Rays are cartilaginous fish closely related to sharks. Manta rays and stingrays often cause confusion due to their shared flat body plans. However, these two marine creatures differ significantly in anatomy, behavior, and interactions with their environment, including humans. Understanding these distinctions clarifies their unique roles in ocean ecosystems.
Distinct Physical Traits
Manta rays and stingrays differ noticeably in physical characteristics, particularly size and unique appendages. Manta rays are considerably larger, with the giant oceanic manta ray (Mobula birostris) reaching wingspans of up to 23 feet (7 meters) and weighing nearly 3,000 pounds (1,400 kilograms). Reef manta rays (Mobula alfredi) are smaller, growing to about 18 feet (5.5 meters) wide. In contrast, stingrays vary widely in size, from species as small as a dinner plate to larger ones like the short-tail stingray, which can reach up to 6.9 feet wide and weigh over 770 pounds (350 kilograms).
Manta rays have distinguishing cephalic fins, often called “horns,” on either side of their large, terminal mouth. These flexible fins funnel plankton-rich water into their mouths during feeding. Stingrays, conversely, lack cephalic fins and have a smaller mouth on their ventral (underside). This placement adapts them for bottom-feeding.
Body shape also differs: manta rays typically have a diamond or triangular form with broad, wing-like pectoral fins, creating a graceful, “flight-like” swimming style. Stingrays often have a flatter, more rounded or disc-shaped body, and they typically undulate their bodies or fins to move along the seafloor or through the water. A crucial distinction lies in their tails: most stingrays possess one to three venomous, barbed spines near the base of their whip-like tails, used for defense. Manta rays, despite having a tail, do not possess a venomous barb.
Contrasting Habitats and Behaviors
Their environments and feeding methods further differentiate manta rays from stingrays. Manta rays are pelagic, meaning they live in the open ocean, often near the surface, in warm temperate, subtropical, and tropical waters worldwide. They constantly swim, requiring continuous movement to pass oxygenated water over their gills. Stingrays, conversely, are predominantly benthic, dwelling on the seafloor in sandy or muddy bottoms, seagrass beds, and coral reefs; some species inhabit freshwater.
Feeding strategies also differ. Manta rays are filter feeders, consuming vast quantities of plankton. They swim with their large mouths open, using their cephalic fins to direct food into their mouths, where gill rakers filter the plankton from the water.
Stingrays are carnivorous bottom feeders, preying on crustaceans, mollusks, and small fish that they find buried in the sediment. They use their strong jaws to crush the shells of their prey and can even expel water from their mouths to uncover buried food.
Understanding Their Interactions
Human interactions with these ray species vary significantly due to their behaviors and defense mechanisms. Manta rays are generally considered harmless to humans and are not aggressive. Their large size can appear intimidating, but as filter feeders lacking a venomous barb, they pose little threat.
Manta rays are known for their curious nature, sometimes approaching divers and snorkelers, making them popular for ecotourism. Observing them often involves witnessing their graceful, wing-like movements as they glide through the water.
Stingrays, while not aggressive, possess a venomous tail barb for defense. Stings typically occur when a person accidentally steps on a stingray, which often buries itself in the sand in shallow waters. The sting is an involuntary reflex, where the ray whips its tail, embedding the serrated spine and releasing venom that causes intense pain.
To avoid stings, beachgoers are often advised to perform the “stingray shuffle” by dragging their feet along the seafloor, which alerts buried stingrays to their presence and gives them time to swim away.