Posted by TFH Magazine in Tropical Fish Hobbyist Blog on July 6, 2012 at 5:30 am
Clownfishes and damselfishes are among the most popular aquarium species, particularly for beginning aquarists. Written by a recognized authority on marine ornamental fishes, this comprehensive guide covers topics essential to keepers of these beautiful aquatic pets including selection, feeding, water requirements, diseases, breeding, and more. Full-color photos show over 20 species of clownfish and damselfish, while sidebars, charts, and tip boxes illustrate key points to consider.
About the Author
Jeff Kurtz is a freelance writer and editor who lives in Toledo, Ohio with his wife, Melissa, and two children, Aidan and Hannah. In addition to editing the health-and-fitness publication Healthy Living News, he is the Senior Consulting Editor for Tropical Fish Hobbyist Magazine and has authored or coauthored several additional books for TFH Publications, including The Simple Guide to Marine Aquariums, The Simple Guide to Mini-Reef Aquariums, The Super Simple Guide to Landscaping Your Garden Pond, and the Saltwater Aquarium Problem Solver. An avid aquarium hobbyist for almost three decades, Jeff focuses primarily on marine fish and invertebrates but enjoys freshwater fishkeeping, as well.
Excerpt from Chapter 4: Diet and Feeding for Clownfish and Damselfish
The majority of pomacentrids that you’re likely to encounter are omnivorous. In nature, some, such as the gregories (Stegastes spp.), have a diet that includes a greater proportion of algae, while others, such as the various Chromis species, rely more heavily on zooplankton. But few pomacentrids are so specialized in their diet that they completely exclude meat or veggies. That’s great news for hobbyists because, as you might expect, fishes that have a generalized diet typically adapt better to aquarium fare and have a much better survival rate in captivity compared to specialized feeders.
Variety Is the Spice of Life
So, being omnivores, pomacentrids should be offered a diet that is not exclusively plant- based or exclusively protein-based. This is very easy to do nowadays, as the selection of fresh, frozen, dry, and freeze-dried aquarium foods available to hobbyists has never been better.
Your pomacentrid menu should include items such as a staple pellet or flake, spirulina pellets or flakes, frozen mysid shrimp, frozen formulas for both omnivores and herbivores, and, at least occasionally, fresh meaty foods of marine origin, such as clams, shrimp, scallops, and fish, chopped to fit the mouths of pomacentrids.
Crazy Over Clams
Though it’s the rare pomacentrid that won’t start feeding shortly after purchase, it can sometimes take a day or two to get some specimens interested in eating. This is nothing compared to some marine fishes, such as certain butterflyfishes, which may take several days or even a week or more of coaxing with foods of all sorts before they’ll deign to accept anything you offer, but, nonetheless, it can be disconcerting when a clownfish or damselfish ignores your offerings. In such cases you can almost always win over a picky pomacentrid with chopped fresh clams. In fact, there’s just something about the scent of fresh clam in the water that really rings the dinner bell for almost any marine fish.
Shucking the fresh clams and chopping the meat is a bit labor-intensive, but you’ll find that it’s well worth the effort. Make sure the clams you purchase are still alive. Choose only those with their shells clamped tightly shut. Skip any that have gaping shells or an off odor, as they are either dead or dying. I usually buy a large quantity of clams, shuck and chop them all at once, set some of the fresh meat aside in the refrigerator to feed over the course of a few days, and freeze the rest for future use.
I prefer to freeze chopped clams in serving-size batches, so I usually dole out equal-sized portions of the meat into an ice-cube tray. That way, whenever I want to offer my fish a nutritious treat I simply pop one of the servings out of the tray, thaw it, drop the bits into the tank, and watch the fish go crazy!
Cyclops for Small Mouths
A great food to use when trying to elicit an initial feeding response from smaller pomacentrids, especially those that feed on tiny zooplankton in nature, is frozen cyclops. Cyclops is a popular item for feeding sessile invertebrates in reef systems, but I’ve found that most pomacentrids can’t resist them either.
When feeding very small foods such as cyclops, it’s helpful to temporarily shut down your filtration and water pumps so there is no water movement. It doesn’t take much force to suck these tiny crustaceans into a sump overflow or filter intake or to scatter them all around the aquarium so the fishes never even notice them. But if they are concentrated in one area and allowed to sink slowly to the bottom, they’ll get the attention of your fishes and it won’t take long for them to start snicking up these minuscule morsels. A little goes a long way when you’re using cyclops, so be careful not to overdo it!
If your clownfish or damsel happens to share an aquarium with a herbivorous fish, such as a tang or rabbitfish, there’s an easy way to make sure your pomacentrid gets its greens. That is, provide the tang or rabbitfish with a sheet of dried marine algae, such as sushi nori or red or brown marine algae, to nibble on each day. Pomacentrids generally won’t tear algae off the sheet, but they will gladly snap up the tiny bits that float around in the water column after the tang or rabbitfish rips into the sheet.
Tasty Tidbits Crawling in the Tank
Though it’s not necessary to feed live foods to pomacentrids, they will certainly appreciate and benefit from eating them, and there are various ways—short of actively culturing them or buying them in small, cost-ineffective batches from your local dealer—to provide an ongoing supply of nutritious live foods that your clownfish or damselfish can nibble on.
Aquascaping your tank with copious quantities of quality live rock is one way to introduce populations of these edible organisms. As your system matures, all sorts of little critters will hatch out from the rocks, such as pods—amphipods and copepods—various worms, mollusks, and echinoderms, and clownfishes and damselfishes will gladly gobble up many of them.
Installing a live-sand substrate—or seeding a non-live sand bed with a small quantity of live sand to get the populations started—also is a good way to enhance the microfauna in your system.
But perhaps the best way to provide a steady supply of live foods for hungry pomacentrids is to connect some form of refugium to your aquarium. A refugium is essentially a vessel that is separate from your main aquarium but shares the same system water (water is drawn from the display tank, flows through the refugium, and is then pumped back into the display tank). A sump or aquarium of any size can be converted for this purpose. You can also choose from the various commercially manufactured hang-on-tank refugia that are available on the market.
As the name suggests, a refugium provides a safe haven, or refuge, for organisms that would be either eaten or harassed in your display tank. These organisms could include the aforementioned amphipods, copepods, and other desired microfauna, as well as fishes or invertebrates that have been injured or are the target of territorial aggression. Because they are isolated from predators and tormentors, organisms kept in the refugium have the opportunity to reproduce more abundantly than they could in the display tank or to recover from tankmate-inflicted injury.
By placing some pieces of quality live rock and/or a bed of live sand in the refugium, you can establish healthy populations of edible microfauna. As these populations grow, some of these little organisms, along with their eggs and larvae, will be carried into the display tank, where the fish can gobble them up. Those that avoid being eaten will help to establish populations in the main tank, thereby increasing the overall biodiversity of the system.
I should add that many hobbyists also grow various forms of macroalgae, such as Chaetomorpha spp. (a.k.a. “chaeto”) and Gracilaria spp., in their refugia for the purpose of nutrient export. These algae take up dissolved nutrients, such as nitrate and phosphate, from the water, and the aquarist routinely harvests a portion of the algae, thereby removing the nutrients from the system. So, in addition to providing an ongoing smorgasbord of pods, worms, and other tiny critters, a refugium can help to keep your aquarium’s water quality at its best.
Should You Feed Live Foods?
Of course, live foods, such as mysid shrimp and newly hatched and adult brine shrimp (preferably enriched by feeding with a vitamin supplement), will be accepted with gusto by clownfishes and damselfishes and can certainly be offered as an occasional treat. However, with the variety of high-quality prepared fish foods on the market today, it’s really not necessary to offer live foods to pomacentrids on a routine basis. An exception must be made if you decide to breed clownfishes, as the larvae must be fed live marine rotifers and newly hatched brine shrimp, but we’ll get into that in greater detail in Chapter 8.
Whatever you do, try to avoid getting too lackadaisical in your feeding, for instance by relying too heavily on only one dry or frozen food for your own convenience.
Kicking Up the Nutritional Value of Your Pomacentrid’s Repast
Offering a varied diet is the best way to ensure that your clownfish or damselfish isn’t missing an important element in its diet, but as added insurance against dietary deficiencies it’s a good idea to occasionally enrich your pomacentrid’s food with a nutritional supplement.
Soaking dry or frozen foods with one of the liquid supplements that are available on the market (most contain important vitamins and highly unsaturated fatty acids, or HUFAs) prior to feeding them to your fishes will help to enhance the nutritional value of the foods, which, in turn, will keep your fishes healthier, more colorful, and better able to recuperate from injury or illness. These products can also be fed to live foods—such as brine shrimp—in order to enhance their nutritional value by adding them directly to the water in the culture container.
Excerpted from the Aquarium Success Guide to Clownfishes and Other Damselfishes: The Complete Guide to the Successful Care and Breeding of these Hardy and Popular Marine Fish by Jeff Kurtz © TFH Publications. Used by permission.