General Description
Manta rays are large sea animals that live in tropical, sub-tropical, and temperate waters worldwide. Their side or pectoral fins have evolved into wide triangular wings that they use to easily propel themselves through the water. With a diamond shaped body and wing spans reaching over 20’ across, manta rays are one of the largest animals in the ocean. Their broad blanket-like bodies earned them the name manta that means cloak or blanket in Spanish. In Hawaiian, they are called hahalua. Like many other open ocean animals, manta rays have countershading coloration - dark on the topside (dorsal side) and light on the underside (ventral side).
Sharks and Rays
Manta rays are related to sharks. Sharks and rays are cartilaginous fishes and belong to the scientific classification Chondrichthyes. Sharks and rays are grouped together in a sub-class called Elasmobranchii. Unlike many shark species, manta rays do NOT have sharp teeth. They do possess a tooth band that is more like sandpaper along the lower jaw only.
Manta ray versus Stingray
Manta rays are related to stingrays. Both have flattened body shapes and wide pectoral fins that are fused to the head. One of the biggest differences between manta rays and stingrays is that manta rays do NOT have a tail "stinger" or barb like stingrays. There are other differences as well. Stingrays dwell on the ocean bottom, but manta rays live in the open ocean. A stingray's mouth is located on the underside of its body whereas the mouth of the manta ray is along the front edge of its body.
Devil Rays
Manta rays belong to the family of rays referred to as devil rays, scientifically called Mobulidae. Devil rays share the common characteristic of cephalic or head fins. When unfurled, the fins help to funnel in food and water into the mouth. To make the fins more streamlined, devil rays can roll up these flexible appendages. When furled, these fins were thought to resemble a devil’s horns.
Manta Species
Based on a study conducted by Marshall (2009), manta rays are divided into two different species: Manta birostris and Manta alfredi. Manta birostris typically roam the open ocean and are migratory. They are regularly sighted at offshore islands, oceanic seamounts, and submarine ridge systems. Manta birostris are located in the Atlantic, Indian and Pacific oceans. This species can reach up to 22’ across. Manta alfredi is a smaller species that has an average size of 11’ across. This species is commonly sighted near shore around coral reefs, often times in residential groups. The species is widespread in tropical waters and found in the Atlantic, Indian, and Pacific oceans. Manta birostris is occasionally sighted along the Kona Coast. Manta alfredi is the species of manta ray that is sighted on the Kona manta ray night tours.
Color Morphology
Typically, manta rays are black dorsally with white dorsal shoulder bars. While the dorsal coloration is relatively similar in mantas worldwide, their ventral side can be very different. Typically, Manta birostris has few spots ventrally with wide gray bands along the back edge of the wings. Manta alfredi has big blotchy spot patterns ventrally located. These spot patterns are unique to each manta and can be used for accurate identification. The most extreme difference in manta coloration comes with the “black manta”. These mantas are predominantly black on their ventral surface with small spots or patches of white. Both Manta birostris and Manta alfredi species have a black coloration. Both black and white mantas can be seen together in some locations, however, the white underside coloration is always more dominant. Black mantas are sighted occasionally on the Kona coast.