Biology
Sexual Dimorphism and Reproductive Strategies in Deep-Sea Anglerfishes
Quick fact
In some deep-sea anglerfish species, males are up to 60 times smaller than females and fuse permanently to her body, sharing her bloodstream for the rest of their lives. This extreme sexual dimorphism is a direct response to the scarcity of mates in the vast, dark ocean.
Why this is interesting
Imagine a male animal so tiny that it becomes a permanent, parasitic appendage on its much larger partner. In the deep sea, this is a survival strategy for anglerfish—how did such an extreme relationship evolve?