Wow, that stranded seahorse was awfully lucky that you came along when you did to rescue him from his plight! If you found him washed up on the Gulf Coast, he has to be a Lined Seahorse (Hippocampus erectus) — what a wonderful find! It’s encouraging that he survived the trip home and it’s a very good sign that a wild seahorse that had just been through such an ordeal has begun eating frozen Mysis for you right away.
You’re absolutely correct, Jen — when feeding seahorses in intricate surroundings like a full-gallon tank full of live rock, 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 your hungry horse can track it all down. Inevitably some of the frozen food will be swept away and lodge in isolated nooks and crannies where the fishes 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. Either outcome can lead to dire problems. The best way to avoid that sort of problem is to target feed your new seahorse, as described below:
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 and 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 scarfing 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?
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.
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.
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.
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. (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. And it’s great for tapping on the cover to ringing the dinner bell and summon the diners for their gourmet feast!)
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.
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.
This is especially important if your rescue seahorse is having problems with positive buoyancy (i.e., the tendency to float), which is hindering his swimming and interfering with his ability to track down the frozen Mysis shrimp.
Another thing that will help clean up the leftovers in your 12-gallon tank is 5-10 Nassarius snails.Nassarius snails are terrific detritivores and amazingly active for snails. They’ll bury themselves until they detect the scent of something edible, and then erupt from the sand and charge out to clean it up. They are great and scavenging the leftovers like frozen Mysis shrimp.
It sounds like your rescue horse is suffering from positive buoyancy — the tendency to float. If he is a male, as indicated by the presence of a pouch on its abdomen at the base of its tail, the problem is most likely to to gas building up within his pouch. This can happen when seahorses are stressed, or kept in an aquarium that’s too shallow, or for quite a number of reasons. Sometimes the gas that builds up is confined to one hemisphere of the pouch only, giving it a lopsided or asymmetrical appearance.
There are a number of ways to release this trapped gas, or flush out the male’s pouch, and I would be happy to discuss them with you, Jen, if you can confirm for me that the seahorse you rescued is indeed a male. The build up of pouch gas is one form of a condition known as Gas Bubble Syndrome (GBS), which can also be treated via a medication known as Diamox (the tablet form of acetazolamide), or even by pressurization in a homemade decompression chamber.
If you can tell me whether or not your seahorse is a male, and also what the water depth is in your 55-gallon and 125-gallon aquaria (i.e., how tall they are), Jen, I can help you determine which of these treatment options might work the best for you and provide you with complete instructions for carrying it out.
Best of luck with your rescue horse, Jen! I hope your back to you again soon.