1. Characteristics and Adaptations
Deep Sea Biology
Characteristics and Adaptations

2. I. Environmental characteristics
A. Sunlight
1. No sunlight
2. No plants
3. Organisms must use other senses to find food; not eyes
4. only light in deep sea comes from the organisms themselves
bioluminescence – light generated from a living organism

3. B. Pressure – means compression
1. measured as atmospheric pressure or ATM’s
2. at sea level, 1 ATMs = 2117 lbs. per sq. ft
*for every 33 ft or 10 m down pressure increases 1 ATMs
*so at a depth of 1000ft or 320m there is 30.3 ATMs = 64,400 lbs/ft

4. 3. Liquid can withstand compression, air cannot
*at 30,000 ft or 10,000m = 909 ATMs = 1,250,000 lbs.ft
3. Liquid can withstand compression, air cannot
(so lungs will implode at great depths)
4. Pressure in the ocean is exerted evenly in all directions
5. Pressure does effect the distribution of organisms
further down in the ocean, the fewer critters

5. 6. How can animals live that deep?
a. most animals from deep were dead by the time they reach the surface – couldn’t really study them
b. deep sea critters have special physiology and biochemical adaptations
c. muscle enzymes very inefficient
d. metabolic rates very sluggish – slow moving organisms

6. f. a lot to still learn about survival of the deep C. Temperature
e. calcium dissolves after 5,500m so skeleton made of something other than bone
f. a lot to still learn about survival of the deep
C. Temperature
1. constant temperature = cold
2. no seasonal changes
3. about 4oC except at hydrothermal vents

7. 5. Critters are slow because of cold and pressure D. Oxygen
4. Temp plays important role in distribution of organisms
5. Critters are slow because of cold and pressure
D. Oxygen
1. Oxygen minimum zone – between 500m-1000m has the least amount of oxygen in the entire ocean

8. 5. Oxygen gets to the deep by currents and density differences
2. most deep sea creatures found here, so O2 is used up quickly through respiration
3. Above 500m, has the most animals in the ocean, but have plenty of plants
4. below 1000m, fewer animals so more O2, also lower metabolic rates (don’t use up the oxygen fast)
5. Oxygen gets to the deep by currents and density differences

9. E. Food
1. Food gets to the deep by:
a. sinking
b. currents
2. most food gets eaten before it reaches the deep
3. no basis for a food chain: because no light = no plants
4. deeper you go less food = smaller critters = fewer critters

10. 5. Sources of food for deep sea creatures
a. baby deep sea creatures
b. large dead bodies
c. fecal matter
d. exoskeleton

11. 6. Must find food
a. use bioluminescence to attract food
b. may have electrical impulses (to detect food)

12. II. Adaptations of deep sea Animals
A. Color
1. fish – gray or deep black, not counter-shaded like surface fish
2. invertebrates – deep purple
3. shrimp-like – bright red

13. 4. No light – dark colors hide the critter
makes invisible to sneak up on prey or hide from predators
5. Bright red will blend with bioluminescence
6. Bottom dwellers are usually clear – no pigmentation

14. B. Eyes
1. upper aphotic (200m – 2000m)
have large eyes for maximum light collecting
2. lower aphotic fish have very small eyes or no eyes at all – live in complete darkness – not like you’re going to see anything

15. C. Large Mouth –
1. lack of food gives rise to the adaptation of a large mouth in deep sea animals
2. mouth has long teeth that curve towards the throat;
3. this ensures what is caught doesn’t escape

16. 4. mouth is also hinged so animals. can open mouth twice the size of
4. mouth is also hinged so animals can open mouth twice the size of its body to
swallow the prey whole
5. some use a bioluminescent lure to attract prey and swallow them

17. D. Finding a mate
1. since the deep sea is so dark and has great pressure, it’s hard for deep sea animals to reproduce
2. Solution:
a. most deep sea critters are hermaphroditic – this ensures someone gets pregnant or in this case both

18. b. Females are usually much larger than males;
1) The males act as parasites on the female;
2) The male attaches to the female
3) and so the male becomes part of the female and reproduction occurs
4) some females have 3 or 4 males attached to her

19. E. Bioluminescence- found throughout. the entire ocean, but very
E. Bioluminescence- found throughout the entire ocean, but very important in the deep sea
1. bioluminescence is simply the production of light by a living organism (fireflies)
2. usually blue or green light occurs (varies from animal to animal)
3. organs called photophores produce the light

20. 4. Or bacteria living inside the animal
5. bioluminescence used for three major reasons:
a. protection – animals produce a “blinding” flash and escape
b. getting food – lures other animals close to them

21. c. mating – photophores are. displayed in certain patterns
c. mating – photophores are displayed in certain patterns (varies from species to species),
but acts as an identification signal
F. Deep-sea animals have many adaptations so they may survive their environment of the deep sea;
still many unanswered questions.