The spotted ratfish is a deep-sea survivor with a venomous spine and rabbit-like face.

Nature · Published 3 October 2026 Swipe more like this →

In short: Separated from sharks nearly 400 million years ago, the spotted ratfish is a strange, iridescent dweller of the Pacific depths. With emerald eyes, a duckbill snout, and a venomous dorsal spine, this cartilaginous fish remains a mysterious, often overlooked inhabitant of the seafloor that occasionally wanders into shallower waters.

The spotted ratfish, Hydrolagus colliei, belongs to the Chimaeridae family, a group that diverged from sharks roughly 400 million years ago. Unlike its shark cousins, the ratfish possesses a fused upper jaw and permanent, mineralized grinding plates instead of replaceable teeth. Its appearance is distinct: a rabbit-like head with large, light-reflecting green eyes, a duckbill snout, and a long, tapering tail that accounts for nearly half of its total length. The skin is smooth, scaleless, and displays an iridescent sheen of brown, gray, gold, and blue, speckled with white spots.

Found primarily in the eastern Pacific from Alaska to Baja California, these fish prefer temperate waters between 45 and 48 degrees Fahrenheit. While they typically reside in deep-water habitats, they are known to migrate to shallower depths in the northern parts of their range. They are slow swimmers that rely on electroreception and smell to hunt benthic prey like crabs, clams, and worms. Despite their slow nature, they are equipped with a venomous spine at the leading edge of their first dorsal fin, a defensive mechanism capable of causing painful wounds to humans and even proving fatal to predators like harbor seals.

Reproduction is oviparous, with females laying leathery, spoon-shaped egg cases on the seafloor every 10 to 14 days during peak spawning seasons in spring and autumn. These eggs can take up to a year to develop, during which time they are often mistaken for inanimate objects. Currently listed as Least Concern by the IUCN, the species is not targeted by commercial fisheries, though it is frequently caught as bycatch. While considered a trash fish today, researchers suggest its status could change if more desirable species become depleted.

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