Transcript Beachcombing - The Aquila Digital Community

Beachcombing
Shells commonly found along the
Mississippi Gulf Coast
BSC 504/L
TA: Christy Hollis Phillipoff
Angel Wing
Family: Pholadidae
Cyrtopleura costata
Pholadidae,
known as
piddocks or
angelwings, are a
family of bivalve
mollusk similar to
a clam. One of
the piddock's
shells has a set of
ridges or "teeth",
which they use to
grind away at clay
or soft rock and
create tubular
burrows.
The piddock stays in
the burrow it digs for
the entirety of its
eight year lifespan,
with only its siphon
exposed to take in
water that it filters
for food.
Angel Wing Cont.
C. costata, like other
bivalves, is a filter feeder, and
uses its incurrent siphon to
transport microalgae and tiny
zooplankton into its body. has
approximately 26 radiating
ribs. It cannot retract its
siphons into the protection of
its shell, so the two valves
can never shut completely.
The muscles fusing the
shell's valves together are
weak, making it rare to find
angelwings with both halves
still intact.
Oysters
Family: Ostreidae
Crassostrea virginica
Oysters
Family: Ostreidae
Crassostrea virginica
• The calcium carbonate from the shells are commonly used in
the following medications: Brand Names: Alka-Mints, Amitone,
Cal-Gest, Calcarb, Calci Mix, Calci-Chew, Caltrate, Chooz,
Maalox Antacid Barrier, Maalox Quick Dissolve, Maalox Quick
Dissolve Maximum Strength, Mylanta Child, Nephro Calci, OsCal 500, Oysco 500, Oyst Cal 500, Oyster Calcium, Oyster Shell,
Rolaids Sodium Free, Rolaids Soft Chew, Tums, Tums 500,
Tums E-X, Tums Ultra
• Atlantic oysters, unlike some species, have separate sexes.
• Folklore says that oysters should be eaten only in months with
"r's" in them—September, October, The notion that oysters
should not be eaten in "r"-less months—that is, months that
occur during warm weather—may have started in the days
when oysters where shipped without adequate refrigeration
and could spoil.
25 different
genera and over
200 species
Cockles typically
burrow using the
foot, and feed by
siphoning water in
and out, sifting
plankton from it.
Cockle Shells
Family: Cardiidae
Cockles are
capable of
'jumping' by
bending and
straightening
the foot.
the zoological name
for one cockle
genus being
Cardium, from the
Greek for heart
Knobbed Whelk
Family: Melongenidae
Busycon carica
• The shell of the knobbed whelk is dextral, meaning that it is righthanded. If you hold the shell in front of you, with the spiral end up
and the opening facing you, the opening will be on the right side.
• The knobbed whelk has two pairs of tentacles on the head. The
larger pair each have a light-sensitive eyespot. The smaller pair of
tentacles is used for the sense of smell and the sense of touch.
• On the shallow-water mud flats whelk prey on oysters, clams, and
other marine bivalves. They eat bivalves by separating the shells
with their own hard shell and inserting their long proboscis to
retrieve the flesh of their victim. They eat using a radula, a rough
tongue-like organ that has thousands of tiny denticles (tooth-like
protrusions).
Whelk Egg Casing
Each disk contains 20 or
more eggs that develop in
about two weeks into hungry
baby whelks, complete with
fully developed shells. On
average each capsule
contains 0-99 eggs, with
most strings having 40-160
capsules. After laying their
egg cases, female knobbed
whelk will bury one end of
the egg case into the
substrate, thus providing an
anchor for the developing
fertilized eggs and
preventing them from
washing ashore where they
would dehydrate. Fertilized
eggs will emerge as juvenile
knobbed whelk
approximately 4 mm in
length.
Lightning Whelk
Family: Melongenidae
Busycon contrarium
Very common on mud flats, bay
waters
Most often, these whelks eat clams-usually one a month. With its large
foot, the whelk pries open the clam's
shell. Then, with the clam shell held
open by the edge of its own shell, the
whelk sends its proboscis and
toothed, tongue-like radula inside to
rasp and eat the softer "meat."
Has been
accidentally
introduced
well outside
of its natural
range.
Oyster Drill
Family: Muricidae
Urosalpinx cinerea
Oyster Drill Cont.
Next to the starfish, this snail is the worst enemy the oyster. Settling
upon a young bivalve, the oyster drill quickly bores a neat round
hole through a valve, making expert use of its sandpaper-like radula.
Through this perforation the oyster drill is able to insert its long
proboscis and consume the soft parts of the oyster.
Mermaid’s Purse
Actually a skate’s
egg casing!!!
Sea Beans
• These sea-beans come from trees and vines that grow
along tropical shores and rain forests all over the world.
The seeds or fruits fall from their parent plant into
waterways, such as the Amazon River, then drift through
inlets to reach the ocean. They travel with ocean
currents until they wash up on a beach somewhere,
perhaps thousands of miles from their origin. Sea-beans
are quite hard and buoyant, which helps them survive
their long-distance voyage.
Sea Beans Cont.
Entada gigas Sea heart from huge
vine in Golfito, Costa Rica.
Sea Beans Cont.
Mucuna fawcettii. Caribbean drift seed. Hilum
thicker than other Mucuna species
Baby’s Ear
Family: Naticidae
Sinum perspectivum
Reaches 1-1½ inches in
diameter. It is almost flat with a
large aperture, or opening, and
a curve like a human ear.
It is a gastropod and
is a carnivorous
snail!
The underside of
the shell has a
shelf like deck
which forms a
niche for the
animal to with
draw into.
Habitat: Found
attached to
rocks, shells,
and other hard
objects, at the
low-tide line or
deeper.
Slipper Shell
Family: Calyptraeidae
Genus: Crepidula plana
This snail
remains in one
place for most of
its existance with
its shell
conforming to fit
where it has
chosen to live
and grow. It
feeds by filtering
water through its
gills which are
covered with
mucous and
moves the food
particles to its
mouth by way of
its cilia.
Spiny Jewel Box
Family: Chamidae
Chama is a sole
surviving genus of
a very prolific
group of fossil
oysters dating
from the Jurassic
and Cretaceous
periods, some
200 million years
ago. It is of
interest mainly
because it seems
to occupy an
intermediate
evolutionary step
between two
extinct families of
the Chamacea
superfamily.
Arcinella arcinella
Chama is an oyster-like
bivalve that has
developed a
permanently attached
mode of life. Its deeply
conical right valve (in
the pictures at right, the
upper valve) is
cemented to some
substrate, while the
somewhat flattened left
valve forms an
operculum-like cover.
Consistent with its
immobility, the foot is
greatly reduced.
•The olive snails
are all carnivorous
sand-burrowers.
They feeding
mostly on bivalves
and carrion and
are known as
some of the fastest
burrowers among
snails. They
secrete a mucus
similar to that of
the Muricidae,
from which a
purple dye can be
made.
Olive Shell
Family: Olividae
Oliva sayana
These
snails are
found on
sandy
substrates
intertidally
and
subtidally.
predatory sea
snails
Shark Eye or Moon Shell
Family: Naticidae
Neverita duplicata
• The called the shells shark eye
shells because if you put the hand
in the middle of the shell it looks
like a shark's eye
• Previously known as Polinices
duplicatus
Shark Eye or Moon Shell
Family: Naticidae
Neverita duplicata
Shark eye shell - or moon snail,lives
in shallow water and near the low-tide
line,eats mussels and clams.
this gastropod plows through sand
search of bivalves and snails .It wraps
its foot around the prey begins the
slow process of drilling a round a hole
in shell to eat the tissues by sticking a
proboscis into the shell to extract the
soft parts. This snail only eats when it
is buried
The Moon snail secretes an acid onto
the victim's shell, then pierces the
softened spot on the shell with its
radula (a fleshly, toothed tongue). One
of the Moon Snail's favorite foods is
the Coquina clam
The name "Scotch
bonnet" comes from
the fact that the
checkered shell of
this species has a
vague resemblance
to a traditional tartan
hat, as used to be
commonly worn in
Scotland.
Scotch Bonnet
Family: Tonnidae
Phalium granulatum
This sea snail lives
subtidally, on offshore
sandy bottoms.
The shell is somewhat
fragile: an intact
Scotch bonnet shell is
a rare find for a
beachcomber.
Florida Auger
Terebra floridana
Auger snails have a
poison gland, and a
harpoon-like “tooth”
which can be ejected
from the proboscis to
stab worms and small
fish. American
Augers, however, do
not pose a threat to
shell collectors.
Pen Shell
Family: Pinnidae
Atrina rigida
may reach a length
of 1 foot. (Some
types of Pen Shells
grow as long as two
feet, and
occasionally contain
black pearls.)
lives in soft bottoms, with
the majority of the shell
buried, point down,
leaving only a few inches
exposed,
It is a filter feeder,
taking in water and
nourishment through
the gap between the
valves
is noted for its ability to heal
breaks and holes made in its
shell
Intertidal
migration
behavior is
well
documented.
Coquina
clams use
their muscular
foot to
repeatedly
rebury
themselves
after being
washed from
sand by
incoming
waves.
Coquina
Family: Donacidae
Donax variabilis
They
are filter
feeders
Kitten’s Paw
Family: Plicatulidae
Plicatula gibbosa
The living bivalve, or
“pelecypod,” lives
attached to coral or
rocks. Collectors usually
find one valve of the
creature, rather than the
two halves joined by
their hinge.