Fishes - the teleosts

Question 1

What is order Clupeiforms?

Answer 1

Herring, anchovy

Question 2

What is order Salmoniformes?

Answer 2

salmon, trout, smelt, pike

Question 3

Order Perciformes

Answer 3

perch, sandlance, tuna

Question 4

Order Scorpaeniformes

Answer 4

rockfish,lingcod, sculpin

Question 5

Order Pleuronectiformes

Answer 5

flounder, sole, halibut

Question 6

How do fishes acheive neutral buoyancy?

Answer 6

Some ray-finned fish use oils, have a cartilagenous skeleton or reduced skeleton or muscular tissue, most have a swim bladder

Question 7

What is a swim bladder?

Answer 7

A modified lung, lungs developed as outpouchings of the gut likely in tropical freshwater where ability to breathe are would be advantageous

Question 8

What are 2 fish that don’t have swim bladders?

Answer 8

mackerel, angler fish, lophius, uranoscophus

Question 9

How do fishes achieve neutral bouyancy?

Answer 9

2 types of swim bladders

1) connected to gut
2) closed

Question 10

What is a connected swim bladder?

Answer 10

connected to gut via pneumatic duct , gas exchange via esophagus
inflate by gulping air
deflate by gas-spitting
herring, salmonoids, pikes catfishes, eels

Question 11

What is a closed swim bladder?

Answer 11

closed to gut, gas exchange via circulatory system
inflate with gas gland and capillary system
deflate by diffusion of gases through the oval (patch of dense capillaries) into the blood
- most teleosts

Question 12

Functions of a swim bladder

Answer 12

buoyant to float
sound producer and receptor
respiratory organ

Question 13

Are most fish ecto or endothermic?

Answer 13

ectothermic with temps close to ambient b/c heat is rapidly lost through skin and gills

Question 14

What methods do fish use to thermoregulate?

Answer 14

behaviorally, physiologically, or both

Question 15

Describe an example of behavioral thermoregulation

Answer 15

salmon digest food after dusk feeding in a warmer temperature selectively
daytime they conserve energy by moving to colder water

Question 16

Describe physiological (metabolic) thermoregulation

Answer 16

based on oxidation of food
only in continuously swimming fishes (tuna, mackerels)
warm red muscles can contract faster than cold white muscles…..
heat loss to environment is limited by counter-current heat exchange of the blood btwn the muscles and gills
body temperatures of warm-bodied fishes are not constant but fluctuate with ambient temp.

Question 17

Describe structure and function of fish gills

Answer 17

water flows in mouth and over gill arches, through gill filaments, and out gill flaps

Question 18

Describe counter-current exchange

Answer 18

oxygenated water flows over lamellae where deoxygenated blood flows towards it from the opposite direction
oxygenation is higher closest to vessels and poorest closest to veins and vice versa for the blood

Question 19

What is an osmoconformer?

Answer 19

no osmoregulation

hagfish

Question 20

Osmoregulation in elasmobranchs is?

Answer 20

Isosmotic

salt concentration 1/3 of seawater but total concentration (urea, TMAO) equal to seawater

Question 21

Osmoregulation in marine teleosts is?

Answer 21

Hyposmotic to seawater

replace lost water by drinking sea water and excess salt is excreted in concentrated urine (ammonia?) and through gills

Question 22

Osmoregulation in freshwater teleosts is?

Answer 22

Hyperosmotic to freshwater

excess water excreted in a dilute urine

Question 23

What is stenohaline

Answer 23

restricted tolerance to changes in environmental saltwater concentration
most fish

Question 24

What is euryhaline

Answer 24

ability to tolerate wide ranges of saltwater concentrations
move between fresh and marine environments
salmon, lampreys, eels

Question 25

Olfaction

Answer 25

Imprecise samplin of small quanitities away from source (smell)
- receptors in nares for food detection and finding natal (spawning) stream

Question 26

Gustation

Answer 26

Precise sampling of large quantities at the source

- Taste buds in mouth and skin, fins, barbels to identify food

Question 27

Acoustico-lateralis system

Answer 27

hearing

- otoliths in inner ear move against sensory hair cells

Question 28

lateral line

Answer 28

neuromasts near lateral line canal dectect water movements

- water movements bend the cupula and this triggers hair cells

Question 29

Chemo rececption relates to?

Answer 29

olfaction and taste

Question 30

Acoustico lateralis system relates to?

Answer 30

hearing and lateral line

Question 31

population parameters; population size needs to take what 4 things into account?

Answer 31

births - deaths

immigration - emmigration

Question 32

Growth is conversion to what?

Answer 32

conversion of calories to somatic and reproductive tissue

Question 33

What is the growth equation?

Answer 33

I = M +E +G
i = ingested food
M = energy expended for metabolism
E = energy excreted (feces, ammonia, urea)
G = energy expended for growth and reproduction

Question 34

What are 5 factors affecting individual growth?

Answer 34

Age and maturity
Temperature
Dissolved oxygen levels
Competition
Food availability

Question 35

What are 3 measurements of individual growth rate?

Answer 35

Mark-recapture - growth rate = change in size/time period
Length-frequency - rates determined by comparing mean lengths between age classes
Growth rings on hard surfaces - scales (annuli), otoliths - daily increments of growth

Question 36

Define migration

Answer 36

Regular Mass movements of fish from one place to another (not individual movements)

Question 37

What are 2 types of fish migration?

Answer 37

Daily - feeding or predator avoidance
Seasonal - migrate long distances in short time spans to specific locations
- tuna, salmon, eels

Question 38

What is Semelparous?

Answer 38

one reproductive bout in a lifetime

Question 39

What are 2 reasons fish migrate?

Answer 39

Reproduction - favourable environment, reduce competition for age classes, reduce cannibalism and disease transfer
Changing environments - temp and movements of prey

Question 40

Why are salmon signatures found in growth rings of trees?

Answer 40

nutrient rich salmon carcasses are moved into the forest by bears that transfer large quantities where the carbon and nitrogen isotopes can be measuredto identify past salmon abundance in trees

Question 41

How do fish migrate?

Answer 41

odor of parent stream and streams along the way
pheromones
magnetic field
ocean currents and gradients
position of sun