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Nekton

Accomplished Swimmers

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What are Nektonic Animals?

Organisms that have developed powers of locomotion; capable of movement at will

Vertebrates?

Invertebrates?

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Nekton Feeding Biology

Practically all members of the nekton are carnivorous

___________________ – eat strictly plankton

Toothed whales, tuna, and sharks are _______________________ eating both other vertebrates and invertebrates

_________________ - eat strictly fish

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Adaptations of the Nekton

To be successful, nektonic animals must develop:

1. Adaptations to float

2. Faster swimming speed

3. Refined defensive mechanisms

4. Complex nervous systems to navigate and capture food

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Staying Afloat

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Staying Afloat

• Fishes use stiff fin elements with movable spines • ________________ tails are used in sharks to generate lifts

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Staying Afloat

Hammerhead sharks possess a large wing (____________) on the front of their head

http://www.divedarwin.net/hammerheadnew.jpg

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Staying Afloat

Image source: http://www.pskf.ca/sd/images/dcp_4932.jpg

Most bony fishes have ________________

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A Swimming Machine

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Faster Swimming Speeds

Some pelagic sharks and large tuna have the ability to conserve the heat their muscles generate

_____________________

Benefit: a warm muscle is more efficient than a cold muscle

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Defense Mechanisms

Color and Camouflage

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Defense Mechanisms Schooling behavior is a

method of protection for small fish

Why does schooling work?

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Unique Sensory Systems

Sense Organs Sight

Hearing

http://www.elkhornslough.org/research/IMAGES/Otoliths.JPG

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Unique Sensory Systems

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Unique Sensory Systems

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Unique Sensory Systems

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Migrations

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Baleen Whale Migrations

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Migrations

What cues are used?