1. Barbels – Atlantic Sturgeon

2. Marine Fishes – Sensory System (cont.)
Finally, many fish have a lateral line that allows them to sense vibrations in the
water…

3. Marine Fishes – Reproductive System
A few species of fishes are hermaphroditic, but most have separate sexes… Sexes
are not always definitive though, with many species exhibiting sex reversal.
What are the advantages of each of these strategies?
Depending on the species of the fishes, they all have a wide range of behaviors
associated with mating. Also, different species exhibit internal versus external
fertilization; and, oviparity, viviparity, and ovoviviparity strategies are
all utilized…
What may be the advantages and disadvantages of each?

4. Broadcast Spawning

5. Basic classification of
vertebrates and fishes:
By the way:
Fish – single individual or
more than one individual
of the same species.
Fishes – more than one kind
of fish.

6. Cartilaginous fishes
Class Chondrichthyes

7. Marine Fishes
Class Chondrichthyes – Cartilaginous fishes; with about 1000 different species, they
include the different species of sharks, rays, skates, and ratfish.
Cartilaginous fishes have well
developed jaws and teeth;
Typically have a ventral mouth;
and, have rough, sandpaper-like
skin because of tiny scales…
In fact, their teeth are simply
modified scales!!

8. Senses

9. Senses

10. types of caudal fin : (A) - Heterocercal, (B) - Protocercal, (C) - Homocercal, (D) - Diphycercal

12. Shark Diet Discovery Channel Videos:
The Ultimate Guide to Sharks: Shark Diet
Air Jaws: Sharks of South Africa: Shark Feeding Frenzy
Air Jaws: Sharks of South Africa: Filming Air Jaws

13. Shark Mating Discovery Channel Videos:
The Ultimate Guide to Sharks: Shark Mating
The Ultimate Guide to Sharks: Shark Birth and Maturation
Sibling cannibalism

14. Skates vs. Rays Different Orders Reproduction Tooth Structure
Rays are viviparous (live bearing) while skates are oviparous (egg laying), releasing their eggs in rectangular cases sometimes called "mermaid´s purses".
Tooth Structure
Although skates may have small teeth, those of rays are plate-like and adapted for crushing prey. 
Morphology
Skates normally have prominent dorsal fins while those of rays are absent or reduced in rays.
Although a few electric rays are capable of delivering a powerful electric shock and some sting rays have large, barbed stingers, in general, these docile animals pose no real threat to swimmers and divers.

15. Skate