Antipredator behavior of newts (Cynops pyrrhogaster) against snakes.

Newts and salamanders show remarkable diversity in antipredator behavior, developed to enhance their chemical defenses and/or aposematism. The present study reports on the antipredator behavior of newts (Cynops pyrrhogaster) in response to snakes. Newts displayed a significant amount of tail-wagging and tail-undulation in response to a contact stimulus from the snake's tongue, which is a snake-specific predator stimulus, as compared to a control stimulus (behavioral scores: tongue, 1.

Genome editing reveals fitness effects of a gene for sexual dichromatism in Sulawesian fishes.

Sexual selection drives rapid phenotypic diversification of mating traits. However, we know little about the causative genes underlying divergence in sexually selected traits. Here, we investigate the genetic basis of male mating trait diversification in the medaka fishes (genus Oryzias) from Sulawesi, Indonesia.

Convergent evolution of body color between sympatric freshwater fishes via different visual sensory evolution.

Although there are many examples of color evolution potentially driven by sensory drive, only few studies have examined whether distinct species inhabiting the same environments evolve similar body colors via shared sensory mechanisms. In this study, we tested whether two sympatric freshwater fish taxa, halfbeaks of the genus and ricefishes of the genus in Sulawesi Island, converge in both body color and visual sensitivity. After reconstructing the phylogeny separately for and using transcriptome-wide sequences, we demonstrated positive correlations of body redness between these two taxa across environments, even after phylogenetic corrections, which support convergent evolution.

Behavioral responses to changes in group size and composition: a case study on grooming behavior of female Japanese macaques (Macaca fuscata yakui).

Primates flexibly change their grooming behavior depending on group size and composition to maintain social relationships among group members. However, how drastic social changes influence their grooming behavior remains unclear. We observed the grooming behavior of adult female Japanese macaques in two groups temporarily formed as one-female groups from multi-female groups and compared their behaviors between the multi-female and one-female periods.

Phylogenomics reveals habitat-associated body shape divergence in Oryzias woworae species group (Teleostei: Adrianichthyidae).

The Oryzias woworae species group, composed of O. asinua, O. wolasi, and O.

The function of body coloration of the hai coral snake .

Background: Prey animals often protect themselves from visual hunting predators via their body coloration, which encompasses various visual effects. When a prey animal displays a certain color pattern on its body surface, its protective function and effect are largely dependent on how a predator would encounter and perceive the prey animal.Asian coral snakes of the genus ,which are venomous, display black bands and stripes on their orange body coloration.

Sleep duration is affected by social relationships among sleeping partners in wild Japanese macaques.

Co-sleeping behaviour, such as sharing a sleeping site or bed, should play an important role in determining sleep structure in mammals by mitigating predation pressure and harsh abiotic conditions during sleep. Although environmental factors surrounding sleeping sites have been studied, there is very little information on the effects of the social environment within the site on sleep in animals other than humans. Here, we quantified the duration of nighttime sleep of wild primates during behavioural observations.

Spatial and temporal instability of local biotic community mediate a form of aposematic defense in newts, consisting of carotenoid-based coloration and tetrodotoxin.

Most animals advertise their unprofitability to potential predators via conspicuous signals. Whether the strength of this aposematic signal indicates the quality and quantity of chemical defenses in animals is controversial. Here, we investigated the relationship between the conspicuousness of an aposematic signal and toxicity, which likely depends, at least in part, on dietary sources, in the newt Cynops pyrrhogaster.

Temperature-dependent aposematic behavior in the newt Cynops pyrrhogaster.

Aposematic animals advertise their unprofitability to potential predators via morphological and behavioral signals. Strong signals are detectable and memorable for the predators, and such signals would therefore be expected to be most effective. However, many apparently well-defended animals do not have very conspicuous signals.

Coprophagy-related interspecific nocturnal interactions between Japanese macaques (Macaca fuscata yakui) and sika deer (Cervus nippon yakushimae).

The influence of sympatric large animals on the sleeping behavior of primates in the wild is still largely unknown. In this study, we observed behaviors of wild Japanese macaques (Macaca fuscata yakui) at their sleeping sites, using a highly sensitive video camera. We found evidence of nocturnal interspecific interactions, such as agonistic interactions, between Japanese macaques and sika deer (Cervus nippon yakushimae).

Food habit of the juvenile of the Japanese newt Cynops pyrrhogaster.

The previous study showed that the red coloration of the ventral skin of the Japanese newt Cynops pyrrhogaster was associated with the number of carotenoid vesicles and the content of carotenoid in the pigment cell of the skin. To elucidate the mechanism for the red coloration of the skin of the newt, we studied the food habit of the juvenile from the Japanese newt Cynops pyrrhogaster. Sixty-two juveniles were collected in Fukue Island in Nagasaki Prefecture from November 2000 to May 2002 and divided into 2 groups according to the snout-vent length (SVL).