chondrichthyes & agnatha

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Chondrichthyes & Agnatha Sienna Navarro 9B

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Chondrichthyes & Agnatha. Sienna Navarro 9B. Chondrichthyes. Meaning It comes from the Greek words chondr and ichthyes = cartilaginous fish cartilage fish. Chondrichthyes. First Fossil Comes from the early Devonian age 416 million years ago Elasmobranches: Cladoselache. - PowerPoint PPT Presentation

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Page 1: Chondrichthyes  &  Agnatha

Chondrichthyes & Agnatha

Sienna Navarro 9B

Page 2: Chondrichthyes  &  Agnatha

Chondrichthyes Meaning

• It comes from the Greek words chondr and ichthyes = cartilaginous fish cartilage fish

Page 3: Chondrichthyes  &  Agnatha

Chondrichthyes First Fossil

• Comes from the early Devonian age• 416 million years ago

Elasmobranches: Cladoselache

Page 4: Chondrichthyes  &  Agnatha

Chondrichthyes Number of Species

• 934 species: 383 species of sharks 516 species of rays• 35 species of chimaeras

Page 5: Chondrichthyes  &  Agnatha

Chondrichthyes Characteristics

• Endoskeleton entirely cartilaginous• Tough skin covered in dermal denticles • No Swim Bladder• Two chambered heart• Acute senses• Sharks shed and replace teeth

Page 6: Chondrichthyes  &  Agnatha

Chondrichthyes Life Cycle & Expectancy

• Average life expectancy: 20-50 years

• Longest living species: whale shark 100-150 years

• 3 types of embryonic development: Oviparous: “egg birth” Ovoviviparous: “live egg birth” Viviparous: “live birth”

Page 7: Chondrichthyes  &  Agnatha

Chondrichthyes Oviparous- “egg birth”

• Female shark deposits eggs cases in sea• Developing embryo receives nutrients from a

yolk formed prior to fertilization

Page 8: Chondrichthyes  &  Agnatha

Chondrichthyes Ovoviparous- “live egg birth”

• Female retains membrane covered eggs

• Embryo sheds membrane develops in uterus Some species receive nutrients from direct lining

Other species the embryo obtains nutrients by swallowing eggs / other embryos

Page 9: Chondrichthyes  &  Agnatha

Chondrichthyes Viviparous- “live birth”

• Embryo and attached yolk grow in uterus• Outside layer of yolk contacts mother’s uterus

• Receives nutrients

Page 10: Chondrichthyes  &  Agnatha

Chondrichthyes Digestive System

• Swallow food whole or in large pieces

• Strong acids and enzymes used to dissolve food Creates liquid mush Nutrients absorbed in intestine

• Indigestible things are vomited

Page 11: Chondrichthyes  &  Agnatha

Chondrichthyes Respiratory System

• Species breathe through 5-7 gills

• Pelagic fish must continue swimming to keep oxygenated water moving though their gills

• Demersal fish pump water in through spiracles; out through gills

Page 12: Chondrichthyes  &  Agnatha

Chondrichthyes Circulatory System

• Closed circulatory system• Two chambered heart:

Atrium Ventricle

• Atrium pumps blood to ventricle• Venticle pumps blood to conus• Blood travels from conus to gills• Oxygenated blood flows through

body• Blood returns to atrium

Page 13: Chondrichthyes  &  Agnatha

Chondrichthyes Sensory System

• One inner ear Detects sound, acceleration, gravity

• Lateral line

• Eye sight Sensitive to light and moving objects

• Smell Very acute Not connected with the mouth Barbels: responsive to chemical movement

Page 14: Chondrichthyes  &  Agnatha

Agnatha

Page 15: Chondrichthyes  &  Agnatha

Agnatha Meaning:

It translates to “no jaws”

Number of Species• 84 species• Lampreys • Hagfish

First Fossil• Appeared during Cambrian period: • 524 million years ago• Myllokunmingia

Page 16: Chondrichthyes  &  Agnatha

Agnatha Characteristics

• Jaws are absent• No appendages• 7+ “gill” pouches • The digestive system lacks a stomach• Cartilaginous skeleton• Two chambered hearts• Slender, eel-shaped body• Notochord persists in adults

Provides support

Page 17: Chondrichthyes  &  Agnatha

Agnatha Lamprey: Life Cycle & Expectancy

Eggs hatch - become larvae

Larvae live in river mud from 3-10+ years Feed off of decaying organisms and fecal matter

Metamorphic Phase(3-4m) / Migrate to sea (12-20m) Develop teeth on sucking disks

Spawning Phase (3m) / Death Lay eggs Die within the month spawning

Page 18: Chondrichthyes  &  Agnatha

Agnatha Lamprey: Digestive System

• Attack prey• Attach mouth to prey’s body• Cut through the skin and scales• Food = fish blood• Mouth Pharynx Esophagus• Esophagus directly to intestine (nutrients absorbed)• Waste released through anus

• Dual immune defense system

Page 19: Chondrichthyes  &  Agnatha

Agnatha Hagfish: Life Cycle & Expectancy Little is knows of hagfish life span

• Born fully developed• Hermaphroditic• Choose sex during mating season (can alternate)• Females lay small number of eggs for their size• Live in numbers as large as 15,000

Page 20: Chondrichthyes  &  Agnatha

Agnatha Hagfish: Diet & Digestive System

• Scavenger• Eats dead animals

Devours from inside out Absorb nutrients through their skin and gills Mouth is designed to tear flesh

• Slow metabolism • Can survive months between feedings• Food is enclosed in permeable membrane• Waste is excreted

Page 21: Chondrichthyes  &  Agnatha

Agnatha Respiratory System Cutaneous Respiration

Diffusion• Dissolved oxygen diffuses into blood• Carbon dioxide diffuses out

Page 22: Chondrichthyes  &  Agnatha

Agnatha Sensory System

• 10 cranial nerves• No external ears• No eyelids

• Hagfish: Poor vision Releases slimy mucus when in danger Lateral line system (sense water currents/vibrations)

• Lamprey: Lateral line system Medial nostril (“smell” perceiving chemicals in water) Pineal organ (perceives light/dark)

Page 23: Chondrichthyes  &  Agnatha

Bibliography• http://palaeo.gly.bris.ac.uk/palaeofiles/fossilgroups/chondrichthyes/

Characters/skeleton.html• http://petrifiedwoodmuseum.org/SOChondrichthyans.htm• http://www.ucmp.berkeley.edu/vertebrates/basalfish/chondrofr.html• http://www.newworldencyclopedia.org/entry/Agnatha#Fossil_agnat

hans• http://biostor.org/cache/pdf/d3/c7/a7/d3c7a7457e177dd918a47080

52141bb4.pdf• http://www.waterencyclopedia.com/En-Ge/Fishes-Cartilaginous.htm

l#b• http://www.scribd.com/doc/38167359/Bio-Presentation-Chondrichth

yes• http://en.wikipedia.org/wiki/Elasmobranchii• http://www.bio.davidson.edu/courses/anphys/2000/martin/introduct

ion.html• http://www.google.com/search?um=1&hl=en&q=organic%20detrit

us&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1088&bih=570&ie=UTF-8&sa=N&tab=iw&ei=2xFET4G7BcGg0QW_t7mPDw

• http://en.wikipedia.org/wiki/Hagfish• http://staff.tuhsd.k12.az.us/gfoster/standard/zoagnath.htm

Page 24: Chondrichthyes  &  Agnatha

Bibliography• http://www.aquaticcommunity.com/mix/hagfish.php• http://www.livescience.com/13025-hagfish-eating-skin-gills-scaven

ger.html• http://en.wikipedia.org/wiki/Peritrophic_matrix• http://answers.yahoo.com/question/index?qid=20100307190830A

AE85Al• http://www.sciencedaily.com/releases/2011/02/110202132340.htm• http://www.enchantedlearning.com/subjects/sharks/anatomy/Diges

tion.shtml• http://answers.yahoo.com/question/index?qid=20080212214748A

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