FAMA Seahorse Forum – October 2001

by Charles Delbeek and Carol Cozzi-Schmarr – from the October 2001 issue of Freshwater and Marine Aquarium magazine (FAMA)

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Horse Forum

I would like to thank Dr. Clyde Tamaru for sharing his scientific expertise and cutting edge research on sea horses with us in the last several Horse Forum columns. We look forward with great anticipation to more contributions from Clyde in the near future.

Our next guest speaker is someone that we have all been waiting to hear from. The farm-raised sea horse has become an extremely popular addition to traditional reef aquariums. Although this is a very natural wild habitat for the sea horse, the successful keeping of the sea horse in the enclosed reef environment does require some special knowledge. I cannot think of a more qualified person to successfully guide the hobbyist in this undertaking other than the legendary reef aquarist Charles Delbeek!!

Charles graduated from the University of Toronto in 1981 with an honors bachelor’s degree in biology, a master’s in zoology in 1985 and a bachelor’s in education in 1986. After enduring one winter too many in his native Toronto, he moved to Hawaii and took a position with the Waikiki Aquarium in the spring of 1995. He has been caring for marine organisms in closed systems for over 30 years and he currently maintains ten exhibits at the Waikiki Aquarium ranging from a 12 gallon live coral exhibit to a 7000 gallon outdoor Hawaiian live coral and fish exhibit. His professional interests include the captive husbandry of marine fishes, corals, and cephalopods.

A certified SCUBA diver since the age of 14, Charles has made over 300 dives in locations throughout the world including Canada, Fiji, Hawaii, Indonesia, Japan, the Marshall Islands, Palau, the Solomon Islands, the Florida Keys, Bonaire, St. Kitts and St. Martin.

Charles has lectured at over 40 aquarium-related conferences and meetings, and published approximately 40 articles in the popular aquarium literature in the last 15 years. In addition to writing a monthly reef aquarium column for Aquarium Fish Magazine since 1997, he has co-authored two popular aquarium books with Julian Sprung, _The Reef Aquarium_ in 1994 and _The Reef Aquarium_ volume 2 in 1997.

We are honored indeed to have Charles as a guest in Horse Forum. He will be with us for the next 3 issues, so please feel free to send your questions.

Mahalo, Carol

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Lets’ hear now what Charles has to say about keeping the sea horse in the reef aquarium:

There has been a lot of interest lately in keeping sea horses in reef aquaria. Although it is possible to do so, there are some things that need to be taken into consideration. Most reef tanks that house corals also have a great deal of water movement. When combined with overflows, it is not uncommon for sea horses to be trapped against or even go over, overflows. Powerheads are also often used and can be death traps for sea horses if the intakes are not properly screened off. To keep sea horses in reef tanks one really must foresee all the possible ways that they could be injured and to take precautions against this happening.

Many corals are powerful stingers, but these belong mainly to the stony coral families. Most soft corals have very little stinging ability and will not harm sea horses. However, since sea horses can grasp onto soft corals with their tails they can cause the coral to retract its polyps. This can be a problem if the coral relies on its polyps to capture light to provide the energy it requires to survive. Fortunately in most cases, the coral will habituate to the constant irritation caused by the sea horse and will not retract its polyps as frequently as in the beginning. The observant aquarist should keep an eye on their soft corals to insure that they are not remaining closed for long periods of time.

In the case of stony corals there are two main groupings to be considered. The small polyped stony (SPS) corals consist of genera that have small polyps that extend out of very small openings in the skeleton. These would include genera such as Acropora, Montipora, Pocillipora, Porities, Seriatopora and Stylophora. These SPS corals are generally considered to be weak stingers and should not irritate sea horses very much. However, the same precaution I mentioned for soft corals also applies to SPS corals. The second major grouping are the large polyped stony (LPS) corals. These include genera such as Catalaphyllia, Cynarina, Euphyllia and Trachyphyllia that have large fleshy polyps often with tentacles that can have powerful stinging cells. Of these the Euphyllia and Catalaphyllia are the strongest stingers, and any sea horses placed into tanks with these corals should be carefully observed.

Despite what many people think, sea horses are quite effective swimmers and can hold their own in strong currents. However, in the confines of an aquarium, it is not impossible for them to come into contact with stinging corals if suddenly caught in a very strong current. The aquarist needs to take this into consideration when placing water returns and corals in the aquarium. People have been keeping fish with corals for several years now and the instances where fish have been taken by corals are few and far between, but it does happen occasionally. Sea Horses, like any other fish, have a natural ability to avoid most powerful stinging corals, and the slightest touch is enough to reinforce this natural avoidance behavior.

Other invertebrates that sea horses should do well with include zoanthids, corallimorpharians (mushroom anemones), sponges, sea cucumbers, shrimp and the smaller detritus or algae feeding snails, worms and crabs. One notable exception is the elephant ear mushroom anemone (Amplexidiscus fenestrafer). This animal is an active feeder on small fish and will envelope them whole with its mantle then slowly digest them by extruding its digestive filaments into the space created. No small fish are safe with these animals in the tank.

Dear Charles,

Has anyone kept royal grammas (Gramma loreto) with their OR’s, and does it make a happy match? I’ve had them before and they seem territorial but not overly aggressive and I’m thinking they’d make a nice addition to my sea horse tank. Any ideas?

Here’s another question. I have a 55-gallon tank with ten OR’s, two cleaner shrimp, a black pearl oyster, hermit crabs, and now a banded cat shark. The short version is I had the shark egg in my other tank, had to treat with copper which is not good for the shark egg I decided to the egg in the sea horse tank for a couple of weeks, and the shark had the nerve to hatch! Question is, are my horses (or any other tank mates) in danger with a baby shark sharing their habitat? Any info would help a lot!

Thanks, Tom

Well Tom, 

A shark is a shark is a shark, in other words it is a predator. Banded cat sharks feed on small fish and crustaceans and it can most definitely make a meal of your sea horses and shrimp if it chose to. I would recommend removing it as soon as possible.

As far as the royal grammas go they would make a good addition for your sea horses, since most of their aggression is aimed towards their own kind and not other fishes. Another fish to consider is the black-capped basslet (Gramma melacara) which is a beautiful dark purple with a black “cap” on its head. My only concern would be getting enough food to the slower sea horses, this really is the key to keeping sea horses with other, more aggressive feeders such as butterflyfish. If you can target feed the horses you should not have any problems. I have kept sea horses with small tangs and raccoon butterflyfish with no problems since I was able to hand feed the horses. These were housed in a seagrass exhibit and often the food would fall down amongst the blades where the sea horses eventually found them. Another trick is to feed the other fish first to lower their hunger level, and then target feed the horses. Other good tank inhabitants include cardinalfish such as pajama and banggai cardinals, as well as pipefish, small species of filefish, dartfish, gobies, mandarinfish and blennies. It is possible to keep a wide range of fish with sea horses provided you can get food to the sea horses and the other fish are not too large or boisterous. The type of fish that can be kept with sea horses depends on a lot of factors not the least of which is tank size and fish density. With a small tank (<125 gallons) and a lot of fish, it is difficult to get enough food to the sea horses on a daily basis without being able to target feed them. A lot of people do not have the patience to target feed their sea horses two or three times a day, and in this case it is often better to house them in their own tank or with small, non-aggressive feeders like gobies, mandarinfish or pipefish.

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Dear Carol,

I have 2 pairs of sea horses in my reef aquaria. They have done fabulously. The other day I noticed that my larger female has disappeared. After a thorough search of the tank I found her with her tail stuck inside my clam!! What should I do?? The clam is a blue Tridacna maxima.

Thanks, Tammy

Dear Tammy,

This is quite a predicament!! Believe it or not I know of a few other people whom have had the same thing happen!! The best thing to do is to not try and open or move the clam or dislodge the sea horse from the clam. This would end up damaging the clam and the sea horse!!

Most likely the clam closed shut as a defensive response to the sea horse tail probing inside its shell as she was looking for a place to hitch herself up to. Once this response has passed the clam will open up and the sea horse will be free. Therefore, the less you do the better. Trying to pull the sea horse out will only cause the calm to stay shut longer. It should not take long but, if the clam is highly stressed it may take as long as a day or two. If your sea horse is well fed and healthy she will be fine during this stay with the clam!

As I am sure you know the Tridacna clam acquires nutrition mainly through its symbiotic relationship with their zooxanthellae (microscopic algae) which live within its tissue. The clam will not consume the tail that is within the shell but may in fact scrape the part of the tail that is touching the edge of the clamshell. This may result in a small wound. It is even possible that the sea horse may loose the very tip of its tail. Don’t be alarmed though as the sea horse has very tough skin and will most likely not be seriously hurt by the incidence.

It is possible that the wound may need a topical antibiotic but a healthy sea horse has a tremendous ability to heal itself if you give them the chance. The best way to avoid having to treat the wound (if there even is one) is to make sure you water quality is excellent and that your tank temperature is not too high. Bacteria grows many times faster at higher temperatures. Keeping the temperature lower will help prevent infections from festering on a small wound such as this. Most tropical sea horses actually prefer temperatures closer to 70F than 80F. 72F is what I recommend.

Also make sure your sea horse is getting the proper nutrition with all the proper fats, vitamins and minerals. Within no time the wound to the tail will be healed up and I bet the sea horse won’t try and hitch up to that clam again!!

Carol

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Dear Charles,

I have a 90 gallon tank, 48″ x 18″x 24″ tall with a crushed coral substratum and 150 pounds of live rock. Filtration consists of a protein skimmer and a mechanical filter with a powerhead in each corner of the tank. My current livestock includes a mandarin fish, a firefish, numerous types of snails and a few hermit crabs. For corals I have three purple ribbon gorgonians, two yellow gorgonians, Anthelia polyps, a lime green leather coral and two gold crown leathers along with a few mushrooms that have grown off the live rock.

They only thing I really feel might be troublesome are the flower anemones. When I ordered the anemones I was told they mainly feed off the zooxanthellae they have and get some of their nutrition from plankton in the water column. Although I would remove them on your recommendation that they could be harmful to the sea horses, I have touched them with my hands and they didn’t produce a sting or cause irritation but they felt “sticky”.

Are people successful in rearing fry? Can you direct me to any sites or books that would have information on rearing fry? Is it something a hobbyist should even try or can the babies survive in the tank on their own?

Thank you,

Jon K.

Jon although you may not feel anything when touching the anemones with your hands, the fact that they feel “sticky” indicates that they do indeed possess numerous stinging cells called nematocysts. These specialized cells send out harpoon-like structures when stimulated by contact. That you felt nothing with your hand is likely due to the fairly thick skin it has compared to others parts of the body making it fairly immune to the stinging cells of most anemones. Often the inside of the arm or wrist is better to use to check for stinging ability than the fingers or palms. However, if you are at all allergic to animal’s stings please DO NOT attempt this!

Without a scientific name it is difficult to know for sure what type of anemone you have. If these “flower” anemones were members of the genus Aiptasia then I would not be too concerned for the health of the sea horses. However, these anemones can over-run a reef aquarium very quickly, I have even seen them growing on sea horses, and they should be held in check. In searching the Internet for the term “flower anemone” I found two possible types it could be, Epicyctis (Phymanthus) crucifer or Actinia equina. These are very similar in appearance so it is not surprising that they could both be referred to as flower anemones; they are also commonly called rock anemones. Since they can commonly be found in seagrass beds of the Caribbean and Florida Keys, sea horses probably encounter them and should be adept at avoiding them. I would not be too concerned that the sea horses would be in danger, however, if caught in a strong current they could be pushed into one. I have kept tank-raised sea horses in a seagrass tank that contained elegans coral (Catalaphyllia) which has a much stronger sting than those anemones and did not have any problems with the sea horses coming into contact with them. If you are not willing to take the same risk, then you should remove the anemones for your own piece of mind.

Raising sea horse fry is not that difficult depending on the species and your ability to provide food. When first born, the fry need live food such as newly hatched brine shrimp. At this age they require a constant supply of live food so it is highly unlikely that any of them will be able to survive on their own without your intervention. You are off on the right track in asking for sites and books for information. I suggest doing a search on the Internet using the keywords “sea horse breeding” and you will easily get over 100 hits. As far as books go, a new book by Neil Garrick-Maidonent called Sea Horses: Conservation and Care published by TFH Publications, ISBN 1852790717, and would make an excellent first book. The other is called Sea Horses, Pipefishes and their Relatives by Rudie H. Kuiter published in 2001 and available through www.seachallengers.com it is an excellent guide to sea horse ID as well as having a useful husbandry section.

Charles