Fish Biology - Juniata Collegejcsites.juniata.edu/faculty/merovich/ichthyology_files/...How common...
Transcript of Fish Biology - Juniata Collegejcsites.juniata.edu/faculty/merovich/ichthyology_files/...How common...
Fish Biology
Life Cycle
Reproductive BiologyChapter 9
Fish Life Cycle
How common is parental
care in fishes?
1. Ubiquitous
2. Very common
3. Uncommon
4. Absent
Why?
Reproductive ‘Units’
Dioecious
Gonochoristic
Lepomis megalotis
Eggs & Milt
Embryo
Water hardening (0-48 hrs)
Tender stage
Eyed stage (a little more hardy)
Ends with hatching
Where does the embryo get energy
(food) if not inside female?
1. Absorption
2. Chemosynthesis
3. Yolk
4. Phytoplankton
5. Zooplankton
6. Photosynthesis
Embryo 3 days
Embryo 6 days
removed from
egg membrane
Embryo 8 days
Larva 17 days
6 mm
7 mm
10 mm
Larval Period
Begin exogenous feeding
Yolk sac (sac fry; alevin; pro-larvae)
Swim up phase
Larval feeding
opportunity
Plankton availability
Larval
predation risk
Win
do
w
Where does a larval
fish get its food?
1. Egg
2. Plankton
3. Yolk
4. Doesn’t need any
5. Plankton and / or Yolk
Juvenile Stage
YOY
Fry
Fingerling
Parr
Smolts
End at gonad development
Adult Stage
Gonads
Reproductive
Behaviors
Senescent Stage
Cohort
What is “trophic ontogeny”?
1. Change in size
2. Change in sex
3. Transformation from larvae to juveniles
4. Change in feeding with development
5. Shift in prey species present
Egg Fertilization and Incubation
Oviparous
Ovoviviparous
Viviparous
Evolutionary Continuum
Gonopodium
Parity
Semelparity
Iteroparity
Single vs. Multiple Batch
Most spawn once in spring
Factors that Induce Spawning
A good example – paddle fish
Spawning—how to pass on genes
Mass Spawning
Pair Mating
Polyandry / Polygyny
Parent vs. cuckoldry in bluegills
Sequential hermaphroditism
Bluegills – alternate strategies
Parental (dominant) nest guarding males
Parental (dominant) females
Parasitizing (functional male) cuckolders
– Sneakers
– Satellites
Neff 2013
Eggs Types
Adhesive
Non-adhesive
Floating
Demersal
Fecundity: indicative of…
…parental care, egg
size, spawning habit
Fish, frogs, toads
– r-selected species
– K-selected species
Relative Fecundity
Why measure it?
Is there a link between
fecundity and harvest?
Life Cycle and
Reproductive Requirements
Habitat and spatial arrangement of its
critical components
– Food
– Water (temp)
– Cover
– Reproduction
Diadromy
– Anadromous
– Catadromous
Sculpins attach eggs to
underside of cobbles.
Nests are defended by
solitary males until
young disperse as
juveniles.
Examples
Darters
Egg mimics I’m good at
this; mate with me…”
Sunfishes and basses excavate small
depressions and defend nests from predators.
Salmonids construct
redds, broadcast spawn
over them, and leave
eggs to the vagaries of
life.
Cyprinid Spawning Mounds
(probably constructed by a
central stoneroller, Campostoma
anamolum)
Used by a mixed species
assemblage
Chain Pickerel
Randomly scatter eggs over vegetation
Don’t really protect them
Splash tetra
Complementary vs.
Supplementary Habitats
Complementary Habitat: necessary
Supplementary Habitat: unnecessary
Example