Nothobranchiuos furzeri

[BillT]

A friend sent me some killifish eggs (dried up, in some peat, in a baggy) because he wants me to keep a back-up population for his a lab.
This gave me a reason to work out how to keep a soft water, peaty aquarium. Something I have been interested in doing because there are some small Danionin-ish fish, like Sawbwa, like this kind of water. Now I have two tanks set-up and apparently fairly stable.

This is my biggest of these and the first one I have gotten to color up. it looks like a male to me.



This guy is about 1.5" long.
He's about 1 1/2 months old. Turns out they should be about 2-3" by now if raised by an experienced lab, and they would be ready to breed. Turns out I should have fed them more early on, but they are growing well now. They are eating baby BS, Walter Worms, Moina, and black worms (some thing else I finally got around to trying).

I think this species has the current record for the fastest fish to go egg to egg (grow up fish get them to reproduce). Rapid turnover of generations is helpful for all things genetic.
The fastest this has been done with a zebrafish is 45 days (generations are normally 3-4 months in most labs however). Medaka and sticklebacks (also common in labs) take about 60 days.

They also don't last very long. They live in ponds that often dry up in a few months, leaving the eggs to survive in the dirt and hatch out when the water returns. There has been no selection for these fish to survive longer than it takes them to reproduce. They should be bred before they are 3-5 months old. It is rare from they survive a year. A single (large) female can produce 250 eggs over it short life span.

[Mugwump]

Here in Illinois we used to go out on field trips back in the waters off Morton Arboretum. They had spring fed pools and very small streams. We were with a group from the Chicago Killiefish club...they were looking for the blue fin killiefish, which are a native state species. They used this wild stock to 'punch' up there stock. It's illegal to take them in Wisconsin, not sure about Illinois. They never returned any stock to the waters here, so no harm, no foul. I believe there are several other natural species here too.    Those trips were about 45 years ago....LOL...

[BillT]

I don't know a lot about killifish right now, but i get the vague feeling that killifish and their relatives are reaally wide spread.
I think pupfish are killifish relatives.

[BallAquatics]

I don't know much about Killie fish either, but these are the fish that started my questioning of all the fish inbreeding speculation.

Dennis

[BillT]

I don't know much about Killie fish either, but these are the fish that started my questioning of all the fish inbreeding speculation.

Its an interesting thing Dennis. I have wondered the same thing and questioned the people I got these fish from. This particular strain (99-4) was collected something like 10 years ago. They probably have gone through a minimum of one generation a year. If one male and one female fish are bred each generation, they will lose, on average, 1/2 of their genetic diversity per generation. Ten generations of this should reduce their diversity by 2¹⁰ which is 1024. So their diversity should be 1/1024th of the wild population they were derived from. Lab mice are frequently inbred for genetic reasons. After 20 generations they are considered "completely" inbred. Because i was interested in doing htis with fish I looked into this. Lab mice have about 1/3 of the number of pups as mice from the wild, and can frequently have genetic problems particular to a given line. One would expect the same from fish. One guy told me "no those fish aren't inbred" while an article on this line said yes they are rather inbred, but they are still fairly good fish (very good in some ways).

It is my feeling that if you are going to inbreed something you should have a pretty stringent selection on the fish to remove any deleterious traits before they become fixed in the line. Fixed in this case means the alternative versions of a gene are removed is there is no alternative to it in further breeding unless either new genes are introduced (from an outside line) or by new mutations (which are usually deleterious).