By Melissa Kim
Geographic Range
The Megamouth Shark was recently discovered in deep water off of the Hawaiian Islands and near the shores of California, Japan and Western Australia.
Biogeographic Regions:
pacific ocean
(native
).
Habitat
The megamouth lives in the deep scattering layer of the ocean. It seems to enjoy warmer climates, though it has been discovered in temperate waters.
Physical Description
(1650 lbs)
The megamouth Shark is five meters long and weighs approximately 750 kilograms. Its body is cylindrical and flabby, its eyes small, and it swims in stiff, slow movements.
Some key physical features:
bilateral symmetry
.
Reproduction
The megamouth reproduces sexually through internal fertilization. There are separate sexes, and the offspring are miniature versions of the adult at birth.
Behavior
This shark behaves similarly to the fish of the deep scattering layer. It migrates vertically during a twenty-four hour cycle, swimming at depths of 200 meters below the surface by day, and ascending to 10-15 meters below the surface by night. It flees from minute disturbances into deep depths, which may explain why this species remained undiscovered for so long.
Key behaviors:
natatorial
; motile
.
Food Habits
The Megamouth is a filter feeder. It uses its enormous mouth to draw in water and filter out small planktonic animals such as crustaceans and shrimp.
Economic Importance for Humans: Negative
No negative economic effects by the megamouth shark have been reported.
Economic Importance for Humans: Positive
Little is known about the economic importance of the megamouth shark, though sharks in general have proven to be an essential element in the aquatic ecosystem. In areas where sharks were killed because of the belief that they threatened fisheries by preying on certain fish, a significant disruption of the ecosystem (such as overpopulation of small fish and planktonic animals) occurred.
Conservation Status
Despite its vast size, this particular species of shark was only discovered in 1976. Less than ten have been studied or even sighted, and as a result, knowledge is limited.
Other Comments
Though its large size and huge mouth can create a sinister appearance, this shark is particularly timid.
Contributors
Melissa Kim (author), University of Michigan.

