Today I’m talking about Ophthalmolebias bokermanni — an annual killifish from Brazil with a Latin name that’s not exactly easy to pronounce.
If you’re new to annuals, this is important:
Don’t just tip the eggs into water the day they arrive and expect them to hatch.
This species has an incubation period of 4 to 6 months, and how you store the eggs during that time makes all the difference.
Incubation & Storage
The eggs need to be stored:
- 24–26°C
- In the dark
- In slightly moist peat (not wet, not dry)
Temperature controls development speed.
Cooler storage = longer incubation.
Warmer storage = faster development.
About a week before the four-month mark, you should begin checking the eggs for signs of development — specifically whether they’ve “eyed up” (you can see the eye spots inside the egg).
Use a magnifier — at least 3x or 3.5x — because the eggs of Ophthalmolebias bokermanni are quite small.
Don’t Dig Through the Peat
If you see some eggs have eyed up:
- Wet the entire batch
- Do not try to dig out individual eggs
- Do not sift through counting them
Rummaging through peat exposes eggs to light, temperature shifts, and pH changes — and you’ll damage more than you save.
If you bought 50 eggs, trust that there are roughly 50 eggs in there. Disturbing them to count is asking for trouble.
The Wetting Process
Once you’re confident they’re ready:
- Pour the entire peat batch into a shallow bowl of water.
- Check the bag carefully — sometimes eggs stick to the plastic.
- Let the peat sink naturally.
Now wait.
If they’re ready, hatching usually begins within hours or over the next couple of days.
After three days, remove any hatched fry and:
- Drain the remaining peat
- Gently dry it back to a damp tobacco-like consistency
- Store it again for a couple of weeks
- Re-wet later for a second hatch
The peat must be:
- Not soggy (or it will mould)
- Not bone dry (or the eggs will desiccate)
- Just slightly damp
It’s a balance.
What Happened With My Batch
Three days after wetting, they started hatching.
I bought 50 eggs.
I ended up with 65 fry.
Clearly, the seller had been generous.
They hatched over a three-day period, and I immediately split them into two separate containers. If anything crashes, you’ve got a backup group.
Feeding – This Is Where It Gets Serious
These fry are very, very small.
I initially fed Paramecium and baby brine shrimp — but many of the fry were too small even for Paramecium.
I started losing fry quickly.
Luckily, I keep green water and infusoria cultures running at all times. Once I introduced green water packed with infusoria, survival improved.
Out of the original 65 fry, I’m left with 24 strong, healthy juveniles — 12 in each container.
They’re now big enough to take brine shrimp comfortably.
The Big Lesson
When breeding annual killifish:
Never assume you know what they’ll eat on day one.
Even if books or guides say Paramecium is fine — have everything ready:
- Green water (infusoria-rich)
- Paramecium
- Micro worms
- Baby brine shrimp
Some species need food within hours of hatching or they decline rapidly. Some hatch with yolk reserves. Others don’t.
A delay of even a few hours can cost you half the batch.
Final Thoughts on Ophthalmolebias bokermanni
This species is absolutely manageable — but only if you’re prepared.
Key takeaways:
- Store eggs warm and dark
- Confirm they’ve clearly eyed up before wetting
- Wet the entire batch — never pick through eggs
- Re-dry peat properly for staggered hatches
- Always have multiple live food cultures ready
If you get the feeding right in the first 48 hours, your success rate improves dramatically.
With annual killifish, preparation is everything.
