Sex and Biology
The megamouth shark is unique among deep-sea sharks in that it feeds on plankton, and is one of the largest deep-sea sharks. This shark gets its name from its large overall size and its very large mouth, which can extend outwards to capture prey. While it lives most of its life at the bottom of the ocean, the megamouth will come to the surface to feed at night, where its prey congregates. Instead of normal teeth, this shark has rows of thin gill-rakers, which it uses to filter food from seawater. Female specimens tend to have fewer teeth than males. These sharks have very small mucus denticles on their tongues. There are two other sharks that feed on plankton, the basking shark and the whale shark, and the megamouth is the slowest of these.
Diet and Predators
The megamouth only eats plankton, mostly krill. The roof of its mouth is made of a reflective substance, which it uses to lure prey towards its huge mouth. It will swim slowly through a huge cloud of krill, ensuring it will get a large mouthful. Due to its slow speed and lack of "teeth," it is vulnerable to large predators like sperm whales and other sharks. Most megamouth sharks are also found with cookiecutter shark bite marks.
Habitat and Location
While there is very little data on the megamouth's habits, one confirmed specimen was observed spending daytime hours at the bottom of the ocean, and coming to the surface to feed at night. It is thought to live primarily in the open ocean.
Very little is known about the mating habits of the megamouth. While the megamouth is thought to be ovoviviparous, a mature pregnant female has not been observed.
Since the megamouth is almost never encountered and has filter-feeding teeth, it poses no threat to humans. Similarly humans likely pose very little threat to them, but there is not enough information on them to definitively confirm that.