Geography and Oceanography - Chapter 24 docx

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

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

• 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!!