There are over 400 known snailfish species, ranging from shallow waters to the hadal zone.
These squishy, scaleless little fish are the apex predators of the trenches!
An unknown snailfish species holds the deepest fish record at over 8300 meters.
Hadal species have developed jelly-like bones and an unfused skull to survive immense water pressure.
Most snailfish have a specially adapted suction cup disc on the underside of their heads, formed from modified pelvic fins. This allows them to attach to the bottom of their environment.
Water puppy!
meet the family
these are some of my favorite deep sea snailfish species, including several undescribed specimens!
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The 'Tianya' lander
Many different tools have been used to study the trenches since the first sampling expeditions in the 1950's. Most recent snailfish studies have been done using deep-sea landers, sturdy frames equipped with cameras and other equipment that can be dropped to the seafloor and recovered later.
AMPHIPODS
are among the most common invertebrates in the hadal zone. They are also the primary food source for hadal snailfish!
Much like the fish, these little crustaceans have undergone special adaptations to thrive in the extreme deep. They are opportunistic scavengers that can withstand long periods of starvation between meals.
Amphipods are found throughout hadal snailfish habitats, and even beyond into waters too deep for any fish! There are over 9,000 species of aphipods described so far, found in a wide range of habitats including oceans, rivers, lakes, beaches, and even in moist areas of land.
Hadal amphipods are up to 20 times larger than those found anywhere else in the world! This phenomenon, known as abyssal gigantism, is common across many types of animals in the deep sea.
the hadal zone
Named after Hades, the ancient Greek underworld, the hadal zone is the deepest part of the ocean. At nearly 11,000 meters, the deepest parts of the hadal zone are almost twice as far from the ocean surface as the average sea floor. This means the hadal zone has as much depth variation as every other ocean zone combined.
There are 47 separate hadal habitats in the world. 27 of them are trenches, which are created by tectonic subduction: when one tectonic plate slides underneath another as they come togther. The other 13 are abyssal basins, troughs unrelated to tectonic plates.
Most trenches are found in the western Pacific on the Ring of Fire. This belt of tectonic plate boundaries is best known for its volcanoes and earthquakes, but the activity in this region has also created some of the most extreme and unique ocean habitats on Earth.
Although these hadal environments have a lot in common, they're separated from one another by large stretches of comparatively high-elevation seafloor. This elevation difference would be challenging to survive for any species accustomed to much higher water pressure and a total lack of large predators. Despite this, we've found unique, highly-specialized snailfish species in ocean trenches around the world!
