1. Wooooo - Boogey - Boogey!
The Ocean Depths! (1)
Wooooo - Boogey - Boogey!

2. Areas of the Deep Sea

3. How Surface Water Masses Reach The Bottom
near Greenland
“Thermohaline Circulation”
Near the Antarctic

4. The Great Ocean Conveyor Belt

5. The Mesopelagic
The Twilight Zone

6. Bottom of Mesopelagic Zone – No Light exists here
Deep Sea Life Is Closely Correlated With Plankton Abundance And Light Intensity
Thermocline
Bottom of Mesopelagic Zone – No Light exists here

7. The Mesopelagic – Home Of The Oxygen Minimum Zone

8. Food Sources in the Deep Sea

9. A Few Mesopelagic Critters …

10. Mesopelagic Crustaceans
Opossum shrimp
krill
true (decapod) shrimp

11. A Very Large Ostracod or Seed Shrimp – This One is 1 cm in Length

12. Mesopelagic Squid Showing Photophores
Photophores, or light organs, are characteristic of many animals in the mesopelagic – they are active in bioluminescence

13. Vampire Squid Exhibiting Photophores

14. Typical Mesopelagic Fishes
hatchetfish
pacific viperfish
lanternfish
dragonfish
barracudina
longnose
lancetfish

15. Adaptations of Mesopelagic Fishes
Small body size – limited food supply
Large mouths hinged to disarticulate
Generalized omnivores with abundant, long, sharp teeth
Feeding habits – migrators and non-migrators
Sense organs – tubular eyes with 2 retinas; well-developed lateral lines

16. Adaptations Con’t.: Coloration and Body Shape
Countershading
Transparency – especially in upper areas of mesopelagic
Lateral compression of the body
Photophores and Bioluminescence

17. Bioluminescent Mesopelagic Fish

18. Mesopelagic Fishes – Vertical Migrators vs. Non-Migrators
Lanternfishes Dragonfishes

19. An Adaptation for Large Prey – Hinged Jaws!
Viper fish
Rattrap fish
Opportunists of the Deep

20. Midwater fish - Scopelarchus
Convergent Evolution of Tubular Eyes in Mesopelagic Organisms
Krill – bilobed eye
Midwater fish - Scopelarchus
Deep-Sea Octopus

21. The Field Of Vision Of A Typical Mesopelagic Fish

22. Having Photophores Is Adaptive !
Squid Without Photophores
Squid With Photophores

23. Cross-Section of a Krill’s Photophore

24. Wooooo - Boogey - Boogey!
The Ocean Depths! (2)
Wooooo - Boogey - Boogey!

25. Below the Mesopelagic – The World of Perpetual Darkness
Below this zone which stops at about 1,000 meters is the:
Bathypelagic - 1,000 to 4,000 meters
Abyssopelagic - 4,000 to 6,000 meters
Hadopelagic – below 6,000 meters and into the trenches

26. The Bathypelagic – Home Of Perpetual Darkness
Mesopelagic
Bathypelagic
(upper reaches)

27. Adaptations of Deep-Sea Pelagic Fishes
An Anglerfish

28. Adaptations In Two Closely Related Bristlemouth Fishes

29. Note very small, parasitic male
Some Deep-Sea Fishes
Anglerfish
Note very small, parasitic male
Swallower
Gulper

30. The Problem Of Finding A Mate …
Produce light ! (bioluminescence)
Produce an odor ! (pheromones)
Be a parasite and attach to the other sex !
Be a hermaphrodite and say “to heck with it” !

31. Fish Life On the Floor

32. The Deep Ocean Floor

33. Characteristics Of Fish From Different Depths Of The Pelagic

34. Anatomy Of The Giant Hydrothermal-Vent Tube Worm

36. Sampling Methods for the Mesopelagic and Beyond …
A Remote-Controlled Midwater Trawl

39. The Chambered Nautilus – A Relic Species From The Past