Transcript THE DEEP

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)
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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”
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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!
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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
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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
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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
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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