Breeding Percula Clownfish
Part 1
Some time ago I started writing down various notes from articles and books I have read on breeding the Common Clown fish (Amphiprion ocellaris). As you are probably aware, finding good information on breeding marine fish is incredible hard so I decided to put my notes on paper in the hope they would be of some use. As yet I have not personally raised marine fish but I am getting ready to do so with the 2 tank bred Common Clowns that are happily living in my Heteractis magnifica anemone. The clowns spawn regularly in my reef tank so I just need to set some time aside to raising the larvae. When I get around to doing this, I will write a daily log and publish it as a kind of idiot's guide to show what I did wrong and hopefully what I did right. Please remember these are my notes on what I have read and not what I have had experience with. There maybe inaccuracies in this article but I hope I have filtered most of them out. I have not found many people who have bred marine fish and I believe this is for two reasons. The first being that the first food the larva require can be hard to produce and secondly people still believe that tank bred fish are not as rich in colour as wild court fish. I will start with the first food problem. Rotifers are the first food and there have been a number of articles written in books and on the WEB on how to produce these so I will not go into depth on this subject in this article. There used to be a number of culture products on the market that where meant to make the problem of feeding the larvae a lot easier. I have recently tried to buy these products in the United Kingdom but have had no luck. I wanted to practice culturing Rotifers before I had to do it for real so if anyone knows where these can be brought from, maybe they would be kind enough to contact me. Your will find my email address at the bottom of this article. As for the colouring of tank bred fish, well it is certainly true that all the tank bred fish in the local marine aquarium stores that I have been to look very dull indeed. However, that did not stop me buying some as I had read that feeding a fish the right type of foods can enhance its colour. I have had my two Clown fish now for two years and they are fed with a variety of foods and you would be amazed at how rich their colouring has become. I use krill, brine shrimp, muscle, octopus and a variety of flake foods. Some could argue that their colour is still not as rich as some wild court fish but it would be incredible hard to tell them apart. The following sections are made up of some brief notes I have made reading all the material I have managed to get my hands on. It is in no way a detail study but it will certainly give you an insight into breeding clown fish.
Sexing The Common Clown
Males are generally half the size of females and are also slimmer in the body. This is true of the pair of Clowns I have. Colour does not appear to be different between males or females and should not be used as a mechanism for sexing. All young Clowns start life as juveniles. The most dominant juvenile becomes the female, the next dominant juvenile becomes a male with the rest staying as juveniles. If the female dies, the male becomes a female and the most dominant juvenile becomes the male. The best way of ensuring you end up with a male and a female is to purchase two of the smallest fish you can. As long as the fish are housed together, you should end up with a pair when they have been in your reef tank for a while. This is certainly not guaranteed but it has proved to work on a number of occasions.
Anemones
The Common Clown prefers Carpet anemones (Stichodactyla mertensii) and Ritteri anemones (Heteractis magnifica) although they will generally investigate most types anemones. As mentioned before, my two live happily in a Heteratis magnifica and rarely leave it. Even when being fed they rush back to the anemone as soon as they have their food. I personally prefer to see Clown fish in an anemone, as this is much more natural for them. Some people say keeping anemones is too hard in which case, I have been lucky. My Heteractis magnifica has grown considerable since I have had it and has never looked healthier than it does at the moment. Obviously, like all invertebrates, they do need a certain type of environment and I would recommend some serious reading before contemplating keeping an anemone. Although I have been lucky, many people have failed to keep anemones for any period of time so ensure you read everything you can before purchasing one. Please consider that although some anemones have been know to split into two providing a form of propagation, this is not a common occurrence so we have no way currently to easily propagate anemones.
Lighting
It appears that by increasing lighting to 14 hours per day can encourage spawning. I personally run my lighting for 12 hours a day and as I have mentioned before, my Common Clowns spawn as regular as clockwork. If you are having trouble getting your pair of clowns to spawn, leaving the lights on a little longer may help.
Temperature
Raising the temperature to 80f can also encourage spawning. Obviously when raising the temperature, you should do this over a period of days and not just a few hours. Also, take care if your tank is a reef tank, as some corals will not appreciate this higher temperature. I have always run my reef tank at 80f at his may have helped towards the regular spawning.
Security
Keeping other fish and invertebrates within the same tank can distract Clowns, as they will be concerned about the safety of their eggs, which can prevent a pair of clowns from spawning. I have also read that it is not recommended keeping Cleaner Shrimps (Lysmata amboinensis) in the same tank, as the shrimps will feed on the eggs after the lights are out. Keeping only the paired Clown fish in a tank will help reduce stress, ensure no distractions and hopefully lead to spawning.
Breeding Site
A flat surface is preferred for egg laying. Ocean rock, live rock, slate or plant pots are all good examples of hard surfaces preferred by the fish. If the fish use an anemone then the flat surface should be placed directly below the anemone. The anemones tentacles brushing over the rock will discourage other fish or invertebrates venturing too close to the eggs making the clown fish feel secure.
Spawning
Before spawning commences the fish will go through some sort of courtship. This will probably be displayed in head wagging, shimmering and biting. The Common Clown fish generally spawns late afternoon or early evening. The pair will select the spawning site about 2 hours before spawning begins. When spawning begins, the female will lay a line of eggs and then the male will immediately follow and fertilise them.
Parenting
After the spawning is complete, the females role is to protect the eggs from predators and the males role is to look after the eggs. The male fans the eggs with his fins to aerate them while the female will chase any other fish, snail, shrimp, human hand etc that gets too close.
Eggs Day 1-3
The eggs begin life as a bright orange colour and then turn a dark brown at about day 3.
Eggs Day 4
On day 4, the egg has a dark pigment which, is the eye of the larvae.
Eggs Day 5-6
Around day 5, the eggs turn a silvery colour.
Hatching
Just before the eggs hatch, they are violet and seem to bulge. Eggs will hatch within 6 to 12 days after spawning and generally on day 7 or 8. They will hatch at night 1 to 2 hours after darkness and the hatching can take 15 to 20 minutes. Generally all un-hatched eggs will hatch the following day.
Larvae
The larvae are 4mm in length and will swim towards the upper part of the tank.
Larvae Tank
It is recommended that all larvae be moved to a separate tank. To move the larvae, shine a flashlight on one of the sides of the tank after hatching has occurred. The larva will be drawn to the light and they can be carefully siphoned out of the main tank. DO NOT use a net, as this will damage their incredible delicate bodies. The larvae tank should have high blacked out sides, good lighting and a continuous flow of fine air bubbles. As a general rule, the tank should be at least 10 gallons in size with 30 to 50 being preferred for bigger spawns. The tank can be a simple affair with a heater and an air stone leaving the bottom bare to ensure for easy maintenance. Obviously the water quality needs to be exactly the same in the larvae tank as it is in the main tank.
Cleaning The Larvae Tank
Siphon settled particles from the tank everyday using a small air hose. Change 10 to 20 percent of the water every 2 days. It is imperative that the larva tank is kept clean. Continually monitor the water conditions.
Feeding Larvae
This seems to be the hardest part. Rotifers should be fed as a first food with baby brine shrimp being feed around day 4. On day 10-15 try pulverised flake food and blended food like shrimp or scallop.
Juvenile Growth
The young receive their colour when they are about 1/4" to 1/2" long at which stage they can be moved to a filtered tank.