The cownose ray (''Rhinoptera bonasus'') is a species found throughout a large part of the western

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

and

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

, from

New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...

to southern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

(the East Atlantic are now generally considered a separate species, the Lusitanian cownose ray (''R. marginata'')). These rays also belong to the order

Myliobatiformes Myliobatiformes (), commonly known as stingrays, are one of the four orders of batoids, cartilaginous fishes related to sharks. They are members of the subclass elasmobranchs. They were formerly included in the order Rajiformes, but more recent ...

, a group that is shared by bat rays, manta rays, and eagle rays. Cownose rays prefer to live in shallower, coastal waters or estuaries. Size, lifespan, and maturity differ between male and female rays. Rays have a distinct shape, and it has two lobes at the front of its head, resembling a cow nose. Cownose rays can live between 16 and 21 years, depending on sex. Rays feed upon organisms with harder shells, such as

clam Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, or

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

. They are migratory creatures, where they migrate South in the winter and North in the summer. The rays are known to occupy the

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Ea ...

in the summer months. In 2019, the species was listed as vulnerable on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

. The species has been subjected to overfishing due to the perceived threat of overpopulation in the Chesapeake Bay. There are not many conservation strategies or efforts for cownose rays.

Taxonomy

The genus name '' Rhinoptera'' is named for the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

words for nose (') and wing ('). The species name ''bonasus'' comes from the Ancient Greek for bison ().

Description

A cownose ray is typically brown-backed with a slightly white or yellow belly. Although its coloration is not particularly distinctive, its shape is easily recognizable. It has a broad head with wide-set eyes, and a pair of distinctive lobes on its subrostral fin. It also has a set of dental plates designed for crushing clams and oyster shells. Male rays often reach about in width, while females typically reach about in width. The cownose ray is often mistaken for being a shark by beach-goers due to the tips of the rays' fins sticking out of the water, often resembling the dorsal fin of a shark. When threatened the cownose ray can use the barb at the base of its tail to defend itself from the threat. A cownose ray has a

spine Spine or spinal may refer to: Science Biology * Spinal column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoology), ...

with a

toxin A toxin is a naturally occurring poison produced by metabolic activities of living cells or organisms. They occur especially as proteins, often conjugated. The term was first used by organic chemist Ludwig Brieger (1849–1919), derived ...

, close to the ray's body. This spine has teeth lining its lateral edges, and is coated with a weak

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

that causes symptoms similar to that of a

bee sting A bee sting is the wound and pain caused by the stinger of a female bee puncturing skin. Bee stings differ from Insect bites and stings, insect bites, with the venom of stinging insects having considerable chemical variation. The reaction of a p ...

Habitat and distribution

Cownose rays are migratory and social creatures and reside on the east coast of the United States,

, as well as in the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

. They prefer to live in near coastal waters and in estuarian ecosystems. Cownose rays are able to tolerate a wide range of

salinities Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ...

because of the areas they occupy. This allows for the rays to have the potential to live in a wider range of habitats if one area gets too crowded and competition for resources is high. Cownose rays are known to be abundant in the

and migrate to the area for mating and nursery purposes, typically in the late spring and summer time. Rays are typically spotted near the surface of waters as well.

Behavior

Diet and feeding

The cownose ray exhibits a

durophagous Durophagy is the eating behavior of animals that consume hard-shelled or exoskeleton-bearing organisms, such as corals, shelled mollusks, or crabs. It is mostly used to describe fish, but is also used when describing reptiles, including fossil t ...

diet, meaning it feeds upon hard-shelled organisms, such as

s, but they prefer

scallop Scallop () is a common name that encompasses various species of marine bivalve molluscs in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related famili ...

s or

s, which have softer shells and are categorized as

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

. The cownose ray tends to feed either in the early morning hours or in the late afternoon hours, when the waves are calm and visibility is higher than during the day. Their feeding occurs in the

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

zone, or at the bottom of the ocean. The rays are able to capture their prey through

suction Suction is the day-to-day term for the movement of gases or liquids along a pressure gradient with the implication that the movement occurs because the lower pressure pulls the gas or liquid. However, the forces acting in this case do not orig ...

and the opening and closing of their jaw. Because of the type of prey cownose rays consume, their jaw needs to be able to handle the hard-shell organisms. Their jaws are extremely robust and have teeth with a hardness comparable to that of cement. Their cephalic lobes also assist with capturing and handling their prey by pushing them towards their mouth.

Predation

The cownose ray sits fairly high up on the food chain, and as a result only has a few natural predators. These predators include;

cobia The cobia (''Rachycentron canadum'') (, ) is a species of marine carangiform ray-finned fish, the only extant representative of the genus '' Rachycentron'' and the family Rachycentridae. Its other common names include black kingfish, black ...

hammerhead shark The hammerhead sharks are a group of sharks that form the family Sphyrnidae, named for the unusual and distinctive form of their heads, which are flattened and laterally extended into a Hammerhead shark#Cephalofoil, cephalofoil (a T-shape or " ...

s, and humans who like to fish for them.

Reproduction and lifespan

Cownose rays breed from April through October. Rays will not reach a mature age until they are roughly 70% of the way to their maximum size. Females reach maturity between ages 7–8, while males reach maturity between ages 6–7. The lifespan of the cownose ray varies by sex; the oldest female ray that has been recorded was 21, and the oldest male ray was 18, which were both observed in the Chesapeake Bay. Cownose rays are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

, meaning that the

embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...

grows within its mother until it is ready to hatch. Rays have a longer gestation period due to their

K-selected In ecology, selection theory relates to the natural selection, selection of combinations of Trait (biological), traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offsprin ...

species attributes. The length of

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

is believed to last between 11 and 12 months, and at full term, the offspring are born live, exiting tail first.

Migration

Rays often travel and migrate in large schools based on size and sex. Their migration pattern consists of rays moving north in late Spring and moving south in late Fall. Much of what we know about their migration has been from studies done in the

. Male and female rays will come to the Bay in the late spring and leave in the fall. While occupying the Chesapeake Bay, the female rays and her pups will live in the estuarine waters. Males have been observed leaving the Bay earlier than the females to arrive at a second feeding ground, and the reason for taking a longer migration route is not fully known. One hypothesis is that males exit the Bay to reduce competition of certain resources, such as food and shelter.

Threats and conservation

The cownose ray is currently listed as vulnerable by the

due to extensive overfishing and

commercial fishing Commercial fishing is the activity of catching fish and other seafood for Commerce, commercial Profit (economics), profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice ...

. The overfishing is due to the perception that rays destroy oyster beds meant for the shellfish industry. The

trophic cascade Trophic cascades are powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed. For example, a top-down cascade will occur if predators are effective enough in predation to redu ...

in the northwest Atlantic Ocean has been cited and used to link cownose ray overpopulation to the decrease in large coastal sharks, which therefore cause bivalves populations valuable for commercial reasons to be depleted; however, there is little evidence that supports this hypothesis. Campaigns such as "Save the Bay, Eat a Ray" in the Chesapeake Bay used these claims to promote the fishery of these rays in hopes of preserving the Bay, which can be detrimental to this species. Cownose rays reach a mature age later in their lifecycle and long gestation periods, meaning that they are a K-selected species. This suggests that they are vulnerable and sensitive to overfishing, and their populations cannot easily bounce back after these events. Even though rays have been used as a scapegoat to explain the decline in bivalves, some studies have found that cownose rays do not consume a great deal of oysters or clams. Other studies have found that much of the shellfish prey that the cownose ray consumes is influenced by the size of the shell, so it has been suggested that oyster growers protect their shellfish until their shell reaches a certain size. There are not many conservation strategies or efforts for cownose rays, besides the fact that cownose ray killing contests have been banned in the state of Maryland.

Relationship to humans

Risk to humans

Stingrays, including the cownose ray, can pose a low to moderate risk to humans. Rays will lash their tails when threatened, posing a risk of being whipped. If threatened, the cownose ray can also use their barb as a weapon to sting the aggressor. A sting from a cownose ray can cause a very painful wound that requires medical attention once stung. While the sting is not usually fatal, it can be fatal if stung in the abdomen. There is also a risk associated with eating meat from the sea animal that has not been prepared correctly.

Shigella ''Shigella'' is a genus of bacteria that is Gram negative, facultatively anaerobic, non–spore-forming, nonmotile, rod shaped, and is genetically nested within ''Escherichia''. The genus is named after Kiyoshi Shiga, who discovered it in 1 ...

may be acquired from eating

meat Meat is animal Tissue (biology), tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates, including chickens, sheep, ...

from a cownose ray that has been contaminated with the bacteria. This bacteria causes

shigellosis Shigellosis, known historically as dysentery, is an infection of the intestines caused by ''Shigella'' bacteria. Symptoms generally start one to two days after exposure and include diarrhea, fever, abdominal pain, and feeling the need to pass ...

, and can result in

dysentery Dysentery ( , ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications may include dehyd ...

. Symptoms can include

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

, pain, fever, and possible dehydration.

Aquariums

Cownose rays can be seen in many public aquaria worldwide and are often featured in special 'touch tanks' where visitors can reach into a wide but shallow pool containing the fish, which have often had their barbs pinched or taken off (they eventually regrow, similar to human nails), making them safe enough to touch. The following aquariums and zoos are known to have touch tanks featuring cownose rays (alone or with other fish):

US

* Adventure Aquarium in Camden, New Jersey * Albuquerque Aquarium in Albuquerque, New Mexico * Audubon Aquarium in New Orleans, Louisiana * Aquarium of Boise in Boise, Idaho *

Arizona-Sonora Desert Museum The Arizona-Sonora Desert Museum is a 98-acre (40 ha) zoo, aquarium, botanical garden, natural history museum, publisher, and art gallery founded in 1952. Located just west of Tucson, Arizona, it features two miles (3.2 km) of walking path ...

in Tucson, Arizona * Atlantic City Aquarium in Atlantic City, New Jersey *

Aquarium of the Pacific The Aquarium of the Pacific (formerly the Long Beach Aquarium of the Pacific) is a public aquarium on a site on Rainbow Harbor in Long Beach, California, United States. It is situated across the water from the Long Beach Convention Center, Sho ...

in Long Beach, California * Butterfly House and Aquarium in Sioux Falls, South Dakota * Brookfield Zoo in Chicago, Illinois *

California Academy of Sciences The California Academy of Sciences is a research institute and natural history museum in San Francisco, San Francisco, California, that is among the largest List of natural history museums, museums of natural history in the world, housing over ...

in San Francisco, California * Calvert Marine Museum in Solomons, Maryland * Children's Aquarium at Fair Park in Dallas, Texas *

Clearwater Marine Aquarium Clearwater Marine Aquarium is a 501(c)(3) non-profit organization, and aquarium in Clearwater, Florida. It is dedicated to the rescue, rehabilitation and release of sick and injured marine animals, public education, conservation, and research. ...

in Clearwater, Florida *

Columbus Zoo and Aquarium The Columbus Zoo and Aquarium is a non-profit zoo located near Powell, Ohio, Powell in Liberty Township, Delaware County, Ohio, United States, north of the city of Columbus, Ohio, Columbus. The land lies along the eastern banks of the O'Shaughnes ...

in Powell, Ohio * Denver Zoo, Denver in Denver, Colorado * Downtown Aquarium, Denver in Denver, Colorado *

The Florida Aquarium The Florida Aquarium is a 501(c)(3) non-profit organization, publicly operated institution located in downtown Tampa, Florida, United States. It is a large scale, aquarium and is accredited by the Association of Zoos and Aquariums. This means t ...

in Tampa, Florida *

Fort Wayne Children's Zoo The Fort Wayne Zoo is a zoo in Fort Wayne, Indiana, United States. Since opening in 1965, the 1,000-animal zoo has been located on in Fort Wayne's Franke Park. The Fort Wayne Zoo is operated by the non-profit Fort Wayne Zoological Society under ...

in Fort Wayne, Indiana * Fresno Chaffee Zoo in Fresno, California *

Georgia Aquarium Georgia Aquarium is a public aquarium in Atlanta, Atlanta, Georgia, United States. The aquarium exhibits hundreds of species and thousands of animals across its seven major galleries, all of which reside in more than of water. It was the larges ...

in Atlanta, Georgia * Gulf World Marine Park in Panama City Beach, Florida *

Henry Doorly Zoo Omaha's Henry Doorly Zoo and Aquarium is a zoo in Omaha, Nebraska. It is accredited by the Association of Zoos and Aquariums and a member of the World Association of Zoos and Aquariums. In August 2014, TripAdvisor rated it the "world's best zoo" ...

in Omaha, Nebraska * IMAG History & Science Center in Fort Myers, Florida * Indianapolis Zoo in Indianapolis, Indiana * Jacksonville Zoo and Gardens in Jacksonville, Florida * Kansas City Zoo in Kansas City, Missouri * Living Shores Aquarium in Glen, New Hampshire * Long Island Aquarium and Exhibition Center in

Riverhead, New York Riverhead is a town in Suffolk County, New York, United States, on the north shore of Long Island. Since 1727, Riverhead has been the county seat of Suffolk County, though most county offices are in Hauppauge. As of the 2020 census, the popul ...

* Lowry Park Zoo in Tampa, Florida * Marine Science Center in Ponce Inlet, Florida * Maritime Aquarium in Norwalk, Connecticut * Memphis Zoo and Aquarium in Memphis, Tennessee * Mississippi Aquarium in Gulfport, Mississippi *

Mote Marine Laboratory Mote Marine Laboratory is an independent, nonprofit, marine research organization based on City Island in Sarasota, Florida, with additional campuses in eastern Sarasota County, Boca Grande, Florida, and the Florida Keys. Founded in 1955 by Eug ...

in Sarasota, Florida * Mystic Aquarium in Mystic, Connecticut * National Mississippi River Museum & Aquarium in Dubuque, Iowa * The New England Aquarium in Boston, Massachusetts *

New York Aquarium The New York Aquarium is the oldest continually operating Public aquarium, aquarium in the United States, located on the Riegelmann Boardwalk in Coney Island, Brooklyn, New York City. It was founded at Castle Garden in Battery Park, Manhattan, i ...

in Brooklyn, New York *

Newport Aquarium The Newport Aquarium is a public public aquarium, aquarium located in Newport, Kentucky. Overview The Newport Aquarium located within the Newport on the Levee shopping mall is owned by Herschend Family Entertainment. Newport Aquarium is an a ...

in Newport, Kentucky * North Carolina Aquarium at Pine Knoll Shores in Emerald Isle, North Carolina * Ocean Adventures in Gulfport, Mississippi * OdySea Aquarium in Scottsdale, Arizona *

Oklahoma City Zoo and Botanical Garden The Oklahoma City Zoo and Botanical Garden is a zoo and botanical garden located in Oklahoma City's Adventure District in northeast Oklahoma City, Oklahoma. The zoo covers and is home to more than 2,000 animals of more than 500 species. It is ...

in Oklahoma City, Oklahoma *

Phoenix Zoo The Phoenix Zoo opened in 1962 and is the largest privately owned nonprofit zoo in the United States. Located in Phoenix, Arizona, the zoo was founded by Robert Maytag, a member of the Maytag family, and operates on of land in the Papago Park ...

in Phoenix, Arizona * Rooster Cogburn Ostrich Ranch in Picacho, Arizona * Ripley's Aquarium of Myrtle Beach in Myrtle Beach, South Carolina * Ripley’s Aquarium of the Smokies in Gatlinburg, Tennessee * Saint Louis Zoo in St. Louis, Missouri * San Antonio Aquarium in San Antonio, Texas *

SeaWorld Orlando SeaWorld Orlando is an animal theme park located in Orlando, Florida. Although separately gated, it is often promoted with neighboring parks Discovery Cove and Aquatica as well as Busch Gardens Tampa Bay, all of which are owned and operated ...

in Orlando, Florida *

Shedd Aquarium Shedd Aquarium (formally the John G. Shedd Aquarium) is an indoor public aquarium in Chicago. Opened on May 30, 1930, the aquarium holds about 32,000 animals. It is the third largest aquarium in the Western Hemisphere (after the Georgia Aquariu ...

in Chicago, Illinois * Shreveport Aquarium in Shreveport, Louisiana South Carolina Aquarium, Charleston South Carolina *

Tennessee Aquarium The Tennessee Aquarium is a non-profit public aquarium located in Chattanooga, Tennessee, United States. It opened in 1992 on the banks of the Tennessee River in downtown Chattanooga, with a major expansion added in 2005. The aquarium, which ha ...

in Chattanooga, Tennessee * Texas State Aquarium in Corpus Christi, Texas * Toledo Zoo in Toledo, Ohio *

Tropicana Field Tropicana Field (nicknamed "The Trop") is a domed multipurpose stadium located in St. Petersburg, Florida, United States. "The Trop" was the home of the Tampa Bay Rays of Major League Baseball (MLB) from 1998 Tampa Bay Devil Rays season, 1998 to ...

in St. Petersburg, Florida ( The Rays Touch Tank) * Turtle Back Zoo in West Orange, New Jersey * Wonders of Wildlife Museum & Aquarium in Springfield, Missouri * ViaAquarium in Rotterdam, New York * Virginia Aquarium in

Virginia Beach Virginia Beach (colloquially VB) is the List of cities in Virginia, most populous city in the Commonwealth (U.S. state), U.S. commonwealth of Virginia. The city is located on the Atlantic Ocean at the mouth of the Chesapeake Bay in southeaster ...

, Virginia * Greensboro Science Center in

Greensboro Greensboro (; ) is a city in Guilford County, North Carolina, United States, and its county seat. At the 2020 census, its population was 299,035; it was estimated to be 307,381 in 2024. It is the third-most populous city in North Carolina, af ...

, North Carolina

Canada

* Aquarium of Quebec in Quebec City * Granby Zoo in Granby *

Ripley's Aquarium of Canada Ripley's Aquarium of Canada is a public aquarium in Toronto, Ontario, Canada. The aquarium is one of three aquariums owned-and-operated by Ripley Entertainment. It is located in downtown Toronto, just southeast of the CN Tower. The aquarium has ...

in Toronto, Ontario * The Vancouver Aquarium in Vancouver, British Columbia * Assiniboine Park Zoo in Winnipeg, Manitoba

References

{{Taxonbar, from=Q10360338 Rhinoptera Ovoviviparous fish Fish of the Eastern United States Fish of the Western Atlantic Fish described in 1815 Taxa named by Samuel L. Mitchill