C. sterbai infertility

[kingborris]

Hi all,

About a month ago I added a shoal of 21 young (~1") sterbais to my 180gal discus tank. Since then, I have had at least three separate spawns from this group of fish, which about 30-40 eggs per spawn.

Sofar, they have all been infertile

Water stats are temp 29C, GH4, KH4, pH ~6.9

Is there anything I can do to increase the chances of fertilisation, or is it just that the fish are still young, and havent got it right yet?

Any advice welcome

[Marc van Arc]

I didn't even know that such small Corys were able to spawn at all, especially since the C. sterbai is one of the larger species. So I would say they're too young/small.
But there are several people who know much more about Corys; let's await their comment.

[CoryWally]

Must be something in the air!

My sterbai have spawned for the first time in the last week, a group of eleven ranging from 3-4.5cm. I too thought they were too small to be spawning but i've had viable eggs laid on the front glass and some fry. Caught me by surprise so popped in a spawning mop and they duly obliged with another spawning.

I know that the adults are only a maximum of 9 months old from 4 seperate sources.

Can't answer the infertility Q though. My parameters are similar but a bit cooler. pH (and/or hardness) certainly affects the fertility in other species.

Good luck,
Mark.

[Coryman]

At one inch I would say that they are a little imature.

Ian

[kingborris]

thanks for the responses people.

They are still at it. I must have 130+ unfertilised eggs covering my bogwood and glass now. still non are fertilised. I guess I will just have to wiat until they are a bit bigger. Roughly what size do they reach sexual maturity?

strangely though, the eggs are showing no signs of fungusing (or being eaten). I run a UV filter, but I still would have thought the first batch of eggs would have decomposed by now?