Both manta rays and stingrays are flattened, cartilaginous fish that glide through the world’s oceans. Manta rays are significantly larger than almost all of the hundreds of known stingray species. These two groups of rays share a distant biological ancestry, yet they represent vastly different scales of life in the marine environment, dwarfing their smaller, bottom-dwelling relatives.
The Definitive Size Comparison
The Giant Oceanic Manta Ray (Mobula birostris) is the largest ray species in the world, with individuals reaching a wingspan of up to 23 to 25 feet from wingtip to wingtip. These animals can weigh as much as 2,980 to over 5,100 pounds, or approximately 1.5 to 2.3 metric tons. The smaller of the two manta species, the Reef Manta Ray (Mobula alfredi), commonly reaches a wingspan of 11 to 18 feet.
In contrast, the scale of even the biggest stingrays is considerably smaller. The largest stingray species, such as the Short-tail Stingray or the Giant Freshwater Stingray, generally reach a maximum disc width of about 6.9 to 8 feet. Their body weight can exceed 770 pounds, which is substantial, but still less than a quarter of the weight of a large oceanic manta. Most stingrays encountered in coastal waters, such as the Atlantic Stingray, are quite small, measuring only about 10 inches across and weighing a mere five pounds.
Anatomical and Behavioral Distinctions
The size difference is closely linked to distinctions in how each animal lives and feeds. Manta rays are pelagic, meaning they spend their lives migrating and constantly swimming in the open ocean and along coastlines. Because they must keep moving to force water over their gills for respiration, they are streamlined for movement in the water column. This open-water lifestyle supports their growth to immense sizes.
Their feeding is designed for this active, migratory existence as filter feeders. Manta rays possess a wide, terminal mouth located at the front of their body, flanked by two specialized, paddle-like cephalic lobes. They swim with their mouths open, using the cephalic lobes to funnel zooplankton and small organisms into their mouths to be strained by their gill rakers.
Stingrays are predominantly benthic, or bottom-dwelling, that frequent shallow coastal areas and can rest on the seafloor. Unlike mantas, they use spiracles on the top of their heads to draw in water and pump it over their gills while stationary or buried in the sediment. Their mouth is positioned on the underside of their body, which is ideal for their predatory feeding strategy. They feed on small fish, crustaceans, and mollusks, often crushing the shells of their prey after using suction to excavate them from the sand.
Another major physical difference is found in the tail structure. Manta rays have a smooth, whip-like tail that lacks any form of venomous barb. Stingrays, however, possess one or more serrated, venomous spines near the base of their tail, which they use for self-defense when threatened.
Taxonomic Relationship
Despite their differences in size and behavior, manta rays and stingrays are classified as cartilaginous fish. They belong to the Class Chondrichthyes, a group that includes sharks and chimaeras, characterized by skeletons made entirely of cartilage instead of bone. Both are part of the superorder Batoidea, which encompasses all rays and skates, and they fall under the same Order, the Myliobatiformes.
The divergence occurs at the family level, which accounts for the differences in their biology. Manta rays belong to the family Mobulidae, sometimes grouped with the eagle rays, and their genus Mobula contains only a few species. This family is characterized by their giant size and filter-feeding habits. Stingrays represent a much broader collection of species categorized into multiple families, such as Dasyatidae, which includes the whiptail stingrays.