Well mate, firstly congrats on your new fry, there is nothing than the feeling that there are animals that give life in your presences, whether the tank is located downstairs, or actually in your bedroom, like myself...
Now as for the drop rate, thi varies with fish to fish, age to age, it varies more than the colours of chickens, so no one can give you an idea of the drop rate, but lets give you a rough idea, the younger newly purchased generally tend to drop 5 to 10 fry at a turn, ome fish will drop fry in intervals, like every hour until they are empty, some will drop once a day, and some will drop all they have... The old fish you are talking between 25 to 30 fry a time...
If your fish gave birth in the main tank, you might find some of the dopy fry wouldhave swam t a early snack time, the smarter ones would dive for cover in small gaps, corners of tanks, of into the lush of artifical or real plants for cover, the only thing you can do is scount the tank for a few hours, if you cant find any sign, go away for a few hours and then come back and do it again...
Another good way of tracking fry in a main tank, is to feed the fish, fry will come slightly out of hiding to uck in SMALL piece's of flack and such and then dart back into hiding, so scount the tank right after you fed the fish... It is amazing where you will find some fry...
Another thing, CHECK YOU FILTER!
Fy sometimes get sucked into the filter and survive in the foam, i found one fry when i was cleaning out my filter, it almost went from the sink when i was cleaning it, when i quickly picked it up gently and ran to put it in a breeding tank, so make sure you check your filter
Another place to check it your gravel, some fry actually dig into the gravel at the side of tanks to protect themselves from bigger fish, depending on the size of your gravel...
These are only a few suggestions on place you could find some more fry, i would suggest you keep looking, because i normally ALWAYS find two fry at least, i have never had just one... 2 or more should be your objective mate... dont give up, fry ar smarter than they look, even smarter than their parents
