Riesenmanta

Identification

Giant manta rays reach wingspans of up to 7 meters and weights over 2 tonnes, making them the largest rays in the ocean. The body is black on the dorsal surface with distinctive white "shoulders" and mostly white underneath, often with a unique pattern of spots used to identify individuals. A dark patch around the mouth on the underside helps separate M. birostris from the closely related reef manta ray (M. alfredi), which has a lighter mouth region.

Distribution & Habitat

Unlike reef mantas, giant mantas are primarily oceanic and spend most of their lives in the open sea, appearing at specific aggregation sites around oceanic islands and seamounts. Famous encounter sites include Revillagigedo (Socorro) in Mexico, the Galapagos, Ecuador's Isla de la Plata, southern Mozambique, and select Maldivian atolls.

Behavior

Giant mantas are intelligent filter feeders with the largest brain-to-body ratio of any fish. They are curious around divers and will often approach at cleaning stations, where small wrasses and angelfish pick parasites from their gills. Feeding behaviors include somersault loops, surface skim feeding, and coordinated chain feeding where multiple animals stack behind each other in a planktonic stream.

Where to See Them

Revillagigedo during November to May offers the most reliable encounters, often at cleaning stations where animals hover motionless for minutes. Socorro and San Benedicto islands are particular hotspots. Divers should approach low and slow from below, never from above, and allow the ray to approach on its own terms.