Survival Of The Fittest

[DHJac]

I'm about 4 weeks in to a new 110g tank that will be brackish but I started off with a couple of mollies to cycle it.  I was out of town for a couple of days about a week into it and when I came back, one of the mollies had given birth and there were a bunch of fry swimming around the tank.  I wasn't really expecting this since the tank was still cycling so I was caught without a breeding net.  It was a day or two before I could pick one up and by then a lot of the fry were gone.  
 
I was able to get 3 of them in the breeders box where I began feeding them with Hikari First Bites multiple times a day expecting to see them start to plump up and get a little bigger.  After a couple of days, I noticed another little guy hanging around the bottom of the tank and in the plants but I couldn't get to him so I just left in the main tank.  He seemed to be feeding on the algae he could find in the tank and looked pretty happy so I decided to just keep an eye on him and see how much he was growing compared to the guys getting the good stuff in the breeders net.  HOLY COW did he grow!!!
 
I just released the other 3 into the main tank today and got my first look at them side by side and he is easily twice their size…take a look.
 

 
There is not much competition in this tank with just the two other adult mollies so they all seem to be getting along but it is making me second guess the nutritional value of the First Bites.  Anyone else every seen such large variances in fry this early on?  They are almost 3 weeks now.  
 
Here's a shot of the tank too.  Lots of room for everyone.
 

 
 

 

[BerryAttack]

wow that's amazing, when looking at the nutrition value compare to what you are feeding the adults to what you gave the fry, it could be that the fry in the main tank was eating the left over of what the parents didn't eat. just a guess.

 

[joe17]

I don't know anything about fry (newbie here) lol but I just love your tank! Sure going to.look great when it's complete!

 

[DHJac]

Thanks.  The plan is to add 3 scats, 4-5 monos and a couple of wild sailfin mollies along with something to hang out on the bottom of the tank, maybe a couple of Columbian sharks.  I was talking to the fish mgr at my LFS today and he said they have a guy who can supply wild mollies from Mexico.  I love watching the big sailfins cruising across the tank with their sails at full mast.  Beautiful fish. 

 

[fluttermoth]

It's almost certainly nothing to do with the feeding, but all down to water volume.
 
A lot of fish produce hormones, and other substances, that stop them growing once they reach a certain concentration; in a larger volume of water, that will happen much more slowly.
 
Basically, they've been slightly stunted.

 

[Paradise3]

How big is the tank? All of those fish get quite big...

 

[DHJac]

It's 110g (48"x18x30).  I may try to do a mixed school of scats and monos and just do 3 of each if they are happy.   

 

[Paradise3]

It's 110g (48"x18x30).  I may try to do a mixed school of scats and monos and just do 3 of each if they are happy.   

 
Ah OK Just paranoid is all lol.

 

[tmoney7]

yea when ever i had mollies that had fry i would have a sponge filter and plenty of java moss and plants and just let the fittest survive, i believe in Darwinism.