Sea Monster or Giant Crustacean?

Giant isopods are important scavengers in the deep-sea; they are found from the gloomy zones at a depth of 560 feet to the pitch darkness of the bathypelagic zone at 7,020 feet and beyond, where pressures are high and temperatures are very low -- down to about 39 degrees. They are thought to prefer a muddy or clay substrate and lead solitary lives. (Imgur)

Although generally scavengers, these isopods are mostly carnivorous and feed on dead whales, fish, and squid; they may also be active predators of slow-moving prey such as sea cucumbers, sponges, radiolarians, nematodes, and other zoobenthos, and perhaps even live fish. They are known to attack trawl catches. (Imgur)

A frontal view of Bathynomus giganteus, showing its large, highly reflective compound eyes. (Borgx/Wikipedia)

A tray full of giant isopods and Rochina crabs recovered in a trap from the ocean floor. (NOAA / OER)

The underside of a giant isopod captured in a trap by the National Oceanic and Atmospheric Administration's Ocean Explorer. This specimen is a male. Image courtesy of Gulf of Mexico 2002, (NOAA/OER)

This giant isopod (a crustacean related to shrimps and crabs) represents one of about nine species of large isopods in the genus Bathynomus. They are thought to be abundant in cold, deep waters of the Atlantic and Pacific oceans. Bob Carney of Louisiana State University caught this specimen in one of his deep-water fish traps. (NOAA Vents Program)

a screen shot from a YouTube video showing the giant isopod in its natural environment: the deepest depths of the ocean. (YouTube)

(YouTube)