Chordata (Fish)

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Chordata (Fish)

• Myxini(Hagfish) Cephalaspidomorphi(Lampreys)
  Chondrichthyes(Sharks, Rays) Actinopterygii(ray-fi
  nned fish) Actinistia(Coelacanths)
  Dipnoi(Lungfish)
• Colin Green, Tyler Simowitz

http//www.utsc.utoronto.ca/youson/images/lamprey
.jpg
Tyler
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What is a fish?

• What we call fish only apply to one clade of
  vertebrates - the Actinopterygians, which we will
  discuss later
• However, for all of our sakes, we will refer to
  all of the following as fish

Colin, Tyler
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Chordata
http//www.cartage.org.lb/en/themes/Sciences/Zoolo
gy/Biologicaldiverstity/AnimalsIII/chordate.gif
colin
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Hagish (Myxini)
http//www.nicholls.edu/biol-ds/biol348/fishsets/p
ics/hagfish.jpg
colin
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Lamprey(Ceohalaspidomorphi)
http//bradyonthebrain.files.wordpress.com/2009/04
/lamprey-mouth.jpg
colin
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Ray-Finned(Actinopterygii)
http//superlative1.files.wordpress.com/2008/03/fi
sh-anatomy.jpg
Tyler
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Shark(Chondrichthyes)
http//static.howstuffworks.com/gif/tiger-shark-an
atomy.jpg
Tyler
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Lungfish(Dipnoi)
http//static.howstuffworks.com/gif/willow/lungfis
h-info0.gif
Tyler
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Body Cavity

• Myxini coelom
• Cephalaspidomorphi coelom, vertebrae
• Chondrichthyes coelom, vertebrae, jaw
• Actinopterygii coelom, vertebrae, jaw
• Actinistia coelom, vertebrae, jaw
• Dipnoi coelom, vertebrae, jaw

Colin, Tyler
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Body Symmetry

• Myxini symmetrical
• Cephalaspidomorphi symmetrical
• Chondrichthyes symmetrical
• Actinopterygii symmetrical
• Actinistia symmetrical
• Dipnoi symmetrical

Colin, Tyler
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Nervous System

• Myxini yes, 2 brains
• Cephalaspidomorphi dorsal nerve, true nervous
  system
• Chondrichthyes yes
• Actinopterygii yes
• Actinistia yes
• Dipnoi yes

Colin, Tyler
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Circulatory System

• Myxini present, 4 hearts
• Cephalaspidomorphi present
• Chondrichthyes present
• Actinopterygii present
• Actinistia present
• Dipnoi seperation of pulmonary

Colin, Tyler
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Digestive System

• Myxini slow metabolism, can go 7 months without
  food
• Cephalaspidomorphi parasite, sucks blood, rows
  of teeth
• Chondrichthyes spiral valve, prolongs passage of
  food, stomach
• Actinopterygii stomach, intestines
• Actinistia stomach, intestines
• Dipnoi stomach, intestines

Colin, Tyler
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Excretory System

• Myxini mouth, anus
• Cephalaspidomorphi mouth, anus
• Chondrichthyes mouth, anus, bladder
• Actinopterygii mouth, anus, large amounts of
  dilute urine, controls saltwater balance
• Actinistia mouth, anus, dilute urine
• Dipnoi mouth, anus, urine

Colin, Tyler
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Locomotion/Musculature

• Myxini paddle like tail, sluggish
• Cephalaspidomorphi tail to propel
• Chondrichthyes power movement of trunk and
  caudal(tail), propel forward, dorsal fins -
  stability, paired pectoral (fore) and pelvic
  (hind) help float
• Actinopterygii fins for maneuvering and defense
• Actinistia fins
• Dipnoi tail and pectoral-pelvic fins

Colin, Tyler
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Skeletal Structure

• Myxini skull contains cartilage
• Cephalaspidomorphi cartilage skeleton
• Chondrichthyes cartilage, mineralized
  skeletonActinopterygii bony
• Actinistia bony
• Dipnoi bony, skull

Colin, Tyler
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Sensory Structures

• Myxinieyes, ears, naval openings, one norstril
• Cephalaspidomorphi large eyes, one nostril
• Chondrichthyes sharp vision, nostrils, detect
  electric fields
• Actinopterygii eyes, nostrils
• Actinistia eyes, nostrils
• Dipnoi eyes, nostrils

Colin, Tyler
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Reproduction

• Myxini lay eggs, no larvae stages, some
  hermaphrodites. Not well known
• Cephalaspidomorphi egg-larvae-metamorphus-adult
• Chondrichthyes eggs fertilized internally,
  pelvic fins-transfer sperm. Oviparous - newborn
  hatches outside of body, Ovoviviparous-
  internally
• Actinopterygii eggs fertalized/born outside
• Actinistiagive birth to live young
• Dipnoi external, dig hole in mud to protect

Colin, Tyler
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Gas Exchange

• Myxini one gill
• Cephalaspidomorphi 7 gills
• Chondrichthyes uses gills
• Actinopterygii gills
• Actinistiagills
• Dipnoigills and lungs

Colin, Tyler
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Unique Features

• Myxini creates slime for protection
• Ceohalaspidomorophi attack humans only when they
  are starving
• Chondrichthyes more dense than water makes them
  sink if they stop swimming
• Actinopterygii includes 96 of all fish species
• Actinistia Still alive, 2 species have been
  found
• Dipnoi In dry periods, they burrow into the mud
  and go into a fish hibernation

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Quiz

• 1. Which was the first bony fish?
• A)Dipnoi
• B)actinopterygii
• C)Chondrichthyes
• D)Ceohalaspidomorphi

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• B is the correct answer

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• 2. Which of the following has two brains?
• A) Myxini
• B)Actinistia
• C)Ceohalaspidomorphi
• D)Dipnoi
• E)Chondrichthyes

Colin, Tyler
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• The correct answer is A, Myxini have two brains
  and four hearts

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• 3. What is the fin called that propels a shark
  forward
• A)Pectoral
• B)Pelvic
• C)Caudal
• D)Dorsal

Colin, Tyler
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• Correct answer is C

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• 4. What do lampreys have that Myxini dont
• A)Nostrils
• B)Bones
• C)Eyes
• D)Vertebrae

Colin, Tyler
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• Correct answer is D