Common Name
Megamouth Shark
Year Described
Taylor, Compagno, and Struhsaker, 1983
Identification
Teeth: (upper/lower): 55-115/75-121
Body very large, cylindrical and strongly tapering posteriorly. Head very large and broad. Eye moderate. Snout very short and blunt. Mouth very wide and with a large internal volume. Jaws protrusible and terminal. Teeth in many rows but very small and conical (first few rows the largest). Gill slits moderate and becoming crowded near pectoral base. First dorsal fin above free tip of pectoral fin and triangular. Second dorsal fin less than half size of first and located in between level of pelvic and anal fins. Pectoral fins very long with a straight rear edge. Pelvic and anal fins located far back on body. Anal fin origin under second dorsal fin tip. Caudal fin large and asymmetric with a strong lower lobe. Precaudal pit only on upper side. No caudal keels. Body with weak musculature. Fins strap-like.
Color
Body and fins brown to dark gray dorsally and white on the belly. A white stripe along upper lip and a pale patch behind eyes. Diffuse dark spots on lower jaw. Fins unmarked but may have white tips.
Size
Maximum size to at least 550cm TL. Sexes similar in size.
Habitat
A midwater pelagic species found near the surface at night and down to over 600m during the day. Specimens often found stranded or dead on shore. A strict filter feeding species.
Range
In W. Atlantic off Puerto Rico and Brazil. Widely distributed circumglobally.
References
Amorim, A. F., Arfelli, C. A., & J.I Castro. 2000. Description of a juvenile megamouth shark, Megachasma pelagios, caught off Brazil. Environmental biology of fishes, 59(2), 117-123.
Castro, J.I. 2011. The Sharks of North America. Oxford University Press, 640 pp.
Rodriguez-Ferrer, G., Wetherbee, B. M., Schärer, M., Lilyestrom, C., Zegarra, J. P., & M. Shivji. 2017. First record of the megamouth shark, Megachasma pelagios,(family Megachasmidae) in the tropical western North Atlantic Ocean. Marine Biodiversity Records, 10(1), 1-4.
Taylor, L.R., L.J.V. Compagno, & P.J. Struhsaker. 1983. Megamouth A new species, genus, and family of lamnoid shark (Megachasma pelagios. family Megachasmidae) from the Hawaiian Islands. Proc. California Acad. Sci. ser a, 43(8): 87-110.
Other Notes
Known so far from three specimens in the area.