Chapter 1: Clownfishes
From Microcosm Aquarium Explorer
All the World Loves a Clown
A Lifetime of Pleasures for the Keeper—and Breeder—of Clownfishes
Rhythmically bobbing and fluttering in midwater or bathing in the sinister tentacles of a sea anemone, here is a group of fishes with an amazing ability to catch the human eye. They seem to hover effortlessly, fanning one pectoral fin in opposition to the other as they peer back at us through our panes of aquarium glazing or dive masks.
Clownfishes mesmerize us with their bold beauty, curious habits, and color schemes as vibrant as the face paints of a circus clown. (To science, they are the “anemonefishes,” but for millions of aquarists, the “clown” name is forever fixed.) Clownfishes are charming beggars that can readily win our hearts. They are among the most popular of saltwater aquarium fishes, well known for grabbing the attention of casual passersby in pet shops and convincing many that they “must have a marine tank.”
The clownfishes, as a group, can be exceptionally hardy, often thriving for years in captivity. Unlike many other saltwater species kept in home aquariums, clownfishes frequently pair off and spawn, attentively tending their nests, and many hobbyists are now learning to raise the young with simple equipment and home-cultivated foods. They are ideal fishes for beginners—and beginning marine breeders—but the fascinating qualities of the clownfishes never seem to wear off.
Symbiotic Associations
Many old hands in the hobby, including veteran reef keepers who preoccupy themselves with the challenges of keeping live corals, still make room for clownfishes in their sophisticated systems. Marine biologists and students of natural history, as well as hobbyists, have an inordinate fondness for these fishes because of their amazing ability to dart into a mass of stinging anemone tentacles and survive, while other species steer clear lest they be painfully injured or even killed.
The intimate association between anemones and clownfishes is a symbiotic scene that aquarists all over the world have tried for many decades to replicate in their captive systems. Unfortunately, as we shall see in Chapter 1, keeping many of the anemone species alive in captivity is no easy matter; all too often the anemone perishes while the clownfish lives happily on. Furthermore, some marine ecologists are now urging us not to support the collection and sale of certain anemones, which may have limited abilities to reproduce in the wild.
For years, aquarists have been told that their clownfishes needed anemones to acclimate properly or to be enticed into a breeding mood. Having kept and bred seven different species of clownfishes myself, I can assure you that an anemone is not essential to the health, well-being, or reproduction of these fishes.
If your dream is to maintain or even propagate your own anemones, this book will attempt to steer you away from the most difficult-to-keep anemone species and suggest at least one promising candidate for captive propagation. We will also discuss several interesting corals that can serve as surrogate anemones while actually being more hardy and easy to keep than many of the anemones themselves.
Aquarium Havens
In the ocean, adult clownfishes seldom venture far from their protective anemones, lest they become prey for one hungry predator or another. Nature is not kind to small, brilliantly colored, poor-swimming fishes—and few fishes swim as poorly as clownfishes.
Fortunately for them, aquariums are far less inclusive than nature. You can easily stock your piece of the ocean with safe companions. The absence of predators may actually help a clownfish live longer in an aquarium than it would on the reef.
In the wild, food sporadically comes to a clownfish, and the fish puts its life at risk each time it ventures from the protection of the anemone to snag a passing tidbit. In aquariums, however, sufficient food routinely falls out of its “sky,” compliments of a human caretaker. My fish have become accustomed to their 7:15 a.m. and 5:30 p.m. feedings (I think they can tell time because at 7:13 a.m. and at 5:28 p.m., they scramble to the surface in anticipation of the feast). They are appreciative guests and never complain about my cooking (unlike certain family members).
Being abandoned to nature, the likelihood of a clownfish growing from an egg to adulthood is remote. The odds against one clownfish egg hatching into a viable larva, surviving through metamorphosis, avoiding predators, and reaching maturity and reproducing are absolutely staggering. A pair of Clark’s Clownfish (Amphiprion clarkii) in the wild may produce as many as 40,000 eggs per year for as long as 10 years. But a lifetime of hatches may yield only 2 successful offspring, just enough to replace the pair and maintain population stability.
The journey from egg to juvenile in the ocean is perilous, including predation and plain old uncontrollable bad luck, such as being carried by ocean currents to barren feeding spots or the open sea. By contrast, clownfish larvae in rearing tanks stand excellent prospects of becoming juveniles and reaching adulthood when their needs are fulfilled. Our miniature glass oceans offer safety, ample nutrition, and successful breeding possibilities. From a clownfish’s point of view, what is there not to like about aquarium life?
Clownfishes, unlike many other groups of ocean fishes, have natural characteristics that are compatible with a life in captivity. In nature, their minimal swimming abilities confine them to small niches of reef, and the space limitations of a home aquarium may not be much smaller than their natural territories. A clownfish quickly learns to recognize its owner and will swim about excitedly when it spies him or her. Clownfishes have the intelligence to learn that their humans are a source of food, and they know how to charm us with their eager feeding behaviors.
Felines to Fishes
You need not be a biologist or master aquarist to offer clownfishes suitable conditions to thrive. I brought to aquarium keeping a solid knowledge of only one rather distantly related subject: cats. Before starting my first aquarium, I had been breeding Himalayans as a pastime for a number of years. The cat business was simple enough: I was able to enjoy the kittens while they were young and adorable, then after they had grown for three months, people gave me money and took them away.
Once, however, I found myself stuck with a maturing kitten that hadn’t attracted a buyer and was not going to be a particularly welcome addition to our own six-cat household. Finally, someone came along and offered to take it in trade for a 55-gallon aquarium. Why not, I reasoned? I could expand my operation and breed reef fishes. I knew virtually nothing about saltwater aquariums, yet the Clark’s Clownfish I acquired grew and thrived. They even began spawning without much provocation, but I soon found that there was much I still had to learn. Thus began my personal journey, affirming that Mark Twain was right when he said, “All you need in this life is ignorance and confidence, and then success is sure.”
Dearth of Research
I quickly came face to face with an unexpected reality: little was known about the captive breeding of marine aquarium species. There were a few books and a smattering of papers, but this was an informational barrens compared to other fields of aquaculture. Understandably, the funding to do scientific studies goes primarily to researching food fishes and near-extinct species. Most marine ornamental fishes do not fit into either of those categories, and we consequently know little about their reproduction and even less about raising them.
In fact, no matter how much we care about the ocean and its wondrous reef inhabitants, there may never be enough research money to study ornamental fish behavior, care, and reproduction. By default, that responsibility has fallen squarely upon marine aquarium hobbyists and hatcheries funded by entrepreneurs and philanthropists. Hobbyists are the self-funded researchers and applied scientists who often lead the way in studying aquarium species and what it takes to reproduce them in captive conditions.
When my clownfish first deposited a clutch of orange eggs in my aquarium, I learned that getting them to spawn was easy; rearing the larvae, on the other hand, was quite another matter. After hatching from an egg the size of a poppyseed, a clownfish must pass through a larval stage in which it resembles little more than a sliver of frosted glass. Rather unfishlike, it needs special care and foods for a few days before metamorphosing into a baby clownfish.
My initial larval survival rates were low. But I read everything I could find on the subject, asked questions, listened, watched, slept less, and did an embarrassing amount of trial-and-error learning. Soon, the young from my breeding pairs began to prosper, and my clowns’ numerous homegrown progeny were occupying every countertop and end table in my house—we called it Marine Explosion Décor. I was selling them to the same retailers who had expressed concern about my mental stability following my announced intentions to rear marine fishes. Although my initial qualifications for breeding fishes were almost nil, that did not stop me from successfully keeping and rearing clownfishes, nor should it discourage you. For anyone who aspires to breed other fishes (or even marine invertebrates), the clownfishes are a great starting point and can provide the lessons and successes needed to move on to more difficult (or unresearched) families.
I’ve now raised thousands of healthy specimens from a growing number of clownfish species. There is a saying among experienced aquarists, “You can never know it all—this hobby provides a lifetime of learning.” While still adding to my own store of knowledge about clownfishes and their reproduction, I’ve been urged to share some of the lessons that might be useful to those drawn to clownfishes and the possibility of breeding them. Some of this, I hope, will prove useful to those interested in propagating other marine species. I am pleased to contribute to the body of knowledge needed to better understand the special needs of these fascinating, spectacular inhabitants of our seas.
From: Clownfishes