MARINE VERTEBRATES

Animals with backbones are in what phylum?

3 subphylum of phylum chordata

Have their notochords in the posterior part

Have their notochords in the anterior part

Presence of backbone, central nervous system, complex organs, and adaptive immune system

Present only in embryonic stage of fishes, reptiles, birds, and mammals.

Support for the nerve cord which will be replaced by the vertebral column in later stages

Lies above notochord

Common feature for all chordates

Tunicates = filter food from the water
o Fish = respiratory structures
o Humans = pharyngeal clefts

Located posterior to the anal opening

aquatic species use post anal tail for?

terrestrial vertebrates use post anal tail for?

for humans post anal tail is equivalent to?

1st major mass extinction event

Cause of Ordovician-Silurian extinction is?

“Age of Fish”

Cause of Late Devonian Extinction is?

Some believed that the cause of Late Devonian Extinction is?

Also known as “The Great Dying”
- Wiped out 90% of all the Earth’s species.
(80% marine inverts; 70% terrestrial verts)
 Due Intense volcanic activity in Siberia resulted in global warming

in what extinction elevated CO2 and H2S levels = ocean acidification, acid rain, and other changes in land and ocean chemistry

Underwater volcanic activity = global warming and dramatic change in the chemical composition of the oceans

Dinosaurs assumed dominance on land on what extinction?

aka Cretaceous-Paleogene Extinction (K-Pg)

End of the dinosaurs and the rise of mammals and birds is in what extinction?

An asteroid crashed in?

(10km wide, 25 km/s speed) =  Crater (200km wide) is called?

1st vertebrates which are filter feeders with hard bony plates with no jaw and lacked paired fins

oldest jawless fish (470 mya)

Evolved during Silurian Period but went extinct at the end of the Permian Period

Lacked jawbones but possess paired fins and armored dermal skin

dominant predators in Devonian seas

Gave rise to Osteichthyes (Bony Fish) and Chondrichthyes (Cartilaginous Fish)

Have skeletons made of cartilage rather than bones.

Cartilaginous fish (Chondrichthyes) lacks swim bladder
True False

examples of Cartilaginous fish (Chondrichthyes)?

1st appeared 430 mya

Appeared in the late Silurian Period and Modern fish belong to this group

a type of fish where skeletons are made up of bones

two groups of Bony Fish (Osteichthyes)?

Evolved from lobe-finned fish 365 mya and First vertebrates to venture into land

Early amphibians retained many fish-like
characteristics until the Carboniferous
period
True False

called “fishapod”, a cross between primitive lobe-finned fish and tetrapods.

is the earliest amphibians with nostrils and efficient lungs

Evolved from reptiles and gained the ability to fly
they have Feathers, hollow bones, and are warm-blooded

______ is the earliest reptile; lizard-like animal about 20 cm long
______ is the early aquatic relatives of reptiles

Have developed powerful legs compared to amphibians and laid amniotic egg (hard shell)
- Lost their gills so they cannot breathe in water like fish and some amphibians

evolved from reptiles and have  four-chambered heart, hair covering, mammary gland, gives birth to live young

1st cetaceans; ancestor of whales

______ whales, dolphins,
porpoise
______ fur seals, sea lions,
walruses, seals
______ dugongs & manatees
______ polar bears & sea otters

cellulose-like polysaccharide ‘tunic’ that encloses the body

Spends their entire life as pelagic organisms

Sea Squirts = metamorphose (Planktonic Larvae → Sessile Adult)
True False

Three classes of Urochordata

a class in urochordata where it is the largest and most diverse class and all of them are hermaphrodites

Most of the chordate characters that were present during larval period disappear during metamorphosis into adult.
True False

In class Ascidiacea the colonial species are smaller than solitary
ones
True False

3 orders of class ascidicea

Order _____ – pharynx lacking both internal longitudinal
vessels and folds
2. Order _____ – pharynx with internal longitudinal vessels but lacking folds
3. Order _____– pharynx with both internal longitudinal vessels and folds

have relatively simple pharyngeal basket and the posterior part of the abdomen contains the heart and gonads
Ex: Sea Squirts (Fernando Lahille, 1886)

longitudinal vessels in the pharyngeal basket and unpaired gonads (present only on the same side of the body as the gut)

Ex. Ciona intestinalis (Vase Tunicate),
Megalodicopia sp., Perophora namei

the presence of folded pharyngeal basket and complete absence of an abdomen have 3 families
Ex: Halocynthia roretzi

free-living pelagic urochordates and contains salps and doliolids (solitary and colonial) and pyrosomids (colonial)

Three orders of Class Thalicea

“unicorns of the sea” and free swimming colony which emits
bright, phosphorescent light when stimulated

Example of Order Pyrosomida

- Barrel-shaped body
- Muscle bands form 8 complete rings
- 2 wide siphons
- tailed larva with notochord present

Example of order dolioda

- cylindrical or prism-shaped body
- very scarce, but can increase their pop’n by phytoplankton blooms

example of order salpida

Simplest tunicates and Known for the large houses they build
around their bodies to assist in filter-feeding

received their name because the adults retain larval characteristics

- Aka amphioxus / lancelets
- spend most of their time buried in sand
- Closest living relative of vertebrates

discovered in the Burgess Shale (Middle
Cambrian, ~ 530 mya)

dorsal nerve cord has a slight swelling at the front = brain
- Small eyelike organs in the nerve cord = detects the direction of light and changes in its intensity

live in marine environments w/ backbone

two groups of vertebrata

Classes of Vertebrata

- Lacks jaw, paired fins, and scales
- Ex. hagfish & lampreys

jaws, paired fins, cartilaginous skeleton etc.
Ex: Shark, skate, ray, chimaera

Have jaws, paired fins, bony skeleton, smaller size, homocercal tail, swim bladders

Two groups of Class Osteichthyes

Orders under Class Osteichthyes:

3 body shapes:

- Torpedo/missile shape
- Streamlined shape with a very high and
narrow tail

- tall, thin shape and flat side to side
- Entering vertical crevices

- broad shape and flat top to bottom
- Lying on or below the surface of the sand

1st group to possess amniotic egg
Ex: crocodiles, turtles, lizards, and snakes

only reptiles with a four-chambered heart (like birds and mammals)

1st group to be homeothermic and Flight ability (most species)
Ex. Oyster catcher, Sea Gulls, Pelican, Terns, Skuas, Penguins

Large, aquatic animals with streamlined bodies ending in a paddle-like fluke

Fin-footed and flippers to move both on land and in the
water

seals cannot enter the water = do not have proper insulation to keep them warm
True False

"sea cows" = diet
Ex: Dugong (Dugong dugon) and Manatee
Ex: Ex. West Indian Manatee (Trichechus manatus)

Ursus maritimus (Polar Bear)

dexterous hands which they use to smash sea urchins off rocks
True False

only marine mammal that catches fish with its forepaws rather than with its teeth

Example of sea otter