Chapter 1: Breeder's Guide to Marine Aquarium Fishes
From Microcosm Aquarium Explorer
Contents |
A Breeder’s Journey
Discovering a passion for amateur aquaculture
I set up my first saltwater aquarium at the age of 12, and that same year my father, an active SCUBA diver, helped me get my first dive certification. Our family spent several weeks in Florida each year, and my freshly acquired diving skills helped me observe the jewels of my newfound fascination in their natural surroundings. I was embarking on something that must have given my parents reason to pause for years to come.
According to a logbook I kept, by the age of 14 I had overrun my bedroom with 26 aquariums dedicated to breeding, trading and selling various species of freshwater fish. I had tanks on the top bunk, the floor, my dresser, and desk—everywhere I could squeeze in one more aquarium for breeding. I stripped my clothes from the closet to make room for shelves holding 10-gallon tanks that I divided in half in order to be able to raise anabantoids. I bred and sold cichlids, tetras, barbs, catfish, killifish, piranhas and myriad others, but nothing kept my attention for long. I can still see the astonished look on the clerks’ faces at the local fish shop when I pulled the pile of change from my corduroys to pay for my fish-of-the-week.
My father and I soon joined a local fish club and I became even more firmly hooked. I went to fish auctions only to set up more aquariums to bring more potential broodstock home.
Throughout my years in grade school and high school I spent more time researching fish than studying math. Whenever possible, I managed English papers and class projects to revolve around some aspect of fish biology or behavior. I wrote short articles for the local fish club newsletter on fish reproduction and had some of them reprinted in a Canadian publication. My first article appearing in Tropical Fish Hobbyist magazine had been an assignment for a high school English class.
Marine breeding started almost as an afterthought. I maintained a 40-gallon saltwater aquarium as a display tank to offset the stark bare-bottom scheme of my breeding tanks. I had gained considerable knowledge of freshwater fish husbandry and reproduction and then, in the marine community tank, a pair of Ocellaris Clownfish (Amphiprion ocellaris) spawned. According to everything I had heard, this was not supposed to happen. “Impossible!” I thought. “ Marine fish aren't supposed to spawn in aquariums.”
Fail First, Then Succeed
I found myself frustrated at the lack of published information on spawning and raising marine fishes. I could not locate a single piece of literature on the topic of raising clownfishes. Granted, published reports did exist, but in my youth (and before the Internet) I lacked the essential networking skills to find them.
I attempted to raise the first spawn the same way I would a freshwater cichlid. It did not work.
Undaunted, I excitedly tore down the freshwater tanks and began feverishly setting up saltwater aquariums. I purchased clownfish, damsels, angelfish, gobies, lionfish and anything else I thought was unusual or appealing. Before long, the spills of saltwater onto the floor forced me to move my battery of aquariums into the basement. I built my own protein skimmers and wet-dry filters along with individual siphon boxes on 53 aquariums and plumbed them into a central filtration system. I still had no clue as to what I was really doing, but I was excited. No one I approached was able to offer advice or insight and most gave a snide look when confronted by a boy wanting to know how to raise captive-bred marine fish.
Before long I came across some literature citing the need for rotifers and microalgae to feed larval marine fishes. My old standby, newly hatched Artemia or brine shrimp, was too large as a first food for most marine species. As soon as I discovered this, I ordered cultures of rotifers and microalgae from Florida Aqua Farms. It took me 14 spawns of clownfish eggs and many months of trial, error and tinkering with rotifers and phytoplankton before I raised my first nine clownfish past metamorphosis. I was 15 at the time.
As soon as I turned 16 I got a job at a local pet shop. It was, I found, a terrific place to experiment with new species. Weekly shipments of saltwater fish allowed me to observe the reproductive habits of different species. Fish such as dwarf angels and triggers that the boss told me had to be kept separate from each other spiked my curiosity.
When I knew the coast was clear, I began putting every individual of a given species into the same aquarium to observe their behaviors toward one another. There were, I confess, battles and some fish ended up the worse for wear, but I ended up with pairs of gobies, angelfish, damsels and butterflies that spawned regularly as a result.
The lesson I learned was that marine fish live to eat and reproduce, and being in an aquarium won’t stop them if their keeper provides the right conditions.
I acquired more aquariums, learned to drill glass, taught myself the fine arts of plumbing and filtration and ended up with a fish room housing more than 68 marine tanks. From a rundown trout hatchery I obtained dozens of round fiberglass tubs and plumbing system parts that turned into ideal larval rearing and juvenile grow-out vessels. This, in conjunction with my newfound knowledge of rotifer and microalgae culture as well as lots more trial and error, allowed me to raise most species I attempted. I gave up many things to work with these fishes and it has taken some time to make up for my lack of interest in other social areas.
Today, boyhood passion has become a life in marine biology and research into reef fish culture. I have refined my ways and no longer raise Artemia in ginger ale bottles. I’ve had the great fortune to have graduated to professional-grade university and commercial aquaculture facilities. Most surprisingly, the ability to breed and raise marine fishes in captivity has begun to take on new significance as the future availability of wild-caught coral reef species is becoming ever more uncertain.
Captive Culture: Why We Need It
Many observers believe that bans on collecting coral reef fishes are drawing ominously closer, and the marine aquarium hobby is facing the fact that it must find alternative means of sustainability. The demand for marine aquarium fishes has increased steadily over the last two decades as a direct result of new equipment, improved husbandry techniques and better foods that are allowing many more marine enthusiasts to be successful.
With an estimated two million marine aquarists worldwide, concern is mounting over the sustainability of fish populations and coral reef habitats. Slightly more than 1,000 different species of reef fishes are collected for the aquarium trade, with an average of 27 million specimens caught each year, according to a report by Edmund Green of the UN Environmental Programme in 2002.
A great many threats face today's oceans, most of them much greater than fish collecting for the aquarium trade. Coastal development and pollution play a significant role in the degradation of near-shore waters and the decline of coral reefs. Capture fisheries aimed to supply food have long been responsible for the depletion of fish stocks. Some food fishermen in developing countries resort to destructive practices such as dynamiting reefs or dumping large quantities of cyanide into the ocean to stun fishes.
Finally, the ominous rise in sea temperatures caused by global warming is a phenomenon that many scientists believe could lead to the worldwide decimation of coral reefs within the coming century.
The aquarium trade has long drawn criticism from certain conservation groups that point to the collection of fish, corals and live rock as a contributing cause to the poor condition of many coral reefs. They point to damaging collection techniques, such as the use of sodium cyanide (NaCN), and the high mortalities often associated with shipping and handling. While there can be no doubt that coral reef habitats are in trouble in many areas, the real impact of collectors and the marine aquarium hobby remains poorly studied and surrounded by controversy. It is certainly minor compared to climate change, pollution from deforestation and shoreline development. In fact, many supporters of the aquarium trade claim the hobby can be sustainable and an integral component of reef conservation.
Still, in view of all the threats that face reef environments, marine aquarists have an obligation to be stewards of these precious resouces and to make informed decisions about the fishes and invertebrates they buy and keep. A marine aquarium is a window on an exotic tropical world and an excellent tool for learning about coral reefs and the life forms that make them so captivating. An informed marine aquarist can be part of the solution, not a contributor to the problem.
Wild Harvest vs. Aquaculture
Today less than 10 percent of marine aquarium fishes available to the consumer are captive-raised, as opposed to greater than 90 percent of the freshwater species sold. Aquaculture has a real potential to alleviate some of the stresses facing coral reef environments, but it does raise some difficult questions.
Wild-capture fisheries supplying the marine ornamental trade provide thousands of jobs throughout the supply chain. Most notably, fishers or collectors in rural coastal areas of developing countries such as Indonesia and the Philippines have few income-generating alternatives to the money they can earn by collecting aquarium animals. These earnings often support entire family units, and without them many fishermen might be forced to resort to drastic measures such as dynamite fishing to supply their families with food. By encouraging sustainable collection, entire villages in undeveloped areas can become stewards of their local reefs and protect them from destructive threats. Millions of people throughout the world rely on the productivity of coral reefs to maintain a livelihood. Impoverished countries rely directly on coral reefs for daily survival, while others rely indirectly on its wealth through tourism and recreation.
Unfortunately, if environmental forecasters are correct, global changes in weather and even the chemistry of the oceans could spell doom for many, if not most, reef areas in the coming century.
While encouraging sustainable collection practices of wild fishes is important to maintain socio-economic benefits in poor tropical countries, there can be no question as to the urgent need to develop aquaculture technologies for marine aquarium species. Securing the knowledge of the life histories of coral reef fishes and demonstrating the ability to culture them in captivity will offer some security in protecting bio-diversity in the coming years. At the same time, captive breeding can offer alternative livelihoods should the fisheries collapse or wild harvests be banned. Indeed, the farming of giant clams (Tridacna spp.) and many species of corals in Third World countries is a success story in the making. The clams, once fished to the brink of economic extinction, have made an amazing comeback, and the sale of captive-grown corals from Pacific Island countries is increasing dramatically. Freshwater Lessons
We need only look at the freshwater aquarium hobby for a view of how things can change. The keeping of freshwater fishes in home aquariums really began to grow when books and magazines started to reveal the successful techniques for their care. Demand for livestock spiraled, fed in part by the new possibilities of using air freight to get wild-caught fish quickly—and alive—from the tropics to places where they could be displayed and sold.
Very little was known about their reproduction at the time, and virtually all specimens were collected from the wild from rivers, streams, and lakes in Central and South America, Africa, and Asia. Before long, species such as the Bala Shark (Balantiocheilos melanopterus), Tiger Barb (Puntius tetrazona), several species of loaches (Botia' spp.), and the beautiful Golden Dragon Arowana (Scleropages formosus) had been seriously overfished and were reported to be commercially extinct in areas where they had been abundant.
It did not take long, however, for aquarists to begin breeding and raising freshwater fishes—both commercially in ponds and at home within the confines of hobbyists’ aquariums. As time went on, the demand for interesting fishes grew and the percentage of amateurs raising aquarium fishes increased. Today, many groups of freshwater fishes such as killifish and many unusual cichlids would not be available in the trade if it were not for dedicated private breeders.
As the captive breeding of freshwater fishes increased, a marked shift from collection to culture took place, greatly alleviating pressures on wild stocks. To be sure, wild collection is likely to continue. For example, those species not suited to mass culture such as Cardinal Tetras (Paracheirodon axelrodi) are still collected from the wild and provide a large economic benefit for Brazilian fisherfolk, who self-enforce sustainable harvests and protection of local waters.
In many instances, however, captive propagation is essential. Human encroachment is a constant threat to aquatic habitats and has driven many species to extinction. The Tecopa Pupfish (Cyprinodon nevadensis) is one example. The native California hot springs occupied by this pupfish were channeled to facilitate building construction; exotic gambusias were introduced to control mosquitos; groundwater use was accelerated and pollution increased, ultimately leading to the complete demise of the lovely Tecopa Pupfish, which was declared extinct in 1970. Several other species of pupfish, such as C. longidorsalis, survive only in captivity as their native habitats have been destroyed. Although the ocean is a massive expanse of water, throughout history humans have demonstrated the ability to drive fish stocks to commercial extinction. Captive breeding may be one answer when wild stocks are threatened.
Pioneering Efforts
Even though we’ve known for decades that some coral reef fishes can be successfully raised in captivity, aquarium enthusiasts have had very little practical advice on how to breed most species. Experimental rearing of reef fishes was successful as early as the 1930s, while commercial techniques were found for many species in the 1950s.
Among the pioneers who deserve credit for cracking the codes of breeding and rearing clownfishes and other species are Martin A. Moe, Jr., Frank Hoff, Tom Frakes, and Bill Addison.
Still, even today, commercial-scale production methods exist for only a handful of marine aquarium species. Successful future production seems probable in a large number of species, but many others seem only a remote possibility. While much of the progress with commercial marine aquarium fish production is cloaked in secrecy, aquarium enthusiasts are playing a crucial role in freely sharing their observations on behavior, feeding, growth and reproduction of marine fishes.
Many aspects of reproduction and larval husbandry remain unknown for a variety of fish families, and dedicated home and public aquarium aquarists are those most likely to observe and report important new information. In my view, there is a real need to encourage captive propagation outside the commercial, profit-driven enterprises. Such facilities have limited capacity for research and the economics of developing new species rarely permit any deviation from production. Breakthroughs in breeding new species are certain to come much faster with the increased participation of amateur and home-scale experimenters.
Additionally, many species of marine aquarium fishes are not suited to commercial culture. The reproductive modes of such species as the Royal Gramma (Gramma loreto) make production difficult in large, consistent numbers. Royal Grammas are ideally suited to hobbyist culture. They are justifiably popular fish and are always in high demand, but are likely never to be mass-produced.
Many species of fish in both the freshwater and marine aquarium hobbies fluctuate in their availability. Driven by ebbs and flows of wild populations and by market forces and catch limits, the market for many marine fishes could be better assured by captive breeders.
Rare fishes that fetch high prices also present great opportunities to determined experimental breeders. Many examples of expensive species that are rarely collected from the wild exist in the marine aquarium trade. Basement breeders have the potential to become key players in supplying these rare fishes to the marketplace. (Public aquarium biologists are actively working on breeding rare and threatened marine species, but they are usually prevented from supplying stocks to the aquarium trade, even when they have surpluses.)
Perhaps the largest difference separating the freshwater and marine aquarium trades today is the lack of home-based saltwater breeders. When I first became interested in propagating marine fishes, the almost total lack of information was daunting. This is still the number one reason aquarists are hesitant to attempt culturing marine fishes.
In fact, there are countless spawning events in salt- water aquariums every year, but relatively few people try to save the eggs or rear the larvae. This could all change if fishkeepers become more aware of culture techniques and if culturing supplies and equipment are more readily available.
Consider that there are over 2,000 known species of gobies, most of them marine, but less than a dozen are reared on a commercial scale. Most of them would prove just as easy as the first, and the only reason they haven’t been captive-bred is that no one has tried. Inspired? Be observant and watch fish at local pet shops. Look for possible signs of courtship, research the species’ requirements, set up some aquariums and raise them. Be the first to bring a new species through spawning and rearing in captivity. Marine aquarists of the future will be indebted to you.
To Your Success
This book is the culmination of many years of trial and error and is the product of my experiences and biological observations in homebased and commercial aquaculture, as well as scientific collaborations with some of today’s leading marine fish propagators. I offer this as a practical guide to give you the confidence and knowledge needed to successfully propagate marine aquarium fish in captivity.
One word of warning: As I learned in my boyhood experiments, you will need to be committed to succeeding and willing to learn all you can about the reproduction and life history strategies of the species that attract your interest.
The aquarium hobby is one based largely on opinion and anecdotal science, rather than laboratory tests and controlled experiments. Techniques and methodology that one aquarist swears by may not work for another. The smartest breeders, however, constantly gain from the experiences of others. This book is intended as a guide. Your culture techniques are sure to evolve, and there are certain to be important breakthroughs in the equipment and foods available. Experimentation will be key in making things work in your own breeding efforts.
Small-scale marine fish hatcheries operated by hobbyists may have a nice potential for earnings, but getting beyond more than modest profitability can be a long and difficult road. This book is about the challenge and tremendous satisfaction to be found in breeding marine fishes at home rather than a business manual. A sense of passion is what first drives most hobbyists to raise these fishes, and it is in that spirit that I have compiled this guide. I believe that curiosity is a tremendous motivator, as is doing something most people still think is impossible.
I wish you luck and success as you make your own discoveries and bring your first batches of captive-bred marine fish to viable size. I hope that you will share your findings with others and, in embarking on your own extraordinary venture, help contribute to the future of responsible marine aquarium-keeping and even the healthy future of coral reefs and the incredible fishes they give us.