Copepods

Dear Haynes:

I’m glad to hear that you’re new seahorses are doing so well. A healthy appetite is always a good sign, and you are to be commended for being such a diligent observer of your seahorses! An alert aquarist will quickly pick up on a potential problem and can often nip it in the bud before it becomes a serious concern. Early detection and treatment is the key to resolving many health problems.

In this case, however, I don’t think you have anything to worry about. As long as the copepod you noticed on your seahorse is the same in appearance to the other ‘pods your Sunburst have been hunting and eating, I’m sure it’s a harmless free-living form rather than a parasitic copepod. No doubt the copepod that was crawling on the seahorse’s belly simply regarded him as part of the substrate, no different than the aquarium glass or rockwork the ‘pods normally cling to. There are a number of parasitic copepods, but we rarely see them in the aquarium, and when we do, it’s on wild-caught fish rather than domesticated seahorses from a High-Health aquaculture facility. And the parasitic types of copepods are entirely different in appearance than the harmless copepods, as discussed in this excerpt from "Working Notes: A Guide to the Diseases of Seahorses:"

Parasitic Copepods

"…Caligariform types (sea lice) infest the skin and have been known to cause serious problems in cultured fish, including salmon. Morphologically they resemble Argulus (fish lice) not only in appearance but also in common name.

"Caligariform types can multiply quickly in aquaria and enclosed environments.

"Leraeid types (anchor worms) possess anchor-like processes to attach themselves to the host. They resemble leeches but do not have posterior suckers.

"The problem is most common in wild-caught species that have not undergone proper quarantine where they would have been identified and treated. It can also occur in any species exposed to infested individuals or parasites brought in with live rock or invertebrates (Martin Belli, M.D., et al., April 2006)."

So as long as the suspicious copepod looked like the other ‘pods you’re accustomed to seeing, and not like a fish louse (Argulus spp.) or a leech, then I don’t think you have anything to worry about, Haynes. Argulus fish lice are unmistakable. They are flattened dorsoventrally (from top to bottom) and have a broad shield over their thorax. They are considerably larger than the harmless free-living copepods and have a pair of a distinct compound eyes. Argulids sea lice have a conical beak they use for piercing and sucking, through which they can inject a toxin that causes tissue damage as they feed on their host’s blood and interstitial fluids (Martin Belli, M.D., et al., April 2006). In other words, Haynes, you’ll know one when you see one! The flattening of their bodies and the wide shield over their thorax gives these sea lice a characteristic "manta ray" appearance (Martin Belli, M.D., and all, April 2006). Here is some additional information on these nasty little bloodsuckers from my old Step-By-Step Book about Seahorses:

Fish Lice (Argulus spp.)

"Seahorses are also subject to a number of parasitic diseases, some of which can be very serious. Fortunately for the aquarist, Argulus — the external parasites that is most often found on seahorses — is readily detected and cured. These small, flat-body parasites appear as semitransparent bumps, ranging from 1/16 to 1/4 inch in size, typically on the seahorse’s head or the nape of its neck.

"Better known as the sea louse, Argulus is a little bloodsucking horror equipped with a long, sharp proboscis that can pierce a seahorse’s body with ease. Like so many diminutive Draculas, they have been observe sucking the blood flowing from the wounds made by their beaks. Fish parasitize by argulids naturally do everything possible to scrape them off, but their flattened bodies are able to cling tightly to their victims with special suction cups on their legs despite every effort of their hosts to dislodge them. Although these diabolical little vampires are only about the size of a water flea, heavily infested seahorses can become so irritated that they refuse to eat, and are further weakened by the loss of blood. In severe cases, death can result. And there is always the danger of secondary infections setting in at the site of the puncture wounds they leave behind.

"Luckily, if you purchase your seahorses from a pet dealer, you’ll probably never have to deal with the sinister sea louse, since they will have been removed by the collector prior to shipment. Wild-caught seahorses can sometimes be lousy with Argulus, but I have never seen a sea louse on a captive-bred-and-raised seahorse. If you buy domesticated seahorses directly from the breeder, this is one parasite you will probably never see in your seahorse tank.

"Needless to say, if you should ever happen to encounter a seahorse infested with these parasites, they should be removed at once. This can be accomplished by prying them loose with a tweezers, a dull pen knife blade, or any similar tool, while holding the seahorse submerged. Any wounds left by the argulids should be dried and disinfected using diluted iodine (one part iodine in nine parts of water) or Betadine or other antiseptics. The "deloused" seahorses should then recover without any ill effects (Giwojna, 1990)."

Seahorses infested with argulids exhibit erratic behavior due to the irritation caused by the sea lice, and would certainly be scratching themselves or attempting to rub off the parasites. Since your Sunburst shows no sign of irritation or scratching, I’m quite confident that you don’t have a problem with Argulus sea lice or parasitic copepods, Haynes. So I would not recommend that you administer a freshwater dip or any other form of treatment at this time, sir.

For future reference, should you ever have a problem with fish lice or parasitic copepods on any of your marine fish, they can be eradicated with Parinox or by administering a formalin bath. In such an unlikely event, if necessary, you could "debug" your tank by treating the aquarium with Parinox after first removing any sensitive invertebrates such as the shrimp or micro-hermit crabs or micro-starfish from your cleanup crew. But that’s a drastic measure that you certainly don’t need to resort to at this time.

Parinox

USE: For Ich, hexamita, costia, ichthyophthirius, ectoparasites, monogenia, hirudinea, parasitic copepods, argulus, lernaea, anchor worms, fish lice, leeches. Also a protozoacide. Anti-bacterial, anti-parasitic, very wide spectrum..

DOSAGE: Use 1/4 teaspoon per 20 gallons. Treat once a week for 2 weeks. If water changes are done, add back the percentage of medication according to how much water was changed.

As you can see, Parinox is effective against parasitic copepods, Argulus and other types of fish lice, anchor worms and leeches, etc. It should certainly eradicate any bloodsucking parasites that may plague seahorses, but right now that’s not a concern for you, so this information is strictly for future reference. Although Parinox is safe for seahorses, it can be hard on crustaceans and certain invertebrates, so be sure to remove any invertebrates during the treatment. After the two-week treatment, perform a major water change and use activated carbon filtration or a Poly-Filter pads to pull out any remaining traces of the medication.

You can obtain Parinox online from National Fish Pharmaceuticals at the following URL:

Click here: Fish Medications
http://www.fishyfarmacy.com/products.html

Here are the instructions for performing a freshwater dip, Haynes — again for future reference:

Freshwater Dips

A freshwater water dip is simply immersing your seahorse in pure, detoxified freshwater that’s been preadjusted to the same temp and pH as the water the seahorse is accustomed to, for a period of at least 10 minutes (Giwojna, Dec. 2003). It doesn’t harm them — seahorses typically tolerate freshwater dips exceptionally well and a 10-minute dip should be perfectly safe. Freshwater dips are effective because marine fish tolerate the immersion in freshwater far better than the external parasites they play host to; the change in osmotic pressure kills or incapacitates such microorganisms within 7-8 minutes (Giwojna, Dec. 2003). A minimum dip, if the fish seems to be doing fine, is therefore 8 minutes. Include some sort of hitching post in the dipping container and shoot for the full 10 minutes with your seahorses (Giwojna, Dec. 2003).

If you will be using tap water for the freshwater dip, be sure to dechlorinate it beforehand. This can be accomplished usually one of the commercial dechlorinators, which typically include sodium thiosulfate and perhaps a chloramine remover as well, or by aerating the tap water for at least 24 hours to dissipate the chlorine (Giwojna, Dec. 2003).

If you dechlorinate the dip water with a sodium thiosulfate product, be sure to use an airstone to aerate it for at least one hour before administering the dip. This is because the sodium thiosulfate depletes the water of oxygen and the dip water must therefore be oxygenated before its suitable for your seahorse(s).

Observe the horse closely during the dip. You may see some immediate signs of distress or shock. Sometimes the horse will immediately lie on its side on the bottom. That’s a fairly common reaction — normal and to be expected, rather than a cause for concern, so don’t be alarmed if this happens. Just nudge or tap the seahorse gently with your finger if it lies down on its side. Normally, the seahorse will respond to the slight nudge by righting itself again and calm down for the duration of the dip. However, if it does not respond, stop the treatment.

Most seahorses tolerate the treatment well and experience no problems, but if you see continued signs of distress — twitching, thrashing around etc. — stop the treatment.

After you have completed the dip and returned the seahorses to the aquarium, save the dip water and examined it closely for any sign of parasites. The change in osmotic pressure from saltwater to freshwater will cause ectoparasites to lyse (i.e., swell and burst) or drop off their host after 7-10 minutes, and they will be left behind in the dipping water. Protozoan parasites are microscopic and won’t be visible to the naked eye, but some of the other ectoparasites can be clearly seen. For example, monogenetic trematodes will appear as opaque sesame seeds drifting in the water (Giwojna, Aug. 2003) and nematodes may be visible as tiny hairlike worms 1/16-3/16 of an inch long. Other parasites may appear as tiny dots in the water. Freshwater dips can thus often provide affected seahorses with some immediate relief by ridding them of these irritating pests and can also aid their breathing by flushing out gill parasites.

A freshwater dip or other treatment for your Sunburst is not indicated at this time. Just keep a close eye on them for any other symptoms or signs of a problem, as you have been doing so diligently, Haynes, and I’m sure they will be fine. At least you should have a better idea of what to look for now should ectoparasites ever become a concern for your seahorses.

There is a new disease book on seahorses that you would find very informative, Haynes. Dr. Martin Belli, Marc Lamont, Keith Gentry, and Clare Driscoll have done a terrific job putting together "Working Notes: A Guide to the Diseases of Seahorses." Hobbyists will find the detailed information it contains on seahorse anatomy, the latest disease diagnosis and treatment protocols, and quarantine procedures to be extremely useful and helpful. It has some excellent dissection and necropsy photos as well as a number of photos of seahorses with various health problems. This is one book every seahorse keeper should have in his or her fish-room medicine cabinet, and I highly recommend it! In time of need, it can be a real life saver for your seahorses. (Of course, it discusses parasitic copepods, Argulus sea lice, and all of the other usual internal and external parasites.) It’s available online at the following web site:

Click here: Working notes: a guide to seahorse diseases > books > The Shoppe at Seahorse.org | CafePress

http://www.cafepress.com/seahorses.55655887

Best wishes with all of your fishes, Haynes!

Respectfully,
Pete Giwojna