Is my fish pregnant or just fat? what kind of fish even is he?

Hi this is my first thread so forgive me if I'm not doing it correctly but I'm new to having fish and my boyfriend and I got a fish tank a month ago and currently we have 8 fish.

The rest of our fish we know what type of fish they are except this particular one we received as a starting gift from a friend. When we first got the fish he/she was quite thin but had a firm round belly it's almost a month now and he/she is huge! We are not sure if it is pregnant or just fat and not sure what fish he/she is or if it's a he or a she! Please help..

Zebra Danio,Looks like a Tumour/Cyst?
Or even Dropsy

jonny-5 said:

Zebra Danio,Looks like a Tumour/Cyst?
Or even Dropsy

Click to expand...

I think it's dropsy because she has red skin lesions and he has pale stringy poop What can I do for her?