care for seahorses

Dear Adventurer:

Howdy, sir!

We have already discussed how to assure that your seahorses are healthy before you make a purchase, as well as the proper procedures for quarantining seahorses that did not come from the High-Health Ocean Rider aquaculture facility in your earlier post titled "avoid sickness," but it sounds like the best source of information for you would be to complete the Ocean Rider seahorse training program. It’s a comprehensive correspondence course that’s conducted entirely via e-mail, Adventurer, and it’s completely free of charge. The training course is designed to teach hobbyists such as yourself everything you need to know about the care and keeping of seahorses in the home aquarium, so it might be exactly what you are looking for…

For example, one of the lessons in the training program is devoted entirely to "Disease Prevention and Control," sir, and it includes a number of full-color photographs illustrating the most common diseases of seahorses. It also includes a helpful list of the medications that are useful for seahorse keeper to keep on hand, and discusses what those medications are used for in some detail.

There are other chapters devoted to "Courtship and Breeding" and "Rearing the Young," which include a complete discussion of nursery tank options as well as rearing protocols developed by professional aquaculturists, with a separate section devoted to culturing rotifers, copepods, greenwater (microalgae cultures), and newly hatched Artemia nauplii.

If you’re interested in the Ocean Rider seahorse training program at no charge whatsoever, Adventurer, just contact me with a brief e-mail off list that includes your full name (first and last), which I need for my records, and I will get you started out with the information packets of lessons right away. You can reach me at the following e-mail address anytime: [email protected]

I will also send you an information packet on collecting and culturing live foods for seahorses, that discuss everything from copepods and amphipods of various types, to different species of feeder shrimp, larval fishes and Poecilid fry, and many others too numerous to mention. Like the lessons for the training program, the files on live food cultures are too large to be posted on the discussion forum such as this.

In the meantime, Adventurer, this is what I normally advise home hobbyists regarding the types of macroalgae that grow well in a marine aquarium for seahorses or that are suitable for use in a refugium:

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Macroalgae — Living Hitching Posts

For live hitching posts, I prefer decorative marine plants or macroalgae in a variety of shapes and colors and color — reds, golds, and yellows in addition to green varieties, some tall and feathery, some short and bushy — to provide them with natural hitching posts and shelter. I like to start with a mixture of red and gold Gracilaria (Ogo), which grow well attached to rocks, and artfully arrange them around a lush bed of assorted bright green Caulerpa, which thrives in a sandy substrate. Any of the plumed (feathery) or long-bladed Caulerpa would be ideal for this, such as Caulerpa sertularioides, C. mexicana, C. ashmedii, C. serrulata or C. prolifera. But they may not be the best choice for tall tanks since none of these species will grow more than about 4-6 inches in height at the most.

Be sure to thin out the fast-growing Caulerpa regularly; when you remove the excess strands and fronds, you’re exporting phosphates, nitrates and other nutrients from the tank, thereby helping to maintain good water quality, and thinning out the runners helps keep it from going sexual.

When thinning out Caulerpa and other macroalgae, take care not to actually cut it. Remember, you’re not pruning hedges or trimming trees — the idea is to carefully pull up and remove continuous, unbroken fronds or entire runners with numerous old fronds. Simply thin out the colony of excess strands, gently plucking up convenient fronds that can be readily removed intact.

Typically, the Caulerpa colony will put out horizontal runners or strands (i.e., the stolon of the plant) and a number of vertical leafy structures or "fronds" will sprout upwards from these runners. When I am thinning out a bed of Caulerpa, I try to weed out the older growth and pluck out whole runners complete with several feathery fronds so that I minimize any breakage when I remove the older plant material from the colony. In other words, rather than plucking off individual fronds at the attachment where they sprout from the runners, I prefer to extract an entire runner or strand together with all of its fronds, which allows me to remove more plant mass with as little breakage or damage to the entire colony is possible. Often there will be older strands and fronds that have separated from the rest of the colony naturally, and these are the best runners to target since there will be little or no breakage when they are removed. By regularly removing the older runners and the associated fronds, you can interrupt the life cycle of the Caulerpa and prevent it from going sexual. This is best done on a weekly basis to be safe, if the Caulerpa colony is growing rapidly.

A little breakage when thinning out the Caulerpa is fine, but cutting or breaking too many strands will result in leaching undesirable substances into the aquarium water as the Caulerpa’s lifeblood drains away. Too much cutting or breaking can thus sap the colony’s strength and cause die offs or trigger the dreaded vegetative events that judiciously thinning out the colony otherwise prevents.

The Caulerpa colony also dies off en masse after reproducing sexually, and the massive die off of Caulerpa for any reason can present a danger to the aquarium. There are undesirable substances leached back into the aquarium from the dying colony, and the resulting decay of a large quantity of organic matter all at once may trigger a bacterial bloom and subsequent drop in the dissolved oxygen level of the aquarium. The combination of these events can sometimes result in the loss of specimens or even crash the entire system.

Such a "vegetative event" is unmistakable because it will often turn the water in a small, closed-system aquarium milky white until the filtration begins to have an effect. If such an event occurs, the observant aquarist can often save the day by performing a series of water changes and employing activated carbon and other chemical filtration media to remove the harmful substances that have been released.

If you find it difficult to obtain Caulerpa (it’s illegal in some coastal areas) or you’re simply concerned about your ability to maintain and control of Caulerpa properly, just use a different forms of macroalgae that grows less rapidly instead and you can get the same sort of benefits at relatively little risk. In that case, some of the other macroalgae you may wish to consider are Gracilaria, Ulva, Codium, Chaetomorpha, and Chlorodesmis. Hawaiian Ogo (Gracilaria sp.) are bushy red-to-brown macros that do well under low light levels. Sea Lettuce (Ulva sp.) are deep green sheets of algae that do best under a little stronger lighting. Maiden’s Hair (Chlorodesmis sp.) are bright green tufts or clumps of very fine-bladed algal mats that grow attached to small rocks. Codium is another bright green algae with an attractive branching structure. All of these types of macroalgae are much less prolific and slower growing than Caulerpa. However, like all macroalgae, they should still be harvested periodically in order to export the excess nutrients they have consumed.

Aside from red and brown Gracilaria and the bright green Ulva and Maiden’s Hair, some seahorse keepers also like the Chaetomorpha turf algae or spaghetti algae, as it is also known. It can best be described as looking like the clumps of the colorful plastic grass we use to fill Easter baskets. It is popular because it is slow growing and doesn’t require the kind of pruning that Caulerpa needs, and because it comes loaded with microfauna: miniature feather dusters, copepods and amphipods, tiny snails and micro stars. In short, Chaetomorpha is another interesting marine plant that can add some extra variety to a lush bed of macroalgae. But it is rather unsightly and unkempt in appearance, and I prefer to use it in a sump or refugium rather than in the main tank.

If you are looking for colorful macroalgae that goes well with live rock and will provide good hitching posts for seahorses, then I think you might like the "red-on-rock" algae species offered by Inland Aquatics. They are more colorful and won’t overgrow or overwhelm your tank.

Other colorful red macroalgae that are well worth trying include Heymenia or Halymenia (commonly known as dragon’s tongue) and Botryocladia red grape algae, which is commonly known as red grape Caulerpa (even though it’s not a species of Caulerpa at all). The dragon’s tongue is a very attractive red species that either likes the conditions in your aquarium and thrives, or doesn’t like the tank conditions and disappears. When it thrives, it’s a beautiful red macroalgae that’s an asset to any aquarium. The distinctive appearance of these Botryocladia and its reddish coloration make it an aquarium favorite which is also useful since a large colony makes a good natural feeding station for seahorses. It does well when attached to the rockwork.

Maiden’s hair algae and sea lettuce (Ulva spp.) are bright green species of macroalgae that normally grow attached to rocks and are typically sold that way for aquarium use. They could also be placed amid your live rock where they would receive bright light.

If you are looking for marine plants to maintain in a sandy area of your tank, many species of Caulerpa, Merman’s shaving brushes (Penicillus spp), Udotea "sea fans," and Halimeda sea cactus are available, all of which are just anchored in the sandy bottom and will put out rhizoids or holdfasts to keep themselves in place. Other species of Halimeda are available that sprout from live rock instead, so that’s another option if you prefer.

But the Halimeda sea cactus, Penicillus shaving brushes, and Udotea sea fans are all calcareous macros that require high levels of calcium in order to thrive. To maintain them successfully, you will need to monitor the calcium levels, total alkalinity, and carbonate hardness of your seahorse setup, provide occasional supplements of calcium or Kalkwasser, and maintain the aquarium more like a reef tank than an ordinary saltwater system.

Codium is another green macroalgae that’s very attractive in the aquarium and very distinctive in appearance (with its branching structure, it looks more like some sort of green gorgonian or bushy seafan, rather than a species of algae). It can grow several inches tall and may develop a bushy branching crown several inches in diameter. The Codium thus makes a good natural hitching posts for seahorses (Peggy Hill, pers. com.) and is a good choice for a well-lit sandy area in the tank.

Some macroalgae are rootless and do not anchor in place. This is true of the Chaetomorpha turf algae or spaghetti algae, for instance. It grows in tangled clumps that look like nothing more than the colorful green Easter grass we use in our Easter baskets as bedding for the jellybeans, marshmallow chicks, and chocolate bunnies. Chaetomorpha is therefore not very aesthetic looking in your main tank, but you can’t beat it for use in refugia or algal filters because hordes of copepods, amphipods, and other microfauna love to shelter, feed, and breed in the tangled masses of the spaghetti algae.

Like the Chaetomorpha, different types of Gracilaria or Ogo are often cultured by tumbling them so that they are always in motion, exposing different areas of the plant masses to the sunlight and assuring that clean water circulates through them continually. Several different types of Gracilaria (red, brown, green) are available and are typically sold in clumps by the bag or the pound. They don’t have roots as such, of course, but if you wedge them in crevices in your live rock or anchor them in place with a small rock or piece of coral rubble, they will attach to a hard substrate and grow well under favorable circumstances. Again, like the Chaetomorpha, these balls or clumps of Gracilaria/Ogo are ideal for culturing copepods and amphipods in your sump or refugium, but they will also look nice in your main tank once they take hold.
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Okay, sir, that’s a brief rundown on some of the macroalgae species that work well as hitching posts or marine plants for a refugium. All of the macroalgae discussed above or saltwater species that are suitable for marine aquariums.

Some of the microalgae species that work well for culturing live foods in saltwater such as rotifers and copepods include Isochrysis galvana, Nannochloropsis aculata, and Chaetoceros sp.

Best wishes with all your projects, Adventurer! I hope to hear from you via e-mail shortly if you would like to receive the information packets and lessons for the seahorse training program, sir.

Respectfully,
Pete Giwojna, Ocean Rider Training Program Advisor