chordata (fish) nealansh gupta, siddhartho bhattacharya, richard tong period 1
TRANSCRIPT
Chordata (Fish)
Nealansh Gupta, Siddhartho Bhattacharya, Richard TongPeriod 1
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PhylaMyxini: jawless Hagfish, snake like
Cephalaspidomorphi: Lampreys; oldest living lineage of verabrates. 35 species
Chondrichthyes: Sharks, rays, etc. The biggest and most successful predators
Actinopterygii: Ray-finned fishes; common fishes: bass, clownfish, tuna, etc.
Actinistia: Lobed fin, spike containing fish
Dipnoi: Lungfish, freshwater
Siddhartho Bhattacharya
Examples
Myxini (hagfish) http://en.wikipedia.org/wiki/File:Pacific_hagfish_Myxine.jpg
Actinistia (coelacanths) http://en.wikipedia.org/wiki/File:Latimeria_Chalumnae_-_Coelacanth_-_NHMW.jpg
Chondrichthyes (Shark)http://en.wikipedia.org/wiki/File:White_shark.jpg
Cephalaspidomorphi) (Lamprey)http://en.wikipedia.org/wiki/File:Diversas_lampreas.1_-_Aquarium_Finisterrae.JPG
Dipnoi (South American Lungfish) http://en.wikipedia.org/wiki/File:Lepidosiren_paradoxa_0.jpg
Actinopterygii (regular fish) http://z.about.com/d/animals/1/G/s/Q/fishes.jpg
Nealansh Gupta
Body Cavity
All contain a coelom (fluid filled space separating digestive tract from the outer body wall; tissue usually derived from the mesoderm.
Richard Tong
Body Symmetry
All fish are bilateral (mirror image halves)
Myxini and Cephalaspidomorphi also contain radial symmetry (symmetry radiating along the center)
Nealansh Gupta
Nervous SystemAll are cephalized with brains
Myxini: contain 2 brains. Lack a SNS. Contain free nerves throughout skin.
Cephalaspidomorphi: Complete CNS.
Chondrichthyes: Simple brain, simple column, simple network of nerves.
Actinopterygii: complete CNS
Actinistia: CNS
Dipnoi: CNS
Siddhartho Bhattacharya
Circulatory SystemALL HAVE CLOSED CIRCULATORY SYSTEMS
Myxini: primitive circulatory sytem with 4 hearts, one is brachial and serves as main pump while the other 3 serve as accessory pumps.
Cephalaspidomorphi: two chambered heart.
Chondrichthyans: two chambered heart. RBC created not in bone marrow but in the spleen and special tissue around gonads.
Actinoterygii: two chambered heart. No separation of oxygenated and deoxygenated blood.
Actinistia: two chambered heart.
Dipnoi: partial four chambered heart. Separation of oxygenated and deoxygenated blood
Richard Tong
Digestive SystemAll ingest through the mouth
Myxini: Eat dead things from the inside out. Food in gut is enclosed in an impermeable membrane.
Cephalaspidomorphi: Use teeth to get through skin to suck blood. Gut is their stomach.
Chondrichthyes: Short digestive tract with a spinal valve within shark intestine to increase SA and prolong food passaging.
Actinopterygii, Actinistia, Dipnoi: Breakdown in esophagus. food digested in stomach and processed in finger shape pouches, secrete enzymes and absorb nutrients. Intestine completes process.
Nealansh Gupta
Excretory System
All fish excrete through anus. All have kidneys
Myxini, Cephalaspidomorphi: Have 2 kidneys. Only use their mesonephric kidney (do not use the other one)
Chondrichthyes: Sharks urinate through penis.
Actinopterygii, Actinistia, Dipnoi: Contain a urinary bladder.
Richard Tong
Locomotion/MusculatureMusculature: All contain a complex muscle system similar to that of humans
Myxini: swim in snakelike fashion by using their segmented muscles to exert force on their notochord
Cephalaspidomorphi: they use an anguilliform (movement by snaking body through water) similar to myxini, but laterally direct a wave along body. Have the ability to swim backwards.
Chondrichthyans: contain fins for movement; shark like chondrichthyans contain a heterocercal tail for locomotion and rays contain flexible pectoral fins
Actinoterygii and Actinistia: anterior to posterior sequential contractions along one side of the body with simultaneous relaxation along other side. Actinistia also use fins.
Dipnoi: contain small leg-like appendages to move over rocks and mud and all other surface obstacles.
Siddhartho Bhattacharya
Skeletal TypeMyxini have no vertebrae but notochord (strong flexible rod of cartilage); all other phyla contain a vertebrae
Myxini, Cephalaspidomorphi, and Chondrichthyans contain cartilage skeletons (Chondrichthyans have calcium cartilage)
Actinoterygii, Actinistia, and Dipnoi have bone skeletons.
Actinoterygii: fins supported by flexible bone rays
Actinistia and Dipnoi: fins supported by rod shaped bones and spikes
Nealansh Gupta
Sensory Structures/Features
All have lateral lines (detects motion/vibration in water)
Myxini: 2 simple eyespots. No eye muscle. Single nostril. 6-8 barbels (whiskerlike tactile sensory organ near mouth)
Cephalaspidomorphi: 2 large eyes. one nostril on top of head
Chondrichthyes: Keen smell. 2 complex eyes (contract/dilate). 2 nostrils. May have sharp hearing. Electroreception.
Actinopterygii, Actinistia, Dipnoi: 2 complex eyes. Inner ears. Smell. two nostrils.
Siddhartho Bhattacharya
Reproduction
All are sexual reproduction. All external fertilizers (oviparous) except sharks. All have testes and ovaries.
Myxini: Some are hermaphroditic (but only one gamete functions) no larva stage
Cephalaspidomorphi: Larva stage
Chondrichthyes: Internal fertilization. Fetus can grow inside female, can be in egg outside body, maintain a placental link.
Nealansh Gupta
Gas Exchange
All have gills, allow for oxygen carbon dioxide exchange through capillary network.
Water pumped over gills pushing oxygen poor water out and pulling in oxygen rich water through mouths.
Myxini, Cephalaspidomorphi, Chondrichthyes: contain multiple gill openings
Dipnoi: Have paired lungs; must surface to gulp air. Some are obligate air breathers (must breathe air periodically)
Richard Tong
OtherMyxini: Produce slime to escape capture and distract predators.
Cephalaspidomorphi: Attack prey by attaching mouths to animal and use teeth to cut through skin and scales to suck blood.
Chondrichthyes: sharks jaw is not attached to its cranium. It has a layer of tiny hexagonal plates which give some strength.
Actinopterygii: comprises of nearly 95% of the 25,000 species of fish
Actinistia: Have a symmetrical tail
Dipnoi: Contain little legs for movement
Siddhartho Bhattacharya
QUIZ QUESTIONS!
Richard Tong
WHAT PHYLUM DOES NOT HAVE A VERTEBRAE?A. ChondrichthyesB. MyxiniC. ActinistiaD. Dipnoi
MYXINI
Which Phylum is a coelomate?A. PoriferaB. CnidariaC. Chordata (fish)D. Platyhelminthes
Chordata (fish)
WHICH CONTAIN A CEPHALIZED NERVOUS SYSTEM?A. ChondrichthyesB. MyxiniC. ActinistiaD. All
All
True or False:All Chordata (fish) contain
lateral lines
TRUE
THE END
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