Notes The Deep Sea Zones of the Ocean

Notes: The Deep Sea

Zones of the Ocean 1. epipelagic – sunlight zone 0 -200 meters photosynthesis occurs here 2. mesopelagic – twilight zone 200 -1000 meters

Zones of the Ocean 3. bathypelagic - midnight zone 1000 -4000 meters 4. abyssopelagic - the abyss 4000 -6000 meters 5. hadalpelagic - trenches 6000 -11, 000 meters

Mesopelagic – “twilight” zone Characteristics l 20% of the food reaches this layer so the fish here (on average) tend to be smaller and fewer. • They funnel their food energy into reproduction NOT growth • Large mouths, hinged jaws and broad diets which allows them to eat anything that is any size. l • Reduction of silhouette – laterally compressed bodies Viperfish

General Adaptations: l l l 1. Eyes – large tubular eyes that face forward and upward. 2. Coloration a. Counter shading b. Transparency c. Red/Orange in color – looks black in deep water 3. Bioluminescence – they have bioluminescent algae in tissue. They contain the enzyme luciferase – when exposed to oxygen it glows.

Comparison of Vertical vs. Nonvertical Migrators l l Vertical migrators – come to the surface to feed. Nonvertical migrators – remain in the mesopelagic zone.

The Deep Sea – Zones 3 -5 l l l Characteristics Only 5% of food from the surface reaches this level Fish are larger in size – more concerned with growth not reproduction. Many are hermaphrodites – can produce both egg and sperm. Deep Sea Angler Fish – female is large, male is small (becomes a parasite on the female). Angler Fish female with parastic male female Angler Fish

Adaptations of Deep Sea Fish • large mouth and teeth • small eyes • no/small swim bladder • flabby muscles • black color