We recently acquired five froglets, all are green healthy, and we have been feeding them fruit flies, all seemed to be fine for the first week.

After that, for the past two weeks one of them has been losing weight and turning more and more yellow while the rest remain healthy and green. We understand that the frogs change colours depending on mood or whatever (we have one that changes to dark brown and back to green all the time), but that isn't the case with this guy, as he has been losing weight progressively. We speculated that he may not be getting fed due to the other frogs getting the flies first, but there are plenty remaining. But still to rule out this possibility, we isolated him in his own vivarium, and at the same time, started feeding all of them crickets. All five ate, but since that night, the yellow guy hasn't had any more to eat, there is plenty of lies and crickets in there with him. It is small enough for him to get the food, the temperature is all good, as is his access to water. He just seems to not want food, as a result is skinny and lethargic, which becomes a vicious circle as soon (or maybe already) he doesn't have the strength to catch his food.

Does anyone have any experience of this, we've looked everywhere and can't find much information on frogs turning yellow and skinny, let alone a big lack of info about Trinidadian Monkey Frogs.

We have run out of options, any help would be greatly appreciated.