Chapter 34-Vertebrate I Flashcards
What is Cranites?
Craniate include hagfish and all vertebrate.
What is the main characteristic of craniates?
- cranium: protective bony or cartilaginous housing enclosing the brain
- Neural crest: embryonic cells that will disperse throughout the embryo and lead to the formation of cranium, jaws, teeth, and peripheral nerves.
Hagfish
- Not true fish
- Jawless, finless, and no vertebral column
- Possess a skull and cartilaginous notochord
- primitive craniates resemble fossil found 530 mya
- Blind scavenger with keen sense of smell
- produces copious slime to deter predators.
chordate phylum
It has vertebrates subphylum:
- 60,000 species
- ranges in size from tiny fish to huge whales
- Occupy all earth’s biomes.
Vertebrates (subphylum)
Possess all chordate and craniates trait, plus,:
- vertebral column
- endoskeleton
- complex internal organs.
Vertebral column
Notochord develops into a bony or cartilaginous column of interlocking vertebrae.
Endoskeleton
Living internal skeleton of cartilage or bones. most have two or more pair of appendages (legs, fins,…)
Complex internal organs
Liver, kidney, endocrine glands, and a heart with two or more chambers.
Fishes
- 5 out of 11 existing vertebrae classes are fish
- about 30,000 species
- fishes are aquatic, gill-breathing ectotherm that possess fins and scaly skins.
Lampreys (class petromyzontida)
- primitive vertebrates that lacks jaws and appendages
- Notochord is primitive vertebral column composed of cartilage
- occur in marine and freshwater
- many are lampreys are parasitic
- circular mouth with rasp like teeth for sucking fluids from other fishes
- decimated important fish species in the great lakes.
Jawed fish
There are four classes of gnathostomes (jaw mouth)
Where does hinged jaw developed from?
Hinged jaw developed from pharyngeal arches and cartilaginous rods. (the original function of these were to flank the gill slits, and support the respiratory gill tissues)
Chondrichthyes class
It include:
- cartilaginous fish
- shark and rays
- skeleton composed of flexible cartilage.
Why cartilaginous fish have cartilage skeleton?
Most vertebral skeleton first begin as a cartilage model during development where cartilaginous fish retain that embryonic trait.
How many fins does shark possess?
Shark posses paired pectoral and pelvic fins, a powerful caudal fin and one or two dorsal fins.
What are the characteristic of the teeth and the skin of shark?
- Sharks possess a rough placoid scales on the skin which contain calcified tissue
- The teeth are modified scales. They continuously get replaced throughout the life.
Characteristic of shark’s gill slit
- Shark possess naked gill slits.
- Oxygenated water enters the mouth and flow over gills for gas exchange.
- Most sharks lack mechanism for pumping water over gills.
The body of the shark
- The body of the shark is denser than water.
- It lacks swim bladder.
- Oil filled liver
Swim bladder, oil filled liver
provide buoyancy to bony fish.
Characteristic of shark’s heart
- Two chambered heart, it has one atrium and one ventricle.
- Closed circulatory system that employs single circulation.
The circulation of blood
- Atrium collect blood, which empties into the ventricle
- ventricle pump blood to the gill for oxygenation
- blood flows to body tissues before returning to the heart.
Shark sensation
- smell sensation: shark have powerful smell sensation via paired nares and olfactory bulbs
- pressure sensation: shark have system of microscopic sensory organs that detect pressure wave from movement in water (lateral line)
- electrical sensation: shark can detect electrical impulses of other animals. (Ampullae of Lorenzini)
Fertilization in shark
- Pelvic fin of males has a pair of claspers for transforming sperm to the female.
- Other species are oviparous.
ovoviviparous
Egg retained in mother’s body and sustained by yolk until ready to hatch.
viviparous
Eggs developed in uterus and is nourished by maternal tissue via placenta.
Classes of osteichthyes
- ray-finned fish
- coelacanths
- lungfish
Features of bony fish differ from Chondrichthyes
- Bondy skeleton
- operculum
- swim bladder
Operculum
protective flap that covers the gills.
Fertilization of bony fish
Most reproduce via external fertilization.
Where does bony fish spawn?
Many fish spawn in shallow, costal waters, or freshwater streams rich in food and oxygen.
Anadromous fish
fishes that lives in marine but migrate to freshwater to spawn.
How many fin does Ray finned fish have?
It possess paired pectoral, pelvic, and dorsal fins, a single caudal fin, and a single anal fin.
How the fin of the ray finned fish is supported?
Fins are supported by thin, bony, flexible rays controlled by muscles in the interior of the body.
Dermal scales of ray finned fish
The overlapping dermal scales are coated with slimy mucus to reduce the friction during swimming.
What is the function of the muscles of operculum?
The muscles of operculum forces the water over the gills, allowing bony fish to breath when not moving.
What class of bony fish is the most successful fish?
class of ray finned fish.
How the fin of the Lobe-finned fish is supported?
They are supported by limb-like skeletal extensions of the pectoral and pelvic areas and controlled by muscle inside fins.
what is the closest relative to Lobe-finned fish?
The closest relative are tetrapods
Feature of coelacanth fish
it has jointed head like land vertebrates
Where do lungfish prefer to stay in?
They live in oxygen poor freshwater swamps and ponds
How do lungfish breathe?
They posses both gills and lungs (gulp air for gas exchange)
Which fish will drown if they are in water?
lungfish will drown if they can’t breath.
