Where does the hatchet fish live?

Hatchet fish, also known as hatchetfishes, are a family of deep-sea fish called Sternoptychidae. They live in tropical and subtropical waters worldwide, typically found in the mesopelagic zone, which is the middle layer of the ocean, between about 200 and 1,000 meters deep.

Here are some key details about their habitat:

* Depth: They prefer depths of 200-1,000 meters, but some species can be found as deep as 3,000 meters.

* Water Temperature: They thrive in cold, dark waters.

* Geographic Distribution: Found in all oceans, but concentrated in tropical and subtropical regions.

* Habitat: They are mostly found in the midwater zone, where sunlight is limited and the pressure is high.

It's important to note that while they are mostly found in the midwater zone, some species can be found in shallower waters at night and return to deeper waters during the day.