Exam #2 Flashcards
Bony Fish, Transition to Land (58 cards)
What are the general characteristics of Osteichthyes?
bony fish
- 1st appearance of the bony endoskeleton.
- swim bladder.
- terminal mouth.
- homocercal tail (=).
- paired fins.
- overlapping scales.
What type of bone do we see in bony fish?
- endochondrial bone = long bones, start out as cartillage.
- dermal bone = form as bone.
Ray-Finned Fishes
Actinopterygii
Lobe-Finned Fishes
Sarcopterygii
Neopterygii
modern ray-finned fishes.
What are the different anatomical features of ray-finned fishes?
compared to Chondricthyes
- pectoral fins moved up & along side of body.
- pelvic fins move forward.
- tail becomes homocercal (=)
- gill slits become opercular cover (pump water over gills).
- increase # of muscles (more movement).
- jaw now able to open extremely wide.
What are the different anatomical features of lobe-finned fishes?
- pectoral & pelvic fins similar to chondricthyes (more stability).
- bone projected into fins.
What is the main purpose of having scales?
- outside protection.
- osmoregulation (doesn’t allow diffusion to take place accross it).
- can age a fish by looking at rings (like trees).
What are the different scale types?
Placoid, Cosmoid, Ganoid, and Cycloid/Ctenoid scales.
Placoid Scales
- Chondrichthyes.
- tooth-like.
- have blood supply.
Cosmoid Scales
- adaptation of placoid scales.
- found in ancestral-type bony fish (ex. lungfish).
- very stiff (less flexible body).
Ganoid Scales
- rhomboid shape ♢.
- modified cosmoid scales.
articulating peg & socket joint btwn them.
Cycloid & Ctenoid Scales
- modern fishes.
- thinner, more flexible (more flexible body).
- cycloid = round edge.
- ctenoid = comb edge.
Can fish have multiple scale-types?
yes, they are usually found in different areas of the body.
What do some fish use in place of scales?
- thick layer of mucus.
- leathery skin.
- bony plates.
What are changes seen in Neopterygii?
modern day ray-finned fishes
- migration towards more mobile body types (lighter skeleton/scales)
- more powerful jaws (pharyngeal jaws).
- Weberian Apparatus.
Pharyngeal Jaws
tooth and tooth-like elements found inside skeletal support in mouth with additional teeth.
ray-finned fishes
- help grasp and orient prey.
- don’t chew!
Weberian Apparatus
a series of bones that sit againts the swim bladder that helps certain fish pick up vibrations from the environment.
- how they “hear”
What Period is “The Age of Fish”?
Devonian Period.
What is the main difference between ray-finned fishes and lobe-finned fishes?
ray-finned fishes fins have bony rays while lobe-finned fished have fins with true bone.
Anguillaform
the entire body moves in a wave-like motion.
eel-like
- slow swimmers
- length of body ↑ drag, ↓ thrust.
Carangiform
only 1/3-1/4 of the body flex for movement.
tuna-like
- fast swimmers
- ↑ thrust, ↓ drag
Ostraciform
body is completely rigid with movement coming from the caudal fin.
box-like
- slow swimmers
- ↑ drag.
Ballistiform
thrust from undulating the dorsal and anal fins.