Grenadier Grenadiers or rattails are generally large, brown to black gadiform marine fish of the subfamily Macrourinae, the largest subfamily of the family Macrouridae. Found at great depths from the Arctic to the Antarctic, members of this subfamily are amongst the most abundant deep-sea fish.
Grenadiers have a worldwide distribution, being found in all oceans from the shallower to the deepest depths. They first appeared during the Cretaceous period and still have living representatives today. As deep-sea fish, they are seldom seen by humans as they live below 200 meters (660 ft), their known habitat. Grenadier ranges in size from 12 to 48 inches (30 to 122 cm). They are usually found in deep water, although they have been caught at the surface by fishing boats.
Grenadiers are thought to feed on crustaceans and small fish. They tend to live alone or in pairs. They make sounds like other rattails which can be heard up to 2 miles (3.2 km) away.
The word "grenadier" is derived from the French for "grenade", which itself derives from this fish's name. This moniker was given to them due to their resemblance to the shape of a pomegranate, rather than for its ingredients or odor.
They have enormous eyes and a wide mouth equipped with many small teeth. Some species also have bioluminescent organs located under their eyes. These photophores can create a sparkling glow that may startle predators, like other bioluminescent organisms.
Grenadiers are difficult to study due to their depth range and relative inaccessibility, so scientific research has been limited. However, a female grenadier was caught by the Melville during a trawl at a depth of 1150 meters (3,770 ft), making it one of the deepest known fish.
Grenadiers prey on other fish, crustaceans, and cephalopods found in their deep-sea habitat. They are thought to be an important link between planktonic organisms and demersal predators due to their position in the food chain. They have been observed feeding near deepwater coral reefs, but their feeding behavior is normally a mystery due to the depth at which they live.
Grenadiers are of some commercial interest, and also display a diverse array of bioluminescent patterns on their heads, possibly used for communication. Due to this diversity in appearance and behavior, grenadiers have caught the attention of many people.