Benthic
Lives on the bottom
Pelagic
Swims in the water column
chordate features
Notochord, Postanal tail, Hollow nerve cord, Pharyngeal pouches
additional structures vertebrates possess
Vertebral column, Brain, Myomeres
myomeres
series of muscle segments along the trunk
List the three groups of living marine fishes
Agnatha, Chondrichthyes, Osteichthyes
Agnatha
jawless fish
Placoderms
- The first jawed fish
- Evolved from gill arches
- Extinct
- Paired Fins
Chondrichthyes
- Effective predators
- Cartilaginous skeletons
- No ribs
- VERY flexible!
- Placoid scales
- Dermal Denticles- Teeth
- No swim bladder
- Oil filled liver
Contrast lampreys and hagfishes
Lampreys- Parasites
Hagfishes- Benthic scavengers/Eat dead & dying
Osteichthyes
bony fishes
characteristics of cartilaginous fishes (Chondrichthyes)
cartilaginous skeleton, no rib cage, placoid scales, no swim bladder,
exposed gill
slits, large oil-filled liver, ventral mouth,
heterocercal caudal fins, more posterior
pelvic fin, and low
pectoral fins
examples of cartilaginous fishes
Sharks, Rays, and Chimaeras
What structure in cartilaginous fishes helps provide buoyancy?
light cartilage skeleton
What structure in boney fishes helps provide buoyancy?
swim bladders
Contrast the placoid scales of cartilageous fishes with the scales of bony fishes
Placoid scales are little teeth. Bony fish do not have that
What is unique about shark teeth
They have a lot and they get replaced in rows.
Claspers
Male sex organ
Spiracle
Holes that takes in water and shoots it out the gills
spiral valve
A modification of the ileum, the spiral valve is internally twisted or coiled to increase the surface area of the intestine which increases nutrient absorption
Ampullae of Lorenzini
Detect weak electrical fields
nictitating membranes
Eyelids
Contrast the two groups of bony fishes
Ray-finned fishes, or Actinopterygii.
Lobe-finned fishes, or Sarcopterygii, which includes the coelacanths and lungfishes.
Recognize these characteristics of bony fishes (Osteichthyes):
bony skeleton, rib cage, overlapping cycloid or ctenoid scales, swim bladder, operculum-covered gill slits, terminal mouth, homocercal caudal fins, more anterior pelvic fin, and high pectoral fins
fish shapes
fusiform, laterally compressed, depressed, and eel-like
fusiform
streamlined
Laterally compressed
flattened from side to side
Depressed
Flattened from top to bottom
Eel like
looks like an eel
Chromatophore
cell with pigment/changes color by stretching
Countershading
Dark on top/light bottom
Warning coloration
bright colors/ indicates venom
cryptic coloration
camouflage/change color
disruptive coloration
patterns break up the outline of the fish
Eye spot
brings attention away from the head
Why does the intestine tend to be longer in herbivores?
So they have time to absorb nutrients
Contrast the cloaca of cartilaginous fishes with the separate anus
and urogenital
opening in bony fishes
Bony fish have two openings
Describe the circulatory system of marine fishes
Fish have two-chambered hearts, blood circulates to the gills and the rest of the body
Describe the difference in the respiratory system between
cartilaginous and bony
fishes
sharks have spiracles. Fish take in water throught the mouth and out the gills
Structure of Gills
•Gill Arches
•Gill filaments
•Gill rakers
•lamellae
countercurrent system of flowHow does countercurrent system of flow help fish extract oxygen from water?
Blood in gills flows in the opposite direction to water
How does countercurrent system of flow help fish extract oxygen from water?
moves water more efficiently
hemoglobin
Protein on RBC that carries O2 & CO2
myoglobin
-Protein in muscles that stores O2
–Makes muscle “red”
Contrast osmoregulation in bony fishes vs. cartilaginous fishes
–S.W. Boney fish
•Drink water
•Salt excreted by kidneys
& chloride cells
–Cartilaginous fish
•Kidneys control amt of urea in
blood
•Salt excreted by kidney & rectal gland
Explain how marine fishes are able to sense their surroundings
through smell,
taste, vision, sound, a lateral line, and the
Ampullae of Lorenzini.
these senses can detect what is around them at all times.
barbels
Whisker like organs near mouth on many bottom feeders
neuromasts
Canals lined w/ sensory cells
What are some possible benefits of schooling in fish?
–Avoid predation
–Reduce drag?
–Mating?
Contrast the terms “anadromous” and “catadromous.”
Anadromous live in saltwater but breed in freshwater and Catadromous lives in freshwater and breeds in saltwater
simultaneous hermaphrodites
has both sets of sex organs throughout life
sequential hermaphrodites
organism is born as one sex but has the ability to change into the other sex
What reproductive strategy predominates in cartilaginous fish
internal fertilization
What reproductive strategy predominates in bony fish
releases thousand of minute eggs into the water where they are fertilized externally by sperm
oviparous
egg birth
ovoviviparous
egg live birth
viviparous
live birth
List the four classes of air-breathing tetrapods
•Amphibia (some-what)
•Reptilia
•Aves
•Mammalia
What does it mean to say that their body fluids are “hypotonic” to sea water?
Less salt inside their bodies than ocean
Are amphibians strictly terrestrial?
Yes
major characteristics of reptiles
Nasal glands (secrete salt) and special kidneys, Shelled egg requiring incubation
4 groups of living marine reptiles
crocodiles, Snakes, turtles, iguanas
Name an extinct marine reptile
Ichthyosaurs
How does sea snake reproduction differ from other marine reptiles?
Sea snakes are ovoviviparous
Describe the life cycle of a sea turtle
lay eggs, run for their life, and come back to the same beach they were born at.
why so many sea turtle eggs hatch simultaneously
possibly the moon or the CO2 levels
List several perils sea turtle eggs and hatchlings face
seagulls, gosht crabs other animals
What is a “Turtle Excluder Device” (TED)
it is a whole in nets to release turtles
List the major characteristics of marine birds
• Endotherms
• Feathers
–Waterproof
•Oil glands
•
Evolved from Dinos?
What criteria are used to categorize a bird as a “seabird”?
These birds have well-developed glands near these bill tubes that allow them to consume seawater and then excrete salt from the solution
How are penguins different from other marine birds?
•Flightless
•Dense bones for diving
•Male incubates egg on
feet for 64 days
•Female returns when egg hatches
How are “shorebirds” different from marine birds?
The seabirds depend on the open water to forage on fish and small invertebrates. The shorebirds are the camouflaged birds that can found along the shore, using their specialized beaks to poke in the sandy areas to forage for invertebrates
List the major characteristics of marine mammals
•Viviparous
•Body Hair
•Milk secreting mammary glands
Order Carnivora
seals, sea lions, walruses, sea otters, and polar bears
Suborder Pinnipedia
seals, sea lions, walruses
Order Sirenia
manatees, and sea cows
Order Cetacea
dolphins, whales
Distinguish “sea lions” from “seals."
sea lions are better equipped for land and seals are better equipped for water
cetaceans
•Terrestrial ancestors
•Lack pelvic appendages
•Dorsal
blowhole
•Echolocation
–Sound waves
–Melon
2 suborders of cetaceans
•Suborder Mysticeti
–Baleen whales
•Suborder
Odontoceti
–toothed whales
baleen
used for filtering food from the water
convergent evolution”
Different species develop similar structures because they have similar lifestyles
homologous structures
same body parts develop differently because they are used differently
vestigial structures
parts of a body without a use
vocalization
communication
breaching
when a whale leaps out of the water
spying
a whale or dolphin raises its head vertically above the water, then slips back below the surface
beaching
jumps on a beach in order to get prey
How would you describe the intelligence of whales
smart
describe whale migrations
• Summer
–Antarctic feeding
• Winter
–Tropical breeding
internal sex organs
sex organs inside the body for warmth
harems
a group of female animals sharing a single mate
bachelor groups
group of males
3rd party male
helps hold the others so the don't float off while mating
marine mammal adaptations for long, deep dives
blowholes, and myoglobin
melon
giant forehead, function like antenna, receiving incoming sound
What roles do vocalizations play in marine mammal groups
talk to one another
Explain how echolocation functions in many marine mammals
rely on sound to acoustically sense their surroundings, communicate, locate food, and protect themselves underwater