- Who
- Professor T W Pietsch, Northern giant seadevil
- Where
- Not Applicable ()
The greatest size difference between a male and female of any animal species is found in the northern giant seadevil or Krøyer's deep-sea anglerfish (Ceratias holboelli). Females, which attain a maximum-known total length of 122 cm (48 in), are 60 times longer and 500,000 times heavier than mature males. Although free-swimming when young, these males effectively become parasites, attaching themselves to the females, feeding off the nutrients in her blood and ultimately being used only to supply sperm for reproduction.
