Bristlenose catfish help please

[hennipenni]

My two yr old female cat developed a fat belly about a week ago - I thought she may be ready to lay eggs but she hasn't. Today we have noticed that her belly is still big but she now has a "bubble"type sack hanging from her bum. Any thoughts as to what this could be? She's still active and swimming and feeding.

Sounds like eggs to me but she doesn't have anywhere to lay them. Does she have a mate in there?

Yes she has a mate and she has a place to hide (under/inside a huge rock ornament), however I know that our pygmy chain loach likes it in there with the two cats.