Aquatic Life - Vertebrate Animals
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In this unit we will discuss
characteristics of aquatic
animals categorized as
vertebrates (animals with
backbones) beginning with
fish.
Summaries = Purple
Underlined = Vocabulary
Photo Credit: Ken Knezick - Island Dreams
Image
Chordate Characteristics
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1.
2.
http://www.gutenberg.org/files/18559/1
8559-h/images/figure30.jpg
At some stage in their
development, all chordates
share four main characteristics…
A dorsal, hollow nerve cord will
later connect the brain to the rest
of the body (internal organs,
muscles, and sense organs in
advanced organisms).
The notochord is a long
supporting rod that runs through
the body just below the nerve
cord (it will be replaced by the
backbone in advanced
vertebrates).
Nerve Cord/Notochord
http://www.theamericanchiropractor.com/images/block-vertebra.jpg
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The nerve cord
becomes the spinal
cord.
The notocord becomes
your backbone.
Think about how your
brain communicates to
the body; through the
nerve cord.
If that is cut, then an
organism is paralyzed!
(Your spinal cord runs here)
http://www.umm.edu/spinecente
r/education/images/vertebra.jpg
Chordate Characteristics Cont.
3.
Pharyngeal
pouches are found
in the throat region
and will develop
into gills or other
structures such as
jaws or inner ear in
some organisms.
4. A tail is retained (kept) by
most chordates throughout
their lives.
 Humans go through a stage
in as a fetus where we have
a tail for about two weeks.
http://www.biologycorner.com/bio2/notes33.html
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Human fetus early in
gestation (after
sperm and egg unite)
at about 2 – 4 weeks.
Sometimes the
human is born with
the tail and doctors
will just remove it
with a laser and cut it
off.
http://www.chanceandchoice.com/
ChanceandChoice/38daysheart.jpg
Traits of All Chordates
http://fig.cox.miami.edu/~cmallery/150/physiol/c34x2chordates.jpg
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Sketch & Label
Introduction to Vertebrates
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Kingdom Animalia
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Phylum Chordata
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Subphylum Vertebrata (animals that have
backbones)
2 subphylums of non-vertebrate chordates that
do not have backbones ()
1. Subphylum Urochordates - Tunicates (sea
squirts)
2. Subphylum Cephalochordata (lancelets)
Tunicates
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Scientists believe that
vertebrates evolved from
ancient marine organisms like
tunicates and lancelets.
These chordates are soft
bodied marine organisms;
they have a nerve cord but
NOT a backbone.
http://www.aboututila.com/Reviews/Charlie-Johnson/Photos/BluebellTunicates.jpg
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Tunicates are filter
feeding; go through a
youth larval stage before
their adult stage (below).
Lancelets
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Lancelets are small, fish
like creatures that live
on the ocean floor.
They have a closed
circulatory system
(blood vessels), but no
true heart and are thin
enough that they filter
oxygen straight through
their skin.
http://upload.wikimedia.org/wikipedia/commons
/thumb/a/a0/Branchiostoma_lanceolatum.png/1
80px-Branchiostoma_lanceolatum.png
Subphylum Vertebrata
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Members of subphylum vertebrata have an
endoskeleton (an internal skeleton) which can
support large body and grows as the animal
grows.
The skeleton includes a backbone which is a
series of bones known as vertebrae that
surround and protect the spinal (nerve) cord
Vertebrates have a distinct skull attached to the
end of the backbone.
Vertebrates also have a well developed brain
and sensory organs located in the skull
(Cephalization).
http://trc.ucdavis.edu/biosci10v/bis10v/week10/brainevolution.gif
Timeline - Vertebrate Evolution
About
Age
Animals
550 million years ago
Ordovician Period
First vertebrates
jawless fishes
400 million years ago
Devonian Period
"Age of Fishes"
Acanthodians
jawed fish
350 million years ago
Carboniferous Period (and
Permian)
"Age of Amphibians"
Amphibians
240 million years ago
Triassic Period
Jurassic Period
"Age of Dinosaurs"
reptiles appeared
dinosaurs dominated the
land for 150 million years sauropods, theropods, etc..
60 million years ago
Tertiary Period
"Age of Mammals"
Dinosaurs extinct
Mammals appeared
340,000 years ago
Quaternary period
Humans appeared
Characteristics: Temperature
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http://www.zum.de/Faecher/Materialien/beck/bild
er/wechsel.jpg
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Vertebrates adapted into 2 different
ways to regulate body temperature.
Ectotherms have a body
temperature that matches the
external environment.
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ecto = outside and therm =
heat
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EX fish, amphibians and
reptiles
Endotherms can maintain a
constant internal body temperature
(using energy and adaptations such
as hair and fat layers).
Endotherms, therefore require more
food than an ectotherm.
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endo = inside
birds and mammals
Characteristics: Circulation
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Vertebrates have a
closed circulatory system.
This means that all blood
flow is contained within
blood vessels.
They also have a multichambered heart pumps
oxygen and nutrients to
the body.
Characteristics: Reproduction
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Oviparous – eggs hatch outside
the mother’s body and the yolk
provides nourishment
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Ovoviviparous – eggs are held
inside and hatch in the mother’s
body and then young are born
alive; yolk = nourishment
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EX chickens, turtles
EX sharks
Viviparous – young develop
inside mother’s body and gets
nourishment from the mother
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EX humans, dolphins
http://courses.washington.edu/vertebra/451/
photos/dogfish_embryo_ventral.jpg
Fish - Reproduction
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http://www.ufz.de/data/5460
Fish can have internal
or external fertilization
to reproduce.
Fish produce many
more eggs
(oviparous) than the
environment can
support.
Only the fastest,
strongest and best
are adapted survive.
Fish - Excretion
http://www.info
visual.info/02/
033_en.html
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Fish get rid of waste products in the form of ammonia.
Fish use a stomach, intestines, and kidneys to filter the wastes
from the blood which then is excreted through the anus.
Introduction to Fish
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Our first group of vertebrates that we will discuss
will be fish - covered by more than two-thirds of
water, Earth displays a huge variety of fish.
Fish (not “fishes”) are aquatic organisms that can
survive only in water.
http://www.noeticart.com/clipart/GreenAngler.jpg
http://www.mikelevin.com/ColorfulFishBig.jpg
Jawless Fish
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http://www.zoo.ufl.edu/courses/vertzoo/Images/B
onyfishlab2/Lamprey.jpg
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http://img.alibaba.com/photo/114
15707/Hagfish.jpg
Class Agnathans
As their name implies, these fish
have no true teeth or jaws.
Lack paired fins and are shaped
more like worms than other fish.
These are the only vertebrates to
retain (keep) a notochord
throughout their life.
Lampreys – parasites that feed on
host’s body fluids; have no paired
fins
Hagfish – scavengers
Sharks & Rays
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http://www.globalj
ourneysmusic.co
m/club%20picture
s/aqwa%20%2004_07_04/im
ages/14%20cool
%20sting%20ray.j
pg
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http://www.tahiti.pictures-pacific.com/bora-bora/shark.jpg
Class Chondrichthyes
This group of fish includes sharks
and their relatives sting rays.
Their skeletons made of flexible
cartilage (like our noses) with
tooth-like scales covering skin that
feel like sandpaper.
They have stiff fins and their gills
do not have covers.
These fish are adapted to deepsea life.
Some are carnivores while others
are filter feeders.
Internal fertilization with live birth.
(ovoviviparous ).
Bony Fish
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http://www.emill.com/emill_dynamic/image6in/puffer_fish.jpg
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Class Osteichthyes
These fish have skeletons
made of a calcified tissue
called bone.
In many fish, the female lays
the eggs and the embryos in
the eggs develop and hatch
outside her body
(oviparous).
These eggs are soft-shelled
eggs.
Flexible fins are used for
movement.
Bony Fish Subclasses – Ray-finned
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Ray-finned fish (the largest, most diverse group) are so
called because of the thin bony spines, or rays, that help to
form the fins.
Ray-finned fish have adapted to every kind of aquatic
environment and evolved into thousands of species.
http://www.goals.com/WorldDiveQuest/Pics/Maldives/lionfish.jpg
http://www.horsehomeopathy.com/im
ages/beta-fish.jpg
Fish - Adaptations for Water
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Fish are characterized by overlapping scales
that cover the skin to provide protection.
These scales are coated in a slippery mucus to
reduce friction in the water and help them to
swim faster.
Fish have paired fins to help steer and provide
stability in the water (movement).
Fish have an internal swim bladder to allow them
to move up or down in the water or remain at a
given depth.
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Think of it as a thin balloon-like sac; with air the fish goes
up in the water, without air the fish sinks (not found in
sharks).
http://www3.telus.net/kerryw/creature/fish.jpg
http://www.kentuckylake.com/fishing/fishf
acts/pics/ext-anat.jpg
Cont. Adaptations for Water
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The lateral line system is a sense organ that
detects vibrations and changes in the water
pressure and alerts fish to movement of other
organisms in the water.
Fusiform shape allows a fish to move through
the water effectively; fish are tapered at both
ends to increase speed through the water.
http://www.hatchesmagazine.com/images/12806.04.01.jpg