Transcript The Deep Ocean - Marine Biology Honors

The Ocean Depths
Zones of the Ocean
• Epipelagic- Photic
Zone (500- 650 ft)
– Sun, plants,
photosynthesis, O2
• Mesopelagic- Dim
light, but no plants
– No photosynthesis
– 660-3000ft
• Deep seaperpetually dark
Mesopelagic: Dim Light
• Main thermocline- large
temperature change
• Animals: Midwater
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Zooplankton
Krill
Shrimps
Ostracods
Amphipods
Jellyfish
Copepods
Comb Jellies
Vampire squid
Mesopelagic Fish:
1. Bristlemouth
Most abundant fish on earth
2. Viperfish
3. Dragonfish
4. Hachetfish
Mesopelagic Adaptations
• Only about 20 % of food produced in the
epipelagic makes it to the mesopelagic.
1. Small size: Hides easily and uses less energy
2. Large mouths- hinged extendable jaws (large
teeth)
– Usually will eat anything that will fit in mouth
3. Non-migrators
(couch-potato fish)
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Fishes:
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Ambush Predators
Flabby, watery, flesh instead of muscle
no swim bladder
soft, weak bones
no spines or scales
Blob Fish
Vertical Migrators
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Swim up at night to feed.
Well developed muscles and bones
Swim bladder for buoyancy
Tolerate temperature changes
Vertical Migration is important in transporting food into deep
water
• This increases food supply in mesopelagic
• Non-migrators feed on migrators
4. Sense Organs
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Tubular eyes- up or forward to increase
field of vision
Lateral lines= touch
Very large eyes = more surface area to
collect light
5. Coloration and body shape
• Countershading
• Reduction of the silhouette
• Laterally compressed bodies reduce
outline
Bioluminescence
6. Bioluminescence
• Counterillumination- light production that
helps animal blend in with background
light filtering down from the surface
• Nearly all is blue.
• Light can be from photophores, special
cells, glands, ink.
• Can be used in communication and to
attract mates, vision, or to lure prey.
Oxygen Minimum Layer
• Gas exchange
from atmosphere
& photosynthesis
• 1,600 ft- O2
minimum layer
The World of Perpetual Darkness
• Bathypelagic3,000- 13,000 ft
• Abyssopelagic13,000- 20,000 ft
• Hadalpelagic20,000 – 36,000 ft
Life in the Darkness
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5% of food makes it to deep water
“Couch potato” fish
Drab gray, off-white or black
Small eyes or blind
Huge mouths and expandable stomachs
Anglerfish use “lure” to catch prey,
communicate and attract mates.
Anglerfish
Sex in the Deep
• Hermaphrodites- both sex organs
• Bioluminescence – attracts mates
• Pheromones- special chemical released
to attract mates
• Male parasitism- anglerfish attaches to
female for life
Life in the Benthos
• Benthic animals have more time to find food and eat
it (deposit feeders)
• Slow decomposition of detritus
• Fecal pellets are an important source of organic
matter.
• Slow growth but long life (Deep-sea gigantism)
Hydrothermal Vents
• Undersea hot springs associated with midocean ridges
• Discovered in 1977 by Bob Ballard
• Tube worms (3.3 ft long)
• Clams (12 in)
• Mussels
• Shrimps
• Crabs
• Fishes
Chemosynthesis
• Seawater trickles down
through the cracks in
the crust, is heated and
emerges at
hydrothermal vents.
• Contains hydrogen
sulfide (H2S) and other
minerals
• Bacteria use H2S to
make organic matter
which is
chemosynthesis
• Primary producer is
chemosynthetic
bacteria
Tube Worms + Bacteria =
Symbiosis
• The giant tube worm
contains symbiotic
bacteria that allow
the worms to absorb
H2S.
• The bacteria give
the worms sugars
from
chemosynthesis.
• Bacteria get a home.