Hi Everyone,
I have some Xenotoca variata. 4 From Zacapu (2 males and 2 females)and 5 from Jesus maria (2 males and 3 females). I have read and heard that Xenotoca variata are predators on their own fry. I had a female drop some fry a few weeks back and I found a fry that was dead on a plant. The fry had been bitten into. I have both populations separated in their own tanks. In both tanks I have a bunch of plants in the gravel and on top of the water floating for top cover. I was just wondering what I should do to save the fry and keep them away from harm? Should I add more plants? Should I just remove the fry to another tank as soon as I see them? Or should I put the pregnant females in a breeder unit and let them drop in there? Also is there a way to tell if a female is pregnant before the obvious sign of them getting bigger? If so what should I look for? Thank you very much! Take care!
Chris

is there a way to tell if a female is pregnant before the obvious sign of them getting bigger?

Assume that they are pregnant at all times.

Should I add more plants?

The question here isn't the number of plants; it's their density. If the parents can fit in there then they can hunt down their young. You want an area of the tank that is so dense with plants that the parents can't squeeze their bodies in.
You can also submerge a plastic collander upside down to make a fry safe spot.

Should I just remove the fry to another tank as soon as I see them?

You can, but it's time consuming. It's easier on you if you can just leave them in the tank and know they're safe. If you have to go in there and catch every single little tiny baby, not only will you scare all of the fish, but you'll spend a lot of time doing it. It's better to make the main tank safe for fry, in my opinion.

Or should I put the pregnant females in a breeder unit and let them drop in there?

If the breeding unit is too small, the mother can panic and it can kill the fry. I once put a female platy into a breeding trap, it was plastic and clear, one of those, and she was ready to drop that day or the next. Well, she was so stressed out in her breeding trap that she held on to her fry for over a week and when they were born they were all dead.

I went to Home Depot and bought some fiberglass screen, to build myself some larger boxes. We're talking ten inches by ten inches by ten inches. I sewed it together with a needle and thread and dropped some plants in there. The mom delivered just fine, but the babies didn't grow up right. They didn't learn to swim and forage for food, so when I released them into the main tank, they starved to death, using up too much energy to swim and not finding enough food to make up for it.

The best method for raising fry is to make your tank fry friendly. This means removing any predacious fish (gouramis, darters, any species of fish that hunts down fry for fun), adding a lot of dense plants and hiding areas, and regularly feeding crushed flake food. Also, if the parents are fed twice or three times a day, they won't hunt down their young as much because they're fat and content.

Edit: And by dense plants I mean this: http://media.photobu...kiimiru/048.jpg
That setup had 100% survival of fry.

Edited by EricaWieser, 21 December 2010 - 02:59 PM.

Thank you very much! I greatly appreciate it! I keep all of my fish in species only tanks so I don't have any other species in with the variata. That is a great setup! I will for sure buy some more plastic plants with density. For a while I was only feeding my fish once a day but I have started feeding them twice a day. I am going to add more plants to the tank and I think I might try putting pregnant females in a small tank like a 10 gal to drop fry in until I get my numbers up on them. Thanks again!

I was just wondering about this and wanted to know what you guys do with your colonies of Goodeids. Eventually down the road should I get more of the same species that I currently have colonies of from other sources to add new blood to the colony? Or will my colonies be ok and I won't need to add new blood to the colony?

What does everyone else do?

Thank you very much!

I was always hybridizing my livebearers to add beneficial traits. I mixed Xiphophorus alvarezi blood in with my X. hellerii to give them longer swords. And I was always adding new females while keeping only males from my bloodline. That kept them from becoming inbred.

I would not hybridize Goodeids. A lot of them are endangered/threatened/special concern. If you are worried about inbreeding then trade with a fellow breeder for fresh stock.

I would not hybridize Goodeids. A lot of them are endangered/threatened/special concern. If you are worried about inbreeding then trade with a fellow breeder for fresh stock.

Thanks for stating what I thought was the obvious; I stand corrected.

Ick, don't hybridize endangered things of course. But I didn't think Xenotoca variata was endangered?

Also, interesting reading on inbreeding: The Xiphophorus Genetic Stock Center of Texas State University has bred brother-sister lines for over 80 generations: http://www.xiphophor...tockcenter.html
Within the strain, the colony of fish are all basically the same genetically. That's in some ways not good; if a disease can kill one of the fish, it can kill the entire colony. But if you need a reproducible experiment setup with the same lab animal in 1980 and in 2010, then genetic homogeny is a must. That way they have the same fish both times they run the experiment.

And an explanation on my breeding program: I would keep mostly females and then only a few select males who came from my previous generation. That way, I could add new (unrelated) females without risking eliminating my line. I was breeding for certain traits (calico coloration, long sword), so outcrossing to different species and strains was conducive to that phenotypic goal.
I wasn't breeding my fish to preserve or conserve them. I was doing the opposite, purposefully hybridizing them to create a coloration not available in the wild. Hybrid vigor was also one of my goals. It succeeded; the fish are very disease and waste resistant.
But if you're breeding for conservation purposes, then no of course don't hybridize things. It's all about what your goals are.

Edited by EricaWieser, 03 January 2011 - 12:18 AM.

Thank you guys very much! I greatly appreciate it! Don't worry I won't crossbreed. I am 100% against hybridizing. I keep all of my species of fish in species only tanks. I care a lot about fish and feel it is important to keep them how they are and not to play God and see what you can create. To me it doesn't matter if a fish is threatened or not they still need to be kept how they are (pure) and preserved. Xenotoca variata is either relatively secure or vulnerable. I will for sure get more from fellow trusting breeders if I feel like I should get some new blood in my colonies. I have Ameca splendens, Xenotoca variata, and Xenotoca eiseni. My non goodeids are X.montezumae and pure Endler's. Thanks again!

Edited by chrissfishes, 03 January 2011 - 12:17 AM.

Thanks for stating what I thought was the obvious; I stand corrected.

I'm here to serve!

If you continue having low survival problems with fry left in the parent's tank, despite dense plant thickets (Najas guadalupensis = guppy grass is excellent for this), you can move the adults to another tank and leave the fry where they were born. Get a few 3 to 5 gal "critter keeper" tanks and just move the breeders when you see new fry. This works great with Elassoma, Badis, killifishes ...

>> Should I just remove the fry to another tank as soon as I see them?

>> You can, but it's time consuming. It's easier on you if you can just leave them in the tank and know they're safe. If you have to go in there and catch every single little tiny baby, not only will you scare all of the fish, but you'll spend a lot of time doing it. It's better to make the main tank safe for fry, in my opinion.

Thank you very much! I greatly appreciate it! I have decided to put pregnant female X.variata in another tank to drop the fry in. Which I have a tank open for them and I have two pregnant females in there at the moment. Thanks again!