fish, amphibians, reptiles, birds, and mammals
Pouch lamprey, hagfish, and lamprey eel
• Nervous system
• Closed circulatory system –Heart ->ventricle->Aorta-> gills
• Excretory
• Respiration
• Feeding
• Reproduction:
• A: Myxini• B. Chondrichthyes• C. Osteichthyes-
• D. Petromyzontida-
CLASSES MYXINI,PETROMYZONTIDA, SARCOPTERYGII
Chondrichthyes and
Actinopterygii
Characterisitics
Class Myxini
Class Petromyzontida
Examples
Mouth
Hagfishes
Lampreys
4 pairs of tentacles
Sucking mouth with
teeth and rasping tongue
Olfactory sacs
Pharyngeal slits
Open to mouth
Blind sacs
5-15 pairs; one opening
7 pairs; separate
openings
Feeding
Scavenge dead or dying
fish; produce copious
slime
Parasitic or predatory;
feed mainly on blood
Characterisitics
Examples
Chondrichthyes
Sharks, skates, rays
Osteichthyes
All bony fish
Digestion
Complete, lack pyloric
Complete, have a pyloric
cecum, have a cloaca (a
cecum (used to increase
common opening for the
absorption in the intestine)
reproductive, excretory and
digestive systems)
Respiration
Gills
Gills covered by an
operculum (helps pump
water across the gills)
Skin
Covered by placoid scales
(feel sandpapery)
Covered by cycloid or
ctenoid scales
Skeleton
Cartilage endoskeleton
Bony endoskeleton
Circulation
Closed, two chambered
Closed, two chambered
heart; 1-loop (from heart
heart; 1-loop
past gills to the rest of the
body and back to the heart)
Swim bladder (gas filled sacs
that regulate buoyancy)
Lacking
Typically present
Temperature regulation
Ectothermic
Ectothermic
Lateral line system (used to
Present
Present
Movement
Paired fins (used for more
precise steering and
increase agility),
heterocercal tail
Paired fins, homocercal tail
Reproduction
Dieocious, internal
Dieocious, variable fert.;
fertilization, ovoviviparous, some are oviparous, some
males have modified pelvic are ovoviviparous
fins called claspers
detect movement in the water)