Overview
- The species, Paracalliactis tsukisome, lives on shells occupied by the hermit crab Oncopagurus monstrosus at depths of roughly 200–500 meters off Mie and Shizuoka, Japan.
- It secretes a hard carcinoecium that expands and reinforces the hermit crab’s shell, effectively enlarging the host’s living space.
- Micro-CT imaging revealed a consistent, one-directional attachment pattern that aligns with both feeding behavior and shell construction.
- Stable isotope analyses indicate the anemone consumes organic particles plus the crab’s feces, pointing to an efficient nutrient-recycling pathway on the deep-sea floor.
- The crab hosts attain larger body size than relatives, supporting mutualism, and the study formally adds a ninth valid species to the genus Paracalliactis in Royal Society Open Science.