Suave

How do i tell the difference between an egg bearing fish and an obese fish? I noticed a few of my female bettas and maybe 2 out of my 11 Zebra Danios, look a little on the plump side... ok maybe not a little.. they look a bit bigger than the others.

Allie

Female betta are always a bit chubby.

Suave

well some of them are a bit bigger than the others. like right behind the head on the bottom.. only on the underside infront of the fins. just a few of my females and maybe 2 zebra danios.

Chief_waterchanger

Female bettas go through fertility cycles where they, usually, go every 3-4 weeks, if conditions are proper and I am remembering correctly, where they become gravid, but if no males are there to go through the breeding "dance" and fertilize the eggs she reabsorbs them.

Danio are egg scatterers, so the females are dropping eggs every few days. The females get the eggs ready and almost immediately begins dropping the eggs as she swims, but if no males are there to fertilize them they just sit and rot or get eatten.

Editted to add:

Danio are similar to guppies in that they are almost always breeding. Everytime you see the male and female danio side by side shimmying they are probably throwing and fertilizing eggs. (People would see a lot more danio fry if they kept them in proper breeding conditions and had a way for the fry to be out of the reach of the adults. )