Fire Belly Toad
Hello. I have a terrarium. I believe it is 40g long. It is separated into about 40% land 60% water with a lot of plants in both. I've had 2 fire bellies in it since the summer began, so maybe 4 months, and one just suddenly died. The water area has a waterfall filter and an UGF. The land area is planted with soil and a few ferns and some other plants. Nothing exotic. They seemed fine, except when I first got them they were very skinny, and were terrified of me or any movement in the room for at least a month. They would submerge or hide, one got over it, but the one that died never did. It would always hide when I fed them, while the other toad eventually figured out what the deal was.
A few days ago, I noticed that the skittish toad was not a bright green like it had been, and like the other toad. It had turned very dark, but it's underbelly seemed okay, so I assumed it was just blending in better or something. Today, I found it dead, floating in the water. I think it may have died from not eating because it looked very skinny, but I can't understand why, the other toad is bordering on fat, and I have never seen them fighting or anything to suggest the other toad was stopping him. And there are always plenty of crickets. I can't really understand.
I did a water change, just in case. The betta that lives in the water seems to be very healthy as well, so I don't think that was the problem. Is there anything specific I should look into/ do to make sure the other toad is okay?