Convict Cichlids as feeder fish - experiences?

At some point I'd like to get a grass/redfin pickerel, and I want to set up my own feeder fish colony. I've had gambusia for a couple of years, but I'm starting to doubt the practicality of them. It's easy to get some fry from them, but doesn't seem easy to produce large numbers without quite a bit of intervention.

I know that gzeiger has had a colony of cichlids going for a while -- hope he'll chime in. I was browsing PetSmart today and saw a convict cichlid tank with fry and and the 2 parents (maybe 2" each) vigorously chasing all other fish away from the nest. Any fish that can breed in a tank at PetSmart has got my respect. I was tempted to buy the proven pair right there and see if I could get them to throw in the fry...

I'm curious if the convict fry require any live foods at all, or if they can start directly on flake food. The fry I saw at PetSmart seemed large enough that they wouldn't have made it to that point if they weren't eating flake food...

Getting production of large numbers of juvenile convict cichlids will not be a problem, with or without proven pairs. Problem will be rearing enough biomass for a redfin / grass pickerel to consume. They are easy to rear without live foods if high quality small particle size feeds are used. You will find the convicts grow faster than mosquito fish but will still be slow relative to what I think you will need. You are going to need a pretty big tank devoted to rearing enough convicts to a size suitable for feeding to pickerel. How many convicts do you intend to feed out per day? How large will they need to be? This information will guide sizing your convict production resources which will need some sorting / grading capacity built in to control stunting and cannibalism.

Thanks for the reply, centrarchid. Yes, obviously there are a number of things to figure out before launching into full-scale convict breeding. I set up my gambusia population as trial feeder fish producers over 2 years ago, and still haven't decided to get a pickerel.

I'm hoping someone who has done this (gzeiger, maybe others?) can let me know their experiences. Knowing how much broodstock and how much grow-out room is required to produce enough food for an piscivore like a pickerel would definitely be helpful.

Off the top of my head, I'd guess I'd need maybe 2-3 smallish convicts per day, meaning 60-90/month. I'm thinking maybe 3 pairs of medium-size convicts to reliably produce that much?

Thanks for the reply, centrarchid. Yes, obviously there are a number of things to figure out before launching into full-scale convict breeding. I set up my gambusia population as trial feeder fish producers over 2 years ago, and still haven't decided to get a pickerel.

I'm hoping someone who has done this (gzeiger, maybe others?) can let me know their experiences. Knowing how much broodstock and how much grow-out room is required to produce enough food for an piscivore like a pickerel would definitely be helpful.

Off the top of my head, I'd guess I'd need maybe 2-3 smallish convicts per day, meaning 60-90/month. I'm thinking maybe 3 pairs of medium-size convicts to reliably produce that much?

MY PICKEREL will eat 3 minnows and two worms and 7 shrimp pellets a week

I actually have been feeding my pickerel a lot of wild-caught Gambusia and H. formosa lately. Partly I've had some experiments go wrong with the convicts and partly it's because I have the tanks in a garage that isn't climate controlled. Lessons learned: even in SC and in an insulated space, convicts will die in mid December if the tank is maintained at ambient temperature. Luckily only one growout tank was unheated, but I lost a couple dozen. Related to this, though, the pickerel's tank is unheated and convicts will appear to be live food for seconds at most at his temperature (in the 60s), so I haven't been feeding any lately. I also don't have a clear idea of what biomass is required to support the pickerel because I'm fairly sloppy about it. Typically I have 3 dozen or more feeders in the tank at a time and I just feed them so he has a ready supply as needed. I've also used a largish number of much smaller fry to feed other things. They're great for acclimating picky eaters like pygmy sunfish and brook silversides to captivity because of their small size.

That said, a single pair of convicts will produce much more than 90 fry per month. I estimate that I get about three times that number from a pair that are now only about 3 inches long. The fry do start small and are not intially free-swimming, but become free swimming before needing to eat and will immediately take flake if crumbled by hand and can live entirely on flake. I transition to a small grain pellet once they're bigger, but I don't think that's necessary.

Keeping the fry with the parents lowers productivity significantly, both in terms of survival rate and rate of egg production. What I do is provide a couple flowerpots turned on their sides as caves. The parents use these as nesting sites and will lay eggs on the inner surface and guard them. The flowerpot can then be easily removed with all the fry still inside any time within about 3 days of hatch. Removing it prior to eggs hatching resulted in fungus and loss of many eggs. An airstone might help, but the parents do fine fanning them and probably picking out bad eggs before disease spreads. I think you might need as many as 5 or 6 growout tanks to keep up with the pickerel in the long run, as it does take a couple months to get them to a size where they make a good meal. You can keep them at quite high densities before they reach sexual maturity though. I use 10 gallon tanks for each cohort, which ends up I think around 150 fish.

I've also recently discovered that this "temperature matching" concept the tropical hobbyists talk about for water changes matters during the winter. I always just run a hose into the native tanks, but I almost killed a whole batch of convicts by doing that. They did recover, but they were floating around upside down and sideways with just the barest hint of gill movement for a while.

I have the tanks in a garage that isn't climate controlled. Lessons learned: even in SC and in an insulated space, convicts will die in mid December if the tank is maintained at ambient temperature. Luckily only one growout tank was unheated, but I lost a couple dozen. Related to this, though, the pickerel's tank is unheated and convicts will appear to be live food for seconds at most at his temperature (in the 60s)

Thanks for all the info, gzeiger. What seems to be the minimum temperature for the convicts? What temp are you maintaining the heated tanks at? If you allowed them to gradually acclimate from heated tank temp to pickerel tank temp over a day or so, would they survive that?

Jase,

Based on our convict cichlid culture (infestation), a single pair can easily produce 150 eggs per clutch when females are about 2.5" long. Clutches can be scheduled to be at 4 week intervals if adults or young moved to another tank. Our convicts can reach nearly 0.75" by 4 weeks of age and 1.5" by eight weeks (females drag down average for latter age group). Tanks we use range from 10-gal glass aquariums to 1500-gal PVC-lined tanks. You should be able to raise about 30 fish to 1.5" in the 10-gal tanks within 8 weeks. You will be feeding heavy, challenging your filtration and likely to consider some sort of automated feeder.

I would also try to produce twice as eggs as needed, so discard most extras. Do not try to raise more than your resources will allow, otherwise you will be overloaded with runts.

Jim

Thanks, Jim. I assume you're raising them as feeders? (For what?) Do you heat your breeding/growout tanks?

Thanks, Jim. I assume you're raising them as feeders? (For what?) Do you heat your breeding/growout tanks?

You assume wrong! They are evil. We have an infestation derived from fish we did not have the heart to kill after use in classroom demonstration of substrate spawning cichlids. They are still a good teaching tool and if we were not so aggressive in our tank cleaning woulf have many more of the fish than we do now. Our tanks range in temperature from 24 to 29 Celcius this time of year. Temperature maintained by air temperature.

I'm not sure of the actual minimum temperature. Tropical forums suggest at least 68F. My tanks are 72-74F. Slow acclimation consisting of the seasonal cooling, moderated by being indoors, resulted in several dozen dead and complete inactivity in the remainder prior to adding the heater.

I must be doing something wrong if he can get that kind of growth rate. I don't really cull much though, and I have high stocking densities. I seem to get more than one batch of eggs in 4 weeks though.

gzeiger and jase,

Our temperatures; even though they are sometimes in the lower seventies, typically run higher than 72-74F, usually in the upper seventies to lower eighties. The couple degrees higher does have a measurable impact. Also, where we have had the faster growth rates, feed application was more consistent, two or more times a day and seven days a week. That is why I suggest considering some sort of automatic feeder (some can be very cheap to make). Increasing stocking densities will decrease growth rate, a lot! Individual females / pairs do have a habit of spawning at shorter than 4 week intervals but that may lower quality of spawns. I suspect females held to longer spawning intervals will produce more eggs in a clutch. That potentially reduces the number of broods required to produce a given production rate of feeder fish. Also reduces the number of management points (= cohorts) with differing culturing requirments.

Haha...this is funny as I started out with the same intentions

About a year ago I discovered some grass pickerel in the stream down he road and said I want some, Thought I would do some research and find out if I can breed my own feeder fish. I decided upon convicts as well, and just picked up a whole batch of free fry, and raised them to breeding age. I sold what I didn't need and kept one breeding pair. They have been producing fry for roughly 1 year now and I was getting roughly 150 fry every 23 days. Since the one tank with convicts I went to buy a tank for the fry and another tank for the pickerel...however I the tanks I bought came with more cichlids and my original intention of having grass pickerel has changed to see how many differnt fish I can breed...I now have 4 tanks for breeding and growing cichlids!

The plan this spring is to empty one tank for the grass pickerel, I just hope it doesn't lead to me buying another tank...

PS. I find for best results is to siphon out the convict fry 2 days after they hatch, Usually the female convict lays the eggs on the inside top of the flower pot and when they hatch they fall to the bottom and as soon as they start to become free swimming I move them to a 10gal tank...Parents are quite aggressive so I wouldn't advise sticking your hand in the tank...

Goodluck!

How do you control spawning?

I finally got to see my pickerel eat today. I had been heating his tank and cooling the oldest batch of convicts, since the biggest ones were reaching the limit of what I thought he could eat. When the tanks were 67 and 69F I rounded up the feeders and dumped them in. I still missed the stalking since I wasn't expecting it, but within a couple minutes while I was still standing there redoing the growout tank he had caught the biggest one, which I thought for sure was bigger than his head, and was chewing on it for a couple minutes trying to get it down.

He probably appreciated the variety after months of nothing but Gambusia and least killies. I wonder if different fish have different flavors for him or if they all taste like slime coat.

Edited by gzeiger, 15 February 2010 - 05:58 PM.

Control Spwaning in the Convicts?

Remove one of the parents...
Better water quality and remove the fry as soon as they hatch

Edited by LiquidPyro33, 17 February 2010 - 09:04 PM.

If you want small fry to feed small pickeral, convicts might make sense. Getting numbers of fry is easy. Problem is, even though they can be raised their entire lives on flake, they will grow slow and take up lots of room. Soon your tank chores get burdensome. There are easier ways, like collecting wild, feeding frozen [with a broom straw to "swim"] and feeding live wiggly garden worms.
Truthfully I find it a pain to cater to live fish eaters. If you can at least get them trained to snap at anything you put on a straw, you can use lots of frozen.

It's interesting that dead shiners lying on the bottom makes effective pike and pickeral bait. They obviously aren't afraid to eat dead stuff.

If you have problems with low temps I'd reccomend rearing fathead minnows. Simply keep breeding colony of adults in one tank, rotate out slate/pvc pieces they spawn on to a jar with aeration. As fry hatch pour them into a growout tank(large tank with greenwater and powdered flake). They should grow quickly.