Clownfish Article


A New Food Source for Fresh and Marine Fish

By Robert Di Marco

Published In: Freshwater and Marine Aquarium Magazine, Page 86-92, February 2003.

About the Author:

Robert Di Marco is a Clownfish Breeder in Montreal, Canada, and has previously contributed articles to FAMA. Robert will be a speaker at MACNA XV in Louisville, Kentucky, in September 2003.

Have you noticed lately that most ads for any new and improved fish foods revolve around their colour enhancing properties? Don’t take my word for it, here are five statements I gleaned by quickly scanning the pages of FAMA! “enhances colour”, “optimal growth and colour”, “spectacular colour enhancement”, “promoting health & colour”, “enhances the colour and vitality”, I am sure if I looked harder I would find many more!


The title of this article might be a bit misleading, this new natural food I am about to describe not only improves the complexion of fish (and birds, but this subject will be dealt with at another time!) but also actually improves their vitality, health and fecundity.


For anyone who really works, as a labour of love of course, at keeping healthy aquarium fish, we have all searched for ways to improve the nutritional benefits of the foods we administer to our captive finny friends. Our goals may not all be the same, mine are to attain the optimum reproduction levels in my marine Clownfish brood stock as well as the various other species of Dottybacks, Cardinals, Gobies and Basslets I am currently attempting to raise. Some, not wishing to devote the effort required in raising marine fish, may simply be content in providing enriched food sources to assure a long and healthy life for their fish. But irrespective of our motivation, there is one result that we can all agree on!


Yes, we all want to retain those astounding bright colours, which attract us enough to lose all reason and compel us to empty our wallets the instant we lay our eyes on them, at the local pet store!


Even if you are not a marine fish fanatic, the food I am about to describe may well change the way you enrich and raise even our fresh water friends.


The challenges in raising fish are numerous. Since this discussion is not the aim of this article, (an updated version of my successes and especially failures involving Clownfishes and Dottybacks is presently in the works) I will point out in a cursory fashion the basic steps we need to go through to achieve successful breeding.


We need to first obtain compatible “pairs” (1), now there are big words! How many times have the aggressive females killed the smaller males of seemingly adapted mated pairs of Maroon Anemonefish (Premnas biaculeatus) or Tomato Anemonefish (Amphiprion frenatus) and especially the sudden gender reverse of maturing Clarkii’s.  Nevertheless, once this hurdle has been overcome, we need to provide the newlyweds with the parameters that will be conducive to reproduction, that is, the right temperature, photoperiod (light), and rich food to power their reproductive instincts and result in strong offspring.


Since the past twelve months, I have been experimenting with a new food; both as a primary source or in combination with home made frozen food formulations. Let me describe this new food discovery in my own words, as best I can.


Last year I learned that in my “neck of the woods”, somewhere in my northern home of Canada, there exists a one-of-a-kind artic salt lake where a very special little critter reigns supreme. Each year when the ice thaws over the shallow nutrient rich water and the long days of intense sunlight fuel rich algal blooms, a "decapod" or ten-legged copepod springs into action busily feeding on the algae substrate.


Our ten legged friends have a fascinating strategy to their feasting; from their meal they concentrate red pigment from the algae as a way to protect themselves from the intensity of artic ultraviolet light.


Herein lie the key, the story and the biology behind it. By mid-summer the 800-micron sized adult ten-legged ones are comfortably basking in the sun, shielded by a deep red concentrate of carotenoid pigment and belly full of omega fatty acid rich lipids.


Full indeed, by one-third they are lipid in content, with an amazing forty times the Highly Unsaturated Fatty Acids (HUFA's) contained in freshly hatched Artemia, and the red pigment, 3,000 to 7,500 ppm Astaxanthene compared to 31 ppm in Artemia nauplii!


A very enterprising company, Argent Laboratories Group selectively breeds and cultures this organism in its very special arctic environment and has developed many applications for its use that are supported by the organism’s exceptional nutrient and pigment profile. The adult copepods are annually harvested through a sophisticated collection process and flash frozen in vacuum-sealed pouches (750-gram) to preserve whole body integrity, nutrient and pigment content. You will be amazed the first time you see a package by the blood red vivid colour of these organisms.


OK, it’s finally time to tell you the trade name of this proprietary organism, it is called Cyclop-eeze.


The product is also available in freeze dried form in vacuum packed tins, in sizes ranging from 30 gram to 400 gram cans or a bulk 4-kg vacuum sealed bags. No company has ever commercialized a copepod - until Cyclop-eeze.


So let me tell you a bit more! Cyclop-eeze is a copepod and we all know that copepods are a primary feed organism of fish. Tom Sawtell of Argent Laboratories Group further explored this statement and made the following observations. “In the natural "food web" of aquatic life, copepods "rule", that is to say most fish depend on them as a primary food source.  However, aquarists have never had a commercially available source for this important feed organism. From this "biological" perspective the multiple benefits of feeding of my fish with Cyclop-eeze began to make more sense: fish evolved over millions of years feeding on this type of organism, it makes sense they will look better, feel better, and reproduce better if they continue to do so.


 It is well documented that copepods are superior to other organisms, such as Artemia for larviculture purposes. (2), (2a), (2b). Prof. Dr. Patrick Sorgeloos, Director of the Larva culture Laboratory and Artemia Reference Center of the University of Ghent, Belgium wrote:


“From a nutritional point of view, (copepods) are far superior to Artemia nauplii; their lower proteolytic activity and better fatty acid composition make them an excellent food with a high energy content. It is not surprising that their use in aquaculture has resulted in better growth, survival, development, and pigmentation.” (2c)


Nancy H. Marcus, Ph.D. and Margaret Murray presented the findings of their abstract on Copepod diapause eggs at the Marine Ornamentals Conference. This manuscript was published in Aquaculture 201. Their conclusions included the comment: “Copepod nauplii are the natural food of most marine fish larvae” (2d) which also corroborates the comments made Tom Sawtell and  by Prof. Dr. Patrick Sorgeloos.


In conversation with Tom Sawtell he indicated that he found “numerous aquarists routinely harvest and culture copepods from the wild in order to satisfy the feeding habits and nutrient requirements of their fish. However, the task is laborious, costly, and the organisms are not always available in consistent condition or quantities”. For those who followed Martin Moe’s saga, recounted in the Breeding the Orchid Dottyback manual, (2b) Tom’s comments ring true. Martin Moe’s first successful raising of large quantities of fridmani Dottybacks was accomplished by regularly harvesting wild plankton, consisting mainly of copepods. Of course, Tom’s reference to the difficulties in obtaining “consistent condition or quantities’ were exemplified by Martin’s struggle to maintain enough plankton to get the Dottybacks through the critical larval stage and avoid predators, which were also captured in the plankton tows, some of which ended up actually feeding on some of the Dottyback larvae! Certainly a tough balancing act to achieve success. Evidently, once the larvae are large enough to be able to ingest a cultured copepod such as Cyclop-eeze, the difficulties encountered by using wild plankton would be eliminated.


This organism has proven to be beneficial to freshwater fish, koi, goldfish, marine fish as well as the shrimp farming industry. For example, my experiences are quite similar to those described in a recent press release by Tom Sawtell circulated to the research Zebrafish laboratory community around the world:


“Aquarists with a fondness for the Zebrafish, will relish the note that the Zebrafish research community has implemented the supplemental feeding of this product to intensify the coloration of male specimens.


This makes the laborious task of visual identification and separation of males far easier and more accurate. These results are the outcome of routine supplemental feeding of Freeze Dried Cyclop-eeze to the research Zebrafish population at the Skirball Institute of Developmental Genetics, New York University. The lab routinely feeds Freeze-Dried Cyclop-eeze as a "snack food" to improve overall fecundity, breeding frequency, and coloration. The Freeze-Dried Cyclop-eeze is fed to the Zebrafish in a blended suspension dispensed through a feeding bottle. The supplemental "snack" feeding is presented several times a day in quantities limited to an amount that will be consumed within a few minutes time.


The lab has determined that the high carotenoid pigment content of Cyclop-eeze imparts red coloration to the male Zebrafish, which makes for easy differentiation between males and females. The easy differentiation has made the practice of "snack feeding" Cyclop-eeze popular with all the fish lab workers because it makes the labor intensive and visually difficult process of sorting males from females much easier, and subject to less error than is common without Cyclop-eeze in the feeding regime.


The fish lab's performance has also benefited from the reproductive stimulus of the Zebrafish that results from supplemental feeding of Cyclop-eeze. Increases in fecundity have resulted in larger and more frequent spawns of viable healthy Zebrafish. The increase in fecundity and breeding frequency are hoped to improve the overall operational efficiency of the Zebrafish culture system.”


Now your mind can begin to race, the uses are endless!


Let me tell you how this product has affected my hatchery. When you raise Clownfish, briefly the difficulties are, retrieving the larvae, feeding the larvae and finally getting them to the stage where they will cease to eat live food and accept inert foods.


One “detail” remains, getting the larvae to saleable size with the vivid colours that attracted us into that hobby in the first place. As you can guess what I am leading up to is the effect Cyclop-eeze has had in this process!


The size of these copepods is in the range of  800 microns, this is too large for newly hatched larvae. In fact, the earliest period in the young Clownfish lifecycle where they can accept food organisms in the 800-micron range (2) is when they are approximately thirty days old. I wanted to test the effects of Cyclop-eeze at the earliest stage possible in newly metamorphosed Clownfish. Unfortunately, I needed to overcome the difficulty posed by the fact that Clownfish cannot chew food as humans and animals do. Clownfish. Like many fish and reptiles are only able to ingest food that is no bigger than they are able to stretch their gaping mouth. Although it may seem obvious, finding appropriate food prey and of the right size for larval marine fish has been the largest stumbling block to full-scale marine reproduction. (3)


To take advantage of the benefits of this new food source sooner, and to remedy the difficulty posed by a too large organism, I began “shaving” Cyclop-eeze. Using a sharp knife or shop razor blade, I shaved the frozen block to create small particles.


The gut of newly fed larvae immediately displayed a red bulge. I knew something was different in my Clownfish by the third day of feeding Cyclop-eeze. A reddish aura could be seen on the fringe of the fins of Tomato Clownfish.


By the fifth day of feeding this copepod at least twice a day, the redness had migrated to the remainder of the fins and by day seven had spread evenly to the remainder of the body. In fifteen days, the Cyclop-eeze fed tomato Clownfish had developed a stunning, vibrant red coloration.


In spite of all the other methods I had used to spike up the colour of my Clownfish up to that day, nothing gave me this incredible result and so quickly!


Just to show you that I am not alone, in the references at the end of this article, I have listed some of the public aquariums that have already incorporated Cyclop-eeze into their feeding regimen to maintain the health and vibrant colours of their fish on display. (4)


Discus breeders in Germany have also been using this product to enrich the broodstock, to feed the juveniles and intensify their overall coloration.  This is referenced in the German fish publication entitled “Discus Yearbook 2002-2003”, Article Title: Cyclop-eeze das neue Superfutter (Cyclop-eeze the New Super Food) by Mr. Bernd Degen, publisher Bede Verlag.


This confirms that many aquarists have experiences consistent with mine in gaining multiple benefits of colour intensification and improved breeding in their fish populations.


For you “reefers”, Cyclop-eeze fed to reef community tanks has a dual benefit; the reef invertebrates readily take the product that is not consumed by the fish!


Then there are people like Jorge Gomezjurado of the National Aquarium of Baltimore, who is miles ahead of many of us! He was using an original powdered formula of Cyclop-eeze, while he was working at the Steinhart Aquarium back in 1998. Since then, as Senior Aquarist -Biological Programs, Syngnathid Breeding Program at the National Aquarium in Baltimore, Jorge and his team have incorporated Deep Frozen Cyclop-eeze into the varied proprietary feeding regimen diet of the Aquarium’s live mysid culture. These mysids are used to feed a variety of species of Seahorses maintained in the Aquarium and to feed their collection of those fascinating Leafy and Weedy Sea Dragons!


Jorge also states that he includes frozen Cyclop-eeze for the following uses:


"Diet for adult H. zosterae, and feeding at various stages in the development of juvenile H. abdominalis, H. kuda, H. erectus, H. breviceps, the Dusky pipefish Syngnathus floridae, the Northern pipefish Syngnathus fuscus. Plus I have used Cyclop-eeze to rear H. coronatus, H.reidi, H barbouri and as the main diet of Aeoliscus strigatus shrimp fish and many species of pipefish, including Janss pipefish, banded pipefish, Gulf pipefish Syngnathus scovelli, Penaeus shrimp larvae and peppermint shrimp."


He adds, “I have noticed that Farfapenaeus aztecus shrimps (that we used to use as seahorse food) that were eating Cyclop-eeze turned bright orange, normally they are transparent or light brown.”


I was fortunate enough to visit these wonderful facilities during MACNA XIII and (even though Jorge is too modest), I would like to extend my personal invite. If you are in the area, take the opportunity to visit the National Aquarium in Baltimore; you will marvel at one of the best Seahorse and Sea Dragons displays I have ever seen! I had to be prodded to give up my viewing area and move along!


From my previous articles in FAMA, you can see that to stay well informed, I try to attend as many marine fish conferences as I can. (6) Of course, whenever I do attend a conference, I always try to combine it with some vacation time. (I have to keep my wife Louise happy so that she will agree to spend the money for the next conference!)


At the same MACNA XIII in Baltimore, a very generous contributor to our hobby and good friend, Bill Addison of C-Quest, offered me a rarely seen pair of miniature banded-pipe fish. But unfortunately we were not scheduled to leave for another three or four days; I therefore reluctantly declined but not before asking him what they were feeding on. Immediately, in the hope of encouraging me to change my mind he replied,


“They’re easy, they are already feeding on Cyclop-eeze!”


I did not want to risk losing these rarities, so thanks to my refusal, Julian Sprung was “forced” to take these two gorgeous specimens home, he also was aware about Cyclop-eeze.


I believe that this product has been a well-kept secret for too long!


What I have done since the initial trials with juvenile Clownfish is to feed frozen bits to the brood stock. Even though it is a small organism for adult Clownfish, after a few taste tests, they attack every little morsel floating in the tank. Also, the accelerated spawns, which occurred immediately after commencing to feed Cyclop-eeze to my four varieties of Dottybacks, convinced me of its beneficial effects. Even my large pairs of Banggai Cardinals pursue actively these tiny morsels of food all around the tank.


I also combined some frozen Cyclop-eeze  into one of my homemade frozen food mixes. The recipe is a derivative of a Martin Moe style shrimp base formulation. The composition was approximately one third Cyclop-eeze and two thirds shrimp, squid, fish etc. (7) This has worked well because the gelatine binds it all together and the small copepod particles are more easily ingested by the larger fish when bound in the little frozen chunks.


The results have been an undeniable intensification of colours:


Vibrant red pigmentation on the “red” clowns such as Maroons (Premnas biaculeatus), Red Saddlebacks (Amphiprion epphipium) and Tomatos (Amphiprion frenatus), as well as beautiful bright reddish orange of my favourite Clownfish, the False Percula Anemonefish (Amphiprion  ocellaris).


The inclusion of Cyclop-eeze into the brood stock feeding has resulted in deeper red egg clutches. Another confirmation of how this copepod affects pigmentation right from the source!


In my experience, I have found that in most cases with adult Perculas (Amphiprion percula), if they are not kept in aquaria equipped with the typical reef environment, (where I believe they consume copepods) their colour tends to fade over time. The addition of this new food maintains their vibrant orange and black colour. Cyclop-eeze is generally not available in local pet stores. The sources are Argent Laboratories Group on a wholesale basis and some mail order houses specializing in fish room supplies.


I look forward to your comments at: See you at MACNA XV and happy propagating!



Argent Chemical Laboratories, Inc.

8702, 152nd Ave. N.E.,

Redmond, WA 98052


Tele: 425-885-3777

Toll Free: 1-800-426-6258


Web I:

Web 2:



World Aquaculture, March 2002, Vol.33, No.1

Aquaculture Advocate April 2001, Vol.4, Issue 2

“Discus Yearbook 2002-2003”, Article Title: Cyclop-eeze das neue Superfutter (Cyclop-eeze the New Super Food) by Mr. Bernd Degen, publisher Bede Verlag





Di Marco, Robert 1998. Battered Husbands! FAMA vol. 21, no.12

Hoff, Frank H. 1996. Conditioning, Spawning And Rearing of Fish With Emphasis on Marine Clownfish

Lieberman, E. 2002. A phenomenal micro-crustacean with incredible aquaculture applications. World Aquaculture, (33-1) 58-60.

Moe, Martin A., 1998. Breeding the Orchid Dottyback, Green Turtle Publications.

Dhert, P. and Sorgeloos, P.; Live Feeds in Aquaculture; 1995, Aquaculture towards the 21st century; Pages 209-219.

Nancy H. Marcus, Ph.D., Margaret Murray, Copepod diapause eggs: a potential source of nauplii for aquaculture. Aquaculture 201 (2001) 107-115.

(a) Frakes, Thomas 2002. New Successes in Angelfish Breeding, Sea scope Vol. 19, winter 2002. and Frank Baensch, Angelfish Culture Update, Sea scope Vol. 19, Summer 2002

(b) Delbeek, J. Charles 2002, Waikiki Aquarium Announces Breeding Breakthrough for One of the World’s Rarest Fishes, FAMA vol. 25, no.7. 

National Aquarium in Baltimore (Comments from Jorge A. Gomezjurado, Senior Aquarist -Biological Programs

Syngnathid Breeding Program).

Personal communication, Thomas A. Sawtell, National Sales Manager of Argent Laboratories Group.

Di Marco, Robert 2002. The Great Canadian Ice Storm, FAMA vol. 25, no.6.

Moe, Martin A., 1982, 1992. The Marine Aquarium Handbook Beginner to Breeder, Green Turtle Publications.



Vancouver Aquarium

North Carolina Aquarium

National Aquarium at Baltimore

Waikiki Aquarium

Maui Ocean Center

John G Shedd Aquarium

Maritime Aquarium at Norwalk

Columbus Zoo

Tennessee Aquarium

New England Aquarium

Long Beach Aquarium

Steinhart Aquarium

Florida Aquarium

Ripley's Aquarium

Toledo Zoo

John Ball Zoological Gardens

Oregon Coast Aquarium

The Oklahoma Aquarium

Indianapolis Zoo

Houston Zoo

Point Defiance Zoo

Pittsburgh Zoo


Cyclop-eeze® is availavable in frozen 3 oz. Freezer Bar®, 1.6 LB bulk blocks, Freeze Dried 30gm, 100gm, 400gm cans,
Cyclop-eeze is a registered trademark of Argent Labs. Freezer Bar is registered trademark of JEHM Co., Inc.

For more information or to locate a dealer near you call:


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