inoffensive when they are small, but even a small crab can cause a lot of trouble as it grows. They may double in size following a molt (i.e., ecdysis) so they grow surprisingly fast, and even a tiny crab that’s completely docile at first can grow large enough to turn predatory almost literally overnight if it’s a species that reaches a respectable size. One day it’s a miniature crab that’s cute and entertaining in its own bumbling sort of way, and the next day following a successful molt, it can become a dangerous bully that regard its tankmates with a culinary eye.)
If you can identify your cleaner crabs for me, Debi, I can give you a better answer as to their compatibility; otherwise, be prepared to relocate the cleaner crabs if you want to give seahorses a try in your community tank.
That brings us to the feeding issues, Debi, which are definitely an area of concern with your particular tank. The clownfish, six line wrasse, Foxface, and Anthias are all active, aggressive feeders that will have a great liking for the frozen Mysis that will be the staple diet of your seahorses. Since the seahorses orient to the substrate of the aquarium, and must wait for the frozen Mysis to drift down to them within reach, the other fish are going to have first crack at the food while it is suspended in the water column.
The feeding system you are currently employing in your community tank is what I call "scatter feeding" or "broadcast feeding," which is frowned on by seahorse keepers under most circumstances because target feeding the ponies or teaching them to eat their frozen Mysis from a feeding tray are much better options for most hobbyists. Seahorses certainly do grab frozen Mysis as it is floating by, and they will carefully search over the bottom for leftover frozen Mysis when they are scatter fed, Debi. In fact, seahorses are more apt to aggressively snap up the frozen Mysis when it is moving, drifting by a lifelike manner. But seahorses are deliberate feeders that must track their prey carefully and then slurp it up from a very short distance away, and if the frozen Mysis is whisked past them too fast, they will be unable to target it properly and feed until it has settled on the bottom.
With this feeding method, Debi, the problem is not going to be getting the seahorses to eat the frozen Mysis when it is broadcast fed, but rather to make sure that they get their fill at feeding time, since the other fish are much faster and can easily outcompete them for the leftovers. You’re going to have to experiment to determine the right amount of frozen Mysis to add to your feeding cups in order to assure that the seahorses get enough to eat during the feeding frenzy.
That’s not as easy as it sounds, since if you go overboard and add too much of the frozen Mysis, overfeeding will cause a whole new set of problems. The worst thing you can do when feeding the seahorses in a intricate reef or live rock environment is to overfeed the tank and scatter a handful of frozen Mysis throughout the aquarium 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.
So the challenge you’re going to face when feeding the seahorses is to determine the right amount of frozen Mysis to add to your feeding cups in order to make sure that the seahorses are getting enough to eat at mealtime WITHOUT overfeeding the tank in the process. A good cleanup crew can be enormously helpful for cleaning up leftovers when you are broadcasting the food throughout the tank, Debi, so you may want to bolster your cleanup crew by adding lots of nassarius snails and more microhermit crabs.
Providing you can work out the proper amount to feed during each meal, I do feel that a pair of seahorses could do well in a community tank such as yours, as long as you stick with hardy, highly domesticated seahorses like Ocean Rider Mustangs and Sunbursts that are hearty heaters and can hold their own in mixed company.
It’s usually best to avoid otherwise docile tankmate for seahorses if they are aggressive feeders that could out-compete them for food, Debi. 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 your Foxface and Anthias, 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 six line wrasse and even the cleaner shrimp. 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 percula clownfish, Lyretail Anthias, (or a Foxface RabbitFish) 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.
And if you scatter feed the frozen Mysis and figure out the proper amount to add to your feeding comes so that you avoid underfeeding or overfeeding the ponies, that can also work well. Hardly an insurmountable problem.
Aquarists that are accustomed to catering to the demands of delicate wild-caught seahorses routinely exclude all butterflies, tangs, rabbitfish and wrasses as a matter of course, and rightly so. But as long as your tank is big enough, such precautions are no longer strictly necessary when it comes to farm-raised seahorses that are born and bred for life in the aquarium. For example, here’s an example of such a mixed community including Ocean Rider seahorses that’s proven to be very successful for a home hobbyist:
“My tank is a 150 gallon tall (3 1/2 feet) with a 50 gallon sump system giving me 200 gallon volume of water!! a good amount of live rock (approximately 125 pounds)! I use Aragonite sugar sized oolitic sand. For filtration and circulation I use a Rio 3500 with a backpack overflow and I have a protein skimmer, UV sterilizer, two sponge filters, a magnum 350, an emperor 400 and I use purigen — NO carbon.
I house approximately 30 sea horses along with a lot of snails both turbo grazers and Nassarius for detritus! I keep two scooter blennies, several wrasses, 3 butterfly fish, and a naso and kole tang! I also have 3 clowns. Usually you don’t see sea horses in a tank with fish and normally this might be a problem! However, I have ONLY … captive raised sea horses and they were in the tank first and I decided to try the fish with a second tank cycled and in the wings to move the fish to should it have been an issue! Well the … horses were not ill effected at all — in fact the truth be told the sea horses were somewhat bullish with the fish (Susan, 2003).”
I’ve said it before and I’ll say it again: wild-caught seahorses and their captive-bred counterparts are very different animals. These differences extend to the types of fishes that make satisfactory tankmates for each. The feeding habits of farm-raised seahorses make it possible to keep them with fishes that would be absolutely out of the question for wild horses.
In short, Debi, I do think it’s worth trying a pair of Mustangs or Sunbursts in your community tank, providing you are willing to target feed the seahorses or to work out the proper amount of frozen Mysis to use when scatter feeding them. Ideally, the seahorses would be the first fish to be introduced to the aquarium, rather than the last, but as we have already discussed, I don’t believe the fish in your marine aquarium are likely to react aggressively towards the seahorses at all.
If you want to give the seahorses a try, go ahead as long as you stick with hardy, highly domesticated, High-Health Mustangs or Sunbursts, but have a Plan B ready to put into action just in case things don’t go as planned. In your case, that could be relocating the seahorses to a sheltered area in your sump temporarily if they are being harassed in any way by the established residents of the tank.
Also, before you give it a go, I would encourage you and your husband to complete the Ocean Rider training program for new seahorse keepers. It’s completely free of charge at this correspondence course that is conducted entirely via e-mail. If you want to give the training course to try, just contact me off list ([email protected]) with a quick e-mail that includes your full name (first and last), and I will get you started off with the first lesson right away.
Best wishes with all your fishes, Debi!