Fish Reproduction

Question 1

Why are dwarf males so small?

Answer 1

because all they are good for is providing sperm

Question 2

What are the basic classifications of reproductive strategies?

Answer 2

live bearers, egg layers with no parental care, and egg layers with parental care

Question 3

What are the types of egg layers with no parental care?

Answer 3

type 1 egg scatters, type 2 egg scatters without diapause, and type 2 with diapause and annual

Question 4

What is diapause?

Answer 4

a period of suspended development

Question 5

What are the types of egg layers with parental care?

Answer 5

labyrinth fish and cichlids

Question 6

What are the major industrialized fish in the united states?

Answer 6

atlantic salmon, coho salmon, rainbow trout, channel catfish and tilapia

Question 7

What are the assumptions about teleost reproduction?

Answer 7

genetic gender unconnected from ferilization, genetic gender does not permanently determine gonadal development, and gonad development does not distinctly express secondary sex characteristics

Question 8

What does gonochorism mean?

Answer 8

they are only male or female for life

Question 9

What influences gonochorism?

Answer 9

genotypic sex determination, environmental factor sex determination, and temperature sex determination

Question 10

What is hermaphrodism?

Answer 10

when they are male or female for segments of life

Question 11

What does protandrous mean?

Answer 11

matures as a male first

Question 12

What does protogynous mean?

Answer 12

it matures as a female first

Question 13

What are the heterogamety genotypes of males and females?

Answer 13

Male (XY) and female (ZW)

Question 14

What are the homogamety genotypes for males and females?

Answer 14

male (ZZ) and female (XX)

Question 15

What are osteichthyes?

Answer 15

bony fish

Question 16

What percent of osteichthyes live in freshwater and marine environments?

Answer 16

40 % freshwater and 60% marine

Question 17

Reproduction ensures what in fish?

Answer 17

species survival

Question 18

What is semelparity?

Answer 18

when reproducing adults can place eggs or offspring out of harms way

Question 19

What is the ontogeny of gonoducts like in tetrapods?

Answer 19

have dual origin (cortico-medullary antagonism - no connection between mullarian and wolffian ducts in embryologic development

Question 20

What is the ontogeny of gonoducts like in teleosts?

Answer 20

there is unitary origin only cortico-derived peritoneal wall, there are no structural connnections between genital and excretory tracts

Question 21

What are the patterns of maturation in fish?

Answer 21

anually (synchronus) or sequential spawning (asynchronous)

Question 22

Explain carp-like ovulation.

Answer 22

mature through vitellogenesis then wait for environmental cues to proceed to ovulation and spawning

Question 23

What are carp-like ovulators more responsive to in order to induce reproduction?

Answer 23

GtH

Question 24

Explain salmon-like ovulation.

Answer 24

mature through ovulation then wait for environmental cues to span

Question 25

What is GtH’s effect on salmon-like ovulators?

Answer 25

GtH only accelerates or shortens the reproduction timeline

Question 26

What is a micropyle?

Answer 26

a funnel-like entrance on the ova to only permit one sperm

Question 27

What happens to the micropyle after fertilization?

Answer 27

it closes

Question 28

What is an anamniote?

Answer 28

animals who lay eggs in the water and are water dependent for growth

Question 29

What occurs to gametes of marine fish?

Answer 29

they become hydrated; they are very condensed until water is added

Question 30

What environmental cues can affect fish reproduction?

Answer 30

photoperiod, water temperature, water quality, flooding and water movements, tides and lunar cycles, spawning substrate, nutrition, disease and parasites, and the presence of other fish

Question 31

What environmental cues affect barramundi spawning?

Answer 31

salinity and temperature by only with the full moon

Question 32

What environmental cues affect grouper spawning?

Answer 32

females spawn with increased HCG but when sex reversed males had not developed

Question 33

What is an example of how temoerature affects spawning?

Answer 33

in the nile tilapia and japanese flounder increased temperature increases male population and decreases aromatase and estradiol

Question 34

How can exogenous steroids can affect spawning?

Answer 34

feminization of the environment causing hermaphrodites and functional gonads of both sexes

Question 35

How can behavioral control affect fish populations?

Answer 35

in hermaphroditic species there is one large individual and multiple subordinates, if the large individual exits then a subordinate modifies its gener to replace it

Question 36

How can pollutants disrupt fish reproduction?

Answer 36

gonadal differentiation, maturation, numbers/quality of gaetes, and behavior

Question 37

What mechanisms of disruption do pollutants use?

Answer 37

endocrine and decreased neurologic/physiological response to prostaglandin pheromones