seahorse in distress

Dear Gordon:

I suspect that your seahorse’s heavy breathing and distress is related to the water temperatures in the aquarium. As you know, sir, the warmer the water, the less dissolved oxygen it can hold. Elevated water temperatures increase the metabolism of your seahorses, and therefore their consumption of oxygen, at the same time that the rise in temperature is reducing the amount of dissolved oxygen in the water. That creates a dangerous situation for seahorses and may well result in respiratory distress and rapid, labored breathing.

Seahorses are more vulnerable to low O2/high CO2 levels than most fishes because of their primitive gills. Unlike most teleost (bony) fishes, which have their gills arranged in sheaves like the pages of a book, seahorses have rudimentary gill arches with small powder-puff type gill filaments. Seahorses are said to have "tufted" gills because they appear to be hemispherical clumps of tissue on stems. Their unique, lobed gill filaments (lophobranchs) are arranged in grape-like clusters and have fewer lamellae than other teleost fishes. Because of the difference in the structure and efficiency of their gills, seahorses are thus especially vulnerable to low oxygen levels and asphyxia.

I would recommend that you increase the surface agitation and circulation in the aquarium, and concentrate on the measures to reduce water temperature we discussed in my previous post. Consider adding an extra airstone or two anchored just beneath the surface of the tank to increase the aeration and promote more efficient gas exchange at the air/water interface. Leave the aquarium light off, remove the hood or lid from the aquarium if possible, and direct a fan across the surface of the water to lower the temperature via evaporative cooling.

If these simple measures don’t relieve the seahorse’s respiratory distress and improve its breathing, it may be necessary to treat the seahorse with methylene blue as a first aid measure. Commonly known as "meth blue" or simply "blue," this is a wonderful medication for reversing the toxic effects of ammonia and nitrite poisoning. Methylene blue transports oxygen and aids breathing. It facilitates oxygen transport, helping fish breathe more easily by converting methemoglobin to hemoglobin — the normal oxygen carrying component of fish blood, thus allowing more oxygen to be carried through the bloodstream. This makes it very useful for treating gill infections, low oxygen levels, or anytime your seahorses are breathing rapidly and experiencing respiratory distress. It is the drug of choice for treating hypoxic emergencies of any kind with your fish. However, methylene blue will destroy nitrifying bacteria so it should be used in a hospital tank or as a brief bath or dip only (if used in an established aquarium, it will impair the biological filtration and the tank may need to be cycled all over again).

Here is some more information that may be helpful if you need to treat with methylene blue after all:

If you can obtain the Kordon brand of Methylene Blue (available at most well-stocked local fish stores), there are instructions for administering it as a very brief, concentrated dip are as follows:

For use as a dip for treatment of fungus or external parasitic protozoans and cyanide poisoning:

(a) Prepare a nonmetallic container of sufficient size to contain the fish to be treated by adding water similar to the original aquarium.

(b) Add 5 teaspoons (24.65 ml) per 3 gallons of water. This produces a concentration of 50 ppm. It is not recommended that the concentration be increased beyond 50 ppm.

(c) Place fishes to be treated in this solution for no longer than 10 seconds.

(d) Return fish to original aquarium.

When you administer such a dip, hold the seahorse in your hand throughout the procedure and thymic closely so that the dip does not exceed 10 seconds.

And here are Kordon’s instructions for administering the methylene blue in a hospital tank if longer-term treatment seems appropriate to reverse more severe cases of nitrite poisoning and ammonia toxicity:

As an aid in reversal of nitrite (NO2-) or cyanide (CN-) poisoning of marine and freshwater aquarium fishes:

(a) Remove carbon filter and continue to operate with mechanical filter media throughout the treatment period.

(b) Add 1 teaspoon of 2.303% Methylene Blue per 10 gallons of water. This produces a concentration of 3 ppm. Continue the treatment for 3 to 5 days.

(c) Make a water change as noted and replace the filter carbon at the conclusion of the treatment.

See the following link for more information on treating with Kordon’s Methylene Blue:

Click here: KPD-28 Methylene Blue

http://www.novalek.com/archive/kpd28.htm

If you obtained a brand of methylene blue other than Kordon, just follow the instructions the medication comes with. Remember that methylene blue will destroy the beneficial nitrifying bacteria in your biofilter, so it should only be administered in a hospital tank or a separate dipping container.

One other tip, sir: if you ever need to handle seahorses to administer first aid measures or treat them in a hospital tank, it’s best not to get them when you are manipulating the seahorse:

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.

In short, Gordon, the best thing you can do for the time being is to increase the aeration, surface agitation, and circulation in the aquarium while lowering your water temperature in order to increase the levels of dissolved oxygen. Obtain some methylene blue in the meantime in case the other measures don’t improve the seahorse’s breathing. And if possible, check the dissolved oxygen levels in your aquarium so that we can verify that low O2 is the primary problem you are dealing with right now.

Best of luck resolving the situation and relieving your seahorses breathing problems, sir!

Respectfully,
Pete Giwojna