Cownose Ray
Hannah West and Kayla Jones
Relates to water?
Our topic relates to water because Cownose rays are a
species that live in the water.
Why?
We chose this topic because it's a very interesting
species. Its also kind of cute.
Name
Known as cownose rays because of their anatomy: their
long, pointed pectoral fins separate into two lobes on their
distinctive, broad head. The lobes and their wide-set eyes
give them a cow-like look. They are also known as Golden
Stingrays.
Scientific name: Rhinoptera bonasus
Where do they live?
They live in the open ocean, although they are
sometimes found in inshore, brackish waters. Unlike other
stingrays, golden rays rarely rest on the seabed (where
unsuspecting humans can step on them) and prefer to be
on the move, about 70 feet down.
In deep water, they have to sleep by swimming slowly
along or “hang-gliding” in a rising current (rays have no
swim bladder, so they sink down if they stop swimming).
Migration
Twice a year up to ten thousand golden stingrays
gather near Yucatan Peninsula and migrate about 800
miles across the Gulf of Mexico. They swim to western
Florida in the spring, and back to the Yucatan in fall.
In the Atlantic Ocean, golden ray populations also
migrate northward as far as New England in late spring and
southward as far as southern Brazil in late fall.
Why do they migrate?
No one yet knows why they migrate or what initiates
the sociable gathering of so many thousands to make
them swim together. Some guesses are the changes in
water temperature.
The migration hasn’t yet been linked to feeding or
mating activity, either. but the southbound groups seem to
be larger than the northbound
Feeding habits
The cownose ray feeds upon clams, oysters, hard
clams and other invertebrates. It uses two modified fins on
its front side to produce suction, which allows it to draw
food into its mouth, where it crushes its food with its dental
plates. Cownose rays typically swim in groups, which
allows them to use their synchronized wing flaps to stir up
sediment and expose buried clams and oysters.
They also eat clams, snails, and crabs
Size
Cownose rays grow rapidly, and male rays often reach
about 35 inches (89 cm) in width and weigh 26 pounds.
Females typically reach 28 inches (71 cm) in width and
weigh 36 pounds.
Predators
Although cownose rays can grow large enough to fend
off most predators, they are still hunted by large sharks
such as great hammerhead and bull sharks.
Protected
According to the International Union for Conservation of
Nature and Natural Resources (IUCN), the cownose ray is
listed as "Near Threatened".
The IUCN consists of a global union of state,
governmental agencies, and non-governmental
organizations in partnership whose goal is to assess the
conservation status of different species
Questions
1. What do they eat? oysters,clams, snails, and crabs
2. Who are their predators? large sharks such as great
hammerheads and bull sharks.
3. Who protects them? The IUCN