Candy cane coral

Dear Michael:

I’ve never kept a Candy Cane coral with my seahorses, but Will Wooten lists the Candy Coral (Caulastrea furcate) as a “1” on his compatibility guide, so they should be safe. (The 1’s are completely safe all the time with small to large horses, almost no exceptions.)

As a general rule, the hobbyist who wants to keep seahorses in a reef system with suitable corals must be willing to make some concessions and modifications to accommodate their special needs nonetheless. For example, the reef keeper must be willing to limit himself to corals and invertebrates that meet the following criteria:

1) Avoid any stinging animals with powerful nematocysts. This means fire corals (Millepora spp.) and anemones should be excluded from the seahorse reef, and any corals with polyps that feel sticky to the touch should be used with discretion and only after careful planning. When a seahorse brushes up against them or attempts to perch on them, the nematocysts or stinging cells of these animals can penetrate the seahorse’s skin and damage its integument. Needless to say, this causes pain and discomfort and can leave the seahorse vulnerable to secondary bacterial and fungal infections, which may take hold at the site of injury. Short polyped stony (SPS) corals are generally fine, but large polyped stony (LPS) corals should be regarded with caution, as discussed in more detail below.

2) Water movement and circulation must be managed with care. Corals that require powerful surge or overly strong water currents could overtax the limited swimming ability of Hippocampus unless slack water areas the seahorses can retreat to when needed are also provided.

3) The corals must be able to withstand being used as hitching posts by the seahorses from time to time; that is, they cannot be so delicate that having a seahorse’s grasping tail anchored around them could cause them any harm. For instance, soft corals may retract their polyps when a seahorse perches on them. This can be harmful to their health if it becomes a chronic problem, because many corals rely on their polyps to absorb light and convert it to energy via photosynthesis. Be sure to watch any soft corals and hermatypic corals to make sure they are not closed up for extended periods. Normally, they adjust to the seahorses’ presence and unwelcome attention after a while, and remain contracted only briefly after each contact. After repeated exposures to grasping tails, each such incident elicits a weaker response, so they tend to extend their polyps sooner and sooner after being disturbed (Delbeek, Oct. 2001).

4) Avoid Tridacna clams and similar bivalve mollusks. Sooner or later a seahorse will perch on them with its tail between the valves and the clam’s powerful adductor muscle will clamp down on it like a vise. At best this will be a very stressful experience for the unfortunate seahorse, since it can be the devil’s own business trying to persuade the stubborn mollusk to release its struggling victim! At worst, it can result in serious injury or permanent damage to the seahorses tail (Giwojna, unpublished text).

5) Beware of unwanted hitchhikers that may have come in on your live rock unbeknownst to you and which can harm seahorses, such as fireworms, mantis shrimp, or Aptasia rock anemones. When setting up a reef system for seahorses, it’s a wise precaution to pre-treat your live rock with a hypersaline bath to drive out such pests beforehand because they can be very difficult to remove or eradicate once they make themselves at home in your aquarium (Giwojna, unpublished text).

As long as the specimens you are considering for your seahorse reef satisfy these requirements, anything goes! Some of the good and bad candidates for such a reef system are discussed below:

Seahorse-Safe Corals

Soft corals have very little stinging ability and generally make good choices for a modified mini reef that will include seahorses (Delbeek, Oct. 2001). This includes most mushroom anemones (corallimorpharians). However, as Charles Delbeek cautions, “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 (Delbeek, Oct. 2001).”.

Hippocampus also does very well with zooanthids and colonial polyps in general. But the hobbyist must be sure to observe a couple of precautions when handling the zoanthids and placing them in your aquarium.

First and foremost, many of the commonly available Zooanthus (button polyps) and Palythoa (sea mats) species contain a very toxic substance in their mucous coat known as palytoxin, which is one of the most poisonous marine toxins ever discovered (Fatherree, 2004). Palytoxin can affect the heart, muscles, and nerves, resulting in paralysis or possibly even death, and many hobbyists have reported numbness, nausea and/or hallucinations after merely touching these corals (Fatherree, 2004). When you handle zoanthids and palythoans, you cannot help picking up some of their protective slime on your fingers, and so much as rubbing your eye, picking your nose, or a small cut on your finger can be enough to land you in the hospital. When handling Zooanthus are Palythoa species, it’s very important to wear disposable latex gloves, avoid touching your mouth or eyes, and carefully dispose of the gloves immediately afterwards (Fatherree, 2004).

Secondly, zoanthids and other soft corals such as mushrooms may wage border battles if you place them in close proximity to each other (and the zoanthids almost always lose out to the mushrooms in these skirmishes). So be sure to allow adequate space between the colonies. Some rapidly growing Zooanthus colonies can be aggressive to soft and stony corals alike as they rapidly spread over the rockwork, but in general they are quite peaceful, and you can always slow down their rate of growth by reducing the nutrient loading in the aquarium.

Other low light corals that should be suitable for a seahorse reef include genera such as Cynarina, Scolymia and Trachyphyllia, as well as non-photosynthetic gorgonians such as Subergorgia and Didogorgia, and perhaps wire corals such as Cirripathes spp. (Delbeek, Nov. 2001).. However, supplemental feedings of zooplankton may be required to maintain these corals in good health.

The hard or stony corals fall into two categories depending on the size of their polyps. The small polyped stony (SPS) corals have tiny polyps that extend out of minute openings in the stony skeleton, and generally have weak stings that should not pose a threat to seahorses. Depending on conditions in the tank, SPS corals such as Acropora, Montipora, Pocillipora, Porities, Seriatopora and Stylophora can be tried freely at your discretion (Delbeek, Oct. 2001).

The large polyped stony (LPS) corals, however, are generally best avoided altogether. These include genera such as Catalaphyllia, Cynarina, Euphyllia and Trachyphyllia that have large fleshy polyps which often have tentacles equipped with powerful stinging cells. The Euphyllia and Catalaphyllia have the most powerful nematocysts among the LPS corals, and can deliver stings that are stronger than most anemones (Delbeek, Oct. 2001).

Some of the soft corals and stony corals that generally do well with seahorses in a modified reef tank are listed below. (By no means is this intended to be a comprehensive list, but rather just a few examples of suitable corals to serve as general guidelines when stocking a reef tank that will house seahorses):

Finger Leather Coral (Lobophyton sp.)
Flower Tree Coral – Red / Orange, (Scleronephthya spp.)
aka: Scleronephthya Strawberry Coral, or Pink or Orange Cauliflower Coral
Christmas Tree Coral (Sphaerella spp.)
aka: the Medusa Coral, Snake Locks Coral, or French Tickler
Cauliflower Colt Coral (Cladiella sp.)
aka: Colt Coral, Soft Finger Leather Coral, Seaman’s Hands or Blushing Coral.
Toadstool Mushroom Leather Coral (Sarcophyton sp.)
aka: Sarcophyton Coral, Mushroom, Leather, or Trough Corals.
Bullseye Mushroom Coral (Rhodactis inchoata)
aka: Tonga Blue Mushroom, Small Elephant Ear Mushroom (rarely)
Clove Polyps (Clavularia sp.)
Stick Polyp (Parazoanthus swiftii)
Green Daisy Polyps (Clavularia sp.), Indonesia
Orange & Green Colony Button Polyps (Zooanthus sp.), Fiji
Pulsing Corals (Xenia spp.)
Red Ricordea (Ricordea sp.), Indonesia, occasionally Solomon Islands
Lavender Hairy Mushroom (Actinodiscus sp.), Tonga
Pimpled Mushroom (Discosoma sp.), Indonesia
Purple Gorgonians

For more information regarding seahorse-safe fish, corals, and other invertebrates, see Will Wooten’s online Compatibility Guide at the following URL:

http://www.seahorse.org/library/articles/tankmates.shtml

Best of luck with your seahorse setup, sir!

Respectfully,
Pete Giwojna, Ocean Rider Tech Support