THE DEEP

Aphotic Zone (Deep Pelagic) Below 1000m (3280 ft) Explored < 1%

Pressure At 1000 m is 100X greater than sea level pressure Surface organisms would be crushed

After nearly 5,000 m down

Adaptations Fluid is almost incompressible Fluid in animals’ bodies match surrounding water

Dive 1000m, over an hour Lungs collapse flat

Cold 1 - 2 C (34-37 F) Body temp close to water Metabolism slow Reproduce less and later Live longer

Food is Scarce 5% of food produced in the euphotic zone No migrators Need to conserve energy…How?

Be Blobby

“Blobby” Flabby, watery flesh Weak skeletons No scales No swim bladder Sit and float

Be small Many angler fish are 10 cm or less! Largest is 1m (3 ft) and 9 kg (20 lb.)

Eat anything!

Huge Mouths and expandable stomachs Swallower Eel

Use vibrations to find food Hairy angler has sensitive antennae Use lateral line to sense vibrations

Go fishing! Dragonfish Anglerfish

It’s Dark! Small eyes Black, red color Bioluminescence: --To attract prey or find mate --Not for counterlighting

Sex in the Dark 1) Use Bioluminescence to ID species 2) Be a hermaphrodite 3) Release chemicals to find mate

Sex in the Dark 4) Attach yourself to your mate! Males Goal: Search for female Have muscular bodies, large eyes, and organ to “smell”

Sex in the Dark Male bites female and they become fused Male provides sperm to female

World’s Smallest Fish Male, sexually mature is 6.2 mm (less than a ¼ inch) Female is 46 mm (1.8 inches)

Disphotic Zone (Mesopelagic) 150 m depth Not enough light for photosynthesis 10-20% food from surface is available

Size and Shape Small 10 to 15 cm Long flattened body

Lantern fish

Large eyes Hatchetfish Light sensitive for dim light Winteria Look up at surface and spot silhouettes of prey Two fields of vision

Mouths Large, hinged extendible jaws Needle-like teeth Eat anything

Sabertooth Viperfish Only a couple of inches long

Color Black, or black with silver sides Counterillumination/counterlighting

Other things besides fish may be transparent

Bioluminescence

Bioluminescence Photophores for camouflage Attract prey Attract mates Defense

Migrators vs. Nonmigrators Swim up to surface to eat at night Well-developed muscles and bone Swim bladder Sit and wait Less muscle,flabby No swim bladder Weak bones

Lantern fish Migrators Largest migration of life on earth 1700 m to 100 m (3 hour trip) Create a false bottom on sonar

Deep-Sea Floor rabbit fish and tripod fish

Deep sea fish Rat tail fish and hagfish

Deep sea fish Cruise the bottom Fecal pellets and the occasional whale for food Larger, long bodies, strong muscles, small eyes Not much bioluminescence Dark brown, black

Hydrothermal Vents

Mid-Ocean Ridge System Oceanic plates are pulling apart

Hydrothermal Vents At mid-ocean ridges Seawater seeps through cracks Gets super heated Forced back up through crust

Black Smokers Warm 50-68 degrees F Hot! 662 degrees F Heated water dissolves minerals When it cools, minerals deposit around vents

Hydrogen sulfide 1. Energy-rich molecule 2. Toxic to most organisms

Bacteria - Chemosynthesis Basis of food chain Use hydrogen sulfide for energy

Bacteria as producers 1. Live inside animals Symbiotic Bacteria get hydrogen sulfide, animals get food

Pompeii worm

Pompeii Worm

Tube Worm

Up to 2 m tall Riftia tube worm

Bacteria as producers 2. Filter feeders (mussels, clams) 3. Eaten directly (shrimp scrape bacteria off chimneys)

Mussels (filter feed) and eel

Submersible

Mussels

Vents don’t last Organisms get “cooked” 20 - 75 years Organisms get very large

Cold Seeps

Cold Seeps At continental margins Hydrogen sulfide and methane for chemosynthesis Grow slower, old and stable

Cold Seeps

Whale carcasses Decomposing - hydrogen sulfide Supports chemosynthetic bacteria Link to vents?? One about every 25 Km

Worms at whale carcass No eyes No mouth, stomach Green “roots” grow into bone and digest fat and oils with the help of bacteria

Worms at whale carcass Females, 2-7 cm with large egg sac Microscopic male worms living inside the females Eggs/larvae float until they find another whale Related to tube worms at hydrothermal vents

Whale bone with worms Females, 2-7 cm with large egg sac Microscopic male worms living inside the females Eggs/larvae float until they find another whale Related to tube worms at hydrothermal vents www.mbari.org/news/news_releases/2004/whalefall.html