1.
Circuli - growth rings
Annuli
Focus

2. 1. Placoid
2. Cosmoid
3. Ganoid
4. Elasmoid

3.
Rigid fin with less surface area means less drag and great acceleration, but decreased maneuvering. Swimmers!!

Example: tuna

4.
vertebrae do not extend into lobe

5. Bony protective layers

6. Mainly the habitat
- Fish with small scales normally live in faster currents
- fish with no sclaes such as catfish live in burrows

7.
A- symmetrical, vertebrae extend into larger lobe

Example: Shark

8.
Caudal fin extends around the vertebral column.

Example: lamprey

9. - Smooth and Striated
- will see myomeres = which are the zig-zag shaped in muscles that you see when flaying a fish
- there is red, white and pink muscle
- different types of muscle can be found in different locations depending one what the fish activity is
* the coloration can be from diet
- Muscle can also be for sound or producing electricity

10.
Function: Large amount of surface area allows for effective acceleration and maneuvering, but creates drag causing fish to tire easily

Example: mosquito fish

11. Rounded, truncate, emarginate, forked and lunate are all homocercal caudal fins

12. the fins help maintain the stability of the fish
- the dorsal and ventral fins reduce the tendency to roll and yaw and also assist in turning movements
- the pectoral and pelvic fins act as hydroplanes and control the pitch.
- the tail fin contributes to the forward thrust.

13. ...

14.
includes both the cycloid and ctenoid scales
- dermal = don't have the enamel layer like in placoid
- lost the ganoine
- two layers
- fibrous outer and bonny inner layer
- layered on fish like shingles - these ones will grow and add material to the outer edge or will absorb parts of them if they are in bad conditions.
- Elasmoid scales are more derived
- difference between cycloid and ctenoid is that ctenoid have ctenii

15.
A- symmetrical, vertebrae extend into larger lobe

Example: Shark

16. important for osmoregulation

17.
Form: Forwardly located, moved up and better for sculling (rowing)
Function: Steering, stability, braking, and potentially thermoregulation
Shape matters: Long and pointed = fast swimming - Rounded = slow swimming - Enlarged = escape preadors or for display - Rigid = shark example

18.
This is

19. less vascularization - fewer mitochondria - do a lot of anaerobic respiration - more likely to have bursts of energy
Trade off: have to recover

20.
Example: the Goby which has developed a suction cup

Another example is of fish that have modified the pelvic fin into a gonopodium = used for internal fertilization

21. 1. Mate selection
2. Predator defense = spines and flaring them out
3. Homeostasis/thermoregulation
4. Camouflage
5. Fins can also be used for tactile (touch)

22.
This is

23. Form: Paired fins, ventral, most variable in position on the body
Function: Fine movement and control, stabilize movement for up and down, side to side, can be used for braking and maintaining equilibrium (roll).

24. Fishes can have an ossified skeleton, a cartilaginous skeleton or a mixture of the two.

Example of mixture: Hagfish

25.
Referring to the point of attachment

Proximal is closer to the point of attachment.