Scales Flashcards
1
Q
What are the largest bony fish?
A
- sunfish
2
Q
What is special about tetraodontiformes order?
A
- major diversity in body form
3
Q
What is the function of scales? (3)
A
- protection
- calcium store (reduced endoskeleton = limited calcium store)
- drag reduction (change flow dynamics)
4
Q
How did scales evolve?
A
- independently in cartilaginous and bony fish
5
Q
What is the origin of scales
A
- dermal
6
Q
What are the 3 main types of scales?
A
- placoid
- ganoid
- elasmoid
7
Q
What are the major features of placoid scales? (2)
A
- tiny/toothlike
- sandpaper
8
Q
What does the sandpaper feature of placoid scales allow for?
A
- improves hydrodynamic efficiency by reducing drag
9
Q
What fish have placoid scales?
A
sharks
10
Q
What are the major features of ganoid scales? (2)
A
- not overlapping, interlocking
- heavy bone base
11
Q
How did ganoid scales derive?
A
- ancestral condition in bony fish
12
Q
What are 2 fish species that have ganoid scales?
A
- gars
- chondrostei
13
Q
Where are ganoid scales found on the body?
A
- along sides and back
14
Q
What are the main features of elasmoid scales? (4)
A
- bony-ridged
- derived in bony fish
- overlapping
- covered by epidermis
15
Q
What are the 2 subtypes of elasmoid scales?
A
- cycloid
- ctenoid
