Effects of overtraining on extinction in newts (Cynops pyrrhogaster).

Effects of overtraining on extinction in newts (Cynops pyrrhogaster).

The overtraining extinction effect (OEE), a phenomenon in which extended training facilitates extinction, has been found in mammals and reptiles. However, fish have never shown OEE. No study has yet investigated OEE in newts, a representative amphibian species. We tested whether newts, Cynops pyrrhogaster, show OEE in a straight-array task. All animals received five trials per day and were give...

Effects of overtraining on extinction in newts (

Imorin: a sexual attractiveness pheromone in female red-bellied newts (Cynops pyrrhogaster)

The male red-bellied newt (Cynops pyrrhogaster) approaches the female's cloaca prior to performing any courtship behaviour, as if he is using some released substance to gauge whether she is sexually receptive. Therefore, we investigated whether such a female sexual attractiveness pheromone exists. We found that a tripeptide with amino acid sequence Ala-Glu-Phe is secreted by the ciliary cells i...

A nephroblastoma in a fire-bellied newt, Cynops pyrrhogaster.

Nephroblastomas seem to be very rare in animals with mesonephritic kidneys (fishes and amphibia), although immense numbers of many species are kept as pets and in laboratories. A single case was recorded in the steelhead trout (5). The steelhead trout (Salmo gairdneri, Rich.) is the same species as the rainbow trout, differing only in that it spends part of its life in the sea and returns to fr...

Evidence for true fall-mating in Japanese newt Cynops pyrrhogaster.

The mating season of Japanese newt Cynops pyrrhogaster is generally thought to occur once a year in spring to early summer, during the months of April to June, as in many other Japanese amphibians. However, in fall, from September to October, we often observed breeding colored males demonstrating a mating behavior with females in the field. In this study, in order to identify their true mating ...