Here’s another annual killifish I’ve been working with – Spectrolebias brousseaui. A stunning little species, but I’ll say this straight away… not one for beginners.
Incubation – Patience Is Everything
The incubation period for Spectrolebias brousseaui is at least 3 to 5 months. The batch I was dealing with had only been collected about a month earlier, so realistically I knew they wouldn’t be ready.
I had a quick look through the peat and could see the eggs weren’t fully developed yet. So back into storage they went.
When storing annual killifish eggs, remember:
- Keep them warm – above 24°C
- Keep them dark
- Avoid cool temperatures and light, as both can slow or hinder development
I usually re-check them every 3–4 weeks.
Checking the Eggs – Tiny Is an Understatement
While inspecting my other species, I decided to check this batch again. They still weren’t technically due for another month… but I noticed something interesting.
The eggs looked like they’d “eyed up” – meaning I could just about make out eye spots inside the egg. That’s normally a sign they’re close to hatching.
The problem?
These eggs are absolutely minute.
I used a 3x–3.5x magnifier and even then it was difficult to be sure. They’re so small you can barely see them properly, let alone confirm development.
Still, I decided to take the risk.
The First Wetting – A Gamble
I poured the peat into a bowl of water and waited.
Now here’s the thing with annuals:
If you wet them too early, you can wipe out the entire batch.
If nothing hatches within three days, I always dry them again and store them warm until I can clearly see the eggs have eyed up properly.
To be honest, I wasn’t confident about this batch. I had a feeling I’d jumped the gun.
Day 1 – Relief (Just About)
I was panicking a bit… but then I spotted movement.
A couple of fry were swimming.
I carefully collected them, but they were incredibly small – easily some of the smallest fry I’ve ever dealt with.
On day one, I managed to collect just two fry.
Because of their size, they can’t take baby brine shrimp straight away. Their feeding schedule looks like this:
- Green water + infusoria for the first few days
- Then Paramecium for another 2–3 days
- Only after about a week to ten days can they take newly hatched brine shrimp
Miss that window and they’ll waste away within hours.
These fry are that delicate.
Day 2 – A Few More
On day two I managed to collect a couple more fry, bringing the total to four.
At this stage, you really have to keep the water rich with micro-food. I make sure the container has:
- Green water
- Infusoria
- Paramecium
Even then, raising them is tricky. This species is noticeably smaller and more delicate than some of the other Spectrolebias species I’ve worked with.
Once you get them past the five-day mark, your chances improve massively. But getting them there is the hard part.
Day 3 – Not Great
By day three I removed two more fry.
Total: six fry.
And that was it.
At that point I had to admit this hatch was a bit of a disaster. Either:
- I wetted the eggs too early, or
- The eggs simply weren’t ready
So I drained the peat, gently dried it, re-bagged it, and put it back into warm storage. I’ll try again in a couple of weeks.
That’s annual killifish for you. Sometimes you get a full hatch. Sometimes you get six.
Final Thoughts on Spectrolebias brousseaui
This is an extremely delicate species. I wouldn’t recommend it for beginners. The fry are among the smallest I’ve ever raised, and they require precise timing, correct micro-food cultures, and constant attention.
But when you get it right?
They’re absolutely worth it.
If you’re going to attempt this species, make sure you:
- Have live micro-food cultures ready before wetting
- Confirm eggs are clearly eyed up
- Keep incubation warm and dark
- Be prepared to re-dry and try again
Breeding annual killifish isn’t always straightforward — but that’s part of what makes it addictive.
