| 1. |
a.
b. |
Sharks with anal fin ....................................................................
Sharks with no anal fin ............................................................... |
|
go to 4
go to 2 |
| 2. |
a.
b.
|
Sharks with flattened raylike body and mouth at end of head ..........
Sharks with body not raylike and mouth on bottom side of head .....
|
|
Squatiniformes (Angel Shark)
go to 3 |
| 3. |
a.
b. |
Sharks with snout extended into a long saw like projection ............
Sharks with short snout not saw-like ...........................................
|
|
Pristiophoriformes (Saw Shark)
Squaliformes (Dogfish Shark) |
| 4. |
a.
b. |
Sharks with 6 or 7 gill slits and one dorsal fin ................................
b. Sharks with two dorsal fins and five gill slits ..............................
|
|
Hexanchiformes (Seven gilled Shark)
go to 5 |
| 5. |
a.
b. |
Sharks with spines on dorsal fins ..................................
Sharks without spines on dorsal fin ...............................
|
|
Hete rodontiformes (Bullhead Shark)
go to 6 |
| 6. |
a.
b. |
Sharks with mouth completely in front of eyes ........................
Sharks with mouth not completely past eyes ......................... |
|
O. rectolobiformes (Carpet Shark)
go to 7 |
| 7. |
a.
b. |
Sharks with nictitating* eye lids ..............................................
Sharks without nictitating eye lids ......................................... |
|
Carcha rhiniformes.(Tiger Shark)
Lamniformes (Mackerel Sharks) |
