Fry to adult survival percentages

[fish_4_all]

My C. trilineatus lay eggs every other day now with no end in site. I just hate leaving the eggs in the main tank for them to eat but I don't have room to raise 1000's of fry.

I also have one die here and one die there which is heart breaking because I took the time to seperate the eggs and hatch them and try to raise them. I know it is natural to lose weak ones and to have some die but I have a question that might help others who want to breed fish get a better idea of how many to babies they need to have them survivie to adult.

If you raise egg layers, what percentage of the eggs do you think survive to adulthood? Live bearers jump in here too because there are just as many of you.

This will give people a better idea of how many tanks they need to meet the goals they are trying accomplish with breeding their precious fish.

[BillD]

Tough question. It depends on a lot of factors. With most fish, if you provide good food and very clean water, most should survive to adult hood. There are different ways to accomplish this. Huge tanks help but are problematic, due to the expense. If you use smaller tanks, with high stocking rates, you have to change a lot of water. This works well as long as you stick with the water changes, but there is little margin for error. On top of all that some species are just hardier than others. I know from experience with angels, that if the fry are strong when they first hatch, and you keep the conditions very good, you will lose very few, perhaps a couple of dozen out of 300. Again this will vary with the type of angel. Silvers and golds are much hardier than double blacks. So, after all that, it seems the only answer is, it depends. It is a topic worthy of discussion.

[Heiko]

very worthy, im no expert but id love to hear what people have got to say.

I know ill be listening in

[BrianNY]

This is an excellent topic. There is no real answer. It's partly philosophical and hugely based on genetics. My gut reaction is to say that there is mortality built into every brood. With so many offspring, so many are engineered never to see adulthood.

Genetics is such that recessive traits are weeded out in nature. Many of the recessive traits are what are needed to develop alot of the strains that we find appealing. Which is why double black angels have a high mortality rate in juveniles. I might say the same for many of the albino species which have become so popular. In nature they hardly stand a chance.

[BillD]

Some good points Brian. Genetics definitely plays a large part in survival, as is clearly demonstrated by selective line breeding. It generally results in lower survival, as you mentioned. I think that guppies are another good example of fish, that in their most decorative forms are no where near as hardy as the wild type, which has been largely relegated to feeder status. As aquarists we make up for these short comings by providing superior care to ensure a larger survival rate. In the case of black or albino angels, we would take extra measures to ensure pristine water conditions and top quality food to skew the results in our favour. The long term consequences may in fact be detrimental to the species, so out crosses with wild stock needs to be done to improve vigor. It is interesting to me that wild caught specimens have become highly desireable, even if they are less attractive and colourful than some of the tank bred sports. I guess the initial question was directed towards providing suggestions to improving survival rate, in which case, [acronym:57f399ff93="In My Experience"]IME[/acronym:57f399ff93], clean water is without a doubt the single most important factor. That means changing as much as necessary as often as necessary. Therein lies the problem, as each situation is different. Personally, I favour large water changes all the time(min 50%), as often as daily in the case of fry grow out. food for thought.

[kyektulu]

I would estimate 20-30% survival rate of fry.

[BillD]

Perhaps we need to differentiate between survival to adult hood ,and survival to juvenile, since one will not likely grow out all the fry from a spawn to adulthood, but rather to a sellable size. For the latter, I would say you should expect somewhere in the 90% range, as a minimum. If the number is lower than this, methodology needs to be looked at. This of course is a generalization, and some species as mentioned above will never reach that high number. For most species, under ideal conditions, that number is realistic.

[DeFeKt]

aberdeen west australia?
lol I think i've asked that before?

sign up to the forums in my sig and ask there
PCS or people from chuckies forums will soon tell you

pm me if you need to know who to ask :P

Matt.

[Tolak]

With angels I get at least 90% survival rate. If I get less than this something went wrong, and needs to be looked into.

[Scooterbug]

Well, in my case, I have yet to lose any mollies that I have. About 6 weeks ago, our dalmation molly gave birth to approx 30 fry. Have yet to have a single death. The other day, she gave birth again. So I now got about another approx 40 new fry. I have moved some of the older ones to other tanks (10 to the 55 gallon, 6 to the 20 gallon).

I do about a 30% water change every 3 - 4 days. Mostly due to excess food in the gravel. I have to keep the food particles small, so some of it goes uneaten. They are also kept in a 10 gallon tank, so that factored into the decision to change water so frequently. They also love Brine shrimp pellets. They can devour 4-5 of them within a matter of minutes.

On a side note, they are wonderful to watch during feeding time. As soon as I walk into the room, they are all sitting in the corner, waiting for the food. As soon as it hit the surface, they all dart up to eat. Quite a site.

Steve