Transcript Knobbed Whelk

Trip to the Beach
Station 1: Whelk
Whelk on mirror
Egg case
Whelk- Carnivore or Herbivore?
• The Knobbed Whelk (Busycon carica) is a gastropod, a soft-bodied
invetebrate (animal without a backbone) that is protected by a very hard
shell. This mollusk is found in shallow waters of the Atlantic Ocean off
the east coast of North America from Massachusetts to northern Florida.
• The shell: The Knobbed Whelk has a spiral shell with knobs (or spines)
along its shoulder. The whelk's mantle, a thin layer of tissue located
between the body and the shell, creates the shell. The whelk builds the
hard shell from calcium carbonate that it extracts from the seas. The
shell is up to 9.5 inches (24 cm) long. The shell is light gray to tan, and
often has brown and white streaks. The shell is not living tissue; it grows
as the snail adds more material to the outer edge.
• Anatomy: The soft body is divided into the head, the visceral mass, and
the foot (which is small). The Knobbed Whelk has two pairs of tentacles
on the head; it has a light-sensitive eyespot located on each of the larger
tentacles. The smaller pair of tentacles is used for the sense of smell and
the sense of touch.
• Diet: Knobbed Whelks eat clams. They open the clam with their hard
shell, and insert their long proboscis. They eat using a radula, a rough
tongue-like organ that has thousands of tiny denticles (tooth-like
protrusions).
Station 2:Horseshoe Crab
Horseshoe Crabs
• Horseshoe crabs, common along the Eastern coast, have evolved
little in the last 250 million years. Still, they have survived because
of their hard, curved shells, which have made it difficult for
predators to overturn them and expose their soft, vulnerable
underbellies. The horseshoe crab has also survived because it can go
a year without eating and endure extreme temperatures and
salinity. The Delaware Bay region is home to the largest population
of the American horseshoe crab (Limulus polyphemus), which is
found along the western shores of the Atlantic Ocean from Maine to
the Yucatan.
• The Horseshoe Crab isn't really a crab. Related to scorpions, ticks
and land spiders, horseshoe crabs have their own classification
(Class Merostomata). Horseshoe crabs do molt
Horseshoe Crab Facts & Figures
• Despite their size and intimidating appearance, horseshoe crabs are not
dangerous.
• A horseshoe crab's tail, while menacing, is not a weapon. Instead, the tail is
used to plow the crab through the sand and muck, to act as a rudder, and to
right the crab when it accidentally tips over.
• The horseshoe crab's central mouth is surrounded by its legs and while
harmless, it is advisable to handle a horseshoe crab with care since you could
pinch your fingers between the two parts of its shell while holding it.
• Horseshoe crabs feed mostly at night and burrow for worms and mollusks.
They will, however, feed at any time.
• Horseshoe crabs grow by molting and emerge 25 percent larger with each
molt. After 16 molts (usually between 9 and 12 years) they will be fully grown
adults.
• Horseshoe crab eggs are important food for migratory shore birds that pass
over the Delaware Bay during the spring mating season. Fish also eat the
juveniles or recent molts.
Station 3: Moon Snail
Station 3: Moon Snail
• Family: Naticidae. These moderately sized shells belong to a
family group numbering several hundred species. Exquisitely
patterned, these shells can be found around the world. When
fully expanded, the live animal is several times larger than its
shell. They are so large, many moon snails cannot fit their
entire body inside the shell. Moon snails are also known as
whale or shark eyes because of the dark spot in the center of
the shell. They have huge appetites and eat several times a day.
Moon snails are carnivorous sand dwellers feeding mainly on
clams and other snails. They lay their eggs in collars made of
sand and mucus. These collars can be commonly found on most
beaches. In about six weeks, the eggs will produce and around
100,000 will hatch. Interesting Facts: Moon Snails can bore a
hole in the shell of their prey in as fast as three minutes, using
their radular teeth. These teeth are attached to tissue that most
resembles a cats tongue. So actually, a moon snail is licking
through the shell and not biting it.
These ultra close-up pictures show the polyps of a Purple Sea Whip Coral. The Sea Whip Coral
is a colony of hundreds of individual animals. Each animal is called a polyp (say "PAH-lip").
Each polyp is white and has 8 tentacles surrounding the mouth. Each polyp is about 1/4 of an
inch tall.
Station 4: Sea whips
• A gorgonian, also known as sea whip or is an
order of colonial cnidarian (coral) found
throughout the oceans of the world, especially
in the tropics and subtropics. Individual tiny
polyps form colonies and may be whip-like,
bushy, or even encrusting. They may be
brightly colored, often purple, red, or yellow.
They feed on tiny fish and plankton.
Station 5: Barnacles
Barnacles
• Like shrimp and crabs Barnacles are crustaceans that have
jointed legs and shells of connected overlapping plates.
Instead of crawling after food, they glue themselves to rocks,
ships, pillings, abalones, and maybe even whales and wait
for food to wash by. When barnacles are under water or
when a wave washes over them, they reach out little
feathery barbed legs to strain out plankton and absorb
oxygen.
• A barnacle's fertilized eggs hatch into larva, then they leave
the parents' shells. They spend their youth swimming. After
many molts they settle down to adulthood, held
permanently by one of the strongest known natural
adhesives. The barnacle's enemies are worms, snails, sea
stars, fish like sheephead, and certain shorebirds. Some are
parasites inside crabs or in other animals.
Station 6:
Sea Stars
Everted stomach
Rather than bring the food to the
stomach, the sea star brings its
stomach to the food. Once the prey is
captured the jelly-like stomach
actually oozes out of the tiny mouth
in a process known as eversion.
When the everted stomach is outside
of the sea star’s body it is literally
turned inside out, exposing the
digestive enzymes to the prey and
partially digesting the meal outside
of the body. The liquified food is then
absorbed through the stomach lining
and into the body and is transferred
to organs in the arms. When it’s all
done feeding the stomach muscles
contract, pulling it back inside the
body again. Anything inedible, such
as shell fragments or spines, are
ejected back out of the mouth by
muscle contractions.
Station 6: Sea Stars
Tube Feet
• Sea stars move by means of
the tube feet, which are
operated by a hydraulic, or
water-vascular, system
unique to echinoderms.
Seawater, circulated through
the radiating canals of this
system, enters and extends
the tube feet. Each tube foot
can be withdrawn by its
attached muscles. The tube
feet are equipped with
suction cups, and the animal
moves in any direction by
gripping with some of its
tube feet and pulling itself
forward. A sea star that is
turned upside down can right
itself by turning an arm
under and walking with the
tube feet.
Station 7: Sea Urchin
•
Sea urchins are echinoderms just like
sea stars, and just like sea stars they
have an internal skeleton that is living
tissue that grows with them. It is
called a “test”. Among the spines,
are five paired rows of tiny feet with
suctions to assist in capturing prey
and holding onto the sea floor. They
have tiny stinging structures that are
used in defense against predators and
for obtaining food. Like all
echinoderms, the purple sea urchin
has no brain; they are able to perform
everyday tasks by sending signals
through their system of nerves. They
are able to consume their food
because of their claw like mouth. The
mouth is located on the underside
and it has five tooth like plates which
point inwards.
Station 8: Sand (2 basic kinds)
Oahu, HI Sand – (Biogenic Sand)
Navarre Beach Sand: (broken rock)
• Hawaiian beach sand is
primarily made up of the
shells of tiny snails and
broken and worn pieces of
larger shells and corals. On
beaches with intense wave
action, the shell pieces are
rounded by the energy of the
waves. On more protected
beaches the sand is coarser
and the particles are more
defined, you can see the shell
shapes.
• Navarre Beach (Fl) sand is white
in color because most of the
individual crystals present are
quartz (clear).
• Old Woman Beach (Canada)
sand is from broken granite
which contains quarts as well as
feldspar (pink), mica (shiny,
grey), and hornblende (dark).
Station 9: Coquina and Oysters
Coquina
• They are filter-feeders, using
siphons to eat - one celled
algae, plant pieces in the sand,
and detritus. Detritus is nonliving particulate organic
material. It typically includes
the bodies or fragments of dead
creatures as well as fecal
material. Detritus is typically
colonized by communities of
microorganisms which act to
decompose (or remineralize) the
material. Coquina are the
favorite food of many sea birds.
Oysters
• OYSTERS BEGIN LIFE IN A CLOUD OF
RELEASED EGGS AND SPERM IN THE
WATER COLUMN. FERTILIZED EGGS
MATURE INTO ZOOPLANKTON AND
PROVIDE FOOD FOR LOTS OF
ANIMALS IN THE
WATER. EVENTUALLY, THEY BECOME
“SPAT”, ABOUT THE SIZE OF A
PEPPER FLAKE, AND SECRETE SHELLLIKE CHEMICALS. AT THIS POINT,
THEY LAND ON A SUBSTRATE
(USUALLY OYSTER SHELLS, BUT
OCCASIONALLY OTHER STUFF LIKE
WOOD) AND BEGIN THEIR LIFE AS A
SEDENTARY CREATURE. LARGE
GROUPS OF OYSTERS FORM REEFS,
WHICH IN TURN PROVIDE HABITAT
FOR A WIDE VARIETY OF OTHER
• Oysters are bivalves that grow straight
MARINE ORGANISMS.
up in the water in the intertidal zone.
Oysters are an indicator species,
They may be submerged part or all of
meaning that their presence in the
the day. Like other bivalves they are
water can be used to gather
filter feeders and get their food by
information on the overall health of
siphoning seawater through their body.
the estuary.
Station 10: Cockle shells
• Cockle is the common name for a
group of (mostly) small, edible,
saltwater clams, marine bivalve (2
shells) molluscs in the family
Cardiidae.
• Various species of cockles live in
sandy sheltered beaches
throughout the world.
• The distinctive rounded shells of
cockles are symmetrical, and are
heart-shaped when viewed from
the end
• The mantle has three apertures
(inhalant, exhalant, and pedal) for
siphoning water and for the foot to
protrude. Cockles typically burrow
using the foot, and feed by filtering
plankton from the surrounding
water.
• Cockles are capable of 'jumping' by
bending and straightening the foot.
Station 11: Nautilus
•
•
•
Nautilus (from Greek ναυτίλος, 'sailor') is
the common name of marine creatures of
cephalopod family Nautilidae.
Nautilidae have survived relatively
unchanged for millions of years, and are
often considered "living fossils.“
Nautiluses typically have more tentacles
than other cephalopods, up to ninety.
These tentacles are arranged into two
circles and, unlike the tentacles of other
cephalopods, they have no suckers, and
are retractable.
To swim, the nautilus draws water into
and out of the living chamber which uses
jet propulsion. While water is inside the
chamber, it extracts salt from it and
diffuses it into the blood. The animal
adjusts its buoyancy by pumping gas and
fluid into or out of the chambers along
the siphuncle.
Station 12: Sponge
Sponges are animals of the phylum Porifera
(meaning "pore bearer"). Their bodies
consist of jelly-like mesohyl sandwiched
between two thin layers of cells. While all
animals have unspecialized cells that can
transform into specialized cells, sponges are
unique in having some specialized cells that
can transform into other types, often
migrating between the main cell layers and
the mesohyl in the process. Sponges do not
have nervous, digestive or circulatory
systems. Instead, most rely on maintaining a
constant water flow through their bodies to
obtain food and oxygen and to remove
wastes, and the shapes of their bodies are
adapted to maximize the efficiency of the
water flow. All are sessile aquatic animals
and, although there are freshwater species,
the great majority are marine (salt water)
species. Sponges are considered animals
because they are multicellular having
specialized cells that are dependent upon
one another.
Station 13: Shark
• The Atlantic sharpnose shark is a small shark that attains a
maximum size of 4 feet. It has a long snout and folds around its
mouth. The triangular smooth edged teeth are similar on both
the upper and lower jaws. The Atlantic sharpnose shark can be
brown, olive-gray or blue-gray turning to white on the underside.
Adults may have some white spots and smaller individuals tend
to have black edged dorsal and caudal fins.
• This shark consumes shrimp, molluscs and small fishes.
• Sexual maturity is reached when an individual is approximately
33 inches. The young are nourished within the female and the
young hatch inside the mother’s body then emerge. Litters of 4 to
7 pups are born in June in shallow waters or estuaries. The
newborns are 9 to 14 inches in length.
• The Atlantic sharpnose shark is common in coastal waters at
depths of 42 feet or less during the summer months. During the
winter this shark can be found at depths greater than 90 feet.
Atlanta Sharpnose Shark