Download IB 362 verts lecture 3

Subclass Actinopterygii
The ray-finned fishes
Other Orders - Tetraodontiformes
– Pufferfish, burrfish and porcupinefish - mostly
marine, but a few freshwater species
– Tetraodotoxin or tetrodoxin
Other Orders - Tetraodontiformes
Fugu
– Tetraodotoxin or tetrodoxin
Other Orders - Tetraodontiformes
Ocean Sunfish – 3 species
Most fecund vertebrate - >300 million eggs
Other Orders – Pleuronectiformes - flatfishes
• Benthic, mostly marine - both eyes on same
side of head
• Eyes on both sides as juveniles, one migrates to
other side as individual matures
• Both left and right eyed families
Other Orders - Pleuronectiformes
• 570 species - flounder, soles, halibut
Other Marine Vertebrates
Class Reptilia
Order Testudines - Sea turtles
Family Dermochelyidae
Family Cheloniidae
- 1 species
- 6 species
Other Marine Vertebrates – sea turtles
Family Dermochelyidae
Family Cheloniidae
- all listed or protected by at least one international
conservation organization
- usually have both herbivorous and carnivorous life stages
- associated with coral reefs during two life-stages
1) immature (growth) and adult foraging (before
reproductive activities)
2) pre-nesting by females
Other Marine Vertebrates – sea turtles
Family Dermochelyidae
Generalized life history
Family Cheloniidae
Other Marine Vertebrates – sea turtles
Family Dermochelyidae
- largest turtle in the world – up to 6 ft
- only turtle that is functional endotherm - can raise body
temperature 18 C above ambient water temp
- can dive to 1230 m (4,000 ft)
- diet is 90% jellyfish
Leatherback
Other Marine Vertebrates – sea turtles
Family Dermochelyidae - Leatherback
esophagus is lined with spines to prevent jellyfish from
swimming out
Other Marine Vertebrates – sea turtles
Family Dermochelyidae - Leatherback
body temperature is maintained above surrounding seawater
- counter-current blood flow system in flippers
- thermal inertia - large size and thick layer of fat under skin
counter-current blood flow
Other Marine Vertebrates – sea turtles
Family Cheloniidae –
Loggerhead Turtle
Flatback Turtle
Hawksbill Turtle
Olive Ridley Turtle
Other Marine Vertebrates – sea turtles
Family Cheloniidae
Kemp’s Ridley Turtle
- rarest of the marine turtles
- ~2000 nests in one location
Other Marine Vertebrates – sea turtles
Family Cheloniidae
Green Turtle – most common
marine turtle
- 20 nesting locations
Family Dermochelyidae
Family Cheloniidae
Sex Determination
In most turtles, sex is determined by the incubation
temperature of the nest. This is called temperature
dependent sex determination (TSD). There are three
major patterns of TSD.
A. Males at high temps
B. Males at low temps
C. Males at intermediate temps
Conservation of marine turtles
- By-catch
- Poaching/Products
- Predation
- Disease
- Pollution
Conservation of marine turtles
- By-catch: both long-line fishing and
shrimp fishing/trawling
TEDs
Conservation of marine turtles
- Poaching - turtle products
Conservation of marine turtles
- Predation
Conservation of marine turtles
-Disease - fibropapilloma tumors
herpes type virus – no known cause
Conservation of marine turtles
-Pollution
•Light
plastics
Other marine reptiles
Order Squamata
Family Elapidae - sea snakes (also includes cobras,
kraits, coral snakes)
-
~ 70 species are marine
all marine species are limited to Indian and Pacific Oceans
most species are fully aquatic, never leaving the water
strong neurotoxins, but rarely aggressive
Olive seasnake
Yellow-bellied seasnake
Other marine reptiles
Family Elapidae Venom delivery mechanism
Proteroglyphousa single, fixed, hollow
fang on the anterior
of each maxilla.
Other marine reptiles
Family Elapidae - toxicity
Venom toxicity - The most common measure of
toxicity is the LD-50.
This is the amount of a substance that is required
to kill 50% of the test animals (e.g. mice or rats)
in one dose.
Name
LD-50(mg/kg)
Box Jellyfish
Taipan
Brown Snake
Yellow Sea Snake
Chinese Cobra
Pufferfish
Timber Rattlesnake
0.02 -0.04 ?
0.025
0.0365
0.067
0.29
0.334
5.1
Range
South Pacific/Australia
Australia
Australia
Pacific Ocean
China
tropical oceans
North America
Marine Mammals – Class Mammalia
• Mammals first appear in fossil record about 220 mya
• at least three lineages have invaded the marine environment
Carnivora
1 species
Pinnipedia
34
Sirenia
4
Cetacea
90
Marine Mammals – Class Mammalia
Most important adaptations
- conservation of body heat – large size, blubber
- extremely efficient at absorbing/conserving oxygen
- carry higher conc.of red blood cells,
more hemoglobin in blood
- muscles carry more myoglobin
Marine Mammals – Class Mammalia
- extremely efficient at absorbing/conserving oxygen
4-5 min.
Up to 30 min.
Up to 30 min.
Over an hour
Marine Mammals – Class Mammalia
Carnivora
Pinnipedia
Found in cold waters
Tail is modified pair of hindlimbs
All are carnivorous
Most reach large body sizes – conform to
Bergmann’s Rule
Marine Mammals – Class Mammalia
California Harbor seal – 6’
Elephant seal – 20’
Bergmann’s Rule (1847) – within a given group of
organisms, those with larger body sizes will be
found at higher latitudes
Larger animals have a lower surface area
to volume ratio – radiate less heat
dugong
manatee
Found in warm waters, fully aquatic
All are the only herbivorous marine mammals
Have lost hindlimbs entirely
Three manatee species occur in Atlantic Ocean coastal
areas - Dugong occurs from East Africa to western Pacific
islands
All four species of conservation concern,
all listed as CITES species
CITES = Convention on the International Trade in
Endangered Species
Commander Islands
Stellar’s Sea Cow
Described by science in 1741
Extinct by 1768
Marine Mammals – Class Mammalia
Cetaceans
Mostly found in colder waters – warmer waters for
reproduction
Most complete transformation to aquatic life
• very streamlined bodies
• loss of hindlimbs
• strong convergent evolution
Marine Mammals – Class Mammalia
Cetaceans
Most complete transformation to aquatic life
• very streamlined bodies – speeds up to 40 mph
• blowhole at top of head – some species can empty and
refill lungs in 2 second
• most efficient use of oxygen
•Best developed system of echolocation
Marine Mammals – Class Mammalia
Cetaceans
Two groups – Baleen Whales
18 species
Toothed Whales
72 species