Marine Biology

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Marine Biology Field Guide
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(No Transcript)
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Table of Contents
All Life
Prokaryotes
Eukaryotes
DomainEukaryota
DomainArchaea
Domain Eubacteria
KingdomMonera
Kingdom Fungi
KingdomAnimalia
KingdomPlantae
Kingdom Protista
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Kingdom Animalia

• Multicellular / Eukaryotic
• Sexual reproduction
• Life cycle
• - adult always diploid
• - embryo undergoes stages of development
• Heterotrophic - most ingest, then digest
• Most motile by muscle fiber
• Grouped into about 30 phyla

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Some major phyla of animalia

1. Chordata (chordates)
2. Echinodermata (echinoderms)
3. Arthoropoda (arthropods)
4. Mollusca (molluscs)
5. Brachiopoda ( lamp shells)
6. Phoronida (phoronids)
7. Bryozoa (bryozoans)
8. Annelida (segmented worms)
9. Nematoda (roundworms)
10. Nemetera (ribbon worms)
11. Platyhelminthes (flatworms)
12. Ctenophora (comb jellies)
13. Cnidaria or Coelenterata (cnidarians or
    coelenterates)
14. Porifera (sponges)

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Animalia (invertebrates)
Phylum Echinodermata
Class Holothuroidea
Class Echinoidea
Class Stelleroidea
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Echinodermata the echinoderms

• Approximately 7,000 species
• Have spiny skin.
• Radially symmetrical as adults. Larvae are
  bilaterally symmetrical.
• Pentamerous radial symmetry.
• Body has no dorsal, ventral, anterior, or
  posterior side, instead one surface is referred
  to as the oral (mouth) side and the other is the
  aboral side.
• Three main classes Holothuroidea, Echinoidea,
  and Stelleroidea (Asteroidea).

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Class Holothuroidea

• Approximately 1400 species.
• Sea Cucumbers
• Worm-like in shape.
• Skin can be smooth or warty.
• Skin imbedded calcareous deposits.
• Some ingest bottom material.
• Others trap plankton or sweep up detritus with
  their tentacles.
• Can expel most of their internal organs to
  confuse predators.
• Bodies can contain toxins that can deter
  attackers.

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Hairy Sea Cucumber Sclerodactyla briareus
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Hairy Sea Cucumber Sclerodactyla briareus
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Hairy Sea Cucumber Sclerodactyla briareus
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Hairy Sea Cucumber Sclerodactyla briareus
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Hairy Sea Cucumber Sclerodactyla briareus
Description  Its body is about 4 ¾ long, 2
inches wide, and resembles the shape of a sweet
potato. It looks a little like a hairy stone. Its
surface can range in color from black and
brown,to green or purplish. Their bodies are
thickest in the middle the mouth and anal ends
are curved upward and are covered with fine
tubular feet. The sea cucumber also has 10 large,
branchlike tentacles around its mouth.
Habitat The Hairy Sea Cucumber uses its tube
feet to creep along the substrate or to build up
a volcano-like formation of sediment around
itself. When buried it leaves only its mouth and
anal opening exposed.
Range The hairy cucumber is a common holothuroid
that occurs in shallow waters along the east
coast of North America from Massachusetts and
south to Florida and the Gulf of Mexico. Sea
Cucumbers are found in higher salinity waters, on
muddy or sandy bottoms, from the low-tide line to
20 feet deep.
Comments  The tentacles sweep food particles
into the mouth and can be retracted into their
body. If a sea cucumber is picked up or otherwise
disturbed, it will (like a sea squirt) expel
water from the rear opening, and if the
disturbance is intense it can even expel some of
their internal parts, which may sometimesnot
alwaysresults in the death of the animal.
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Generalized Sea Cucumber Anatomy
The body of the sea cucumber is elongated,
leathery and muscular spines are contained
within the skin. These echinoderms have no arms,
but do have five-part symmetry. Surrounding the
mouth are 8 to 30 tentacles (modified tube feet).
Five double rows of tube feet (with tiny suction
cups) run along the body they are used for
crawling along the sea bed or anchoring to a
rock. A sea cucumber breathes by pumping sea
water in and out of an internal organ called a
respiratory tree.
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Class Echinoidea

• Sea Urchins and Sand Dollars
• Skeleton consists of calcareous plates fit
  together in a rigid outer covering.
• Body is covered in fine to coarse movable
  spines.

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Generalized Sand Dollar Anatomy
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Sand Dollar Echinarachnius parma
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Sand Dollar Echinarachnius parma
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Sand Dollar Echinarachnius parma
Description This animal lacks the five arms that
are characteristic of the phylum but does possess
the same five-part radial symmetry (Raven and
Johnson 1999). It is generally about 5-10cm in
diameter when fully grown. They have spines on
the somewhat flattened underside of the animal
allow it to burrow or to slowly creep through the
sand. Fine, hair-like cilia cover the tiny
spines. These cilia, in combination with a mucous
coating, move food to the mouth opening which is
in the center of the star shaped grooves on the
underside of the animal (Page 2000). The opening
for the anus is opposite the mouth on the aboral
surface.
Habitat Sand dollars are found in the intertidal
zones and a little deeper. Often their skeletons
will wash ashore after a storm. They burrow into
the sand for protection and for food (Banister
and Campbell 1985).
Range This species is the common sand dollar of
the North American east coast from New Jersey
north. It is circumpolar and also occurs in
Alaska, British Columbia, Siberia and Japan (Fox
1997).
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Sand Dollar Echinarachnius parma
Comments The sand dollar burrows in the sand at
the sea bottom feeding on algae and fragments of
organic material found in there. They scrape off
substrate with large, triangular teeth that ring
their mouth. The teeth visible in the center of
the mouth are continually growing while being
worn away at their free ends. Therefore, although
they are held firmly in place by ligaments and
other ossicles of the jaws, the teeth must be
periodically shifted toward the mouth. This
shifting is apparently accomplished by tiny
muscles (Telford Ellers 1997). The tube feet
aid in moving substrate to the mouth. Sand
dollars generally feed on the detritus found in
the filtered substrate, but they will also feed
on small plankton and algae (Grzimek 1972).
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Generalized Sea Urchin Anatomy
mouth
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Purple-Spined Sea Urchin Arbacia punctulata
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Purple-Spined Sea Urchin Arbacia punctulata
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Purple-Spined Sea Urchin Arbacia punctulata
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Purple-Spined Sea Urchin Arbacia punctulata
Description The Arbacia punctulata has a deep
purple color all over the spines and body (test).
Their body area, called a test, can grow to a
diameter of 3-5 cm. In addition, they are
radially symmetrical.
Habitat These purple sea urchins are found most
commonly on rocks and shells in somewhat deep
salt water. They prefer to live on rocks or shell
bottoms from the low-tide line to a water depth
of about 750 feet (229 meters).
Range Arbacia punctulata is a common urchin from
Cape Cod to the West Indies.  
Comments  Purple sea urchins, like all sea
urchins, are the porcupines of the sea. They have
long spines in order to deter predators. Even the
name, Sea Urchin, comes from the Old English term
for spiny hedgehog. This test is made up of ten
fused plates that encircle the urchin. Each of
these fused plates has small holes from which the
feet extend. These feet are controlled by an
internal water vascular system. This system works
by varying the amount of water inside which
regulates if the feet are extended or contracted.
Sea urchins also have a unique structure called
Aristotle's lantern. This structure is made of
five hard plates that move together like a beak.
They use this beak like structure to scrape rocks
clean of algae. These 'teeth' can also grow back
after too much wear. They have a mouth at the
underside and an anus at the top of the animal.
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Class Stelleroidea (Asteroidea)

• Sea Stars and Brittle Stars
• Most have 5 arms that radiate from a central
  disk.
• Each arm has a channel that runs its length
  called the ambulacral groove.
• Ambulacral grooves have hundreds of tube feet.

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Generalized external anatomy of Stelleroidea
Oral side
Aboral side
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Generalized internal anatomy of an Echinoderm
Water vascular system Forces water around the
body using muscular action
(a hydraulic system), is
unique to the group and is
used in respiration,
locomotion, and feeding.
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Margined Sea Star Astropecten americanus
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Margined Sea Star Astropecten americanus
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Margined Sea Star Astropecten americanus
Description  These are handsome sea stars with
distinct upper and lower marginal plates. Upper
plates without continuous spines lower plates
with a fringe of spines. Upper side covered with
paxillae. Radius is 3-5 inches.
Habitat They live on bottoms ranging from coarse
gravel to fine mud, although they usually live on
sand. Sand stars live partially or completely
buried. They travel into deeper water during the
winter and swarm closer to shore when the
seawater warms between May and July. They then
release their eggs and sperm into the water,
where fertilization takes place.
Range Common on the East Coast of the United
States from New Jersey to Cape Hatteras. Found
from the low tide line to 150 ft.
Comments Sand stars are greedy predators of
mollusks, worms, crustaceans, and other sea stars
and their relatives. They dig up their prey and
swallow it whole. Starfish are well known for
their powers of regeneration. A complete new
animal can grow from a small fragment such as a
arm. In some species (Linckia multifora and
Echinaster luzonicus) one of the arms will
virtually pull itself away, regenerates and forms
a new animal. Autotomy (self amputation) usually
is a protective function, losing the body part to
escape a predator rather than being eaten. But
here it serves as a form of asexual reproduction.
In other species of sea stars (Allostichaster
polyplax and Coscinasterias calamaria) the body
is broken into unequal parts ( fission) then the
missing limbs regenerate.
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The madreporite structure
This structure will be found on the top, or
aboral (away from the mouth) surface, of most sea
stars. It is usually about 1/50th of the diameter
of the sea stars arms, so it can be easily
missed. When 18th century biologists studied sea
stars closely with a microscope, they thought
this structure looked like a miniature brain
coral. Brain corals belong to a group called the
madreporarian corals, so the name of this sea
star structure became the madreporite. Sea water
can pass through the madreporite and enter the
animals water vascular system. The madreporite
acts as an effective filter, keeping out floating
particles and living organisms (such as
parasites) that might harm the sea star.
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Forbes' Asterias