The Ocean Depths

Zones of the Ocean Epipelagic- Photic Zone ( ft)Epipelagic- Photic Zone ( ft) –Sun, plants, photosynthesis, O 2 Mesopelagic- Dim light, but no plantsMesopelagic- Dim light, but no plants –No photosynthesis – ft Deep sea- perpetually darkDeep sea- perpetually dark

Mesopelagic: Dim Light Main thermocline- large temperature changeMain thermocline- large temperature change Animals: MidwaterAnimals: Midwater Zooplankton CopepodsZooplankton Copepods KrillKrill ShrimpsComb JelliesShrimpsComb Jellies OstracodsOstracods AmphipodsAmphipods Jellyfish Vampire squidJellyfish 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.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) Fishes:Fishes: –Ambush Predators –Flabby, watery, flesh instead of muscle –no swim bladder –soft, weak bones –no spines or scales

Blob Fish

Vertical Migrators Swim up at night to feed.Swim up at night to feed. Well developed muscles and bonesWell developed muscles and bones Swim bladder for buoyancySwim bladder for buoyancy Tolerate temperature changesTolerate temperature changes Vertical Migration is important in transporting food into deep waterVertical Migration is important in transporting food into deep water This increases food supply in mesopelagicThis increases food supply in mesopelagic Non-migrators feed on migratorsNon-migrators feed on migrators

4. Sense Organs Tubular eyes- up or forward to increase field of visionTubular eyes- up or forward to increase field of vision Lateral lines= touchLateral lines= touch Very large eyes = more surface area to collect lightVery large eyes = more surface area to collect light

5. Coloration and body shape CountershadingCountershading Reduction of the silhouetteReduction of the silhouette Laterally compressed bodies reduce outlineLaterally compressed bodies reduce outline

Bioluminescence

Bioluminescence 6. Bioluminescence Counterillumination- light production that helps animal blend in with background light filtering down from the surfaceCounterillumination- light production that helps animal blend in with background light filtering down from the surface Nearly all is blue.Nearly all is blue. Light can be from photophores, special cells, glands, ink.Light can be from photophores, special cells, glands, ink. Can be used in communication and to attract mates, vision, or to lure prey.Can be used in communication and to attract mates, vision, or to lure prey.

Oxygen Minimum Layer Gas exchange from atmosphere & photosynthesisGas exchange from atmosphere & photosynthesis 1,600 ft- O 2 minimum layer1,600 ft- O 2 minimum layer

The World of Perpetual Darkness Bathypelagic- 3, ,000 ftBathypelagic- 3, ,000 ft Abyssopelagic- 13, ,000 ftAbyssopelagic- 13, ,000 ft Hadalpelagic- 20,000 – 36,000 ftHadalpelagic- 20,000 – 36,000 ft

Life in the Darkness 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 organsHermaphrodites- both sex organs Bioluminescence – attracts matesBioluminescence – attracts mates Pheromones- special chemical released to attract matesPheromones- special chemical released to attract mates Male parasitism- anglerfish attaches to female for lifeMale parasitism- anglerfish attaches to female for life

Life in the Benthos Benthic animals have more time to find food and eat it (deposit feeders)Benthic animals have more time to find food and eat it (deposit feeders) Slow decomposition of detritusSlow decomposition of detritus Fecal pellets are an important source of organic matter.Fecal pellets are an important source of organic matter. Slow growth but long life (Deep-sea gigantismSlow growth but long life (Deep-sea gigantism)

Hydrothermal Vents Undersea hot springs associated with mid- ocean ridgesUndersea hot springs associated with mid- ocean ridges Discovered in 1977 by Bob BallardDiscovered in 1977 by Bob Ballard Tube worms (3.3 ft long)Tube worms (3.3 ft long) Clams (12 in)Clams (12 in) MusselsMussels ShrimpsShrimps CrabsCrabs FishesFishes

Chemosynthesis Seawater trickles down through the cracks in the crust, is heated and emerges at hydrothermal vents.Seawater trickles down through the cracks in the crust, is heated and emerges at hydrothermal vents. Contains hydrogen sulfide (H 2 S) and other mineralsContains hydrogen sulfide (H 2 S) and other minerals Bacteria use H 2 S to make organic matter which is chemosynthesisBacteria use H 2 S to make organic matter which is chemosynthesis Primary producer is chemosynthetic bacteriaPrimary producer is chemosynthetic bacteria

Tube Worms + Bacteria = Symbiosis The giant tube worm contains symbiotic bacteria that allow the worms to absorb H 2 S.The giant tube worm contains symbiotic bacteria that allow the worms to absorb H 2 S. The bacteria give the worms sugars from chemosynthesis.The bacteria give the worms sugars from chemosynthesis. Bacteria get a home.Bacteria get a home.