Picking eggs

[Back in the fold]

@GaryE Everything you said about male and female ratios I’ve read many times in several different sources and as you also said it seems that guys are looking for that ONE thing to blame for their mismatched sex ratios . I have sort of soft water that I make mixing R/O and tap and I get one third male A. lineatus to two thirds females . That is fine for me and my species maintenance of a common aquarium strain but I was horrified to read about your Aphyosemion escherichi . I hope things change for you and that you get a few males so that they don’t go the way of your striatum and ogoense . That would be heartbreaking given that you collected them personally from a distant land .

 

[GaryE]

It's fun to pick eggs, but sometimes it becomes a bit more though. If I can get to 3 males...

But I'm not sure why I am getting none in such a large brood.

All I can do is pick eggs and hatch them, and hope I get males. I was having this problem as well with ottogartneri, a beauty, and all of a sudden with no changes made, I have a few males now. I got through a generation with dozens of females and only 2 males - now I have 5 males. So if you work at it, there's hope.

There is a theory, advanced by serious researchers, that many Aphyosemion killies have existed in such tiny populations in such tiny habitats, unconnected to any others of their species that they are relatively impervious to inbreeding. They are already inbred and have been for uncountable generations. My zygaima, which are possibly an ancient species that once was widespread but only seem to exist a short spring fed ravine stream only a couple of km long are interesting. You can see how they would adapt to that environment and have trouble with other conditions. The population I started with was collected in 1989. I got them in 1992.
Until 2021, no one had found them again. The easily accessed stretch of river had been modified to make an industrial farm, a habitat they couldn't survive in. In 2021, a group of French aquarists climbed into the ravine uphill from the farm and brought a few out. I got eggs from them, and am delighted to see that to the eye, my 1989/1992 ones are identical to the 2021 collection. I can't see into the genome, but it is a testament to the stability of some of these fish, which in turn is just sort of interesting.

It keeps me amused. You can pick killie eggs, your friends and your nose, but you shouldn't pick your friends' noses. Your friends should send you killie eggs they've picked.

 

[MuddyWaters]

Very interesting . . .

this makes sense, because there's so much about the process that is completely random and just hoping for the best. At least the little fishies get SOMETHING they can do to help increase their odds. Wonder what can be done in the aquarium to better produce the conditions they look for before releasing that hormone. I would imagine it's less of a thought and more of some kind of chemical reaction? Although, the one fish released it when they're washed out to sea- wonder what indicators are used to know that has happened.

 

[Back in the fold]

this makes sense, because there's so much about the process that is completely random and just hoping for the best. At least the little fishies get SOMETHING they can do to help increase their odds. Wonder what can be done in the aquarium to better produce the conditions they look for before releasing that hormone. I would imagine it's less of a thought and more of some kind of chemical reaction? Although, the one fish released it when they're washed out to sea- wonder what indicators are used to know that has happened.

Who would have ever thunk there could be this much science to a little glass box full of water and fish . The mind boggles . But seriously , this hobby has a lot to keep a guy interested and it’s fun to be doing something that takes some thought .

 

[GaryE]

A great thing about egg picking is you learn when you've gone wrong quickly. Feeding the wrong foods? No eggs. With the killies I have, only bug based flake (they don't like pellets unless I grind them up) produce eggs. But I get at best half the eggs I would with unprocessed foods. I can look at what I feed and see what they give.

The literature says Daphnia are great, and they are good. But for egg production, they are only so so. Freshly hatched artemia, bloodworms, white and grindal worms and especially mosquito larvae are better, by far. Many much hyped flake and pellet diets won't give a single egg.

When I had moderately hard water, at 140ppm, I got at best 2 eggs a day. When I moved to 80ppm, suddenly 5 was the new normal. That told me something. At 50ppm, after 20 years of never getting more than 5 eggs a day, I had days with 18 eggs in the mop.

Some eggs seem to have active chemical defenses against snails. I wonder if any of them can repel or be chemically invisible to other predators, like fish?

With the sheer number of killifish species, everything you say about them can be contradicted by nature. There are killies that need hard water, and others that can't live in it. Foods work differently for different species. Some species have digestive enzymes that only work efficiently in a 2 or 3 degree range, if not at an exact temperature. Others can handle anything. Some die if you cough in the next room, but 5 km from here, some Fundulus are living in a stream running though an old, active oil refinery, adapted to levels of pollution that astonish researchers.

Plus, if temperatures are between 15c and 24c, Aphyosemion eggs travel well in the mail. They really are amazing creatures, these eggs. I like them more when they become fish, but they are a good start.

 

[Back in the fold]

A great thing about egg picking is you learn when you've gone wrong quickly. Feeding the wrong foods? No eggs. With the killies I have, only bug based flake (they don't like pellets unless I grind them up) produce eggs. But I get at best half the eggs I would with unprocessed foods. I can look at what I feed and see what they give.

The literature says Daphnia are great, and they are good. But for egg production, they are only so so. Freshly hatched artemia, bloodworms, white and grindal worms and especially mosquito larvae are better, by far. Many much hyped flake and pellet diets won't give a single egg.

When I had moderately hard water, at 140ppm, I got at best 2 eggs a day. When I moved to 80ppm, suddenly 5 was the new normal. That told me something. At 50ppm, after 20 years of never getting more than 5 eggs a day, I had days with 18 eggs in the mop.

Some eggs seem to have active chemical defenses against snails. I wonder if any of them can repel or be chemically invisible to other predators, like fish?

With the sheer number of killifish species, everything you say about them can be contradicted by nature. There are killies that need hard water, and others that can't live in it. Foods work differently for different species. Some species have digestive enzymes that only work efficiently in a 2 or 3 degree range, if not at an exact temperature. Others can handle anything. Some die if you cough in the next room, but 5 km from here, some Fundulus are living in a stream running though an old, active oil refinery, adapted to levels of pollution that astonish researchers.

Plus, if temperatures are between 15c and 24c, Aphyosemion eggs travel well in the mail. They really are amazing creatures, these eggs. I like them more when they become fish, but they are a good start.

Holy Killifish Batman ! That’s an awful lot of information in one post and all of it very useful . Thank you for taking the time to write all that out . I’m definitely bookmarking this for future reference .