OCN 201 Biology Lecture 11

http://www.berkeley.edu/news/media/releases/2005/03/24_octopus.shtml

Adaptations from the Surface to the Deep Sea

Camouflage

• Often important for predators and prey to avoid being seen

• Predators to catch their prey and prey to hide from their predators

• Camouflage: Passive or adaptive

Passive Camouflage Countershading

http://www.nmfs.noaa.gov/pr/images/cetaceans/orca_spyhopping-noaa.jpg

Countershading coloration of the Caribbean reef shark© George Ryschkewitsch

JONATHAN CHESTER

SharksBirds

Mammals

Fish

shiftingbaselines.org/blog/big_tuna.jpg

Passive Camouflage

http://www.cspangler.com/images/photos/aquarium/weedy-sea-dragon2.jpg

Adaptive Camouflage

Adventitious CamouflageDecorator crab

Friday Harbor Marine Health Observatory

http://www.projectnoah.org/

Camouflage by Mimicry

http://www.berkeley.edu/news/media/releases/2005/03/24_octopus.shtml

Mimicry

• Mullerian: two or more inedible species all evolve to look similar maximizing efficiency with which predators learn to avoid them

• Batesian: an edible species evolves to look similar to an inedible species to avoid predation

Batesian MimicryPufferfish (poisonous)

Filefish (non-poisonous)

An edible species evolves to resemble an inedible species to avoid predators

http://www.rzuser.uni-heidelberg.de/~bu6/Introduction06.html

Batesian MimicryNudibranchs & Flatworms

Non-Toxic Flatworms

Toxic Nudibranchs

Sabre-toothed Blenny

Cleaner Wrasse

Instead of looking dangerous… do the opposite and look like something harmless!

In this case mimicry is not a defense, but an offense!

Adaptations in the Deep-Sea

• Physical Conditions•- Cold•- High Pressure•- Dark

• Animals (and food) are sparse

• se

Deep Scattering Layer

Sonar

Vertical Migration by Plankton

• Detritus from the surface ocean food web falls down to the deep sea

• This falling detrital material is marine snow, fecal pellets and occasional dead animals

• Marine Snow consists of bits of aggregates of algae, discarded larvacean houses, microorganisms, etc.

Food for the Deep

- Clear bodies or reflective sides and counterillumination (disphotic zone)

- Red or Black bodies (aphotic zone)

- Oversize mouths

- Specialized eyes (or degenerated)

- Bioluminescence

Adaptations in the Deep Sea

Reduced Silhouette

Reflective Sides

100%

5%

<1%

LightCounterillumination

bioluminescence

Architeuthis

Vampyroteuthis infernalis

• Counterillumination (camouflage)

• Communication (finding mates)

• Lures (enticing prey)

• Searchlights (illuminate prey)

• Decoy or surprise (escape from predator)

Bioluminescence Light produced by a biochemical reaction

USED FOR:

Some fish that use bioluminescence

✦ Low Numbers (not much food)

✦ High Diversity (resource limited)

✦ Long Lives (low metabolic rates)

✦ Many deposit feeders and scavengers

✦ Epifauna - urchins, brittle stars, crinoids, etc

✦ Infauna - crustaceans, worms, etc.

Deep Sea Floor(about 3 km deep)

(about 4.8 km deep)

Tripod FishBrittle Stars