Deraniyagala's beaked whale is rarely seen alive. Five sightings in the South China Sea from 2019 to 2023 were confirmed as this species, and the paper described differences in markings by age and sex.
The calf or juvenile had distinctive facial coloration and dorsal stripes. Adult males had a dark rostrum.
Five sightings were confirmed during six survey cruises and 120 sea-days from 2019 to 2023. Mean group size was three (n = 5); the observations were in deep, warm water.
An extinction-risk assessment has not been added yet.