Rattail fish are deep-sea dwellers, and their diet reflects this environment. They are carnivores and primarily feed on:
* Smaller fish: Lanternfish, bristlemouths, and other rattail species.
* Crustaceans: Shrimp, krill, and other small crustaceans.
* Squid: Observed in their diet, though perhaps less frequently.
Their diet is opportunistic, meaning they eat whatever prey is available in their deep-sea habitat. Their long, slender bodies and strong jaws are well-suited for catching and consuming these prey items.