AG Cynolebias


A hobbyists experience with South American Annuals.

For sometime now my main interest has been keeping killifish of the South American annual type. I have not included all the species I keep because I havent got enough reliable information on them all.

The first part of the article comprises of a quick reference table of methods and condition. The second part consists of a few notes on each of the species, wich may be of some help and guidance tor those of you which might want to keep these species of those of you who have tried.

Failed and lost interest.

My own personal measure of success with a species is being able to maintain them over a number of generations rather than breeding by the thousands or obtaining perfect 50/50 sex ratios.

General contions which apply to all species are as follows.

Water- 100% Rainwater of ph 6,8 3°DH

Temperature- I space heat my fish house and the Temperature varies between 76°F and 84°F depending on the time of year.

Food- Brineshrimp, Daphnia, Tubifex, Mosquito Larvae, Bloodwurm and Frozen Bloodwurm.

Spawning Medium- My own perference is "Fisons F" seed and potting compost

Incubation Temperature- 80°F to 84°F

The measuring of peat wetness has been the subject of much discussion over the years. I use the following system based on a lump of peat the size of a tennis Ball.

Emty the peat and eggs into a large fine mesh net, then squeeze dry until water stops running out.

Leave to dry for 48 hours = dry

Leave to dry for 24 hours = medium

Leave to dry for 8 hours = wet

I then put the peat in Plastic bags as you would fish, with plenty of air an shake vigorously so that this procedure increases the chance of egg survival during the incubation period. Especially with long term incubation species like Pterolebias when it is time to wet the peat. I use water with a temperature of around 10°F and only add enough to cover the peat by about 50 mm. If the eggs hatch. I add more water and then siphon the young fish into a clean container.

For this operation I use small. Transperent plastic containers.

All of my Aquariums have either sponge or filter floss, air operated Filtration.

The reason for not using coll water for wetting eggs (some people use water with a temperature of around 50 - 60 °F) is that if the eggs arent quite ready to hatch. The low Temperature can kill them. I lost 3 bags of Pt. xiphophorus eggs before I reaused what was happening. If the eggs are ready to hatch then they will, regarduess of water temperature. Why run the risk of killing them, or trying to indole eggs to hatch which may not be developed enough to glue the fry a good chance of surunal.

Reference Table


Peat depth for Spawning

Wetness for Incubation


Fist Food

C. flammeus 70 mm medium 8-10 weeks infusoria
C. magnificus 50 mm medium 7 months infusoria
C. myersi 70 mm medium 8-10 weeks artemia naupli
L. citrinipinnis 25 mm medium 8-10 weeks microworms
N. paraguayensis 80 mm dry 10 weeks artemia naupli
R. brevis 70 mm dry 8 weeks microworms
R. limnaeus 80 mm dry 8-10 weeks artemia naupli
R. pyropunctata 50 mm dry 8-10 weeks infusoria
Pt. peruensis 100 mm dry 6 months artemia naupli
Pt. phasianus 80 mm dry 14 weeks microworms
Pt. xiphophorus 70 mm dry 8 months artemia naupli
Ren. oscari 80 mm dry 7 months artemia naupli
T. dolichopterus 20 mm dry 14 weeks infusoria

Notes on species

A. - Cynolebias flammeus

The strain I have kept is the BR 93/10. This fish comes from Brasil and doesnt seem to mind my fish house high Temperatures. I provid the fish with some form of cover for them to hide under as they are a little shy. If positioned correctly. You will still be able to see them. Which is a must. Because the males have beautiful colors.

From 1 weeks spawning with 1 male and 2 females. I usually get 100 - 150 fry. Which is just as well as the sex ratio is around 8 males to 1 female. This fish shows no aggression. Remove large males from the batch. To give the females a chance to grow.

B. - Cynolebias myersi

Another Cynolebias from Brasil with nice color pattern. They are quite bold and do not need any cover. A trio will yield appoximatley 60 fry from a weeks spawn and sex out evenly. From 3 males and 5 females I have had up to 400 fry from a week spawn. I would class this as a good beginners fish and is the easiest for me to maintain. I have kept an aquarium strain and more recently some 1 st generation from wild. The aquarium strain was big budied with short finnage and the green stripes were more proninent. The F Fish were smaller with long finage and the males were blood red in colour.

C. - Leptolebias fluminensis (citrinipinnis) = Synonym opalescens

Most people would class this fish as not very colourful. But it appealed to me. If kept as a Pair they are shy and jittery. If kept in a large group in a large Aquarium with some lover they become much bolder and will always be in view. These fish will finnip but no real damage is done. They are not very prolific so spawn as a group of say 3 males and 5 females and you should get 30 - 40 fry from a weeks spawn. Sex ratios tend to be 2 males to 1 female.

D. - Neofundulus paraguayensis

It appears from talking to people on the telephone that not many people have had success with this species. And from there descriptions of keeping and breeding methods. I am not sure why. Nobody seems to be doing anything different from myself. N. paraguayensis is a fish from the Brazil/Paraguay border. The 10 week incubation period appears critical for this species. If I try to hatch them any earlier I get nothing. If I try them any later. They are nearly all "sliders". Another prblem I had with this fish was as they grew, a large number of them turned into "sliders" at about 20 - 25mm long. They seemed develop problems with their swimbladders. I only experienced this over the first to third generations from my orginal pair. I am now on my sixth Generation and the problem has nearly disappeared. Coul it have been an inherited disease?

As the young fish start to show first signs of colour. They all develop a red tint to the Anal fin. Dont despair they are not all males. As the fish grown. This caracteristic disappears in the females. Leaving me with a 50/50 sex ratio. They can be spawned in pairs or groups. Expect around 40 fry from a weeks spawn from a pair.

E. - Rachovia brevis

The strain I have is mainley blue. with orange anal fin and long black extensions to the top and bottom of the caudle fin.

Problems with maintaining and breeding rachovia species have been pubushed many times in the past. I have not experienced any of them with my methods and set up. R. brevis has proved reliable for me with 50/50 sex ratios. A group spawning of 2 males and 6 females in a large aquarium with 2 spawning containers will yield 200 + fry. Large males will suppress the growth of Brothers and sisters so remove them to new quarters.

F. - Rachovia pyropunctata

I have been informed that the strain I have is the 88/14 collected by R. Roberts in Venezuela althouggh I obtained the fish uncoded. All notes as per R. brevis except numbers of fry are smaller and ratios of 3 males to 1 female.

G. - Rachovia limnaeus

A big bodied fish from Venezuela. The males can reach a length of about 100mm. I spawn this fish in a group of 1 male and 3 females. I usually get around 30 - 40 fry which sex out 3 males to 1 female. Two interesting points with this fish are that males are variable in markings. Showing either spots or blotches on body and fins or nothing at all. Also the young fish are prone to velvet disease. I watch for this and add salt to the water if it occurrs.

H.- Pterolebias peruensis

Some of the so called "Peat divers" will spawn in shallow peat. I have found that this fish will not. In my experience. Dominant females will suppress other females. Who eventually wither away and die if not removed from the Aquarium. For this reason. I spawn them in pairs. From a pair I only manage to get between 5 and 20 fry after 6 months incubation. The good thing is that they sex out evenly.

I. - Pterolebias xiphophorus

A well coloured Pterolebias which can hold its own against any notho or Aphyo in the beauty department. A peacful fish which can be spawned in a group in just 50mm of peat. Even less if you havent got much!

I expect about 30 fry from a weeks spawn per pair. Which sex out ! male to 2 females.

J. - Pterolebias phasianus

Along with peruensis. I hav found that a good layer of peat is best for phasianus. This fish seems very inactive. Spending most of ist time motionless near the water surface. I get around 15 fry per pair from a weeks spawn which sex out eventually at 2 males to 1 female. There is not a lot of difference colourwise between the sexes. These fish are peaceful and appear happier if kept in a group.

K - Renova oscari

Formerly Moema spec RDB 92/22. A large fish of 100mm + which doesnt know whether ist a moema or a rivulus, nor di I ! They are realitivley peaceful and can be kept in a group if you have enough room. The males are well coloureded with horizontal stripes of red and the females display a rivulus spot. The fry are large and grow at a rapid rate. So give lots of food and change water regularly when growning them on. I have managed to get 30 * fry from a group of 2 males and 2 females which sex out evenly.

L. - Terranatos dolichopterus

An extremley shy fish. I keep 3 sides of the tank blacked out along with the top and bottom. They have only ever eaten small live food. If there appehrs to be no sign of spawning no disturbance of the peat., dont despair. I have stored peat in which there appears to be no sign of spawning, and I havent been able to find any eggs, yet after 14 weeks storage- hey presto !! 5 fry . I know it isnt many. But with an even sex ratio the species is maintained for another generation.

M. - Cynolebias magnificus

I have not maintained C. magnificus over a number of generations but I have included it in this Articel to give information on a relativly rare fish.

Arguably the most colourful Cynolebias to date, it is a small fish of around 2 in length. With a similar body and fin sharpe to C. nigripinnis. Thats where the conparison ends. In the right light it shows all the colours in the rainbow. Females lock exactly the same as C. flammeus. This fish seems quite profic in reguard to egg production. The drawback being the long incubation period. The fry are small. Like c. Flammeus. I have kept this fish in a large group with no signs of agression. C. magnificus hasent proved sensitive to water contition. I have kept them in rainwater and tapwater with no problems. I was sent a bag of eggs from another BKA member which started to hatch after 7 months, over a period of 4 weeks with 3 re- dryings. 150 fry hatched. 3 months on the peat still has resting eggs in it.

This articel details my experiences and my methods. Whilst many of the notes and details are based on my own trial and error. Some were valuable aduce given by other killikeepers who pointed me in the right direction. The point being. There is no excuse for not communicating. Whoether it be through the BKA journal the telephone or rthe post. You will have everythink to cain and nothing to lose.


Aktualisiert: 18.05.2003
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