Marine%20Fishes

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Marine Fishes

• Part 1 Jawless Cartilaginous Fishes

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(No Transcript)
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Vertebrates

• What defines a vertebrate?
• Backbone or spine
• Spinal cord

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Jawless Fishes

• Most primitive
• Feed by suction
• round, muscular mouth
• Rows of teeth
• Elongated, cylindrical body (like snake)
• No paired fins or scales

Lampreys
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Hagfishes

• aka slime eels
• No eyes
• Feed on dead or dying fishes
• Can bore into prey and eat from the inside out
• Pours slime out of mucus sacs
• Can fill a 2 gallon bucket instantly!

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Hagfish

• Deep sea environment (1000 ft)
• Been around 300 million years
• No eyesvirtually blind
• Highly acute sense of smell and touch
• Smooth body helps it move around inside dead
  animal
• Eat prey from the inside out
• Slime
• used as defense mechanism
• Protein explodes when in water

Hagfish Sliming Video - YouTube
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Lampreys

• Primarily freshwater
• Breed in rivers and lakes, move to sea as adults
• Attach to fishes and suck blood

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Cartilaginous Fishes

• Sharks, rays, skates, and ratfishes
• Skeleton of cartilage
• Lighter, more flexy than bone
• Paired lateral fins for swimming

Tiger Shark
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Cartilaginous Fishes

• Movable jaws and teeth
• Mouth is ventral
• Underneath the head

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Cartilaginous Fish

• Placoid Scales
• Rough, sandpaper like
• Pointed tip that points backward
• produces a covering that offers low resistance
  and turbidity
• copied in the body suits of Olympic swimmers.

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The Perfect Predator
https//www.youtube.com/watch?vSsnjczQVLcY
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The Perfect Predator Body Shape

• Torpedo shape
• Body tapers at each end
• Well developed, powerful caudal fin
• Arching the body laterally into a shallow curve
• Tremendous speed, low energy useage

Mako Shark
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The Perfect Predator Coloration

• Dark on dorsal (top) side
• Light on ventral (bottom) side
• Why?
• White blends with light, dark blends with bottom

The Great White Shark
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The Perfect Predator Teeth

• Up to hundreds of teeth in jaw at one time
• Embedded in flesh
• Not attached to jaw
• Multiple rows
• Serrated
• Replaced when lost for entire life!

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The Perfect Predator Eyes

• Extremely sensitive
• Able to magnify amount of light
• Rolls eyes backwards when attacking
• Exposes tough, fibrous coat

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The Perfect Predator Nostrils

• ONLY used for smell
• Skin flaps
• Inflowing/outflowing current
• Water passes over lamellae
• Lamellae
• Covered with millions of sensory cells
• Single drop of blood in an Olympic size pool
• Smell is directional
• Can tell where its coming from

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The Perfect Predator Ampullae of Lorenzini

• Thousands of small capsules filled with jelly
• Picks up vibrations in water of prey
• Detects electrical fields of moving animals
• Detects magnetic field of earth
• Used in migration
• More detail

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Other Sharks Whale Shark

• Largest shark (and fish) in ocean
• 65ft, 10 tons
• Filter feeders
• Fish eggs
• Plankton
• Krill
• Small fish and squid
• Process over 6000 gallons of water/hr

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Other Sharks Hammerhead

• Sensory mechanisms all along flattened scull
• Head acts as airplane wing
• Can detect a billionth of a volt
• Excellent 3-D eyesight
• Excellent navigation

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Importance of sharks

• Meat
• Nutritional, boneless, mild-flavoring
• Eyes
• Corneas used as substitutions for human corneas
• Skin
• Used in research and engineering of ships,
  aircraft, pipelines and swimming suits

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Importance of sharks

• Liver
• Contain high amounts of vitamin A (helps us see)
• Squaline
• Skin rejuvenator
• Cartilage
• Cancer research
• Ecosystem
• Apex predators
• Control disease
• Quick article

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As Sharks Vanish, Chaotic New Order Emerges

• What are some impacts that have resulted in the
  overfishing in sharks on the east coast of the
  US?
• In your own words, what is an apex predator?
• What is an example of a trophic cascade?
• What is shark finning? What are some problems
  with it?

This is how we do it in Oklahoma, boy.
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Sharks are in great decline

• Overfishing
• K-selected species
• Low fecundity
• Do not produce many young
• Reproduce every two years
• Slow growth
• Late age of maturation
• Great White 9 years Sandbar 25 years
• Cartilage
• It cures cancer! NO IT DOESNT! No evidence!
• 100 million-a-year industry

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Sharks are in great decline

• Bycatch
• Occurs in several fisheries tuna longline,
  shrimp trawl, and swordfish
• Millions of sharks a year
• Finning
• Removing the fins and discarding the carcass
• This makes me sick to my stomach

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Shark Finning
https//www.youtube.com/watch?vmO7hvOtYnck
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Shark Fin Soup
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Dont be a shark huggerOr you may end up like
this guyHow to Hug a Shark
https//www.youtube.com/watch?vUtQAfRrD8oc

WARNING Dont try this at home
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Rays
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Characteristics

• Adapted to living on bottom of ocean
• Flattened bodies
• Gill slits (5 pairs) on underside of body
• Feed on clams, crabs, small fishes

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Stingrays

• Lie camouflaged in sand
• Finds food by smell, touch and electrical senses
• Up to 6 ft across
• Spine found at base of tale laced with poison
• Use in defense only

http//video.nationalgeographic.com/video/stingray

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A closer look at the tail

• This is a bull ray
• Same type of ray that killed Steve Irwin

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Manta Rays

• Largest of all rays
• Up to 22 feet across (average size is 12 ft)

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Electric Ray

• Organs on side of head that produce electricity
• Shocks up to 200 volts
• Used to stun prey
• Used by Romans to cure treat headaches and other
  ailments
• Confrontational if harassed.
• Swim directly up to diver

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Skates vs. Rays

• Rays live bearing (viviporous)
• Skates are egg bearing (oviporous)
• Rays have longer, skinnier tale with spine
• Skates have fleshier tale, no spine
• Rays have plate like teeth
• Skates have small teeth
• Which is which?