I thought that I should post this here even though they are Mexican. After all Chris saw fit to include them in the checklist that he put together. First up, I aquired a group of 11 Xiphophorus couchianus, the Monterrey Platy, this past spring at my local fish club, the Aquarium Club of Lancaster County. I noticed several weeks ago that the females were really getting fat. The first fry dropped about a month ago. I saw it one evening, but then couldn't find it for about three days. I was excited but also apprehensive. I thought maybe I was mistaken because the fry are so small. Jump ahead to now and I have no idea how many are in there, but it's a bunch. They are different sizes, so I think that they drop over a period of time like Heterandria formosa.

Also this spring, I got a pair of Xenatoca eiseni and they have been growing out nicely, the female getting fat. Well, tonight I went down to the fish room and she dropped about 15 fry. I was just reading an earlier post about a different Xenatoca species and their aggressiveness, so I may have to move the parents in the morning.

Both of these species are endangered, I registered them in the C.A.R.E.S. program, and I am very excited. I just thought that I would share this with the forum. Oh yeah, I guess I should register them in our B.A.P. Do we still do this?

Harry Knaub

Very cool! I think they are extinct in the wild, from a spring system that dried- I think from overdepletion of the aquifer. Monterrey is a pretty crazy city, lots of people and sprawl, some very nice mountains. I was dying to visit some of the waters around there when I visited, but I didn't get the chance. Flying over there seemed to be some riparian in the area.

Both of these species are endangered, I registered them in the C.A.R.E.S. program, and I am very excited. I just thought that I would share this with the forum. Oh yeah, I guess I should register them in our B.A.P. Do we still do this?

I tried to resurrect it a couple of years ago but to no avail. We do have the section on the forum, but no updates in quite awhile.

Are these Platies here legally? Being Mexican, I mean....

Very cool! I think they are extinct in the wild, from a spring system that dried- I think from overdepletion of the aquifer. Monterrey is a pretty crazy city, lots of people and sprawl, some very nice mountains. I was dying to visit some of the waters around there when I visited, but I didn't get the chance. Flying over there seemed to be some riparian in the area.

My understanding is that the X couchianus is extinct in the wild. I've seen it referred to as an ark species.

Harry Knaub

Are these Platies here legally? Being Mexican, I mean....

As far as I know, they are. I've read various art....I'm sorry. I'm just slow sometimes. My guess is they probably snuck over at El Paso. Don't tell Gov. Perry, though.

Harry

What sort of plants and cover do you have in the breeding tank? Do you have a picture of the tank?

When I was running a breeding tank for Xiphophorus hellerii, my technique was to severely overplant the tank and then to leave the parents in with the fry. When I say overplant, I mean something along the lines of this: http://img.photobuck...14th2009006.jpg
The fry would all survive. The more plants you have, the more chance they have.

Tanks with 100% fry survival:
youtube.com/watch?v=8zmjBRd7Qkg
youtube.com/watch?v=irH8o-tZME0&feature=related
http://img.photobuck...1075_16-1-1.jpg

Also, it's very important to remove species of fish that enjoy hunting down and eating fry. Gouramis, darters, other fry eating fish species. It's like the highlight of their life is squeezing themselves into the tiniest spaces possible to hunt down and kill your baby fish. It doesn't matter how overplanted your tank is; if you have that kind of fish, they don't stand a chance. The Xiphophorus parents generally aren't very murderous, it's the fish that in the wild are primarily egg and fry eaters that you have to watch out for.

Edit:
Oh, and just because the fry are different sizes does not necessarily mean that the mother birthed them at different times. Fry can grow at drastically different speeds, which in some species results in cannibalism among the fry as larger fry eat smaller ones. This is magnified in situations with limited food. By feeding the tank twice, one and then again five minutes later, you can feed the weaker fish who were driven away from the food by their larger siblings.

Edited by EricaWieser, 09 July 2011 - 04:19 PM.

[quote name='EricaWieser' timestamp='1310245752' post='90345']
What sort of plants and cover do you have in the breeding tank? Do you have a picture of the tank?

The X couchianus tank is heavily planted with Hornwort, covering must of the surface. I had pulled a breeding report off of the 'net and followed their suggestions, including a piece of mopani wood and sand as a major part of the substrate. Interestingly, when I went to change the water about three weeks ago, noticed that fry also hid in the dead Hornwort leaves on the bottom of the tank. So, for the time being at least, I have stopped vacuuming the bottom of the tank.

Sadly, I'm not currently set up to download photos. I don't even have a digital camera of my own. Maybe once my tanks are set-up in South Carolina later this year, I can concentrate on improving my digital skills.

Also, they are the only species in that tank

The size difference amounts to 1/2 inch of a couple weeks and 3/16 inch that are just tiny. Interestingly, the Xenotoca eiseni are at least a 1/2 inch at birth.

Harry Knaub

Interestingly, the Xenotoca eiseni are at least a 1/2 inch at birth.

Whaaaat? Are you sure you're seeing them right after birth? I really wish you had a camera.

Also, if you're not vacuuming the bottom of the tank you might want to buy a nitrate test kit. Hornwort is notorious for stopping growing if it exhausts certain nutrients in the water column, so your nitrate can get really high really fast with the combination of rotting plant matter and no water changes. Don't let nitrates get above 30 ppm.

My 10 gallon guppy tank is set up exactly that way right now, though, and it's working out great. Here's a picture of it taken today: http://gallery.nanfa...er/002.JPG.html You might not be able to tell from the picture, but there are dozens and dozens of fry and juveniles.
Here's the same tank about a month ago, when I accidentally trimmed the Ceratophyllum demersum too much and I was afraid the fry would get eaten: http://gallery.nanfa...er/048.JPG.html
So you can see that it's okay to stuff the tank totally full of hornwort, as long as you keep an eye on it and it doesn't suddenly stop growing because of nutrient deficiency. I've got a kitty litter substrate in there instead of bare glass to provide some minerals. Sand is only silicon dioxide, and does not contain any nutrients that the hornwort can use to grow.

Edited by EricaWieser, 09 July 2011 - 05:11 PM.

Whaaaat? Are you sure you're seeing them right after birth? I really wish you had a camera.

Also, if you're not vacuuming the bottom of the tank you might want to buy a nitrate test kit. Hornwort is notorious for stopping growing if it exhausts certain nutrients in the water column, so your nitrate can get really high really fast with the combination of rotting plant matter and no water changes. Don't let nitrates get above 30 ppm.

My 10 gallon guppy tank is set up exactly that way right now, though, and it's working out great. Here's a picture of it taken today: http://gallery.nanfa...er/002.JPG.html You might not be able to tell from the picture, but there are dozens and dozens of fry and juveniles.
Here's the same tank about a month ago, when I accidentally trimmed the Ceratophyllum demersum too much and I was afraid the fry would get eaten: http://gallery.nanfa...er/048.JPG.html
So you can see that it's okay to stuff the tank totally full of hornwort, as long as you keep an eye on it and it doesn't suddenly stop growing because of nutrient deficiency. I've got a kitty litter substrate in there instead of bare glass to provide some minerals. Sand is only silicon dioxide, and does not contain any nutrients that the hornwort can use to grow.

The tank with the eiseni is not that heavily planted and the only occupants were the pair of adults and the female was fat at 7 PM, 10 PM and the fry were all over the place. Maybe they were just really good at hiding, I don't know. Also, I had only been back in PA for 24 hrs, so I could have missed something.

And Yeah, I do need to work on the camera thing.

Referring to the X couchianus tank, I am doing 50% water changes. I just don't vacuum the substrate.

Actually, this tank looks a lot like your photo.

Harry Knaub

It doesn't sound weird at all that a Goodeid would have huge offspring at birth. That's pretty much their thing.

Also this spring, I got a pair of Xenatoca eiseni and they have been growing out nicely, the female getting fat. Well, tonight I went down to the fish room and she dropped about 15 fry. I was just reading an earlier post about a different Xenatoca species and their aggressiveness, so I may have to move the parents in the morning.

Goodeids usually have big fry but lower numbers. A full grown female for some species can have up to 30 fry. However, there have been reports of up to 54 fry from one species. Which is a bunch of fry for how big they are. A young female usually has around 5 - 10 and gradually grows bigger numbers as they get older. The post you were referring to was probably mine. I have a thread on here about Xenotoca variata. I have two populations "Jesus maria" and "Zacapu". I also have Xenotoca eiseni along with a few other species of Goodeids. I have found that you can keep the fry with the adults in the same tank with these two species and the other species I have as long as you heavily plant the tank and have a lot of floating plants at the top. Goodeid fry like to stay at top until they are big enough to take an adventure around the tank. I have had no problems with adults eating or bothering the fry with either of my species. My X.variata are very productive and my favorite goodeid specie!

I have found that you can keep the fry with the adults in the same tank with these two species and the other species I have as long as you heavily plant the tank and have a lot of floating plants at the top. Goodeid fry like to stay at top until they are big enough to take an adventure around the tank. I have had no problems with adults eating or bothering the fry with either of my species. My X.variata are very productive and my favorite goodeid specie!

Yeah, so far the fry are doing just fine with the parents.

Harry Knaub