Fish Reproduction Flashcards
Why are dwarf males so small?
because all they are good for is providing sperm
What are the basic classifications of reproductive strategies?
live bearers, egg layers with no parental care, and egg layers with parental care
What are the types of egg layers with no parental care?
type 1 egg scatters, type 2 egg scatters without diapause, and type 2 with diapause and annual
What is diapause?
a period of suspended development
What are the types of egg layers with parental care?
labyrinth fish and cichlids
What are the major industrialized fish in the united states?
atlantic salmon, coho salmon, rainbow trout, channel catfish and tilapia
What are the assumptions about teleost reproduction?
genetic gender unconnected from ferilization, genetic gender does not permanently determine gonadal development, and gonad development does not distinctly express secondary sex characteristics
What does gonochorism mean?
they are only male or female for life
What influences gonochorism?
genotypic sex determination, environmental factor sex determination, and temperature sex determination
What is hermaphrodism?
when they are male or female for segments of life
What does protandrous mean?
matures as a male first
What does protogynous mean?
it matures as a female first
What are the heterogamety genotypes of males and females?
Male (XY) and female (ZW)
What are the homogamety genotypes for males and females?
male (ZZ) and female (XX)
What are osteichthyes?
bony fish
What percent of osteichthyes live in freshwater and marine environments?
40 % freshwater and 60% marine
Reproduction ensures what in fish?
species survival
What is semelparity?
when reproducing adults can place eggs or offspring out of harms way
What is the ontogeny of gonoducts like in tetrapods?
have dual origin (cortico-medullary antagonism - no connection between mullarian and wolffian ducts in embryologic development
What is the ontogeny of gonoducts like in teleosts?
there is unitary origin only cortico-derived peritoneal wall, there are no structural connnections between genital and excretory tracts
What are the patterns of maturation in fish?
anually (synchronus) or sequential spawning (asynchronous)
Explain carp-like ovulation.
mature through vitellogenesis then wait for environmental cues to proceed to ovulation and spawning
What are carp-like ovulators more responsive to in order to induce reproduction?
GtH
Explain salmon-like ovulation.
mature through ovulation then wait for environmental cues to span
What is GtH’s effect on salmon-like ovulators?
GtH only accelerates or shortens the reproduction timeline
What is a micropyle?
a funnel-like entrance on the ova to only permit one sperm
What happens to the micropyle after fertilization?
it closes
What is an anamniote?
animals who lay eggs in the water and are water dependent for growth
What occurs to gametes of marine fish?
they become hydrated; they are very condensed until water is added
What environmental cues can affect fish reproduction?
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
What environmental cues affect barramundi spawning?
salinity and temperature by only with the full moon
What environmental cues affect grouper spawning?
females spawn with increased HCG but when sex reversed males had not developed
What is an example of how temoerature affects spawning?
in the nile tilapia and japanese flounder increased temperature increases male population and decreases aromatase and estradiol
How can exogenous steroids can affect spawning?
feminization of the environment causing hermaphrodites and functional gonads of both sexes
How can behavioral control affect fish populations?
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
How can pollutants disrupt fish reproduction?
gonadal differentiation, maturation, numbers/quality of gaetes, and behavior
What mechanisms of disruption do pollutants use?
endocrine and decreased neurologic/physiological response to prostaglandin pheromones
