Shift between aquatic and terrestrial stages in newts
Posted: Wed Feb 28, 2018 5:01 pmI have a question regarding the time it takes for the European newt species to shift from terrestrial to aquatic/nuptial stage after hibernation in spring, and from aquatic to terrestrial in late summer. I couldn't find the answer online, so I'm hoping somebody here might have something to say about it.
I read in this book - https://www.amazon.com/Cold-Blood-Adventures-Reptiles-Amphibians/dp/0099581396 how the author when he was a kid in England caught a couple of male Palmate newts and kept them in his home. They were in their aquatic stage (tail fins, filaments and all) and when he woke up one morning and went to see them they have transformed into their terrestrial, dry warty skin stage and had climbed on top of a stone he placed in the jar he kept them in. No tail fin or filament, no webbing on the hind legs, and no breeding colours!
I was rather surprised because I was certain that from the many newts I've seen in spring and late summer, both Lissotriton and Triturus I have observed on many occasions some newts that are in a transitional state between the two stages, i.e. half-way developed crests and webbing on the toes, faded nuptial colours (but still with some traces of them) and so on. I always thought it takes some time (maybe a few days) for them to go from one to the other but the author of this book claims it happened overnight with his Plamates. That to me sounds really quick for such hormonal and morphological changes to happen...but I really don't know. So here's my question - do you think this is possible or usual and if yes, what were this intermediate stages that I have seen?
I read in this book - https://www.amazon.com/Cold-Blood-Adventures-Reptiles-Amphibians/dp/0099581396 how the author when he was a kid in England caught a couple of male Palmate newts and kept them in his home. They were in their aquatic stage (tail fins, filaments and all) and when he woke up one morning and went to see them they have transformed into their terrestrial, dry warty skin stage and had climbed on top of a stone he placed in the jar he kept them in. No tail fin or filament, no webbing on the hind legs, and no breeding colours!
I was rather surprised because I was certain that from the many newts I've seen in spring and late summer, both Lissotriton and Triturus I have observed on many occasions some newts that are in a transitional state between the two stages, i.e. half-way developed crests and webbing on the toes, faded nuptial colours (but still with some traces of them) and so on. I always thought it takes some time (maybe a few days) for them to go from one to the other but the author of this book claims it happened overnight with his Plamates. That to me sounds really quick for such hormonal and morphological changes to happen...but I really don't know. So here's my question - do you think this is possible or usual and if yes, what were this intermediate stages that I have seen?