Possibly the Last Fry Update

Posted 2009.09.26 22.04 in Aquaria by Stephanie

So my zebrafish fry are about a month old, perhaps even a bit more than that. Their numbers have dwindled to only seven, out of over 3 dozen. Those who remained, however, have been growing. They’ve doubled their size I think, from when I first found them. The longest is about 7mm long. They’re developing tail fins and their wee bodies are developing. When I am able to see them using a loupe I can even see their stripes are coming in.

Zebra FrySo, I figured that I shouldn’t be still keeping them in that inadequately small plastic ‘tank’ any more. Especially considering that ‘tank’ has no filtering and no way to add filtering. I figured, I have a breeder box that hangs inside a larger tank, it has little slits to let water move in and out but keeps the big hungry fishes away. I know when the fry were first born they were small enough to drift in and out with the water which is why I didn’t use it in the first place. But now, they’re much bigger. Well, doubled in size anyways.

Not big enough, it seems.

I put all seven into the breeder box and before I knew it there were only five. Ingenious thing about the design of the breeder box – the slits are angled in such a way that the fry can figure out how to exit but they can’t figure out how to get back in. I spotted one trying to get back in, he was poking at it and swimming into it over and over but couldn’t get through the slots. So I scooped him up and put him back in. Still, it’s fairly easy for them to get out, it seems.

Within an hour, there were only four. Now at last check, there’s just two left in there.

Zebrafish Fry

The ones who’ve moved on out into the big wide open world (well, big wide open tank anyways) are in a dangerous place. There’s four harlequin rasboras and two peppered corydoras, all of whom would love to eat a little wriggly fish fry. I did spot one of the rasboras chasing a fry, and on this one occasion, the fry escaped. But who knows if that will happen next time around.

So, the fry seem bound and determined to strike out on their own and I suppose I have to sit back and let them do their thing. Maybe they’ll all end up being fish-food in the first 24 hours. Maybe one or two will even survive. I suppose it’s just up to luck now.

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