Re:Sick horse

Pete Giwojna

Dear Carianne:

You’re very welcome!

Okay, that sounds good — if the spasming is merely your new male performing pouch displays and "Pumping," then that’s normal behavior and nothing to be concerned about. In fact, it may be helpful in this instance since pumping water in and out of his pouch will also release any gas that may have built up within his marsupium, thereby preventing problems with positive buoyancy.

Yes, if your new male is swimming normally now, eating well, and able to perch at the bottom of the tank without any difficulty, it’s quite possible that he could be courting the female. The change in coloration you observed and the side-to-side movements you noticed are characteristic courtship displays, as discussed below, and together with the pouch displays, they do suggest that the new seahorses might be courting.

Tropical seahorses typically lighten or brighten coloration when they are courting. For example, dark colored Hippocampus erectus typically turn a silvery white or pale cream color when courting, and may also assume pastel yellow coloration when displaying. They will retain this light coloration for several days throughout the courtship process during initial pair formation, as well as for a short period (10-30 minutes) during their daily greeting ritual thereafter.

This change in coloration is known as "Brightening," and typically involves the seahorse turning much paler or later in coloration, with the exception of the head or face and dorsal surface of the seahorse, which usually remain quite dark. This has the effect of making the seahorse more conspicuous and signals its interest in mating.

Courting seahorses also perform another display known as "Reciprocal Quivering." This maneuver involves repetitive side-to-side movements that can range from a slow swaying to a rapid trembling or shaking, depending on the size of the seahorse and the species involved. If the seahorse being courted is receptive, it will answer the shimmying of its suitor with a shimmy of its own, and the pair of seahorses may exchange short bouts of quivering back and forth, becoming more excited in the process.

And, as you know, courting males inflate their brood pouches with water during courtship displays known as "Pumping" and "Ballooning," in order to demonstrate to the nearby females that they are healthy, vigorous stallions that can carry a large brood of developing young.

So it’s certainly possible that your new seahorses may be engaging in the preliminary stages of courtship, Carianne. In fact, in the absence of any other symptoms of a problem, that is likely to be the case. But male seahorses will also pump and shake themselves when something is irritating their pouches, so it’s difficult for me to be certain of what is going on from afar.

If you contact me off list ([email protected]), I will send you a detailed discussion of all the courtship displays commonly seen in seahorses along with a description of how initial pair formation and mating typically take place so you’ll have a better idea of what to look for, and which behaviors are normal and which could be signs of a problem.

Okay, since your new male seems to be back to normal, it’s time that we addressed the water circulation in your aquarium, Carianne. You’re quite right — if the water flow is so powerful that it is overwhelming the seahorses, whisking them away, and banging them into things, then you need to reduce the water current or diffuse it in some way to moderate the water flow.

The simplest solution would be to switch to smaller powerheads for the undergravel filters. I believe the Penguin 550 is the smallest powerhead that Penguin makes, but there are other brands you can consider. For example, the Maxi-Jet 400 HP Powerhead would also work great for powering your undergravels and it is rated at right around 100 gallons per hour, so switching to the Maxi-Jet 400s instead of the Penguin 550s would be a good start. (Check with your LFS to see if they have any powerheads that may be even smaller and put out even less water flow.)

In addition, you might consider positioning some tall decorations directly in front of the output from the powerheads in order to deflect and diffuse the water flow. I would suggest using the Sea Garden synthetic Sargassum plants for this, Carianne. They make good hitching posts for seahorses, look completely natural, and are tall enough to effectively intercept and diffuse the water flow from the powerheads. The Sea Garden saltwater series of "Fancy Plants" are very realistic, completely safe for saltwater, and very easy to maintain. Just rinse them under warm running water before installation and periodically thereafter for cleaning. There’s a very nice selection of them available and seahorses can’t seem to tell the difference between them and the real thing.

For background decorations in a tall tank like your 55-gallon aquarium, I especially like the SeaGarden synthetic Sargassum plants because seahorses are often associated with Sargassum in the wild so these plants look perfectly natural and very attractive in a seahorse tank. The Sargassum is a natural biotype for seahorses, and of course the Sargassum grows nice and tall, which is what we want for aquascaping the extra-tall tanks that are best suited for seahorses. I like to obtain one or more of the Large, Tall, and Extra Large examples of both the Sargassum fluitans (reddish brown in color) and the Sargassum platycarpum (green in coloration) and arrange them together across the back of the aquarium. They range in size from 12 to 24 inches in height, so if you group the tallest of the plants together, they should effectively conceal the uplift tubes from your undergravels and enhance the beauty of the aquarium, creating a colorful natural background with shades of green, brown, and red. They sway in the current just like the real plants and will work very well for moderating the output from your powerheads. They will deflect some of the water flow and absorb much of the energy of the water, which will go into rippling and ruffling the broad Sargassum leaves and be depleted accordingly, thus reducing the water current.

The SeaGarden Fancy Plants I mentioned above are available online from Drs. Foster and Smith at the following URL:

You could also consider replacing the powerheads by installing airlifts or airstones to operate the undergravels instead. That would introduce air bubbles to the aquarium, of course, but it would certainly reduce the water current to manageable levels, and as long as you keep the bubbles fairly coarse they should not present a problem for your seahorses.

Regarding the brown algae that has appeared in your aquarium, Carianne, it should not be harmful for the seahorses in any way. Nuisance algae such as red slime algae or hair algae are very unsightly and undesirable in the aquarium, and usually indicate a water quality problem (e.g., high nitrates and/or phosphates), but I am thinking that the brown algae is most likely just a bloom of diatoms in your case, which is nothing to be concerned about.

As I have are ready pointed out, diatoms are harmless and most newly set up marine aquariums go through a stage where the diatoms or brown algae grows on surfaces in the aquarium. In most cases, the brown algae will disappear as suddenly as it appeared once it uses up the available supply of some key nutrient in the aquarium (usually silicates). Ordinarily, once the available silica has been exhausted, the population of the diatoms will crash and they will then typically die off on their own.

Otherwise, there are some simple measures you can take to help eliminate the diatoms more quickly. As I said, brown diatom algae is usually the first problem algae that a new marine aquarist encounters. A bloom of brown algae often occurs soon after one introduces new live rock to a marine aquarium. This bloom occurs because the curing of the live rock introduces silicates and nutrients (even pre-cured live rock from your LFS will have some die off after it is transferred to a new aquarium; that’s normal). As a result of the diatom bloom, a brown film soon coats everything inside the tank.

Control of brown diatom algae is relatively easy. The first thing to do is to purchase Trochus or Astraea snails that eagerly consume the brown diatom film. I’ve had good results purchasing Trochus snails from IndoPacific Sea Farms (IPSF). There are other snails that will clean the glass such as Nerite and Strombus snails, but Trochus and Astraea snails are the brown diatom cleaner workhorses. The second thing to do is to perform regular water changes to remove any excess nutrients and silicates from the water. The third thing to do is to have an effective protein skimmer to help with the nutrient removal. The fourth thing to do is to cut down light intensity or duration. The final thing to do is to have some type of chemical filtration such as carbon or ChemiPure help with the nutrient removal. I would rank the methods above from most important to least important in the order they are listed.

One of the easiest and most effective ways to help eliminate unwanted algae is to avoid overfeeding your seahorses and to remove any uneaten Mysis promptly after feeding your ponies. Training the seahorses to eat from a feeding station or target feeding them are excellent ways to cut down on the wastage and to help eliminate uneaten food. And be sure to rinse the frozen Mysis thoroughly before you feed the seahorses. (Mysis juice is rocket fuel for nuisance algae!)

One other thing to keep in mind is to double check the type of activated carbon you are using. Carbon is activated two ways, either with steam or with phosphoric acid. The type of carbon that is activated with phosphoric acid contains phosphates, which can be leached back into the aquarium water and promote the growth of nuisance algae. So you will want to avoid that type of of activated carbon. The carton or box that the activated carbon comes in should be clearly labeled and state specifically that it is "steam activated" or "phosphate free" or something to that effect if it’s a suitable brand for your aquarium.

In short, you needn’t be overly concerned about the diatom bloom and it won’t be harmful for seahorses or any of your other specimens. Just be patient, reduce your photoperiod, add some Trochus and Astraea snails to your cleanup crew, don’t overfeed or introduce Mysis juice into the aquarium, and the situation will eventually resolve itself.

If your new seahorses were sold as Hippocamus kelloggi, Carianne, that’s almost certainly an accurate identification. You are correct in that little is known about this species in the US, but it has been imported in large numbers over the last few years, primarily from fish farmers in Southeast Asia and Vietnam. Unfortunately, you have chosen a very challenging seahorse beasties to work with, since the specimens that are imported to this country have proven to be very delicate and demanding to keep.

Here is what little information I have been able to compile regarding the genuine H. kelloggi, Carianne:

Hippocampus kelloggi (Lourie, Vincent and Hall, 1999)

Common name: Kellogg’s seahorse (US); Great Seahorse (Australia); Offshore Seahorse (Vietnam);.o-umi-uma (Japan)
Scientific name: Hippocampus kelloggi, Jordan & Snyder 1902
Hippocampus suezensis

Maximum size: 11+ inches (28.0 cm).

Climate: subtropical to tropical according to latitude, but these deepwater seahorses appear to be accustomed to cooler water temperatures and have proven to do best under temperate conditions in the aquarium.

Red Sea and Indian Ocean: Tanzania (Zanzibar), Pakistan (Kurachei), India (Madras, Malabar);
Southeast Asia: Danang Sea, Philippines, China and Taiwan; Japan and Australia (southeast Queensland, north New South Wales, Lord Howe Island.

Meristic Counts:
Rings: 11 trunk rings + 40 tail rings (tail rings vary from 39-41).
Dorsal fin rays: 18 rays (varies from 17 -19) spanning 2 trunk rings + 1 tail ring.
Pectoral fin rays: 18 soft rays (varies from 17-19).
Snout length: 2.1 (2.0- 2.3) in head length. (The length of the snout fits into the length of the head only about 2 times. In others, this seahorse has a relatively long snout that measures about 1/2 the length of its head.)
Other distinctive characters:
Coronet: medium-high, with five short spines, and a distinctive high plate in front of the crown.
Spines: low and rounded, always blunt tipped, even in the youngest specimens which have better developed spines. Adults are relatively smooth bodied.
Key Features: a prominent cheek spine (long but rounded) that points backward slightly; a deep head with a thick snout; a slender body with a long trunk and noticeably thick rings, a long tail, and a prominent eye spine (fairly tall but rounded).
Adult height: 6-10 inches (15.0-25.0 cm).

Color and Pattern:
H. kelloggi is typically a pale seahorse with uniform coloration, often adorned with tiny white spots that coalesce to form vertical lines (Lourie at all, 1999). There is some evidence suggesting sexual dimorphism in this species, with the males being darker (brownish to black), while juveniles and females are sometimes lighter in coloration (cream or yellowish), often with pale saddles or patches (Kuiter 2000). The stallions also tend to be slimmer than the females (Coit, pers. com.)

Cultured specimens often exhibit a color pattern that is similar to H. kuda, featuring a yellowish to pale olive green background coloration sprinkled profusely with small dark spots.

This is a very slender seahorse with a long trunk, a long tail, and a thick snout that tends to flare out at the tip (Kuiter 2000)

Natural History:
Very little is known about the life history or behavior of this large slender seahorse, except that it is primarily a deepwater seahorse (> 66 feet or 20 m deep) that is often found well offshore over soft, muddy bottoms (Kuiter 2000).

I have never worked with the species, so at the present, I cannot even tell you if it produces pelagic or benthic fry, or how long the gestation period for the species may be, but now that H. kelloggi is being cultured in large numbers, that information should be forthcoming soon.

Preferred Parameters:

Hippocampus kelloggi seahorses appear to do best under temperate conditions when kept in small, closed-system aquariums. The H. kelloggi keeper should therefore maintain the systems for the seahorses within the following aquarium parameters:

Temperature = range 64°F to 75°F (18°C-24°C), optimum 66°F-68°F (19°C-20°C).
Specific Gravity = range 1.022 – 1.026, optimum 1.0245
pH = 8.2 – 8.4
Ammonia = 0
Nitrite = 0
Nitrate = < 20 (ideally 0-10 ppm)

Suggested Stocking Density:
When fully-grown, this is a very large seahorse with a recommended stocking density similar to other giants such as H. abdominalis and H. ingens: one adult seahorse 2-3 years old per 57 liters (15 gallons) or one pair of 6-month old young adults per 15 gallons (57 liters).


H. kelloggi can easily be confused with H. kuda, which is another large, smooth-bodied tropical seahorse with similar coloration. Upon close examination, however, it is not difficult to distinguish between the two. H. kelloggi has a slimmer body build than kuda, with a more slender profile due to its exceptionally long trunk, as well as a longer tail, and the coronets of these two species are quite different (Lisa Coit, pers. com.). The small spines that form the 5-pointed crown on H. kelloggi are nothing like the low, rounded coronet of H. kuda, which may have broad flanges and overhang at the back, but is not at all spiny.

Captive-bred-and-raised Hippocampus kelloggi have only recently become available in the US and very little is known about their behavior. Hobbyists who keep captive raised H. kelloggi tell me that they tend to be real bottom huggers that rarely perch higher up then about 4 inches above the bottom (Coit, pers. com.). Their behavior in that regard is said to be similar to the Cape seahorse (H. capensis), an estuarine species that always orients to the substrate and is notorious for its bottom-hugging behavior. I’m told that they have a big appetite and feed aggressively on frozen Mysis, and are almost fearless in the aquarium — flaunting themselves in the open, never hiding, and not at all shy or retiring (Coit, pers. com.).

When courting, H. kelloggi stallions perform the usual pouch displays (Ballooning and Pumping) in which they inflate their brood pouches with water in an effort to impress the females with the awe-inspiring dimensions of their fully inflated marsupium.

New arrivals may alarm their keepers with their propensity for performing unusual color changes, in which they exhibit pale patches in various places on their body for short periods before reverting to their normal coloration again just as suddenly (Coit, pers. com.). These lighter patches can appear almost anywhere on their body, from head to tail, and are typically not symmetrical but rather confined to one side of their body only (Coit, pers. com.). This can be disturbing to the uninitiated, since depigmentation and localized loss of coloration are often signs of potential disease problems ranging from fungal and bacterial infections to ectoparasites that attack the skin and gills. In H. kelloggi, however, these unpredictable, transitory, patchy color changes simply appear to be normal behavior for the most part.

However, they have proven to be delicate aquarium specimens overall that cannot seem to adapt readily to the standard conditions typically found in the home hobby tank, especially when tropical temperatures (75°F-78°F) are maintained. The Southeast Asia Hippocampus kelloggi simply don’t appear to be a particularly hardy strain of seahorses at this stage in its development. I believe part of the problem is simply that H. kelloggi have not been cultured or selectively bred for aquarium life as other species that have been around much longer, and as a result, the kelloggi are just not as well adapted to aquarium conditions as of yet.

Many people suspect that the H. kelloggi are merely pen raised, and have therefore not benefited from the sort of intensive aquaculture and selective breeding that produces superior captive-bred livestock here in the US. Net pens are a low-tech, low-maintenance method of farming seahorses that basically involves raising them in large enclosures in coastal waters. It is a common practice in Indonesia, many Asian countries, and the Philippines. In some cases, entire lagoons may be fenced off for that purpose. In the simplest form of pen rearing, broodstock are released into these enclosures, and then they and their progeny are pretty much allowed to fend for themselves thereafter. Any offspring that survive to marketable size are periodically harvested from the holding pens or lagoons.

The benefit of this technique is that it allows seahorses to be raised cheaply, and therefore produces specimens for the aquarium trade that are relatively inexpensive. (It is the low-cost of the H. kelloggi that attracts most hobbyists.) The downside is that pen raising does not strengthen and improve the seahorses generation after generation, making them ever better adapted for aquarium conditions, as does Western-style aquaculture. So the pen raised ponies are not generally as hardy and adaptable as captive-bred-and-raised seahorses.

Such operations (net pens) are controversial with environmentalists for a number of reasons. Since the enclosures are open to the ocean, there is a real risk that adults or their fry may escape from the pens and establish colonies in the wild that may pose a threat to endemic seahorse populations. The pens are no barrier to disease organisms or parasites, so pathogens and parasites imported on foreign broodstock may spread to fishes in the wild (or vice versa). Wastes from the high density of penned animals are carried directly to ocean on prevailing tides and currents and may have a negative environmental impact on the surrounding area. There is no way to monitor the penned animals, hence no way to determine whether the seahorses they contain are actually born and raised in the enclosures or are merely wild-caught seahorses maintained in holding pens prior to being shipped off to unsuspecting consumers.

Pen-grown ponies can thus be risky for the hobbyist because of the circumstances under which they were raised. In essence, a mesh barrier is all that separates them from wild seahorses. There is no guarantee they will be disease free. Although many of them learn to accept frozen Mysis, there is no guarantee they will eat frozen foods since they are often accustomed to foraging for live prey. There is no guarantee they will be able to adjust to aquarium conditions since they are essentially raised in the sea. There is no guarantee that they are even captive bred, since the pens are not secure and livestock is introduced and removed from the pens and lagoons on a continuous basis. There is no guarantee they will be friendly and sociable rather than shying away from their keepers, since they are unaccustomed to the human presence. Pen-raised ponies are particularly misleading because they are almost never advertised as such — they are typically called captive raised or even captive bred seahorses, which can lead the unwary consumer to assume that they have been painstakingly raised using intensive mariculture techniques and rearing protocols. Nothing could be further from the truth.

In light of the health problems so many home hobbyists have been having with their H. kelloggi for some time now, I have been discussing the needs and requirements of this species with advanced aquarists and experts that have worked with H. kelloggi in the past. The consensus seems to be that the current crop of H. kelloggi are being shipped out to hobbyists while they are still too young (the two-inch long juveniles are no more than 3-4 months old) and that they are not well adapted to aquarium conditions because they are likely being pen raised. The tiny H. kelloggi juveniles would fare better if they allowed them to grow up for a few more months and shipped them at the age of around six months.

However, the primary problem folks have been having with their H. kelloggi may be due to their temperature requirements. The people I conferred with maintained that H. kelloggi is a deepwater seahorse and is therefore adapted for lower light levels than most seahorses and also requires cool water temperatures (Lisa Coit et al., pers. com.). They feel that this species should be maintained in temperate tanks rather than tropical aquaria, and that H. kelloggi will only thrive if they are maintained at a water temperature of 68°F or less (Lisa Coit et al., pers. com.). They report that if the H. kelloggi are maintained at standard aquarium temperatures for a tropical marine aquarium (i.e., 75°F-78°F) they will be plagued by various bacterial infections and suffer as a result.

So there are several problems with the H. kelloggi at this point in their development. They are likely being pen raised in Southeast Asia, they are consistently being shipped to the consumer while they are too young and small to thrive, and they are typically being kept in tropical aquariums rather than the cool water or temperate tanks that they need. This combination of unfavorable circumstances is quite deadly and is dooming most all of the H. kelloggi that come into this country to an early demise. Heat stress is making the H. kelloggi susceptible to a variety of health problems, but especially bacterial infections, most often Vibrio in one form or another.

All things considered, I cannot recommend H. kelloggi for the home hobbyist at this time. Beginners should avoid this seahorse and experienced hobbyists may want to wait for the strain to be strengthened and improved over several more generations before they consider giving H. kelloggi a try.

That’s it, Carianne — that skimpy information is pretty much the grand total of what is known in the US regarding H. kelloggi at this time.

Because the H. kelloggi are little more delicate, I would recommend keeping them in a species tank at least 24 inches tall with lots of elbow room. Give them a tank devoted only to H. kelloggi and concentrate on maintaining optimal water quality. Make sure the water temperature remain stable at 75°F or below at all costs, and try to keep the tank as cool as possible. Installing an ultraviolet sterilizer and a chiller on their aquarium would be a worthwhile investment for this species.

Best of luck with your new seahorses, Carianne! Your 55-gallon aquarium has the right size and water volume for these delicate ponies to do well, so if you can adjust the water flow as we discussed earlier and keep their aquarium reasonably cool, hopefully they will respond to the good conditions and remain in good health. At the present, they seem to be displaying a healthy interest in courtship and breeding, which is always a good sign.

Pete Giwojna

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