Gravid fire bellied?

I just got 4 Japanese Fire-bellied newts from a pet shop two days ago. One of the newts is big, but not necessarily in the abdominal area. These are my first newts and the pet store wasn't able to sex them(I tried, but I didn't know how. I had done some research but it didn't help much.) It started to get very rough with the other newts and even violently thrust one around the tank. At first, I thought they were two males competing for a female and I should separate them, but then someone suggested that it was "pregnant". I looked it up, but I still can't tell if it's bloated or gravid. I can't provide a picture, but I can tell that its belly is more of a grayish tint than red, is bigger than all the other newts in the tank, doesn't have any gray highlights on its tail, and was with five newts at the pet store. I separated the newt from all the others, but it's in a smaller tank and with one plant. I'm counting on it being gravid for a school project(they won't be harmed in the process). And by the way, if the female is gravid, will the eggs be developing in the female and is it too stressed to lay the eggs due to small enclosure and new home. }

Hi Kathrine, welcome to the site! without a picture it's hard to answer your questions but i'm guessing your newts are paramesotriton. The best advice i can give you is to go to the section named commen name, family genus and species, go to the paramesotriton section and see if they are like your newts. You should find what you need to know there. Good luck!

Thanx. I don't think it's any of the warty newts bcuz it's skin is smooth and it is larger than them. i was thinking maybe it was a Chinese fire bellied newt bcuz it is so large and it looks a little bit more like the pics. I'm still not sure, though bcuz it isn't yellow on the belly. By the way, it doesn't have long toes, if that helps @ all.

I now kow it is gavid cuz i looked @ the pics of gravid females. still not sure about what kind. it has been like thos since i got it so why won't it lay the eggs? is it bcuz i had it w/three others? as i mentioned, i put it in a different tank, but it's very small. there's 1 plant in there.

Kathrine, it is very important to identify the correct species. Note that Paramesotriton (warty newts) are usually larger than either kind of firebelly. See:
http://www.caudata.org/cc/articles/firebelly.shtml
If its skin is smooth, then it might be a paddletail, which would certainly explain the large size and the aggressive tendencies. See:
http://www.caudata.org/cc/species/Pachytriton/P_labiatus.shtml

I bought a fire belly newt that was much bigger than the others and it turned out to be a female. And she does get fat and lay eggs every year. However, she does have the typical orange belly and she isn't aggressive unless its towards food.

Thanx, Jennifer! They are paddletails. i'm glad you suggested that because i know nothing about paddletails so ill have to look into the species.