Breeding Zebra Plecos, My First Success by Graham Summersgill

I first bought a Zebra Plec about four or five years ago to put in my three-foot community tank. I had kept various Corys and I liked the look of the Zebras. I think soon after I bought three more and these four appeared quite happy together. As I read up more on them, I decided to buy more as the advice was to keep quite a few together. I should say at this stage that at this time Zebras were a lot cheaper to buy. I remember feeling guilty having spent £90 for five small fish, how times change! The fish always appeared happy and healthy in the community tank and I have never had a fish die under normal circumstances. I have lost about five or six when an unknown disease decimated the tank but never under normal circumstances).

I have found that these fish live for quite a number of years. I continued to buy more fish until I had about fourteen in the tank. Because of the other fish in the tank I felt that the Zebras did not have enough space to be at their best. As I learned more I also realized that I was over the biggest hurdle if I wanted to try and breed them. i.e. I had quite a number of the fish and, hopefully, a mixture of males and females. Incidentally, I thought that it was easy to tell males from females but the longer I keep Zebras the more I see fish I’m not sure about. Following an injury at work, I needed a “project” at home. I decided to buy a separate tank just for Zebras. I chose a Juwel “Rio 180” tank and also fitted an Eheim “Professional” external filter suitable for up to 77-gallon tanks. At the time, the advice was that to breed Zebras they required very warm, flowing water. This set up provides flowing water all right! I set the new tank’s temperature to about 82/83 degs. I added about an inch and a half layer of small gravel, some pieces of bogwood and added the fish. I also added a small shoal of Corydoras sterbai to help clean the tank and because this was what the Zebras were used to.(I know Ian Fuller is going to kill me very slowly when he hears this about using Cory’s to “clean up” after other fish but at the time the Zebras did not stray far out of the caves and there was noticeable uneaten food in the tank. Cory’s love Bloodworms anyway) At the time I was using an RO water maker for the community tank and, I figured, as this was what they were used to I would use soft water in the Zebra tank as well. I had set up the tank in a spare bedroom so that the tank would be quiet and undisturbed. I then sat and watched then for hours on end! Guess what, nothing happened. I did notice that the Cory’s were getting very jumpy when I was moving around. They were not settling in at all so I took them out and they went back to the community tank. To be honest, I then started to lose interest. I had never had any success with breeding fish in the community tank and my expectations were obviously too high for a fast result with the Zebras. I had other things on my mind and the tank was not getting the attention it should have had. The Zebras however had other ideas about things. I had stopped doing regular water changes and no longer regularly monitored the water parameters. I occasionally cleaned the glass of all the algae so that I could see the fish and fed them almost entirely on frozen bloodworm and anthemia. I did get round to checking the water and found that it had a pH of about 8 and a GH of about 13 /14. Zero Ammonia, Nitrite and Nitrate. Whenever I look at the power head in the Tank’s internal filter it is covered in “lime scale” The fish appeared as happy as fish can appear and I could see that each one had it’s own cave or hiding place. I also noticed that after the territories had been established, the fish came out more so that I actually saw more of them.

About January / February this year I was sitting watching the tank when I saw a very small fish darting about in the tank. I remember thinking that a Cory must still be in there. I quickly noticed that this was not a Cory but a VERY small Zebra! Yippee a new arrival. About two days later I was due to go away for a week and invariably whenever I go away leaving my wife Janet to look after the fish something dies. - Sorry Janet, but it’s true isn’t it) You can probably guess how we both felt at this time. Over the next two days we counted four fry. We also found the remains of one more. We found that as it became dusk, we could see the fry eating algae of the back of the tank and could watch and count them easily. When I was away I received daily reports from Janet. Ever day she saw another until when I was due home she had seen 8 together. Her new regime prior to going to bed was to watch the tank for up to an hour in almost total darkness counting baby Zebras! Bet she would have divorced me if I had suggested she do this! As I had not heard of any one breading these fish I did not know what to do for the best. Working on the assumption that what ever I did was going to be wrong, I did nothing! As time went on I started to loose these fry. Every now and again I would find a dead one floating on the surface. If I had been asked three months earlier I would have been happy to know the adults were breading but, by now, I was very disappointed whenever I found a dead fish. I am one of these strange people who cannot leave things alone and I decided to try changing one or two things. I changed the direction of the filter outlet and decided to change the water temperature as well. Don’t ask why, because I don’t know! As soon as I did this of course I realised that this was the thing not to do and tried to get things back how they had been. If it’s not broken, don’t fix it!

I did decide to leave the temp at about 86 degs though. As time went on I ended up with three surviving fry. They were about one inch long and starting to fill out. They spent all of their time in amongst the pieces of slate and appeared to be causing no problems to the tank set up. About two weeks ago - last week in June 03) I was trying to show Janet how they were getting on when she pointed out another fish. This one was VERY VERY small and obviously a new arrival. We sat and watched for a time and saw another new fish. These were noticeably smaller than the first fry we had found at the start of the year. We ended up counting about six or seven new fry. As usual when something happens, we had booked a holiday away the next week and my mother was going to house / fish sit for us. Knowing what happens when I am away this filled us all with doubt about the future for the fry. I found one dead before leaving but I also found one of the original three fish dead. I had decided to put these three in a separate plastic tank floating in the original. I had drilled lots of holes in the sides and base of the plastic tank so that it held the same water as the original. I did this because I did not want these three to compete with the new arrivals for the algae on the tank wall and as the first step towards moving then to another tank as the original was getting quite crowded. I have now returned from holiday and can report that there have been no fatalities. I am starting to notice another problem though. In the adults tank there are regular “disagreements” over territory. I can see that some of the adult males are starting to look a little battle scarred. Two ore three of them have marks on their sides. The only way I can describe these marks is that they look like they have had their black stripes rubbed down with sand paper. I have no doubt that this is where they have been rubbing against the slate and wood in the tank during their quite violent pushing matches. I am planning to move these males to another tank to provide more space for them. No doubt I will find that in doing this I separate the breading pair! I intent to leave the new arrivals in the established adult tank for at least a few months or, hopefully until the next batch of fry arrive. Well you have to be positive don’t you. They appear to do well foraging around in the gravel and between the pieces of slate.
At no time have I ever seen anything I would describe are breading activity, I have never seen any eggs, and I have only seen the new fry when they have been free swimming having digested their yolk sack. I can only suggest that, from my experience, if people are interested in breading Zebra plecs they do better when quite a few are left alone in warm flowing water, in private, but I would like to hear from any one else who has had success breading Zebras to compare notes.

Since I wrote this article I have noticed even more small fry in the tank. I have moved the original batch on to another tank with unrelated adults. They appear to be doing well and are filling out nicely. These fish are now about 7 months old and are about 1 ½ inches long. I did this to make more space for the younger fry. At no stage have I seen any adult show any aggression towards any fry and I have no fears about leaving the growing fry in with the adults. I have noticed that larger fry do compete, quite physically, with their smaller relatives for food though. Ideally, I would like to separate the different generations of fry to stop this competition but I’ve found that trying to catch then creates too much disturbance to the others.

I have also noticed at lease one, possibly two, new batches of fry. - I do not know how many fry are now in the tank). It is obvious that the adults are breading on a very regular basis. I am wondering if more than one female is involved. I don’t know if one female would be able to produce eggs twice, or more, per month? The same male appears to look after the majority of all the fry, but I am not sure which females are involved.
Recently the tank temperatures have risen because of the weather to over 92 degs.F. This does not appear to have slowed the parents down at all. I continue to see the fry exploring and foraging for food amongst the gravel and slate. Because of this I would not recommend a bare tank set up.

Finally a warning. I recently fed the adults some frozen Blood Worm. I have found that they love this food. I hadn’t fed them worms for a few weeks. The next morning I found three dead fry. All had pieces of worm protruding from their mouths. I am assuming that the fry choked on the worms. I will not be feeding worms to very small fish again.

I hope this is of interest.

PS. One of my adult fish is marked differently to the others. Every other Zebra I have seen has straight black limes but this one - he’s called Wavey) has wavey lines. I have seen a drawing of a similarly marked fish in a book - the aqualog Plec book I think) but I am interested if anyone else has seen another one or owns one in the flesh???

Return to Articles index