Transcript Types_Fishes

Marine Vertebrates
Types of Fishes
I) Vertebrates
A) Subphylum Vertebrae
B) Four characteristics of
chordates
C) Backbone: AKA Spine
or Vertebral Column
1) Dorsal row of hollow
bones
2) Protects the Nerve or
Spinal Cord
II) Jawless Fishes
A) Class Agnatha
B) Around 30 known
species
C) Includes hagfish &
lampreys
D) Feed by suction with
aid from teeth
E) No fins, & lack true
vertebrae
III) Cartilaginous Fishes
A) Class Condrichthyes
B) Skeleton made of
cartilage
C) Movable jaws
D) Mouth ventral
1) Underneath the head
E) Paired lateral fins
F) Sandpaper-like skin
because of Placoid
Scales
III) Cartilaginous Fishes
G) Sharks
1) ~350 living species
2) Caudal Fin is
Heterocercal
a) Upper lobe longer than
lower lobe
3) Fusiform, or spindleshaped bodies
4) Five to seven gill slits
5) Powerful jaws with rows
of teeth
a) Continuously replaced
6) Carnivores & Filter
Feeders
III) Cartilaginous Fishes
H) Rays & Skates
1) ~450-500 known species
2) Dorsoventrally flattened
3) Demersal: fish that live
on the bottom
4) Five ventral gill slits
5) Stingrays
a) Whip-like tail with stinging
spines
6) Electric Rays
a) Electric organs on each
side of head
7) Skates lack the stinging
tail
III) Cartilaginous Fishes
I) Ratfish: AKA
Chimaeras
1) ~30 known species
2) Only one pair of gill slits
covered by a flap of skin
3) Long, rat-like tail
IV) Bony Fishes
IV) Bony Fishes
A)
B)
C)
D)
Class Osteichthyes
~23,000 known species
Skeleton made of bone
Cycloid or Ctenoid
Scales
E) Operculum: Gill Cover
F) Upper & lower tail fin
same size:
Homocercal
Operculum
Homocercal
IV) Bony Fishes
G) Fin Rays: thin
membranes supported
by bony spine
H) Anterior, terminal
mouth
I) More flexible jaws with
teeth attached to
jawbone
J) Swim Bladder: gasfilled sac above
stomach & intestines
that helps in buoyancy