Lab stuff to know

Question 1

Using beach seining, what types of fish can be collected in large numbers?

Answer 1

Small benthic fish

Question 2

Where are backpack electroshokers used?

Answer 2

Streams + shallow rivers

Question 3

Trawling techniques catch what types of fish?

Answer 3

Pelagic ones

Question 4

What are the four parts of a beach seine net?

Answer 4

1 - Float line
2 - Webbing
3 - Lead line
4 - Poles

Question 5

Minnow seines have a ____- inch mesh. A __ foot depth is sufficient for minnow seines.

Answer 5

1/4

4

Question 6

Electrofishing more easily catches ________ fish than ______ fish.

Answer 6

Larger

smaller

Question 7

What are the main purposes of electrofishing?

Answer 7

Stock assesment
sampling/health surveys
tagging
catching spawners
anaesthetising or eliminating species

Question 8

What are the three pieces of gear used during electrofishing?

Answer 8

1 - power unit
2 - transformer
3 - electrodes

Question 9

The anode is _______ and the cathode _______.

Answer 9

negative

positive

Question 10

The choice of material and size of electrode can influence ______ _______ and the shape of these will influence the electrical field _______.

Answer 10

fishing efficiency

strength

Question 11

What is the back of the trawling net called?

Answer 11

Bag

Question 12

Trawling can either be done ___-____ or at the ______ of a body of water.

Answer 12

mid-water

bottom

Question 13

Trawl mouths can range from ___ to ____ feet.

Answer 13

30-100

Question 14

The mouth of the trawling net is held open by two large ______.

Answer 14

Doors

Question 15

Mensual characters are ________.

Answer 15

Continuous

Question 16

Mertistic characters are _______.

Answer 16

discrete

Question 17

What is one issue with morphometrics? How is it remedied?

Answer 17

Certain absolute measures cannot distinguish juveniles and adults.
Remedied by taking proportions or percents of the fish’s SL or TL.

Question 18

What is SL?

Answer 18

Standard length:

Tip of snout to base of caudal fin.

Question 19

What is TL?

Answer 19

Total length:

Length from tip of snout to tip of caudal fin.

Question 20

Who and what fish eat is strongly correlated with what?

Answer 20

Internal and external morphology

Question 21

_____ and ______ of the mouth and jaw are important indicators of food items since they will _____ the type of prey that a fish can ingest.

Answer 21

Size
protrusibility
limit

Question 22

_________ (more than one word) is correlated with the digestibility of the main food items of fish.

Answer 22

Length of the gut/intestine

Question 23

Piscivorous fish tend to have larger _____ but smaller _______ ______ than hervivorous fish.

Answer 23

stomach

intestinal length

Question 24

Fish with ________ mouths capture things above them and often eat small things off the surface of the water.

Answer 24

superior

Question 25

Fish with ______ mouths eat material in the water column.

Answer 25

terminal

Question 26

Fish with ________ mouths eat things that live in the bottom.

Answer 26

inferior

Question 27

What is a protrusible jaw?

Answer 27

Premaxilla can separate from the maxilla.

Question 28

Piscivorous fish tend to have _______ teeth that are either: _____, ______ or ________.

Answer 28

pointy | triangular, canine, villiform

Question 29

Fish that have to crush hard parts with have flattened _________ teeth.

Answer 29

molariform

Question 30

Molariform teeth can be either on the _____ or as ________ ______.

Answer 30

jaws | pharyngeal teeth

Question 31

Some fish have no teeth. these fish strain ________ out of the water column or subsist on soft food found in the ____.

Answer 31

plankton | mud

Question 32

What are gill rakers?

Answer 32

Projections of bone/cartilage that project off the gill arches.

Question 33

What do rakers do?

Answer 33

Prevent food entering the mouth from escaping through the gills.

Question 34

Piscivorous fish will have _____, ______ spaced rakers. | Species that filter small things out of the water will have _____, _____ rakers that are _______ packed together.

Answer 34

short, widely | long, thin, tightly

Question 35

The _____ ____ is a mechanosensory system used by fish to detect ______ _____.

Answer 35

Lateral line | water motion

Question 36

The lateral line has been described as _____ _____.

Answer 36

distant touch

Question 37

What are the receptors in the lateral line for detecting water motion?

Answer 37

Neuromasts

Question 38

Each neuromast has an individual ______ ____ with an attached _______.

Answer 38

hair cell | cupula

Question 39

How is the hair cell stimulated?

Answer 39

Water pushes it and bends it to stimulate it

Question 40

All fish have at least some free _______ neuromasts on their body surface or at the bottom of shallow pits (_______ _________)

Answer 40

Superficial | canal neuromasts

Question 41

Schooling fish use their lateral line to _______ and predator fish used it to ________.

Answer 41

Detect their schoolmates | detect minute prey movements

Question 42

What is rheotaxis?

Answer 42

Orientation to water current

Question 43

What is the scientific name for a zebra fish?

Answer 43

Danio rerio

Question 44

Growth rate and age estimates are important for what?

Answer 44

1 - Assessing health of the fish populations 2 - setting catch limits 3 - Identify stressors 4 - Predict future population sizes

Question 45

Growth is rarely measured in the wild because?

Answer 45

Difficult to catch the same fish repeatedly

Question 46

What are the two ways to estimate growth rate and age?

Answer 46

1 - Peterson method - length-frequency distribution | 2 - use hard parts like scales and otoliths

Question 47

What is an assumption of the Peterson method?

Answer 47

That fish can be placed into distinct year classes

Question 48

What is a cohort?

Answer 48

fish born in the same year

Question 49

What is a problem with scales? Why dont otoliths have this problem?

Answer 49

Fall off and are replaced. | Stay with the fish for life.

Question 50

What are circuli?

Answer 50

Rings

Question 51

What are annuli?

Answer 51

Yearly rings

Question 52

What is the equation for back-calculation of growth rates?

Answer 52

lt = l (st/s) lt - length at time t l - length st - distance from the center to the annual ring of interest s - total distance from the center of the otolith to the edge

Question 53

What plot is used to estimate growth rates and maximum fish sizes?

Answer 53

Walford plots

Question 54

True measures of diversity can be influenced by what?

Answer 54

1 - number of samples 2 - method of collection 3 - timing of samples 4 - other factors

Question 55

When is number of individuals relevant?

Answer 55

If only interested in total biomass or restrict sample to few species

Question 56

Does number of individuals indicate diversity?

Answer 56

No

Question 57

What is species richness?

Answer 57

number of species