Breeding Percula Clownfish

Part 2

If you have read the article "Clownfish Spawning - Part 1" then you will know that I committed to writing up another article on how I bred Clown fish. Well as I have not yet had the time to raise the Clown fish larvae, I can only write about the actions I have noticed while the Clown fish have spawned. This article will go into some detail on what I have observed while my two Common Clown fish (Amphiprion ocellaris) went through during courtship and spawning. I hope this will not only encourage people to try and breed marine fish but also confirm for them if their Clowns are ready to spawn. I will find the time soon to raise the larvae and publish my observations in another article. Obviously each Clown fish has its own peculiarities so the actions that my fish performed may not necessarily correspond with what you are seeing. However, most Clown fish go through the same procedures so there should not be too much difference.

Reef Setup

I suppose I should start by giving you a brief explanation of my reef tank. The tank itself is only a 4 foot long by 21 inches high and 18 inches deep drilled tank. The overflow enters a 3-foot sump, which is situated directly below the tank. I have an Eheim 1250 pump that returns the water through a Tropic Marin 30watt UV back to the main tank. The complete system holds approximately 50(UK) gallons. The sump houses a Berlin Skimmer powered by an Eheim 1060, 30watt heater, filter wool, a small bag of carbon, a small bag of phosphate remover and obviously the Eheim 1250 for the return. The only hardware in the main tank are three Mini-Jet MN606's which are used to circulate the water. I use Tropic Marin salt and all makeup water is run through a Kent Maxima RO/DI unit. I drip Kalkwasser overnight and my water quality is as follows -

• Temperature = 79f-80f
• Salinity = 1.023
• pH = 8.1(am) and 8.3(pm)
• Ammonia = 0
• Nitrite = 0
• Nitrate = 0
• Alkalinity = 2.86meq/L
• Calcium = 390-410ppm

There is no sand and all filtration is performed by the live rock in the tank. I have a number of soft corals (too many to mention in this article) and the only other fish I have are two Green Chromis (Chromis caerulea). One Cleaner Shrimp (Lysmata amboinensis) keeps the fish in check and the rather large Ritteri anemone (Heteractis magnifica) plays home to the two tank bred Common Clown fish (Amphiprion ocellaris). The tank is lit by 6 fluorescent tubes, which consist of -

• 1 x 30watt Phillips Aqua
• 1 x 30 watt Marine Glow
• 1 x 40watt Marine Glow
• 1 x 38watt Triton
• 2 x 40watt Power Glows

The lighting is all timed to come on over a two hour period and go off over a two hour period. The lights are on for 12 hours each day.

The Clowns Fish

I decided that the first thing to be introduced into my reef tank was going to be two tank bred Common Clown fish. I had seen a tank full of very young clowns about 1 inch in length at my local aquarium store. All the Clowns looked healthy but their colouring was almost a light yellow and not the lovely orange that it should be. I believe this was due to them being so young and the fact that they where tank bred. I chose two of the smallest fish in the tank to ensure that both Clowns would be juveniles. This way, the dominant Clown would turn into a female and the other would turn into the male. The only problem with buying two fish from the same tank is that you do not know if both are from the same spawning e.g. brother and sister. As most aquarium stores buy from one distributor which house all its tank raised Clowns together, there is a slim chance that this may happen but there is no way of telling. The two Clowns were introduced into my reef tank on the 5th September 1997. Both were small and very pale in colour. One month went by and I started to notice that the slightly larger Clown become much more dominant and started to pick on the other. The smaller one would not retaliate but would just swim away. The smaller one acted and looked very week. There was no biting or fighting but the smaller Clown was being chased around the tank and did nothing to defend itself. On the 18th October 1997, disaster struck. I did my weekly water change and after turning on the return pump back on, I notice the flow of water was being restricted. I turned the pump on and off a few times to try and remove the blockage and out popped the smaller Clown. As I had turned the pump off to do my water change, the smaller Clown must have been right next to the return pipe. The return pipe siphons back some water when the pump is turned off and the poor Clown must have been sucked in. Needless to say, he was dead. This was not a good start on trying to pair some Clowns. That same day I purchased another very small tank raised Clown. This fish was less than an inch in length and much smaller than the one left in my tank. Again, the new Clown fish was picked on by the larger Clown but did not seem to bothered by it. The larger Clown would swim right up to the smaller one probably expecting it to swim away. Instead the smaller Clown would turn its body 180 degrees and wait for the bickering to stop. This continued for about two weeks after which, the two Clowns swam around quite happily together with only the occasional squabble. At this stage, I assumed that the slightly larger Clown (the original fish) was the female and the smaller was the male but as both were still very young, it was hard to tell.

Anemone

Like so many other people who start in Reefkeeping, I wanted to keep an anemone. I talked to several people about this and most agreed that anemones are too hard to keep alive and should not be kept in a reef tank. I then read a number of articles and books on anemone and most of what I read said the same thing. I was determined to keep an anemone so that I could offer my Clowns as natural a home as possible. I was looking through the tanks in my local aquarium store when I noticed lovely pinkish Ritteri anemone (Heteractis magnifica). It was about 4inches in diameter and already had a pair of Common Clown fish swimming in and around it. I could not resist it, I purchased it there and then. I had already read a lot about Ritteri's and knew that it was one anemone that the Common Clown prefers. On the 19th October 1997, I released the anemone into my reef tank.As soon as the anemone settled onto a rock, the two Clowns started to investigate it. The smaller Clown appeared to find the anemone more interesting with the larger Clown looking rather sheepish. The smaller Clown would at first swim within six inches from the anemone and then without taking his eye off the anemone back away from it. Ever since I have had the two Clowns, this was the first time the larger Clown looking more nervous than the smaller one. After an hour of the anemone being released into my reef tank, both Clowns were swimming nearer and nearer to it. Anything else did not bother them, as they were concentrating on the anemone. The smaller Clown was the fish to rub itself against a tentacle. It quickly swam up against it and then quickly swam back. After doing this three times, the larger Clown did the same thing. This continued for over two hours with both Clowns spending more and more time in the anemone before swimming back out again. Only once did I see one of the Clowns quickly retreat from the anemone, obviously being stung. Within four hours of the anemone being released into my reef tank, both Clowns had made it their home. Before the anemone was introduced into the tank, the Clowns would swim around the tank with not a care in the world. Now that they have an anemone, they only leave it for feeding and even then, they grab the food and swim straight back to their home. Obviously the anemone makes them feel safe but what I can't understand is that they felt quite safe before the anemone so what changed? Also, remember that these Clown fish are both tank bred and had never seen an anemone in their life yet as soon as they saw it, they knew that they were meant to make it their home. If that's not instinct then I don't know what is. The anemone moved around the tank for the first few weeks trying to find the best spot and everywhere the anemone went, so did the Clowns. The anemone eventually positioned itself right at the top of the tank near the return pipe. From this position it receives the maximum light possible and has a nice flow of oxygenated water being swept across its tentacles. For the first few weeks, the anemone deflated and inflated making it look as though it was dead. This is normal behaviour for newly introduced anemones. Also, although I tried to feed it every three days, it did not take food until the end of the second week. Ever since then, it has eaten everything and anything I have fed it.

Site Preparation

After the anemone was introduced both Clown fish seem to get on really well with next to no bickering. There was the occasional shimmering were one of the Clowns swam next to the other and shook its whole body several times. I believe this was all part of the sex change process and also can also be courtship.. The larger Clown grew larger and the smaller grew slightly but at a slower rate. By what I had read, I assumed that the smaller one was the male as females are generally larger. At this stage it was guesswork, as they had not shown any signs of spawning. That all changed on the 31st August 1998 when I noticed the smaller Clown cleaning a piece of live rock that was situated just to the right of the anemone. His cleaning started after the first 2 of the 6 fluorescent lights went out which was around 8pm. During the day the anemone stretches out over this area and at night the tentacles brush over it. The Clown fish obviously felt this area was secure enough to lay the eggs. The cleaning comprised of him biting small sections of uneven rock to try and remove them. The male was doing most of the work, with the female only helping periodically and even then it appeared she would only bit the rock half heatedly. However, the female started shimmering her whole body over the cleaned area almost as if she was doing a dummy run on laying her eggs. When she did this, the male would stop his work and then follow her as if he was fertilising them. The cleaning continued until all lights went out after which both Clowns settled in the anemone and stopped their work. The following day the male appeared to be bit more intent on cleaning the spawning sit. He would occasionally return into the anemone and then dart back to the site and carry on cleaning. One thing I noticed was that the other Green Chromis fish (Chromis caerula) still swam quite close to the site without being chased off. The Clowns did not seem to be protecting the site at this time. On the evening of the 2nd September 1998, the male did not start his work until the second set of lights went out and this continued the following evening as well. The female still seemed content on letting the male do most of the work. On checking the reef tank on the morning of the 5th September 1998, I found both the male and the female cleaning the same area. I started to believe that spawning would follow very soon. On the following evening, the Clowns started the cleaning after the first of lights went out. The evening, the female became very annoyed with a snail that was unknowingly heading towards their spawning site. The female started to push the snail away without much success. She then decided to ram the snail and I could see the shell move by her violent attacks. This still did not seem to bother the snail but the snail changed direction as snails do.

Egg Laying

Unfortunately, my work requires me to travel a lot so I had to leave on the 7th September 1998. On the 12th September I returned and found that my Clowns had laid their first batch of eggs. I suspect that the Clowns actually spawned on the 10th September but obviously I can not confirm that. The male was swimming very close to the eggs to aerate them and he never moved away. I could see about 50 eggs approximately and they where a red orange colour. This was quite a low count of eggs but as it was their first spawning, it was only to be expected. Also, the eggs did not appear to be attached to the rock securely. The male occasionally mouthed the eggs and I was unsure if he was eating them or purely cleaning them. The female only periodically helped to aerate the eggs and spent the rest of the time in the anemone. When I fed the fish the male did stop his work to eat but would then return to care for the eggs. The female appeared more aggressive at eating as though she wanted all the food I was feeding. Yet again, I had to leave to work away again almost as soon as I had returned so I was unable to view the Clowns actions over the next few days. I returned on the 18th September to find only 20-30 eggs left. I assume the others were infertile and the male had either removed them or eat them. By this time, all the remaining eggs were dark in colour.

Egg Hatching

The evening of the 18th September, either the eggs hatched or they had been eaten. When I checked on the Clowns on the 19th, all the eggs had gone. I could not see any larvae in the tank but either the fish had eat them, the filtration had scooped them up or they never hatched and were removed by the Clowns. Although I was disappointed that I could not study the Clowns closely due to my work, I now new that I did have a male and a female Clown and that they were capable of breeding.

Spawning Habits

It is now 4th April 1999 and believe it or not, I have been away from home more than I have at home so I have not been able to properly study the breeding habits of my Clown. However, my Clowns have continually spawned ever since they first started back in early September 1998 and I have managed to notice the following behaviour every time they breed.

• Male always cleans the site a day or two before spawning starts.
• The females mouth appears white when about to spawn (I have yet to work out why).
• The female is much larger than normal just before spawning.
• Female appears to have become much more aggressive at feeding time.
• The male always aerates the eggs and the female only helps occasionally.
• Female becomes very aggressive towards anything that approaches the eggs.
• More eggs have been produced with each spawning.
• Eggs always hatch after all the lights have gone out (not sure how long after).

Summary

One thing I have learnt is that as long as you provide the right environment in the way of excellent water quality, consistent lighting intervals and emulate their natural living environment, getting Clowns to spawn is not a matter of luck, its a matter of time. I believe that like all animals it is a natural urge to continue the species. I also believe that although raising the larvae will be hard it is not only something the experienced hobbyist can master, it is something that everyone can try.

By Reefs UK