External Anatomy Flashcards
body shape
- associated with foraging and swimming habits
- many unrelated species will converge on similar body shapes
shape of eel-like fishes
- elongate bodies
- wedge-shaped heads
- rounded tails
- bodies vary from compressed to round
how do eel-like fish use their body and tail?
they use their body and tail in a sigmoidal motion
eel-like fish lifestyle
- live in crevices and holes in reef rocks
- can also be found in open water
examples of eel-like fish
- eels
- Loaches
rover predator shape
- fusiform
- terminal mouth
- fins evenly distributed over the body
- elliptical in cross scetion
rover predator life style
- chases active prey
- often in flowing water
examples of rover predators
- minnows (Leusicidae)
- jacks
- tunas
shape of lie-and-wait predator
- sagittiform - elongate
- flattened head
- large tail
- dorsal and anal fins posterior
lie-in-wait predator life style
motionless for long periods of time and then rapid lunges for prey
examples of lie-in-wait predators
- pikes
- barracuda
- gar
- needlefish
surface skimmer/feeder shape
- head dorso-ventrally flattened
- superior mouth
superior mouth
mouth turned upward
surface skimmer/feeder dorsal fin location
posterior dorsal fin
surface skimmer/feeder lifestyle
- feed at surface
- use thin oxygen-rich layer of water at air/water interface
surface skimmer/feeder examples
- topminnows
- mosquitofish
- flying fish
bottom dweller
rovers
bottom dweller shape
- humped nuchal region
- terminal/subterminal mouth
- large pectoral fins
- barbels and small eyes
bottom dweller lifestyle
move actively along bottom seeking benthic prey, algae, or carrion
bottom dweller examples
- catfish
- suckers
- sturgeon
clingers and hiders shape
- large, flattened heads
- large pectoral fins
- modified pelvic fins
clingers and hiders lifestyle
- live and feed along bottom
- eats mostly invert prey
- high current velocities for some species
clingers and hiders examples
- darters
- clingfish
- sculpins
flatfish life style
rovers or ambush predators
flatfish (Pleuronectiformes) shape
laterally flattened
flatfish (Pleuronectiformes) example
flounders
flatfish (Batoidea) shape
dorso-ventrally flattened
flatfish (Batoidea) examples
skates and rays
mid-water crevice hiders shape
- laterally compressed
- small protrusible mouth
- large eyes
mid-water crevice hiders lifestyle
- live on reef or rocks
- pick small invert prey or algae
mid-water crevice hiders examples
- butterflyfish
- surgeonfish
- angelfish
skin
- first line of defense, separation of body and environment
- structure similar to that of other vertebrates
- may contain specialized cells and glands
skin order from surface to deep
- epidemis
- scale pocket
- dermis
- muscle
- scales
- squamous epithelial cells
- undifferentiated basal cells
- alarm cell
- mucous cells
- taste bud
epidermis
- mucus, composed of glycoprotein Mucin
- photophores
- venom glands
dermis
- blood vessels, nerves, sense organs, connective tissue
- scale formation
- chromatophores
scale coverage
- naked
- partially scaled
- boney plates
- imbedded
- small scales
- fully scaled
naked scale fish example
catfish
partially scaled fish example
paddlefish
boney plates fish example
- sturgeon
- pipefish
imbedded scales fish example
eels
small scales fish example
salmon
fully scaled fish example
most fish
types of scales
- placoid
- cosmoid
- ganoid
- cycloid
- ctenoid
placoid scales
- cartilaginous fish
- dermal armor broke up into smaller pieces, scales in mouth became teeth
cartilaginous fish
arose independently of scales in bony fish, homologous with vertebrate teeth
cosmoid scales
- fossil coelacanths and lungfish
- fusion of placoid scales
ganoid scales
- ancestral condition for bony fish
- bone covered by enamel
fish who have ganoid scales
- gars
- bichirs
cycloid scales
found in ray-finned fishes
fish who have cycloid scales
- pikes
- herrings
- minnows
- trouts
ctenoid scales
found in spiny-finned fish
which scales can be used to age fish
cycloid and ctenoid scales grow with annuli, this can age fish
fins
location and shape of fins are related to fish activity patterns
caudal fin
- “tail”
- homocercal or heterocercal
homocercal tail
top and bottom of caudal fin are symmetrical
heterocercal tail
top and bottom of caudal fin are different
pectoral fin
near bottom of the side of the body
pelvic fin types
- abdominal
- jugular
- thoracic
pelvic fin location
- side of body
- where the “pecs” would be
dorsal and anal fin modifications
length modifications for rover predators
dorsal fin
on top of body
anal fin
fin near fishes anus
spines
- hard, pointed tissue
- unsegmented
- unbranched
- solid
rays
- soft, unpointed
- segmented
- usually branched
- bilateral
