Oh, look: The first embryos from our new and improved fish system!
We only got a handful today, but you can see why. Those are about 3½ hours old, so we collected too late and the little babies’ mommies and daddies had spent the previous few hours assiduously poking around in the marbles sheltering the eggs, and had sucked up their little brothers and sisters in a cannibal feast, as they like to do. We’ll be adjusting our schedules, as developmental biologists often have to do, to do much earlier collections starting tomorrow.
The parents look happy and comfortable, perhaps a little plump after their breakfast of caviar and shrimp, so we expect more tomorrow. Right now we’re raising these little guys at a couple of different temperatures to calibrate our staging adjustments.
Congratulations! Back when I kept koi, I used to fervently wish they’d vacuum up the tasty caviar coating every freaking surface and clouding the water.
How the hell does that sort of cannibalistic behaviour evolve into a species? The only thing I can think of is that it cuts down on over population in cramped environments.
Put the marbles in plastic produce mesh bags. The mesh will allow eggs and milt to fall through while keeping the parents from rooting around in the marbles. Just wash and rinse the bags thoroughly before use.
Hee hee, the middle one looks like a butt.
Why, you’re right, I haven’t been sleeping well lately…
Jacob:
I take it you haven’t done much fishkeeping…
Absolutely none, Caine. And if such behaviour is common, I’m even more confused.
Jacob:
It’s fairly common. Fish breed like crazy. With some types, it’s damn near constant. Plenty of fry survive to grow up and breed like crazy themselves, while also allowing for a tasty food source. Some don’t do that, like varieties of cichlids, which tend to be very good, protective parents. Depends.
“Oh, look: The first embryos from our new and improved fully operational fish system!”
FTFY.
“Hey look, Howard’s being eaten!”
“Is he?”
“Makes you think, doesn’t it?”
Wait…. as a liberal feminist, aren’t you supposed to be aborting those?
I’m so confused.
Only things with souls. Fish don’t have souls. Hope that clears it up!
Ooh, very cool!
I only have experience with platyfish, which don’t eat their young very much at all. Actually I had a batch that did and now I have a batch that don’t. I don’t know why. I guess I should do more research.
Jacob Schmidt: It’s pretty common. It’s possible that a lack of kin recognition is the “default state”, and that the ability to recognize and avoid eating one’s own is a relatively recent and advantageous mutation, with paternal/maternal strategies expanding on that.
It’s also possible that other evolutionary pressures are more effective: If competition for food is high and reproduction is prolific, then the defensive strategies for laying eggs in places that even the parents can’t reach would be a stronger evolutionary pressure. Parents who fail to lay eggs in properly protected areas, or fry which are less cautious are less likely to survive in general.
So, if the egg is going to be eaten by something anyway, it’s better if you just eat it yourself and recover some of the energy?
PZ, have you tried using the grill-bottomed tank-within-a-tank set-up? The inner tank also has a removable divider, letting you choose when to let your fish spawn, so you can hate early mornings as much as I do and still get work done.
The bonus to tank-within-a-tank is that the eggs fall far beyond the reach of the hungry fish.
Yes — we have a bunch of egg collection solutions in the lab right now. Marbles are just fast and easy with the temporary set up we have right now (new fish coming in Thursday morning, then we start breeding and raising embryos to adulthood).
Oooh! What are their names? From left to right I like Fluffy, Steve and Petunia.
Look a bit too small to make a decent omelette.
Let me know when the bait shop is fully stocked.
PZ, please don’t truncate your RSS feeds! You’ve stripped all formatting and images from the feed also, basically defeating the entire purpose of RSS. Not cool!
Not even soles?
Fish don’t have feet. It’s one of their defining characteristics.
OMG, PZ, don’t you know that those embryos are people? PEEEE-PULLLL!
Well, OK, they’re actually fish but let’s face it all embryos look pretty much the same so maybe you should wait until they grow up just to make sure.
There was a sole with a soul once. But that one has died, so the sole sole soul is no longer with us.
Tetrapods, such as humans, evolved from fish. That puts us and a lot of other things that walk the Earth in the fish clade. Assuming I understood what Aron Ra was saying, that is.
I’m a fish, you’re a fish and we have feet with soles; therefore some fish have soles.
I think I’m about to learn something.
PZ can’t abort the embryos, he hasn’t got admitting privileges at the nearest hospital.
Everywhere you go are fishies,
lot’s of folks you know are fishies.
Wouldn’t you like to be a fishy too?
I’m a fishy,
you’re a fishy,
he’s a fishy,
we’re all fishies.
Wouldn’t you like to be a fishy too?
Life begins at consumption.
Clams got legs!
Mmmm. The resident felines will be watching this thread with interest.
Leftwingfox
Yeah, I can see I was making a bad assumption. I’ll be more careful about that stuff from now on.
No worries. I’ve heard a lot of interviews with scientists on Quirks and Quarks who expected X adaptation, found Y instead, then learned something interesting about the species environment as a result of finding out why. :)
If you try to make stem cells from one of those embryos, I’ll tell Rick Perry on you!
For spawning zebrafish in my experience this thing works the best (throw the plastic plant away).
http://www.amazon.com/industrial-scientific/dp/B005V2KZ8O
A container inside a container. The inside one having a false bottom of sorts–really a screen that lets the eggs fall through. And of course you can keep more than one mating pair in the container at a time. So much less work than siphoning between marbles.
They even come with clear plastic dividers so you can isolate the males and females until the lights come on…but it doesn’t appear your setup utilizes light cycling.
Wow, gilly, that is one expensive breeding box. I swear you can get really similar ones for a quarter of the price, or is there something special about that one?
I’m reminded of a disaster using the plastic ones. I had used a plastic floating breeder box to isolate a really nice cherry shrimp with eggs, plus moss. A bunch of snails climbed in overnight and the circulation wasn’t good enough so the water fouled, killing them(and probably attracting even more snails to their dooms), along with the shrimp. :C I had to get another container to catch that water so it didn’t just pour back into the main tank when I took the box out. Sad times. I use the net traps now.
I guess it is expensive but in my mind everything in science is pricey. Also, if setting up a lot of crosses siphoning between marbles can be a huge, tedious task. With these you just pour the eggs into a wire-mesh strainer, rinse, add to blue water in a petri dish and set in the incubator.
I’ve always wanted to try my hand at breeding the various strains of freshwater shrimp. Some of them command ridiculously extravagant prices. Btw., Takashi Amano is a god!