Seahorse not Eating

Dear Jamie:

if you are q certain that offering choice live foods won’t tempt your female Hippocampus kuda to eat, then the first things I would concentrate on are increasing the aeration and surface agitation in your Biocube to raise the levels of dissolved oxygen and performing a series of water changes to improve the water quality even if the basic parameters (ammonia, nitrite, nitrate, pH and specific gravity) look good.

In the meantime, I would be happy to discuss some of the things that have been known to cause a seahorse to stop eating and what to do about these common causes for a hunger strike.

For starters, I have listed some of the factors that are commonly known to contribute to a loss of appetite in seahorses:

(1) deteriorating water quality.

(2) low oxygen and/or high CO2 levels.

(3) a deficiency of trace elements and minerals.

(4) various disease processes — in particular, internal parasites.

Regardless of how your water chemistry appears right now, a good place to start addressing this problem would be to perform a 25%-35% water change immediately to safeguard the water quality and replenish depleted trace elements and minerals. (At first glance your aquarium parameters may look great, but there are some water quality issues that are difficult to detect with standard tests, such as a decrease in dissolved 02, transitory ammonia/nitrite spikes following a heavy feeding, pH drift, a deficiency and trace elements/minerals, or the gradual accumulation of detritus. A water change and cleanup is a simple preventative measure that can help defuse those kinds of hidden factors before they become a problem and stress out your seahorses. These simple measures may restore your water quality as well as your seahorses’ appetite.)

Be sure to check your dissolved oxygen (O2) level in addition to the usual pH, ammonia, nitrite and nitrite readings.. A significant drop in O2 levels (6 – 7 ppm is optimal) or rise in CO2 levels is very stressful yet easily corrected by increasing surface agitation and circulation to promote better oxygenation and gas exchange. Add a shallow airstone just beneath the surface if necessary and increase the circulation throughout your tank it possible.

Whether the beneficial effects are due to improving water quality or replenishing depleted trace elements or something else altogether, performing a major water change as described above often sets things right when seahorses are off their feed for no apparent reason.

If you improving the water quality and raising the level of dissolved oxygen in the aquarium don’t restore your female’s appetite, Jamie, then it’s time to consider force-feeding (i.e., feeding by hand) or tube feeding the seahorse instead in order to provide it with nutritional support. Those are the only remaining options if the seahorse refuses even choice live foods…

Before you resort to the more invasive tube feeding, Jamie, I suggest that you try force feeding your female by hand. By handfeeding in this case I mean holding one entire, intact (whole and unbroken) frozen Mysis that you have carefully thawed in your fingertips and then placing the tail of the Mysid directly in the mouth of the seahorse. Many times the seahorse will simply spit it out again, but often if you can insert the Mysis into her open mouth far enough, her feeding instincts will kick in and take over so that she slurps up the frozen Mysis almost reflexively. That’s a much less stressful and less invasive method of force feeding a seahorse that sometimes works well (especially if the seahorse is accustomed to being hand fed and doesn’t shy away from the aquarist). Force feeding the seahorse by hand sounds much more difficult than it actually is, and seahorses will often respond well to this method of feeding, Jamie. Even the professional curators at the large public aquariums will use this technique when their highly prized (and very expensive) seadragons are experiencing problems with weak snick, as explained in the discussion thread below:

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Has anyone had problems with syngnathids having a problem
getting food into their mouths? Currently I have a few ribbon
pipehorses (seadragons) that have lost the ability to take in food,
either live or frozen when attempting to eat. It is as if they have
lost the suction power when they attempt to snap up the food. They
can see the food and chase it and attempt to eat but don’t have
enough snap to create the suction needed to get the piece of food
into its mouth. Even when putting the affected animal in a smaller
tank with lots of food, it still can’t get the food in.

This condition seemed to develop even though the ribbon
pipehorses were eating aggressively before the problem started. They
were mainly eating frozen mysis and occasionally were fed live mysis.
I was thinking that possibly the diet of mainly frozen mysis could
not be enough for them nutritionally as they were developing??? Not
sure.

I have occasionally seen this problem before in weedy and
leafy seadragons as well as some seahorses.
Has anyone else had this problem? Any ideas of what may
cause this problem? Any ideas on how to get them to eat again? Has
anyone had luck with force feeding seadragons to get them to eat
again?

Thanks,
Leslee Matsushige

Leslee Matsushige (Yasukochi)
Assistant Aquarium Curator
Birch Aquarium at Scripps
Scripps Institution of Oceanography
University of California San Diego

Hi Leslee,

Over the years, we have seen mouth problems develop in some of our dragons. Sometimes it’s attributed to injury. Sometimes we don’t know what causes it, but we are often successful in getting them to recover on their own with just supportive feedings until we observe that they are back to catching food normally. Sometimes this can take a long time…as in a month or two of force feedings before they are back to catching enough on their own to sustain themselves.

Although I have not had experience force feeding ribbon dragons, I have both force fed and tube fed leafy and weedy seadragons. Typically, we force feed numerous frozen mysids to a sick dragon up to 3 times a day. By force feeding, I mean that we very gently place a mysid in the mouth of the animal and then lightly hold a finger in front of it so that it can’t easily spit out the food. Usually they learn pretty quickly that they are getting food this way and start to slurp mysids up as soon as they are put in their mouth. I usually try to get 6-10 mysids in per feeding. It takes good eyesight and a steady hand to make sure you don’t injure their mouth with this method. We have also tube fed using a thick slurry of cyclopeeze or pulverized and moistened pelleted food…usually giving around .3cc per feeding…though it’s dependent on the size of the animal. I think we usually use a 2-3mm french catheter cut down to fit on a small syringe. Again we do this 3 x day. We find that the animals do better with the frequent feedings and usually they go right back to searching for food after being released.

Teryl Nolan
Aquarium Supervisor
SeaWorld Florida

Hi Teryl,
Thanks for your response to my posting. We are currently trying to tube feed one of our leafy seadragons. We have been feeding it 1x/day for now to see how it handles the feedings.
I was wondering what was the size of the seadragon that you feed .3cc of the food slurry to? Our leafy is about 10-11 inches in length. I am not sure of the amount to feed. Since we are feeding only 1x/day we are trying .6cc per feeding.
Do you find force feeding or tube feeding to be better in certain situations? Our leafy still attempt to get the food but can not snap its jaw with enough force to get the food into its mouth.
When you force feed the seadragon do you hold it upsidedown? What do you use to put the mysid in its mouth? If you could give more details about force feeding that you think might be helpful, can you pass this on?
Your response has been helpful!
Thanks,
Leslee

In a message dated 7/16/2009 1:20:44 P.M. Central Daylight Time, [email protected] writes:
Hi Leslee,
We usually feed our full-sized leafies just .3cc at each feeding. I don’t know that you can’t go higher, we just don’t. I try to be conservative and part of my philosophy about having to force feed them is that since they naturally tend to graze on food all day long, I like to feed them smaller amounts more frequently.

In our experience, the dragons usually go back to their normal routine after a tube or force feeding. If they were actively looking for food, but just not following through and eating it, that’s what they go back to. If prior to the feeding, they were acting pretty lethargic…maintaining a stationary position on the water, usually facing a wall, and not showing any interest in feeding…then we’ve noticed that after they get a little energy from the force feeding, they often come out, act a little more normally, and even show signs of hunting for food. The reason we started force feeding the sick ones 2-3x a day years ago, is because we see such a dramatic turn around in their behavior after they have gotten some food. If we don’t follow it up with another feeding that day, then they seem to lose steam and go back to their wall-facing behavior.

I’ve come to the point that I believe it’s better to force feed than to tube feed (unless I need to tube with an oral medication or the dragon won’t take the force feeding). If you have the very small mysids available because you purchase live or culture your own, that’s what I prefer to use. We freeze our mysids prior to feeding them out. If you lightly restrain the dragon, in an upright position, but completely under the water, I find it’s easier to use latex gloves and very carefully insert a small mysid into the dragon’s mouth tail first using my fingers. We can usually get them to eat 10-20 per feeding. They will usually slurp it up pretty quickly. Sometimes they spit them out the first couple times though. In which case, I lightly hold my finger in front of their mouth until they’ve swallowed the mysid. That keeps them from spitting them out completely…usually. We have a few that we hold under water and pour mysids in front of, then we just move them directly in front of the food and they slurp them up. I think they probably get more from the whole mysids than from the gruel.

We don’t even move them off exhibit unless there are other health issues. We just lean over the side of our system and handle the dragons quickly beneath the surface. Then release them. I think it is much less stressful on the animals if you don’t have to move them. They tolerate this extremely well in my experience and we have had numerous that required supplemental feedings for awhile, but then recovered.

I hope this helps!

Teryl Nolan
Aquarium Supervisor
SeaWorld Florida
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All things considered, Jamie, I would recommend performing a series of water changes to improve the water quality, adding additional aeration to raise the levels of dissolved oxygen, and concentrating on hand feeding your female individual Mysis as described above to provide her with nutritional support. If force feeding your little female by hand proves to be impractical, then tube feeding is probably the next best option at this point. Let me know if the tube feeding becomes necessary, and I can provide you with some additional instructions to help guide you through the procedure.

Aside from her lack of appetite, Jamie, I am also concerned about your female’s lack of movement. Sometimes seahorses will latch onto a nearby hitching post and cling to it stubbornly when they are having buoyancy problems because the moment they release their grip on their holdfast, they have great difficulty swimming normally due to the tendency to float.

One simple way to determine if the seahorse is struggling with positive buoyancy is to observe her while she is swimming, Jamie. The first indication of positive buoyancy is a loss of equilibrium. The seahorse’s center of gravity shifts as it becomes more buoyant, and it will have increasing difficulty swimming and maintaining its normal posture, especially if it encounters any current. It will become apparent that the seahorse has to work hard to stay submerged, as it is forced to abandon its usual upright swimming posture and swim with its body tilted forward or even horizontally in order to use its dorsal fin to counteract the tendency to rise.

So I would like you to gently induce your seahorse to release its grip on its hitching post, Carianne, and then release her at the bottom of your aquarium and observe her closely to see if she can swim normally, in the typical upright swimming posture of Hippocampus, or if she struggles as described above and tends to float back up to the top of the aquarium again. (This will also be a good way to test whether or not you have too much water current or turbulence in your aquarium, by observing if the seahorse is getting blown around by the water flow and has to struggle mightily to fight against the current.)

Here is the proper way to encourage your seahorse to release its grip and to handle it when performing this simple test, Jamie:

Handling Seahorses

I do not like to use an aquarium net to transfer or manipulate seahorses, since their delicate fins and snouts can become entangled in the netting all too easily. I much prefer to transfer the seahorses by hand. Simply wet your hand and fingers (to avoid removing any of the seahorse’s protective slime coat) and scoop the seahorses in your hand. Allow them to curl their tail around your fingers and carefully cup their bodies in your hand to support them while you lift them out of the water. When you gently immerse your hand in the destination tank, the seahorse will release its grip and swim away as though nothing out of the ordinary has happened.

Composed of solid muscle and endowed with extraordinary skeletal support, the prehensile tail is amazingly strong. Indeed, large specimens have a grip like an anaconda, and when a 12-inch ingens or abdominalis wraps its tail around your hand and tightens its hold, its vise-like grip is powerful enough to leave you counting your fingers afterwards!

In fact, it can be quite difficult to remove an attached seahorse from its holdfast without injuring it in the process. Never attempt to forcibly detach a seahorse from its hitching post! When it feels threatened, it’s instinct is to clamp down and hold on all the tighter. When you must dislodge a seahorse from its resting place for any reason, it’s best to use the tickle technique instead. Gently tickling the underside of the tail where it’s wrapped around the object will usually induce the seahorse to release its grip (Abbott, 2003). They don’t seem to like that at all, and will quickly let go to move away to another spot. Once they are swimming, they are easy to handle.

Let me know right away if your female is having buoyancy problems, Jamie. That could indicate a swim bladder disorder, which could account for the seahorse’s lack of appetite, and in that case you would need to treat her with the proper medications and procedures for such a condition.

Best of luck getting good nutrition into your female H. kuda one way or another, Jamie.

Respectfully,
Pete Giwojna

Dear Jamie:

Okay, that’s encouraging that at least your female Hippocampus kuda is not having buoyancy problems, Jamie, and it is good to hear that she was being more active this morning and swimming around the bottom of the tank.

Yes, if your Biocube is well-established and has an abundant population of copepods, amphipods, and meiofauna, it’s certainly possible that your female is grazing on live prey in the aquarium between meals, and that this accounts for her lack of interest in frozen Mysis, especially if you have seen her actively hunting and searching around the bottom for pods. So if her belly rings and abdomen are not pinched in or sunken in, and she has a lack of appetite, it could be that your female is scrounging up enough of the nutritious copepods and amphipods to keep her satisfied. Seahorses have excellent visual acuity under low light conditions and certain species (e.g., H. comes, H. ingens) have adopted nocturnal habits in order to escape heavy fishing pressure during the day in the wild, so it’s even possible that your female could be a secretive feeder that prefers to do most of her pod hunting after dark, when you aren’t around to observe her, Jamie.

A good way you can doublecheck to see if your female is getting enough to eat on a daily basis, even if she is feeding secretively, is to examine her fecal pellets. If the fecal pellets she is producing have not changed in quantity or appearance, you can be assured she is getting plenty to eat. As long as she is eliminating well-formed feces, that’s a pretty good indication that your female is getting plenty to eat, so if she hasn’t been scarfing up the frozen Mysis at all lately, it’s safe to assume that she has been dining on the pod population in the aquarium, just as you suspect. But beware if she starts producing white, stringy feces, or no feces at all, rather than her usual well-formed feces — those pale, stringy feces are often a sign of a seahorse that is underfed and not getting enough nourishment (or an indication of a seahorse with intestinal parasites, which could also account for a loss of appetite).

So here’s what I would like you to do for the time being, Jamie: maintain the extra aeration and stay on top of the water changes just as you have been doing but also keep a very close eye on your female for any kind of fecal production. If she is not producing feces of any kind, or if she is producing white stringy, mucoid feces, she may need further treatment.

If she still looks plump and well fed, yet she isn’t eating and is not producing feces at all, it’s also possible that she could be constipated or perhaps even egg bound. So let me know about her fecal production tomorrow or the next day and we can proceed accordingly…

Here’s hoping that she has simply developed into a secretive feeder and is getting her fill of copepods and amphipods on the sly.

Respectfully,
Pete Giwojna