Geography and Oceanography - Chapter 24 docx

Marine Ecology
Selected Adaptations
Let’s set sail for adventure!!!
Basic Ecology
•
factors regulating the distribution and
abundance of organisms in the ocean.
•
influence of physical and chemical
parameters on organisms in the various
ecosystems that constitute the ocean.
Selected Adaptive Strategies:
Bioluminescence
•
Fishes - important nektons
•
Many are deepsea predators
•
Need their own light to attract prey
•
… to attract mates
•
photophores
•
luciferin + luciferase
The Blue Planet
The Blue Planet
PREDATOR
•
Fangtooth
•

Striped tuna, Bluefin tuna
•
Marlin
•
Sei whale
•
Manta ray, Ray
•
Pacific Mackeral
•
Spotted Dolphin
•
Sailfish
•
Blue Shark
•
Deepwater crab
•
Wahoo
PREY
•
Sardines
•
Flying fish
•
Surgeonfish eggs
•
Yellowfin tuna eggs
•
PLANKTON

•
NUTRIENTS
More Nekton Strategies
•
predator/prey
•
must be swift and efficient swimmers
•
move swiftly to
–
eat
–
avoid being eaten.
•
Thus fish have evolved to maximize
their ability to move through water.
Caudal (Tail) Fins
• most important for speed
• flared to increase vertical thrust
ROUNDED fin (e.g., angelfish)
very flexible, slow-speed manuevering
TRUNCATE fin (e.g., coho salmon)
somewhat flexible, manuevering
FORKED fin (e.g., yellow goatfish)
somewhat flexible, manuevering
The Blue Planet
LUNATE fin
(e.g., bluefin tuna or blue marlin)
very rigid, no good for manuevering,
built for pure speed

HETEROCERCAL fin (“uneven tail)
• most of mass & surface area in upper
part to produce lift
• pectorals balance to aid lift, but limits
manueverability
Caudal Fins
•
rounded
–
very flexible, manuevering
•
truncate & forked
–
somewhat flexible, manuevering
•
lunate
–
very rigid, propulsion
•
heterocercal
–
“uneven tail” for lift and propulsion
Built for Speed
•
speed related to body length
–
4-foot yellowfin tuna, 46 mph
–
13-foot bluefin tuna, 90 mph (theoretically)
–

9-foot porpoise, 25 mph
–
30-foot killer whale, 34 mph
Giant Squid:
• traps water in mantle and
forcefully jettisons it from siphon in
head
• active predator of fish
• arms to capture
• tentacles to bring to beak
• both lined with suckers
The Kraken is a legend, but
giant squid DO exist!
…~20 feet long!
Colossal Squid Captured
Wellington, NZ, April 2003
330 pounds - 16 feet long
Go to the
web now
matey!!