Not moving around

Dear Potter:

Yes, that’s fairly normal behavior for a well-fed seahorse – particularly a stallion.

As ambush predators, seahorses have a relatively sedentary lifestyle compared to more active marine fishes such as tangs, wrasse, and butterflyfish that spend their time swimming back-and-forth tirelessly all day long. Our pampered ponies tend to spend significant portions of their day perched on a convenient hitching post waiting for a suitable prey item to blunder within easy striking distance.

Seahorses are therefore most active when they are busy feeding, courting or conducting their daily greeting ritual, competing for mates or otherwise engaging in various social interactions, or swimming from one hitching post to another. When they get hungry, they may abandon their preferred stealth hunting technique of the ambush and go exploring their tank in search of copepods or amphipods. But they do spend large blocks of time anchored to their favorite hitching posts.

However, there is quite a bit of variation in the daily habits of seahorses depending on gender and individual personalities. All seahorses have distinct personalities. Females generally tend to be more active and outgoing than the males. They will often swim around more and explore the aquarium to a greater extent than the males, which tend to pick out a favorite perch or home base and hang around in the same general area most of the time (think of your Dad hunkered down in his favorite easy chair in the den). As a result, mature males are often naturally more shy and retiring than females, which can be quite brazen at times.

Researchers studying seahorses in the field therefore refer to males as "site-specific" because they can be found at the same tiny patch of reef or seagrass day after day, rarely straying from their chosen spot. I suspect this is due to their parental duties — during the breeding season, pair-bonded males are ordinarily ALWAYS pregnant, and they can’t risk exposing their precious cargo to any more risk than absolutely necessary.) And, of course, a greatly distended brood pouch full of developing young both limits their mobility and makes them more conspicuous to predators, so it behooves gravid males to lay low while they are gestating So normally the unfettered females tend to be far more footloose and fancy free, a little more on the frisky side, and in the wild they typically roam over a home territory of up to 100 square meters centered around their mate’s tiny home base, while the males are often much more reclusive. (I am wondering if both of your pet-shop ponies might be males, Potter?)

Much of the time, both males and females anchor to hitching posts, relying on their camouflage ability to escape notice from predators. In the home aquarium, they quickly learn to associate their keeper with good things such as gourmet Mysis and will then often interact with you whenever you approach the aquarium. But it’s no mistake that, in the aquarium, both of your ponies’ favorite hitching posts is within easy reach of their feeding station, and now that your seahorses have learned where the goodies are going to be deposited at mealtime, they naturally prefer to stay close to their pantry.

One other thing to keep in mind is that seahorses need high levels of dissolved oxygen and low levels of dissolved carbon dioxide in the aquarium, and they will be lethargic and sedentary if the levels of dissolved oxygen are low. So make sure that you have good surface agitation and aeration in your aquarium to promote better oxygenation and to facilitate better gas exchange at the air/water interface, Potter.

If you want to encourage your seahorses to be more active, it’s a good idea to build up a thriving population of Gammarus amphipods in the aquarium. The Gammarus are fast and agile, and very difficult to catch, but seahorses love to slurp them up and they can amuse themselves for hours searching for ‘pods amid the rockwork, macroalgae, and gravel bed in the aquarium, hoping to scare up an unsuspecting amphipod. That’s a good way to provide them with some behavioral enrichment to liven up their day and to give them an opportunity to graze on live treats between meals. As an added bonus, it helps to diversify the diet of the seahorses and watching your seahorses hunting Gammarus can be a lot of fun.

Best of luck with your new ponies, Potter.

Respectfully,
Pete Giwojna, Ocean Rider Tech Support

Dear Potter:

Okay, that sounds like you have already established good water circulation and surface agitation in your seahorse setup, Potter, and the Hydor Koralia 240 Nano Powerhead is a good choice for use in a seahorse tank.

As you know, we are striving for a turnover rate of 5-7 times per hour in a well circulated seahorse setup, Potter, and your Hydor Koralia 240 Nano Powerhead has an output of 240 gallons per hour, so whether or not you have sufficient water flow or should consider adding another Hydor Koralia 240 depends on the size of your seahorse tank. Remember, a turnover rate that is significantly higher than seven times per hour can become problematic for seahorses, and turnover rates that approach are exceed 10 times per hour are almost always too overpowering for the limited swimming ability of the seahorses (depending on whether or not spray bar returns and other measures for moderating are diffusing the water flow are utilized).

But I’m thinking that if you have a Hydor Koralia 240 weighted upwards towards the top of the tank so that it roils the surface, thereby providing plenty of surface agitation, you’re probably already doing very well in that regard without the need for another powerhead. But that something that you might want to consider if there are any dead spots in your seahorse tank once you have completed the aquascaping. It’s just as important to avoid stagnant areas and dead spots in a seahorse tank as and any other marine aquarium.

Also, remember that you do need to take special precautions when using powerheads or internal circulation pumps in a seahorse tank in order to assure that a curious seahorse does not get its tail injured or damaged by the impeller for the powerhead/pump. In general, this just means that whenever the intake for a powerhead pump is large enough to allow an unsuspecting seahorse to get its tail inside, it’s a good idea to shield or otherwise screen off the intake, regardless of how strong the suction may be, just to be on the safe side. Often this merely involves positioning the powerhead amidst the rockwork or anchoring it in place with the suction cup where there’s no possibility for a seahorse to perch on the powerhead or wrap its tail around the inflow/intake for the unit.

The Koralia powerheads are relatively safe compared to other types of powerheads, in that regard, Potter, which is one reason I like the Hydor Koralia Nano Powerheads for use in seahorse tanks. For one thing, since they are not impeller-operated, the intake or suction is fairly weak compared to a normal powerhead, and there is therefore no danger that a curious seahorse will have its tail injured by an impeller. Secondly, the "egg" or basket-like structure that covers the powerhead often offers sufficient protection so that an adult seahorse really cannot injure its tail. For example, the gaps in the Koralia 1 are only 1/8 of an inch wide, which is too small for grown seahorse’s tail to fit to the gaps.

Just to be on the safe side, some seahorse keepers will encase the entire egg for a Koralia powerhead in a veil-like material, especially if they have smaller ponies, as explained below:

<Open quote>
"I have a Koralia that works great in my anemone tankI have a Koralia that works great in my anemone tank(no seahorses). Just in case I bought a piece of Tulle (bridal veil material) to cover it. I got the purple tulle that looks just like coraline algae. Just cut it into a square and put it over the Koralia and secure the ends with a zip tie. Think of it like a lollipop wrapper-if the pump is the lollipop the tulle is the wrapper and instead of twisting the paper at the bottom like a lollipop you secure with a zip-tie. I have H. fuscus and H.barbouri and they could definetly hitch on the Koralia (and I have the nano) The pump still works great and nothing can get in it."
<Close quote>

The Tulle trick will work just as well for screening the intakes of other types of powerheads or circulation pumps as well, and the bridal veil material is not so fine that it will easily get clogged up or impede the flow through the device.

Also, Potter, Koralias have a sort of "flow focuser" that you can snap on the front of the egg to help direct the flow. I would recommend keeping this collar on, since it will act as an additional barrier if a seahorse was to try and hitch to the very front of the egg. (Which seems improbable given the strength of the flow, but it’s better to be safe than sorry!)

However, with the full focuser in place, you will likely find that the water flow from a Koralia is concentrated in a smaller stream and is therefore considerably stronger, so make sure that there’s no danger of overpowering your seahorses with the flow focuser in place.. If that’s the case, that would be better to leave the flow focuser off, since that will diffuse or moderate the water flow from the powerhead.

In general, if your seahorse setup is a relatively small aquarium, the Koralia nano powerheads will more than suffice.

Respectfully,
Pete Giwojna, Ocean Rider Tech Support