T is for twilight zone

Page 1

Nicole Kang


Table of Contents   The Blue Earth   Zones of the Sea   Life in the Sea   Challenges   Adaptations   Bioluminescence   Biomimicry   Deep Sea Vents   Deep Sea Creatures


What can you tell me?


The Blue Earth   More then 70% of the Earth is covered by water and

that’s just the surface!   The ocean is deep and holds an enormous living space   Majority of the sea floor is covered in deep-­‐sea mud,

where microscopic animals live in the top 10cm

  It represents more than 99% of the living space on

this planet




Life in the Sea?   Untold billions of organisms live beneath the ocean.   Life survives and lives well– even in a habitat that

some scientists once believe it could not possibly support life.

Axolotl


Discussion Ques<on! © Gary Larson

  Which one of the

following would you rather live without?   Sunlight   Oxygen   Food   Safety   Friends


How Can Life Exist…?

Without sunlight? NASA


How Can Life Exist…? How Can Life Exist…?

At near freezing temperatures? Kari Liimatainen


How Can Life Exist…? With little to no oxygen?

National Geographic


How Can Life Exist…?

At pressures that could flatten a submarine?


How Can Life Exist…? With scarce food supplies?

© Gary Larson


How Can Life Exist…? While avoiding predators?

© Gary Larson


How Can Life Exist…?

MediaBistro.com

While needing to find a mate?


And yet…   These waters are full of life   Life that is perfectly adapted to these challenges and

have evolved in strange and amazing ways


Life Span   Many deep-­‐sea animals

grow slowly and live very long lives   Deep-­‐sea rockfish can live more than 200 years old…   Some corals can live to be hundreds, even thousands of years old

Biggest rockfish caught, weighs 27kg!


Let There Be (No) Light…   Sunlight is rapidly absorbed

in the sea.   At 1 m only 60% is left.   Long waves in the color spectrum disappear more rapidly

In deep waters: substances on reef fishes’ bodies capture light at other wavelengths and release the energy as red light


Darkness Survival Strategies   No sunlight means no photosynthesis! What does this

mean?!   Giant Squid-­‐ cope with low levels of light by having enormous eyes the size of dinner plates!   Tripod fish-­‐ detects their prey by sensing vibrations instead of seeing National Geographic


Buoyancy   How do some fish and other sea

creatures not sink to the bottom?   Very light bones and flesh   Gas bladders that stop them from

sinking

Brown Sharptail Eel

  Heavier species sink if they stop

swimming so they spend much of their time resting on the sea floor searching it for food. Pancake Batfish


Pressure   The weight of air in the Earth’s

atmosphere is 1kg per square centimeter at sea level   In the ocean the pressure is much greater because of the water pressing down heavily   At 4km half a ton of weight presses

on every square cm

  Many survive because their body is

mostly made of liquid which can’t be compressed.

Sad fish live down here… D=


  There is little to eat in the deep

Marine Snow   sea Bits of food drift slowly down

from surface waters in what is called “marine snow”   This includes dead and dying

organisms, animal waste, sediment, and dust

  Most but not all of the marine

snow is consumed by microbes and plankton.   The rest ends up on the seafloor which sustains animals living on the bottom


Avoid GeNng Eaten!   Hide!   The vampire squid which lives in

depths where there is very little oxygen

  Be too big to be eaten!   A Big Red Jelly is too big…   Be invisible!   Camouflage-­‐ many deep sea

animals are dark red which absorbs light rather than reflects like Red Jelly

  What are some other ways?

Midwater Polychaete Slickhead Fish


Lazy Fish   Fish don’t ‘drink’ water, but they do breathe oxygen

inside of it.   There is a low amount of dissolved oxygen in the deep sea waters.   Therefore, to conserve energy, many fish have low metabolic rates, so they are less active and need less energy. arctic.uoguelph.ca


Ma<ng and Reproduc<on

Environmental News Network

  Some squid female stores the sperm

but does not develop her eggs until the time is right.   Anglerfish males are tiny compared to the females

Glass Squid Pixar

  Male latches and fuses onto her female

and stays there for the rest of his life.

  Hermaphroditic animals such as comb

jelly are able to reproduce on their own.

NOAA


Bioluminescence   Nature’s artificial light uses chemicals within their

bodies to produce light. What other organisms do this?   Mainly a marine phenomenon though not found in freshwater.


Deep Sea Hydrothermal Vents


Deep Sea Hydrothermal Vents   Discovered late 1970’s   Nearly 8000 ft (2,438.4

meters) below the surface was what looked like chimneys expelling clouds of black smoke.   Proof for the first time that life could be sustained by the Earth itself


Chimneys and Black Smokers   Seawater goes into the Earths’ crust through cracks and fissures

in the ocean floor.   The water is heated by magma below the surface, expands and rises back to the surface   On the way up the hot water dissolves minerals and other chemicals from the rock to make a dark chemical soup   Some minerals harden on the rim of the vent which build to a tall chimney-­‐like structure.   The dark color of the water was then named “black smokers.”


Living off the Earth   Organisms get food directly from the vents themselves.   This process is known as chemosynthesis.   Bacteria in the water feed on what is normally a lethal

soup of chemicals.   An entire ecosystem totally separate from the world of light is made.

  These waters are so fertile that shrimps have been known to

number in the millions near these vents.


Biomimicry   Copying nature and using

it to solve human problems.   Olympic athletes now wear swim suits designed from Sharklet Technologies shark skin!   The scales speed up surrounding water with ridges.   89% of swimming medals won in the Beijing Olympics were won by shark suit swimmers!


David Gallo   Renowned

oceanographer who travels under the sea to explore and map the ocean.   He has visited the sunken Titanic!   Biomimicry   Deep Sea Life


Vampire Squid   Vampyrotenthis Infernalis   Means ‘vampire squid from Hell’   Found 3000 feet under the sea level   Last surviving member of order Vampyromorphida   Similar to both squids and octopuses as all three are

descended from the cephalopod mollusk   Lacks ink sacs, but can eject a cloud of thick bioluminescent mucus


Firefly Squid   (Watasenia scintillans) 7 cm :D   Found 365 m in the day but at night

migrate to surface to search for food   Equipped with light producing organs, photopores, which emit blue light.   Lights can be flashed in unison or alternated thought to serve...   as communication with mates or rivals   to disguise the squid’s shape   confuse predators allowing for escape

  Believed to be the only squid with

color vision


Lights in Japan   Famous for the light

show that occurs each year off the coast of Japan as millions of these tiny animals gather to spawn.   Found to be a delicacy in Japan and widely fished during the spawning season PinkTentacle.com


Giant Isopod   (Bathynomus giganteus)   Found 77m to 2,140m under sea

largest member of the isopod family (related to shrimps and crabs)   Can grow to over 16 inches


Giant Isopod (cont.)   Some researches believe large size may

have been an adaptation to help the animal deal with enormous pressures   They reproduce by laying eggs which are stored in a pouch


Fangtooth (Anoplogaster cornuta) Why do you think this fish is called “Fangtooth”?   Largest teeth for body size


Fangtooth: Quick Facts!   Lives in temperate and tropical ocean

regions (commonly 600-­‐6500 ft. deep, but have been found as deep as 16,000 ft. = can withstand intense pressure, near-­‐freezing temperature!)

  Is actually small-­‐-­‐ maximum 6 inches (16

cm)   Eyes set high on its head; poor eyesight


Baby Fangtooth   Eggs hatch into tiny plankton-­‐

sized larvae   Look very different from adults (at first, marine biologists mistook them as a different species!)   Feed by filtering plankton from water using specially-­‐formed gill rakes that disappear as they reach maturity


Fangtooth   The juveniles begin to resemble adults as they reach a

size of about 3 inches, and then they start to descend down to deeper waters   We still do not know how long they live!


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