Re:seahorses keep floating

Pete Giwojna

Dear Chris:

Thank you very much for clarifying the situation regarding your floating seahorses. If they are still juveniles and none of them have developed pouches as yet, then we can rule out pouch emphysema and air bubbles trapped in their pouches as the cause of their positive buoyancy.

If the juveniles are very young — just a few weeks old, for example — they may be floating because they have a gulped air, in which case neither Diamox nor pressurizing them in a homemade decompression chamber will resolve the problem. Newborn seahorses need special nursery tanks (i.e., kriesels or pseudokreisels) with gentle currents designed to keep them away from the surface so that they don’t accidentally ingesting air and become floaters. Seahorse fry that develop problems with positive buoyancy and become floaters are unable to feed properly and are doomed to starvation.

Methods for measuring dissolved oxygen in the aquarium can be as simple or as sophisticated as you desire, ranging from basic test kits under $10 to electronic probes costing hundreds of dollars. Fortunately, the humble seahorse keeper doesn’t require anything too fancy along those lines, and the basic O2 test kits will do nicely for our purposes.

For instance, the Tetra Oxygen Test Kit (TetraTest 02) is a good liquid reagent test kit for fresh or saltwater with simple color scales for comparing readings that tests for 02 in the range of 2-14 PPM. It will cost you between $8.50 to $14 depending on where you shop and should be available at any well-stocked LFS. Salifert also makes a nice 02 Test Kit (their 02 Profi-Test) that will run you about $20.

Either of those test kits fit the bill very well and are worthwhile investments for the seahorse keeper.

Dissolved Oxygen (02): Optimum level = 6 – 7 ppm

High levels of dissolved oxygen are vital to the well being of both fish and invertebrates. The key to maintaining high O2 levels in the aquarium is good circulation combined with surface agitation (Webber, 2004). Wet/dry trickle filters and protein skimmers facilitate efficient gas exchange and oxygenation. It is important for the hobbyist to monitor the dissolved oxygen levels in the aquarium because a drop in O2 levels is often an early indicator of impending trouble — a precursor of problems ahead. A drop in O2 levels will tip off the alert aquarist and allow corrective measures to be taken, nipping the problem in the bud before it adversely affects his seahorses. For example, a drop in O2 levels could be an early indicator of overcrowding — a signal that your system has reached its carrying capacity. Or it may merely signal a rise in the water temperature due to a summertime heat wave or indicate that the tank is overdue for a water change and/or a thorough cleaning to remove excess organics and accumulated detritus. Or it could be telling you that your tank is under circulated and you need to increase the surface agitation and water movement.

The point is that checking the O2 levels in your aquarium can alert you to impending problems and allow you to do something about them before they have dire consequences. A drop in O2 levels is often the first sign of a water quality problem and it can tip off the alert aquarist that trouble is brewing before his seahorses are gasping for air in obvious respiratory distress. Checking the dissolved oxygen levels regularly is the next best thing to continuously monitoring the Oxidation-Reduction Potential (ORP) or redox of the water, which is a luxury few hobbyists can afford.

In your case, Chris, we would be concerned about gas supersaturation rather than low oxygen levels. If the water become supersaturated with oxygen or other gases, that can lead to the formation of gas emboli in the blood and tissues of the seahorses, resulting in various forms of Gas Bubble Syndrome (GBS), as we have previously discussed. But if your youngsters are only three or four weeks old, then they are much more likely to be floating due to accidentally ingesting air than they are to be suffering from GBS.

Unfortunately, Ocean Rider only ships within the continental United States, Chris, so that won’t be an option for you in Singapore. However, seahorses typically tolerate all of the usual fish medications at the appropriate therapeutic dosages without difficulty. You need not consider them delicate or sensitive when it comes to disease treatments. Very likely, any of the medications designed for aquarium use that are available to you in Singapore are safe to use with your seahorses.

As for all the different diseases that seahorses are susceptible to, what the symptoms are, and how to treat them, that’s a topic that goes well beyond the limits of this simple discussion forum to address properly, but I’ll try my best to give you an idea of what to look out for, Chris. When it comes to health problems, seahorses are like other tropical marine fish. They are susceptible to the usual diseases and infections and parasites that plague other reef fish, as well as a few afflictions that are specific to seahorses (e.g., prolapsed pouch, white tail disease, and gas bubble syndrome). The bony exoskeleton and protective slime coat of Hippocampus gives the seahorse limited immunity from certain ectoparasites such as marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium), so the telltale white spots that characterize those conditions may never show up (or may be visible only on the unarmored fins). So those particular diseases are relatively uncommon in seahorses, although when they do occur, the parasites can still freely invade the seahorse’s gills, with deadly results.

Ocean Rider seahorses come to you direct from a High-Health aquaculture facility and are certified to be free of pathogens and parasites when they arrive, so if you can provide them with a stress-free environment and proper care, you should find them to be quite hardy and relatively disease resistant. But that may not be the case with your Vietnamese seahorses.

Seahorses that are subjected to chronic stress, which alters their blood chemistry, affects key hormones, and suppresses their immune system, become vulnerable to diseases and health problems just like any other fish. So the best thing you can do for your seahorses is to create a stress-free environment for them in which they feel right at home. We will discuss how to accomplish that and eliminate many of the common aquarium stressors later in this message, Chris, but first let me review some of the obvious signs of stress or illness you should be aware of.

Respiratory distress is one such sign. Seahorses that are stressed or suffering from gill disease or parasites that attack the gills will exhibit rapid respiration, labored breathing, huffing, panting, yawning or coughing behavior, and other indications of respiratory distress. So familiarize yourself with your seahorse’s normal respiration rate, which will vary somewhat with water temperature and their activity level or degree of arousal/excitement, and subsequent changes in their normal breathing pattern can alert you to a possible problem.

Your seahorses’ respiration rate may increase naturally when they are feeding, actively courting, being handled, or excited in general, and then return to their normal resting respiratory rate afterwards. That’s natural and nothing to be concerned about. Symptoms of respiratory distress are ordinarily pretty obvious and you should have no trouble determining when your seahorse is laboring or struggling to breathe.

Seahorses that are stressed may also go off their feed, which is another obvious symptom that’s easy for the diligent aquarist to detect. So take a moment to enjoy the show when feeding your seahorses. Make sure they’re all eating well, and use this opportunity to look them over closely for wounds, injuries, or signs of disease. Seahorses are natural-born gluttons. Ordinarily, these galloping gourmets are ALWAYS hungry, so when one of these chow hounds is off its feed, that’s often an excellent early indicator that something’s wrong. Early detection of a potential problem can be the key to curing it, so it’s a good idea for the alert aquarist to observe his prize ponies while they put on the ol’ feed bag. Make sure they all show up for mess call, are acting normally, and have a well-rounded abdomen when they’re done eating.

Abnormal changes in coloration are another indicator of stress and certain disease problems. For example, seahorses will often darken over their entire bodies in response to stress, and pallor can be a sign of low dissolved oxygen levels or high CO2 levels since seahorses may blanch when subjected to hypoxic conditions. Skin infections and parasites that attack the skin will often cause a localized loss of pigmentation or discoloration, so be on the lookout for pale patches or white blotches that appear on your seahorse suddenly, particularly if these pale spots are not symmetrical (that is, they don’t appear in the same place on both sides of the seahorse’s body).

However, it’s important to distinguish between normal color changes and transitory color phases that all seahorses go through, and the type of abnormal changes in coloration we have been discussing above. Seahorses are truly the chameleons of the sea with a propensity for changing color in response to a wide range of environmental factors, hormonal influences, and behavioral interactions, or simply to better blend into their background.

With a little experience, you will become familiar with their normal color pattern and the transitory color phases they occasionally go through, which will make it easy to determine if an unnatural marking or suspicious pale blotches suddenly appears.

The hobbyist should also be aware that there are any number of environmental conditions that can affect the coloration of their seahorses, often by affecting the ability of chromatophores to contract and expand. These include the following factors:

Stress — seahorses often respond to stress by darkening.

Emotional state — when excited, seahorses typically brighten in coloration, reflecting a state of high arousal.

Competion for mates — dominant individuals brighten; subordinate seahorses darken in submission.

Poor water quality — high levels of nitrogenous wastes (e.g., ammonia, nitrite or nitrate) can cause chromatophores to contract and colors to fade.
O2/CO2 — low oxygen levels (or high CO2 levels) can cause colorful seahorses to fade and they will blanch when subjected to hypoxic conditions.

Background colors — seahorses will often change color in order to blend in with their immediate surroundings.

Medications — some antibiotics and malachite-green-based remedies negatively affect color.
Tankmates — seahorses may change their base coloration to blend in with the rest of the herd or to match their mate (or a potential partner).

Temperature — chromatophores tend to contract at high temperatures, causing colors to fade; cooler temps can make pigment cells expand, keeping colors bright.

Disease — skin infections (bacterial, fungal, or parasitic) can cause localized loss of pigmentation or discoloration of the affected areas.

Diet — seahorses cannot synthesize the pigments used in their chromatophores. It is therefore important to enrich their food with pigments such as carotenoids in a form that’s easy for them to absorb. If color additives are not provided, the chromatophores will gradually lose their pigments and the seahorse’s color can fade. Vibrance, for example, is exceptionally rich in Vitamins A and C as well as natural carotenoids, which are not found in Mysis relicta. This is important because the carotenoids are a class of yellow to red pigments, which include the carotenes and the xanthophylls. Like all cells, individual pigment cells have a limited life expectancy in the body and must be regularly renewed. Marine organisms cannot synthesize carotenoids, so if they do receive adequate amounts in their diet, they will have difficulty replenishing their red and yellow pigments. This means that the colors of bright yellow, orange, and red seahorses will gradually fade over time if their daily diet is lacking in carotenoids. So don’t neglect the enrichment step in your daily feeding regimen! If seahorses are fed a strict diet of Mysis relicta without additional enrichment, they may begin to develop dietary deficiencies over time, and both their health and coloration will eventually suffer.

Beware of tenderness and especially a loss of color or prehensility in your seahorse’s tail.
Tail rot and white tail disease typically begin with a loss of prehensility in the very tip of the tail (Giwojna, Oct. 2003). At this stage, the seahorses can grasp large objects just fine, but cannot take hold of slender objects with a small diameter (Leslie Leddo, pers. com.). Next the loss of prehensility spreads further up the tail and the seahorses begin to act as if their tails are very tender and sensitive. They will drape their tails over objects rather than grasping onto them and begin to drag their tails behind themselves, often arching the end of their tail upward in the shape of "U" (rather than the usual "J" or tight coil) as if to lift it off the ground and keep it from touching anything (Leddo, pers. com.).

Scratching and the erratic behavior are often an indication of the irritation ectoparasites cause. So when a seahorse attempts to scratch itself with its tail, or repeatedly attempts to scratch itself by rubbing against various objects, it’s often a sign of a parasitic infestation. If such symptoms persist, you’ll need to treat the seahorses with a good antiparasitic.

Buoyancy problems are another obvious sign of a health problem. Positive buoyancy — the tendency to float — can result from a number of causes such as hyperinflation of the swimbladder, pouch gas, or various forms of Gas Bubble Syndrome (GBS). Negative buoyancy — the tendency to sink — can be an indication of generalized weakness, and underinflated gas bladder, or fluid (ascites) building up within the abdomen or coelomic cavity.

Those are some of the signs of stress and early symptoms of health problems the diligent seahorse keeper should be aware of, Chris. One of the best ways to prevent bacterial infections and other disease problems is to provide them with a stress-free environment. Many of the parasites and pathogens that plague our pampered ponies are ubiquitous — present in low numbers in most everyone’s systems or within the seahorse’s body itself (Indiviglio, 2002). As a rule, healthy fish resist such microorganisms easily, and they only become a problem when seahorse’s immune system has been impaired, leaving it susceptible to disease (Indiviglio, 2002). Chronic low-level stress is one of the primary factors that suppresses the immune system and weakens the immune response, opening the way to infection and disease (Indiviglio, 2002). Long-term exposure to stressful conditions is very debilitating. Among other effects, it results in the build up of lactic acid and lowers the pH of the blood, which can have dire consequences for seahorses for reasons we’ll discuss later.

When disease breaks out in an established aquarium it is therefore generally an indication that something is amiss with your aquarium conditions. A gradual decline in water quality is often a precursor of disease (Indiviglio, 2002). Poor water quality is stressful to seahorses. Prolonged stress weakens their immune system. And an impaired immune system leaves the seahorse vulnerable to bacterial, viral, and fungal infections to which healthy, unstressed seahorses are immune. As if that weren’t bad enough, there are a number of environmental diseases that are caused directly by water quality problems.

With this in mind, it’s important to review the most common stressors of captive seahorses. These include the design of the aquarium itself. A poorly designed seahorse setup that lacks adequate cover and shelter, or has too few hitching posts, will be stressful to the occupants (Topps, 1999). Seahorses are shy, secretive animals that rely on camouflage and the ability to conceal themselves for their safety and survival. A sparsely decorated tank that leaves them feeling vulnerable and exposed will be a source of constant stress (Topps, 1999). The seahorse setup should have plenty of secure hiding places so they can conceal themselves from view completely whenever they feel the need for privacy. It should be located in a low traffic area away from external sources of shock and vibration.

Needless to say, rapid fluctuations in temperature, pH, salinity and other aquarium parameters must also be avoided. A large aquarium of 40 gallons or more provides much greater stability in that regard than does a smaller setup. The greater the water volume in the aquarium and sump, the more stable the system will be.

Heat stress is especially debilitating and dangerous for seahorses due to a number of reasons (Olin Feuerbacher, pers. com.). For one thing, elevated temperatures can have a very detrimental effect on the immune system of fishes. This is because many of the enzymes and proteins involved in their immune response are extremely temperature sensitive (Olin Feuerbacher, pers. com.). Some of these protective enzymes can be denatured and inactivated by an increase of just a few degrees in water temperature (Olin Feuerbacher, pers. com.). So when seahorses are kept at temperatures above their comfort zone, their immune system is compromised and they are unable to fend off diseases they would normally shrug off.

At the same time heat stress is weakening the seahorse’s immune response, the elevated temperatures are increasing the growth rate of microbes and making disease organisms all the more deadly. Research indicates that temperature plays a major role in the regulation of virulence genes (Olin Feuerbacher, pers. com.). As the temperature increases, virulence genes are switched on, so microorganisms that are completely harmless at cooler temperatures suddenly become pathogenic once the water warms up past a certain point. Thus both the population and virulence of the pathogens are dramatically increased at higher temperatures (Olin Feuerbacher, pers. com.).

This is true of Columnaris and certain types of Vibrio. At cool temperatures these bacteria are relatively harmless, but at elevated temperatures they become highly contagious, virulent pathogens that kill quickly.

In short, it’s doubly important to keep seahorses at the proper temperature. Because of the reasons mentioned above and the fact that water holds less and less dissolved oxygen as it warms up, seahorses generally tolerate temps at the lower end of their preferred range much better than they handle temperatures at the upper limit of their range.

Incompatible tankmates are also stressful for seahorses. This includes not only aggressive, territorial fishes and potential predators but also inoffensive species that are restless, active fishes. Seahorses may be uneasy around fishes that are always on the go, swimming tirelessly back and forth.

Other common stressors for seahorses include overcrowding, overfeeding, stray voltage, and a host of issues related to water quality: ammonia or nitrite spikes, high nitrate levels, inadequate circulation and oxygenation, high CO2 levels and low 02 levels, low pH, etc., etc., etc (Giwojna, Jun. 2002).

In short, if hobbyists provide their seahorses with a stress-free environment, optimum water quality, and a nutritious diet, they will thrive and your aquarium will flourish with a minimum of problems. Preventing disease in the first place is infinitely preferable to trying to treat health problems after the fact. Good seahorse husbandry and diligent maintenance will be rewarded; sooner or later, negligence and poor aquarium management will be punished.

When disease breaks out in an established aquarium it is therefore generally an indication that something is amiss with your aquarium conditions. A gradual decline in water quality is often a precursor of disease (Indiviglio, 2002). Poor water quality is stressful to seahorses. Prolonged stress weakens their immune system. And an impaired immune system leaves the seahorse vulnerable to bacterial, viral, and fungal infections to which healthy, unstressed seahorses are immune.

Here’s some relevant information from my new book (Complete Guide to Greater Seahorses in the Aquarium, TFH Publications, unpublished) to will give you an indication of what some of these diseases and disease organisms looked like.. (I should point out that these are very brief excerpts which I have limited to the pertinent information that will help you identify various pathogens and parasites using a microscope. The actual discussions of these disease problems in my book are quite comprehensive, with detailed descriptions of the diseases and their symptoms, diagnostic procedures, preventative measures for each specific problem, contributing factors, discussions of treatment options, and complete treatment instructions and protocols.)

White Patch Disease: Myxobacteria (Marine Columnaris)

Marine columnaris is a highly contagious disease caused by a Myxobacterium (Flexibacter sp.) that corresponds to the columnaris infections so commonly seen in freshwater fish (Basleer, 2000). The bacterium Flexibacter is a long, slender rod-shaped organism (0.5- 1.0 microns in diameter, and some 4-10 microns long) that is easily identified under the microscope by its characteristic gliding motion (Dixon, 1999). They are unusually mobile bacteria. They are very active when observed microscopically, gliding rapidly across the viewing field (Dixon, 1999). This family of bacteria (Cytophaga or Myxobacteria) causes a condition commonly known as columnaris because of their tendency to stack up in columns (Prescott, 2001b). When large numbers of the bacteria pile up, they form distinctive haystacks several layers thick where the infection is heaviest (Dixon, 1999).

Marine Ulcer Disease, a.k.a. Hemorrhagic Septicemia, a.k.a. "Flesh-Eating Bacteria", a.k.a. Vibriosis

Marine ulcer disease is a particularly nasty type of infection that most hobbyists have come to know as "flesh-eating bacteria," and indeed it can often be attributed to bacteria, most notably Vibrio or Pseudomonas species (Giwojna, Nov. 2003). Vibrio in marine fish is the equivalent of the Aeromonas bacteria that plague freshwater fishes (Dixon 1999; Basleer 2000), causing external hemorrhagic ulcers (bloody lesions). Vibriosis is probably the most common bacterial infection of captive seahorses and one of the most difficult to eradicate from your system. Vibrio bacteria are motile gram negative rods, which measure about 0.5 X 1.5 micrometers (Prescott, 2001). When grown on suitable media they appear as shiny, creamy colored colonies (Prescott, 2001).

Mycobacteriosis, a.k.a. Piscine Tuberculosis, a.k.a. Granuloma Disease

Fish tuberculosis is caused by pathogenic Mycobacteria, of which two different species are the primary culprits: Mycobacterium marinum and Mycobacterium fortuitum (Giwojna, Sep. 2003). Unlike most bacteria the plague fish, these Mycobacteria are gram-positive, and take the form of pleomorphic rods that are acid-fast and nonmotile (Aukes, 2004). When cultured on solid media, they form cream-colored to yellowish colonies (Aukes, 2004).

Intestinal Flagellates

Intestinal flagellates are microscopic organisms that move by propelling themselves with long tail-like flagella (Kaptur, 2004). Such flagellates can be found in both the gastrointestinal and reproductive tracts of their hosts. In low numbers they do not present a problem, but they multiply by binary fission, an efficient means of mass infestation when conditions favor them (such as when a seahorse has been weakened by chronic stress), Kaptur, 2004. When they get out of control, these parasites interfere with the seahorse’s normal digestive processes such as vitamin absorption, and it has difficulty obtaining adequate nourishment even though it may be eating well and feeding heavily (Kaptur, 2004). Suspect intestinal parasites are a work when a good eater gradually wastes away despite its hearty appetite (Giwojna, Dec. 2003). Their presence can be confirmed by examining a fecal sample under a microscope, but they can be easily diagnosed according to the more readily observed signs described below (Kaptur, 2004).

The symptoms to look for are a seahorse that’s losing weight or not holding its own weightwise even though it feeds well, or alternatively, a lack of appetite accompanied by white stringy feces (Kaptur, 2004). When a seahorse stops eating aggressively and begins producing white, stringy feces instead of fecal pellets, that’s a clear indication that it’s suffering from intestinal flagellates (Kaptur, 2004).

Intestinal Nematodes (Roundworms)

Intestinal nematodes (roundworms) are usually spotted visually. This happens when one or more of the nematodes are actually sighted protruding from the seahorse’s vent, where they appear as red hairlike worms emerging from the anus. Weight loss is the primary symptom of a heavy cestode infestation. Suspect tapeworms when an aggressive eater gradually wastes away despite a hearty appetite.

A case like that is usually due to either intestinal flagellates or cestodes. To confirm which is the culprit, an examination of the fecal pellets is often revealing. If microscopic organisms having long "tails" or flagella are present in the sample, treat with metronidazole. If not, administer fenbendazole. There are very few intestinal parasites that cannot be controlled with one or the other of these medications.

Glugea (White Boil Disease)

White boil disease is an insidious affliction that is specific to seahorses and pipefish. It is fatal, highly contagious, and incurable. In the older literature, Glugea is often referred to as "white spot disease," since the first outward system is the appearance of tiny white spheres (pinhead to pin point in size) on the skin. Thus, Glugea may easily be mistaken for an outbreak of Cryptocaryon at this early stage of the disease. Indeed, you will sometimes read that Glugea can be treated with copper sulfate. That is untrue; such reports are based on misdiagnosed cases and confusion over which type of white spot disease is at work. Don’t make that mistake. Copper has no effect on microsporidians, which spread from within the host, and Glugea can readily be distinguished from Cryptocaryon as the disease progresses.

The most commonly seen form of this dread affliction is caused by the microsporidian parasite, Glugea heraldi, which may attack any part of the body, including internal organs, depending on how the disease progresses. Spores enter the host after being accidentally ingested while feeding or simply breathing. When it spreads outward, the first symptoms of Glugea are often white spots that merge together and coalesce to form whitish-gray, spore-filled ulcers called xenomas. When the tissue begins to break down and the xenomas rupture, they release new spores that infect additional hosts. This is what makes Glugea so contagious.

There is a good description of a case of G. heraldi, including photographs of the infectious stages of the microsporidian, in a paper titled ”Parasitic infection of the seahorse Hippocampus erectus–a case report” by Amanda Vincent and Clifton-Hadley which appeared in the Journal of Wildlife Disease in 1989 (Volume 25, Number 3, pages 404-408.) Hobbyists with access to a good microscope may be able to compare notes and confirm their diagnosis through a microscopic examination.

Uronema marinum

Uronema marinum is the marine equivalent of the Tetrahymena pyriformis parasites that plague freshwater fish (Basleer, 2000). Uronematids are probably the most commonly encountered protozoan parasites of seahorses in the aquarium. They frequently plague wild-caught seahorses and store-bought fish in particular. Unfortunately, they are also one of the deadliest and difficult to eradicate marine parasites.

They live in seawater and normally feed on bacteria and dead tissue, but they are opportunistic invaders that are always on the lookout for food, and are quick to take advantage of weakened fish (Kollman, 2003). It is when conditions favor them and their numbers get out of hand that Uronema becomes a problem. Under those circumstances, they soon begin to attack healthy tissue as well as dead material, invading the gills and muscles, eating red blood cells, and infiltrating the internal organs (Kollman, 2003).

Microscopic examination of skin smears can confirm the diagnosis of Uronema. Under the microscope, Uronema marinum parasites appear as pear-shaped, single-celled ciliates with a single large macronucleus and long hairlike cilia at the rear end (Kollman, 2003). Numerous small (35-50 microns), fast-moving, oval or pear-shaped parasites will appear on skin and fin smears (Basleer, 2000).

Amblyoodinium ocellatum (Marine Velvet, a.k.a. Coral Reef Disease)

Marine Velvet is another highly contagious disease caused by protozoal parasites. In this case, the parasites are dinoflagellates and Oodinium is fatal if untreated. These parasites attack the gills primarily, as well as the skin of their hosts, and the fresh-swimming stage of the Amyloodinium protozoans causes massive reinfection of aquarium fishes, leading to death by asphyxiation (Basleer, 2000). Typical symptoms include huffing and respiratory distress, excessive mucus production, and scratching (Basleer, 2000).

These unicellular parasites use their rootlike rhizoids to anchor themselves deep in the mucosa of their host (Basleer, 2000). They do their greatest damage to the mucosa layer, thus destroying the integrity of the fish’s slime coat. This weakens the fish’s first line of defense, leaving them susceptible to secondary infections that produces bloody red patches of skin in the advanced stages of the disease (Basleer, 2000). The characteristic dusting of fine white or yellow spots often never appears when seahorse’s are the hosts, making this condition difficult to diagnose for the seahorse keeper.

Positive identification can be made by microscopic examination. The Oodinium parasites are easily visible on skin or gill smears at a magnification of 100x or 200x power (Basleer, 2000). They appear as dark, cone-shaped unicellular organisms measuring 50-60 microns embedded in tissue (Basleer, 2000).

Cryptocaryon Irritans (Saltwater Ick, a.k.a. White Spot Disease)

Cryptocaryon is another protozoal parasite that invades the gills and burrows into the skin of marine fishes, including seahorses. The life cycle and modus operandi of Cryptocaryon are very similar to that of Amyloodinium ocellatum, so it should not be surprising that it also produces strikingly similar symptoms. Infected fish show labored breathing, excess mucus, and scratch themselves against objects. Along with the characteristic pinhead-sized white spots and excess mucus production, affected fish sometimes show cloudy eyes and secondary infections (Basleer, 2000). The latter can result in skin rot and fin rot accompanied by red or pale patches on the body of the fish (Basleer, 2000).

The white spots seen on infected fish are the adult stage of the parasite, known as trophonts (Basleer, 2000). When they mature, they fall off the fish and encyst themselves. The encapsulated parasites are known as tomonts (Basleer, 2000). Well protected within these cysts, the tomont stage cannot be killed by any medications. The encapsulated tomonts divide into hundreds of daughter cells, which develop into small, ciliated, free-swimming parasites, called tomites (Basleer, 2000). When the cysts rupture, the motile tomites swarm out to seek a new host. In the aquarium, they reinfect the same fishes, and bore into the mucosa of the skin, gills, and fins of their hapless hosts. Once embedded in the tissue, they mature into typical trophonts, appearing as pinhead-sized white spots on most fish, and start the cycle of infection all over again (Basleer, 2000). It is these heavy infestations that can overwhelm even healthy fish.

At 100x magnification, Cryptocaryon parasites can easily be identified in skin and fin smears. They appear as large, dark, bell-shaped or conical organisms measuring about 350-400 micrometers in diameter (Basleer, 2000).

Brooklynella hostilis (Clownfish Disease)

Typical symptoms include turbidity of the skin (a thick, whitish mucus coating in the affected areas), cloudy eyes and breathing difficulty (Basleer, 2000). At first there are no apparent symptoms, but cell division occurs very rapidly and Brooklynella parasites multiply to life-threatening numbers quite quickly in a closed system (Basleer, 2000). These ciliated parasites attack the gills first and then spread to the skin. Clear signs of infection soon appear in the form of respiratory distress and strong turbidity of the skin, often accompanied by excess mucus sloughing in shreds and tatters or hanging off in dark slimy strings (Basleer, 2000). Loss of appetite and listlessness soon follow and skin lesions develop where the turbidity or change in coloration had been, often as the result of secondary bacterial infections. Skin rot and fin rot are common in the advanced stages of Brooklynella. Heavily infected seahorses may die within 24 hours after the first symptoms appear (Basleer, 2000

The symptoms of Brooklynella are similar to those of other parasites that commonly attack the skin and gills of their hosts. An exact identification can only be made through microscopic examination of the parasites. This requires making a wet-mount of mucus taken from the skin of the infected fish, which can be studied under the microscope. The Brooklynella parasites are heart- or kidney-shaped organisms measuring 50-80 microns by 30-50 microns (Fenner, 2003c). A large oval macronucleus and several micronuclei and other endoplasmic organelles should be visible, as should the hairlike cilia it uses for locomotion (Fenner, 2003c). Another key feature to look for is a prominent adhesion organ on the posterior-ventral area (i.e., located on the underside of the parasite at the rear; Fenner, 2003c). This is the device the parasite uses to attach itself to the unfortunate host.

Costia & Cryptobia

These are flagellated parasites that are commonly found on skin and gills of freshly imported marine fishes (Basleer, 2000). Affected fishes exhibit the usual symptoms of parasitic infection by protozoans, including heavy mucus build up, rapid respiration, loss of appetite, and sometimes darkening or turbidity of the skin (Basleer, 2000). In the latter stages, secondary bacterial infections often taken hold and complicate the picture, causing pale skin patches or red patches, which lead to skin rot and fin rot (Basleer, 2000).

Costia are small, bean-shaped flagellates that are very similar to the Ichthyobodo and Costia sp. that parasitize freshwater fish (Basleer, 2000). Cryptobia are similar in appearance. They are small, mobile parasites measuring about 5-12 microns in length with a long tail (flagella) used for locomotion (Basleer, 2000). Both these flagellates can be readily identified in skin and fin smears using a microscope at 200x to 300x magnification (Basleer, 2000).

Snout Rot

Snout rot is the result of an infection, which can be either bacterial or fungal in nature (Giwojna, Oct. 2003). The initial symptoms are discoloration and slight swelling in the affected area of the snout. At this early stage, the seahorse is often not bothered by its affliction and eats and feeds normally. But don’t let that lead to complacency — you cannot afford to take a "wait-and-see" approach with this affliction! As the disease progresses, the infection will begin to eat away the underlying tissue, and if left untreated, snout rot is both disfiguring and deadly (Giwojna, Oct. 2003). The tip of the snout is often the first area affected, becoming inflamed and eroding away, and once its mouthparts are involved, the seahorse can no longer be saved. It is unable to feed, its jaws disintegrate, and the tip of the snout is progressively eaten away (Giwojna, Oct. 2003).

There is considerable anecdotal evidence suggesting that bacterial snout rot can be differentiated from the fungal form of the disease by a close visual inspection (a hand lens or magnifying glass may be required for this). If the snout rot is due to a fungal infection, the affected area of the snout is often pinkish and may appear lumpy or raised, whereas when bacterial infection is at work, white tissue is exposed upon flaking or sloughing of the skin (Giwojna, Oct. 2003). Thus, many hobbyists maintain that if the affected area of the snout looks pinkish, it’s fungus, but if the affected area appears whitish, it’s a bacterial problem (Giwojna, Oct. 2003). This information can help guide you to the appropriate treatment.

If you have seahorses with any of the symptoms described above, do a search on this forum for that particular disease problems and you will find detailed suggestions regarding treatment options, Chris.

Finally, there is an excellent new book about the diseases of seahorses that you would find very informative. 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. It’s available online at the following web site:

Floating seahorses that are unable to feed because of their condition will die unless you can relieve their positive buoyancy, and allow them to swim and feed normally again. If your juvenile seahorses that are floating and unable to swim normally are more than a few weeks old, indicating they have not accidentally ingested air at the surface, and you are unable to obtain Diamox, then I would suggest you try pressurizing them in a homemade decompression chamber, as we discussed in my previous post. In the meantime, do your best to maintain optimum water quality and get your pH back up into the normal range (8.1-8.4), Chris.

Best of luck getting your floating seahorses back to normal, Chris!

Pete Giwojna

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