external anatomy Flashcards
(30 cards)
1
Q
anterior (placement)
A
towards the top or head end of the body
2
Q
posterior (placement)
A
towards the back or tail end of the body
3
Q
cranial (placement)
A
head region
4
Q
caudal (placement)
A
tail region
5
Q
dorsal (placement)
A
towards the top (back / spinal) area of the body
6
Q
ventral (placement)
A
towards the underside of the body
7
Q
tall, narrow body shape
A
adapted to live in slow moving water
8
Q
torpedo-shaped body
A
adapted to live in fast moving water
9
Q
superior mouth
A
- top swimmers
- straight dorsal surface
- upturned, scoop like mouth
10
Q
terminal mouth
A
- mid water swimmers
- mouths at the tip of the snout
11
Q
inferior mouth
A
- bottom-dwellers
- flattened ventral surface
- downturned / underslung mouth
12
Q
larger eyes
A
generally seen in deep-water fish
13
Q
smaller eyes
A
generally seen in shallow-water fish
14
Q
dilating pupils
A
- seen in some species (e.e. shark and eels)
- not seen in bony fish usually
15
Q
nostrils
A
- not used for breathing
- water will pass through
- detects chemical traces at the base of the nostril
- essential in low visibility
- may have one pair, two pairs or a single nostril
16
Q
skin
A
- defence against pathogens through mucous layer that entraps and immobilises pathogens
17
Q
scales
A
- bony material
- placoid scales, ganoid scales, ctenoid scales, cycloid scales
- scutes (on catfish)
18
Q
placoid scales
A
- found in rays and sharks
- resemble teeth-like projections
- do not increase in size, but in numbers as the fish grows
19
Q
ganoid scales
A
- mosaic in arrangement with overlaps
- seen on sturgeons and gar fish
20
Q
ctenoid scales
A
- have a spiny comb or teeth-like extensions to the outer edge
- perch fish have ctenoid scales
21
Q
cycloid scales
A
- are round or oval shaped
- grow with the fish → creates growth rings which determines a fish’s age
22
Q
scutes
A
- in place of scales on armoured catfish
- their bodies are covered with two or three overlapping bony plates
23
Q
fin functions
A
- stability
- propulsion
- steering
- balance
24
Q
dorsal fin
A
- located along the back of the fish (between tail fin and head)
- provides lateral stability to allow swimming in a straight line and prevents it from rolling over
25
caudal fin
- aka tail fin
- located at the rear of the fish
- responsible for propulsion + fast swimming patterns
- can be used to slow forward movements and for turning
26
anal fin
- located on the underside of the body between the pelvic and caudal fin
- helps with stability + steering
- prevents fish from rolling over
27
pectoral fins
- paired and located near the bottom of the fish, directly beneath the gill openings
- used in navigation and stability
- provide the upward lift that helps fish maintain depth + enables the flight go flying fish
- can be adapted for "walking" above or below water on some fish
- can have defensive spines
28
pelvic fins
- located in front of the anal fin, on the abdomen of the fish (underside)
- used for braking, stabilising + changing direction
29
adipose fin
some fish (e.e. tetras) have an additional fin located between the dorsal and caudal fins
30
lateral line
- helps detect vibrations and currents while underwater
- senses water movement and pressure
- pressure around objects are distorted which is detected by the lateral line; allowing a fish to change direction
- enables fish to escape predators, catch prey and take part in a shoal
