Cownose ray
The cownose ray is a fascinating marine creature belonging to the family of eagle rays, recognized for its distinctive diamond-shaped body and broad, wing-like pectoral fins. Named for its resemblance to a cow's nose, this ray glides along the sandy bottoms of shallow bays and coastal inshore shelves in the western Atlantic Ocean, from North to South America. Typically averaging three feet (90 centimeters) in width, cownose rays can weigh around 50 pounds (22 kilograms), although some may grow up to seven feet (two meters) across.
Cownose rays are opportunistic feeders, primarily consuming marine worms, sea snails, and crustaceans, using unique techniques like fanning sand or squirting water to uncover prey. A notable feature is their long, poisonous spine, which serves as a defense mechanism against predators. Socially, they are known to travel in schools during warmer months and migrate in groups for breeding, usually giving birth to up to 12 young.
Despite their resilience, cownose rays face threats from commercial fishing practices and are currently classified as vulnerable by the International Union for Conservation of Nature (IUCN). They have a lifespan of 15 to 20 years, making conservation efforts vital for their continued existence in marine ecosystems.
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Cownose ray
This marine creature receives its name from the slight resemblance it bears to the four-hoofed land animal. It is a smaller member of the family of eagle rays, but its body still carries a dangerous, poisonous spine to defend itself.
Kingdom: Animalia
Phylum: Chordata
Class: Osteichthyes
Order: Batiformes
Family: Myliobatidae
Genus: Rhinoptera
Species: Bonasus
Cownose rays glide smoothly over the bottoms of shallow bays and along the western Atlantic Ocean of North and South America. They can be found in the inshore shelves, which run along the coasts of the continents and are the points at which the ocean floor suddenly drops and becomes deep. Sometimes these rays swim in schools in the bays during the summer. They migrate together during the winter.
The average three-foot (90 centimeter) wide body of the cownose ray is nearly 1 1/2 times wider than it is long. Some have reportedly grown to be up to seven feet (two meters) across and to weigh nearly 100 pounds (45 kilograms), though most weigh around 50 pounds (22 kilograms). Smooth brown skin covers the upper surface of its flattened body, while the underside is white or yellowish white. The body is diamond-shaped with broad, pointed, wing-like pectoral fins, a whip-like tail, and a head which extends in front of its fins. The face has large eyes and a round nose which some say looks like that of a cow.
Like others in its family of 20 species, the cownose ray has a long, thin spine attached to its body behind its dorsal fin. As a young ray, it can flip its tail and this spine in almost any direction. When it becomes an adult, it can flip it only over its back. The spine is sharp enough to seriously injure an intruder or attacker and contains poison which may be deadly on occasion.
As the cownose rays swim along the bottom, they find food in two ways. One technique is to fan the sand with their wing-like fins and blow away the sand from prey hiding beneath the surface. The other effective technique is to squirt water from their mouths at the sand and drill holes into it. They are able to uncover food nearly one foot (30 centimeters) deep. They are oportunistic feeders, meaning they eat what they can find. Their diet includes marine worms, sea pens, sea snails, and sometimes oysters, mollusks, clams, lobsters, and crabs. Strong teeth help crush the hard shells, which they discard, and allow the rays to eat the soft flesh. For some time, they were incorrectly linked to a declining oyster population. However, scientists found that oysters make up less than five percent of their diet, so the connection was incorrect.
Cownose rays often travel to shallower, inland waters during the summer breeding months. Young cownose rays are born tail first. Their poisonous spines are soft when they are first born, but they quickly harden in the water. A female may have six babies when she is young but may have as many as 12 when she is fully grown.
Because of their breeding patterns, cownose rays are subjected to commercial fishing as bycatch, or secondary, unwanted catch. This is harmful to their population, and they are currently listed as vulnerable on the International Union for Conservation of Nature (IUCN) Red List, which means they are subject to extinction.
Cownose rays have a typical lifespan of 15 to 20 years.
Bibliography
“Cownose Ray.” Georgia Aquarium, 16 Nov. 2022, www.georgiaaquarium.org/animal/cownose-ray/. Accessed 11 Apr. 2024.
“Cownose Ray.” Movement of Life, movementoflife.si.edu/species/cownose-ray/. Accessed 11 Apr. 2024.
Crysler, Zoe, et al. “American Cownose Ray.” IUCN Red List of Threatened Species, 21 June 2019, www.iucnredlist.org/species/60128/3088381. Accessed 11 Apr. 2024.