Top predators strongly influence food webs, often because they reach large body sizes. Amphibians are typically regarded as prey in such systems, but giant salamanders are a rare exception. Because gigantism entails extreme ontogenetic body size variation, it is expected to drive strong trophic niche shifts and reshape interactions within and among species as individuals grow. However, such trophic shifts in giant amphibians a...

Many species of sea cucumbers (Echinodermata, Holothuroidea) perform evisceration, i.e., ejection of internal organs including digestive tracts when responding to environmental stresses. After evisceration, they also show a high regenerative capacity, in which all the eviscerated organs regenerate. Especially in anterior evisceration species, the oral complex structure consisting of multiple organs, including the digestive tra...

Parental care among salamanders is typically provided by females. A rare case of parental care by male salamanders appears to occur in Cryptobranchidae. Yet, paternal behaviors have rarely been reported from natural populations of any Cryptobranchid salamanders, and their adaptive significance is poorly understood. The present study aimed to examine paternal care behaviors in a fully aquatic Japanese giant salamander ( Andrias...