1. CHAPTER 14 Animals of the Pelagic Environment

2. How organisms avoid sinking
Increase buoyancy
Gas containers
Rigid container such as shells (internal or external) or…
Swim bladder
Fig. 14.2

3. How organisms avoid sinking
Float – less dense than saltwater or neutral
Microscopic zooplankton have shells or tests
Radiolarians
Foraminifers
Copepods
Macroscopic zooplankton may have oil droplets
Krill (resemble mini-shrimp or large copepods)
Fish egg with oil droplet
Krill

4. How to avoid sinking Floating macroscopic zooplankton Cnidarians
Hydrozoan (Portuguese man-of-war) gas-filled float
Scyphozoan (jellyfish) soft low-density bodies

5. How to avoid sinking Active swimming
Fish – swim by curving body from front to back

6. How to avoid sinking Active swimming – Squid
Swim by trapping water and expelling it
Also swim by using fins
Unknown deep sea squid

7. How to avoid sinking Active swimming sea turtles use flippers
marine mammals use up/down tail movements
Different from fish

8. Fin designs in fish Vertical fins as stabilizers
dosral and anal fins
Paired fins for “steering” and balance
Pelvic and pectoral
Tail fin (caudal) for thrust

9. Fin designs in fish
Rounded caudal fins flexible, maneuver at slow speeds
Truncate fins and forked fins, useful for both maneuvering and thrust
Lunate fins rigid, lots of thrust for fast swimmers
Heterocercal fins asymmetrical, lift for buoyancy (shark)

10. Adaptations for finding prey
Mobility
Lungers wait for prey and pounce (grouper)
Mainly white muscle tissue
Cruisers actively seek prey (tuna)
Mostly red muscle tissue

11. Adaptations for finding prey
Swimming speed
Speed generally proportional to size
Can move very fast for short time (mainly to avoid predation)

12. Adaptations to finding prey
Most fish cold-blooded but some are warm-blooded
Homeothermic-body temperature above sea water temperature
Modifications in circulatory system
Mainly in fast-swimming fish

13. Adaptations of deep-water nekton
Mainly fish that consume detritus or each other
Lack of abundant food
Bioluminescence
Fishing lures
Large, sensitive eyes
Anglerfish w/ males
Lanternfish

14. Adaptations of deep-water nekton
Large sharp teeth
Expandable bodies
Hinged jaws

16. Adaptations to avoid predation
Schooling
“Safety in numbers”
School may appear as single larger unit
Schooling maneuvers confuse predator

19. Some taxonomy…… Fish Kingdom Animalia Phylum Chordata
Class Chondrichtyes – cartilaginous fish
Sharks, rays
Class Osteichthyes – bony fish

20. Chondrichthyes
Cartilaginous Fish

21. Osteichthyes
Very diverse group!

22. Marine Mammals Kingdom Animalia Phylum Chordata Class Mammalia
Order Carnivora
Sea otters
Polar Bears
Pinnipeds – Family Odobenidae (walrus), Family Otariidae (Sea lions), Family Phocidae (seals)
Order Sirenia
Manatees and dugongs
Order Cetacea
Whales

23. Whales Kingdom Animalia Phylum Chordata Class Mammalia Order Cetacea
Suborder Odontoceti (toothed whales – dolphins, orcas, sperm whales)
Suborder Mysticeti (baleen whales – blue whale, gray whale)

24. Marine mammals Land-dwelling ancestors Warm-blooded Breathe air
Marine mammals
Land-dwelling ancestors
Warm-blooded
Breathe air
Hair/fur
Bear live young
Mammary glands for milk

25. Marine mammals Carnivora Prominent canine teeth Sea otters Polar bears

26. Marine mammals Carnivora Walruses Seals Pinnepeds
Marine mammals
Carnivora
Pinnepeds
Walruses
Eat crustaceans with tusks
Seals

27. Marine mammals Carnivora Sea lions Fur seals Pinnepeds
Marine mammals
Carnivora
Pinnepeds
Sea lions
Fur seals

28. Marine mammals Sirenia Herbivores Manatees
Marine mammals
Sirenia
Herbivores
Manatees
Coastal areas of tropical Atlantic Ocean
Dugongs
Coastal areas of Indian and western Pacific Oceans

29. Marine mammals Cetacea Stream-lined bodies for fast swimming
Specialized skin (dermal ridges) structure for fast swimming
Whales
Toothed - carnivores
Baleen – filter feeders

30. Cetacea

31. Marine mammals Dolphins vs. porpoises Dolphins (Delphinidae)
Marine mammals
Dolphins vs. porpoises
Dolphins (Delphinidae)
35 species
Beaks
melon (fatty organ in forehead)
Prominent, curved dorsal fin
conical, undifferentiated teeth
Range in size from 1.5 m Hector's dolphin to 9 m killer whales
Porpoises (Phocoenidae)
6 species
Lack prominent beak
laterally compressed teeth
More triangular dorsal fin
Bottlenose dolphin
Harbor porpoise
education/images/harbourporpoise/teeth2_small.gif

32. Cetacea Adaptations for deep diving Use oxygen efficiently
Able to absorb 90% of oxygen inhaled
Able to store large quantities of oxygen – high levels of myoglobin and hemoglobin
Able to reduce oxygen required for noncritical organs
Slowed cardiac rate
Muscles insensitive to buildup of CO2
Collapsible lungs

33. Cetacea Suborder Odontoceti (toothed)
Cetacea
Suborder Odontoceti (toothed)
Dolphins, porpoises, killer whale, sperm whale
Echolocation to determine distance and direction to objects
Clicks produced in nasal air sacs are focused by the melon
Echos received thru lower jaw  middle ear
Determine shape, size of objects

34. Cetacea Suborder Mysticeti Baleen whales
Fig
Baleen whales
Blue whale, finback whale, humpback whale, gray whale, right whale
Fibrous plates of baleen sieve prey items
Vocalized sounds for various purposes
Right whale baleen

35. Marine reptiles Sea turtles Prey depends on species
Marine reptiles
Sea turtles
Prey depends on species
Greens eat seagrass (gut flora digests cellulose)
Loggerheads eat conch
Leatherbacks eat jellyfish
Nest on beaches: predation, lights on dunes
Many overexploited
Green

37. Marine iguanas of Galapagos Islands
Feed on submerged algae
Dive for up to 20 minutes
Must surface before they become too cold and can’t climb out of water

38. Truly aquatic - reproduce in water - live-bearers
Sea snakes of Pacific
Highly poisonous
Truly aquatic - reproduce in water - live-bearers

40. Misconceptions

41. Florida Sunshine State Standards

42. Ocean Literacy Principles
3e. - The ocean dominates the Earth’s carbon cycle. Half the primary productivity on Earth takes place in the sunlit layers of the ocean and the ocean absorbs roughly half of all carbon dioxide added to the atmosphere.
5a. - Ocean life ranges in size from the smallest virus to the largest animal that has lived on Earth, the blue whale.
5b. - Most life in the ocean exists as microbes. Microbes are the most important primary producers in the ocean. Not only are they the most abundant life form in the ocean, they have extremely fast growth rates and life cycles.
5c. - Some major groups are found exclusively in the ocean. The diversity of major groups of organisms is much greater in the ocean than on land.
5d. - Ocean biology provides many unique examples of life cycles, adaptations and important relationships among organisms (symbiosis, predator-prey dynamics and energy transfer) that do not occur on land.
5e. - The ocean is three-dimensional, offering vast living space and diverse habitats from the surface through the water column to the seafloor. Most of the living space on Earth is in the ocean.
5f. - Ocean habitats are defined by environmental factors. Due to interactions of abiotic factors such as salinity, temperature, oxygen, pH, light, nutrients, pressure, substrate and circulation, ocean life is not evenly distributed temporally or spatially, i.e., it is “patchy”. Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while much of the ocean is considered a desert.
5g. - There are deep ocean ecosystems that are independent of energy from sunlight and photosynthetic organisms. Hydrothermal vents, submarine hot springs, methane cold seeps, and whale falls rely only on chemical energy and chemosynthetic organisms to support life.
5h. - Tides, waves and predation cause vertical zonation patterns along the shore, influencing the distribution and diversity of organisms.
5i. - Estuaries provide important and productive nursery areas for many marine and aquatic species.