adding a fish

Dear Tammy:

In a nutshell, I would say that adding a Mandarin to your seahorse tank is worth the risk if you can obtain a captive-bred-and-raised dragonet rather than a wild-caught specimen, and providing your seahorse setup is a larger, well-established aquarium with plenty of live rock. On the other hand, if you are considering a wild-caught Mandarin dragonet, or if your seahorse tank is newly established or is on the small side and lacks abundant live rock, then, no – it’s not worth the risk under those circumstances.

Mandarin dragonets have a heavy slime coat that seems to make them quite resistant to protozoan parasites such as marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium), which makes them much less risky than most marine fish in that regard. But I would not recommend introducing a Mandarin goby into a newly established aquarium under any circumstances. They require optimum water quality and do best in large, well-established reef tanks with lots of live rock and one or more thriving refugia that have had time to build up a very substantial population of copepods, amphipods, and other microfauna.

Variously known as mandarinfish, Mandarin gobies, dragonets, Mandarin dragonets, or simply mandarins, these little jewels are members of the genus Synchiropus. There are two main types – the spotted or peacock Mandarin dragonets, which have a series of bright, multicolored bull’s-eyes scattered all over their bodies and fins, and a greenish variety which features a psychedelic pattern of green, blue, and orange swirling stripes over its body and fins. Both are extremely colorful and gaudy, as well as completely passive and nonaggressive, and you will be pleased to hear that they make wonderful companions for seahorses.

I absolutely love the spectacular coloration and peaceful nature of Mandarin dragonets, Tammy! There’s no disputing that they are gorgeous little fishes and make ideal tankmates for seahorses. They are docile, slow-moving, passive fish that are beautifully marked and very deliberate feeders. And they are quite hardy fish providing they can be fed properly.

However, until quite recently, feeding mandarins and providing them with good nutrition in the aquarium was nearly impossible, and most wild-caught Mandarin dragonets were doomed to a depth by slow starvation in the aquarium, Tammy. For that reason, they were considered extremely difficult to keep and a fish that should only be attempted by expert aquarists with large tanks having sandy bottoms and live rock and a large population of copepods and amphipods in their aquariums.

Nowadays, thank goodness, it’s largely a different story. Captive-bred-and-raised Mandarin dragonets from Oceans, Reefs and Aquariums (ORA) in Florida are trained to eat prepared foods and are hardy little fish that are relatively easy to keep in the right type of aquarium. They are every bit as spectacular as the wild-caught Mandarinfish, perhaps even more so, and infinitely easier to feed. ORA has even developed a reddish color form of the Mandarin dragonets, which as much more of the bright red orange swirling stripes than the normal psychedelic Mandarins do. So, as long as you can get the tank bred specimens that have been raised in captivity, Tammy, there is no compelling reason for you not to include a Mandarin Dragonet in your seahorse tank.

It has been my experience that the captive-bred-and-raised Mandarin dragonets from ORA are quite hardy when they are maintained in a suitable aquarium with compatible tankmates such as seahorses and pipefish. I suspect that the home hobbyists who are unsuccessful with the tank-bred Mandarin dragonets are either attempting to keep them with incompatible fish that are active feeders and that outcompete the mandarins at feeding time, or they are offering them the wrong type of prepared foods, or both.

Often, the best way to feed captive-bred-and-raised Mandarin dragonets is to set up a special feeding station for them, just as you would do for seahorses. One thing I have noticed about the captive-bred-and-raised Mandarin dragonets is that they tend to be lazy feeders. They are not great at hunting for food and seem to have lost some of the foraging skills of their wild counterparts. But they do really well when provided with a feeding dish they can come and go from as they please. When they are hungry, they will come and sit in the feeding dish and pick out choice morsels to eat, and then they will go off and about their business when they have had their fill, returning to sit in the feeding dish and pig out again the next time they are hungry.

Also, I find the favorite food of the Mandrins is chopped frozen bloodworms. That’s what I would fill the Mandarin feeding dish with, Tammy, and you can be quite confident that your Dragonet will love bloodworms of suitable size. They also go for frozen baby brine shrimp, for a change of pace, but that’s messier to feed. For that reason, I prefer to provide them with live newly hatched brine shrimp from time to time, rather than the frozen baby brine shrimp. Aside from finely chopped Hikari Frozen Blood Worms and live baby brine shrimp, Mandarin Dragonets will often eat Nutramar Ova and other fish roe, as well as frozen Daphnia (which is messy to feed them), and if you can get them to accept the New Life SPECTRUM Small Fish Formula pellets, which some of them will do readily, then they will really thrive in the aquarium.

So, I think if you set up your own Mandarin diner and then offer your Mandarin Dragonet the proper prepared foods, I think you will find that he will do very well, Tammy. Heck, I’ve even known the tank-red mandarins to visit the seahorses’ feeding station to clean up scraps of frozen Mysis!

For best results, I would recommend equipping your seahorse tank with a well-stocked, well-planted refugium that includes thriving populations of copepods, Gammarus amphipods, and larval shrimp, if you will be adding a captive-bred-and-raised Mandarinfish to your herd of ponies, Tammy.

I have had good luck establishing the populations of Gammarus amphipods, copepods, live Mysis, and other larval shrimp species in a refugium that’s connected to the seahorse tank, Tammy. That way the Gammarus and copepods and other small crustaceans can build up a very large population well they are safely protected within the refuge, and some of them will be released into the seahorse tank to provide tasty treats for the Mandarin dragonets and your ponies.

A refugium is simply a self-contained protected area, isolated from the main tank but sharing the same water supply, which provides many of the same benefits as a sump. A refugium can help newly added fish or invertebrates easily acclimate to a new tank. It can provide a safe haven for injured fish or corals to regenerate damaged tissue without the need for a separate quarantine tank. But perhaps its main benefit for the seahorse keeper is provide a protected area where macroalgae can be grown and small live prey items (copepods, amphipods, Caprellids, etc.) that will eventually become a food source for the inhabitants of the main portion of the tank can be cultured safely, allowing their population to build up undisturbed.

For instance, Charles Delbeek likes to use glass shrimp and cleaner shrimp that are too large to be eaten in the refugium for his seahorse tank, where the regular reproduction of these hermaphroditic crustaceans will provide a continuous supply of nutritious nauplii for his ponies: "There is a method that can be used to offer an occasional supply of live food for your sea horses. By setting up a separate system housing several species of shrimp such as peppermint shrimp (Lysmata wurdemanni), or Rhynchocinetes uritai or R. durbanensis, you can get a fairly regular supply of live shrimp larvae. These species are best to use since they can live in large groups and spawn on a regular basis. Such a system is commonly called a refugium. A refugium is a small (10-20 gallon) aquarium that contains live sand, live rock and/or macroalgae such as Caulerpa or Gracilaria. It is plumbed such that water from your main system is pumped to the refugium and then returns via an overflow to the main tank. Some of the pods and larval crustaceans will then be carried from the refugium into the sea horse tank in the water that overflows from the refuge. For this type of arrangement to work, the refugium must be slightly higher than the main tank. Shrimp are added to the refugium and within a few months they should start spawning and hatching eggs every few weeks. The larvae are then carried back to the main tank by the overflow, where they become a food source for your sea horses. Of course other life will also thrive in the refugium and it is not unusual for copepods, mysis and crab larvae to also be produced on a regular basis. The key to the refugium is to keep predators out of the system so that the smaller micro-crustacean population can thrive. You would need a fairly large and productive refugium to produce enough food to maintain even a pair of sea horses, so at best, a typical refugium can provide a nice source of supplemental live food; the basic daily diet still needs to be provided by you in the form of the frozen foods mentioned above." (Delbeek, November 2001, "Horse Forum," FAMA magazine)

Aside from the one Delbeek favors, refugia are available in a number of different designs. For example, there are easy-to-install external hang-on refugia and in-tank refugia as well as sump-style refugia that are mounted beneath the main. Here are a couple of online sites where you can look up more information on refugia, including articles explaining how to set up and install a refugium of your own:

Click here: Refugium Setups Information – From About Saltwater Aquariums
http://saltaquarium.about.com/od/refugiumsetups/

Click here: Refugiums
http://www.wetwebmedia.com/refugium.htm

Best wishes with all your fishes, Tammy! I would avoid adding a wild-caught Mandarin to your seahorse tank, but you may consider introducing a captive-bred-and-raised Mandarin goby if your tank is well-established, large enough, and includes abundant live rock, and you are prepared to feed the Dragonet as explained above.

Respectfully,
Pete Giwojna, Ocean Rider Tech Support

Dear Tammy:

Excellent! A well-planted, well-established refugium will be a very nice asset for both your seahorses and a Mandarin goby, Tammy.

Just make sure that you obtain a captive-bred-and-raised Mandarin and your Dragonet should do well. Provide him with his own Mandarin diner and stock his feeding dish with chopped Hikari Frozen Blood Worms, Nutramar Ova, and New Life SPECTRUM Small Fish Formula pellets that the Dragonet can feed on at his leisure. That way the copepods and amphipods from the refugium should suffice to provide both the Mandarin and your ponies with an opportunity to graze on live treats between meals.

Good luck!

Respectfully,
Pete Giwojna, Ocean Rider Tech Support