Non-gaurding , Pelagic
Alwife - inshore waters, eggs settle
Gizzard shad - Often move up rivers, eggs drift down
High fecundity
High early stage mortality
Non-gaurding , Pelagic
Freshwater drum eggs float on surface until hatch
Paddlefish eggs are sticky when fertilized, adhere to the first thing they touch
Non-gaurding , Benthic – fine substrate
Spottail shiners spawn on gravel and silt substrates
Non-gaurding , Benthic - Crevice
Spotfin shiners use rock crevices to hold eggs
Non-gaurding , Benthic –vegetation
Northern pike prefer flooded vegetation in backwaters
Non-gaurding , Benthic –vegetation
Banded killifish spawn gets entangled in aquatic vegetation
Non-gaurding , Benthic – coarse bottom
Lake trout and lake whitefish spawn over large broken coble areas
Non-gaurding , Benthic – stream
Pacific salmon and brown trout dig redds – clean gravel where stream water upwells
Non-gaurding , Benthic – stream
Brook trout exclusively use groundwater upwelling areas in lakes and streams
Sticklebacks make nests of algae and macrophytes and then lay eggs inside the nests
Guarding , Nests – nests of plants
Guarding means higher survival
Gaurding , Benthic – Underside of rocks
Both round gobies and Johnny darters spawn under rocks, attaching the eggs to the underside of the rocks
Aggressive defense can incur high costs to parents or death
Gaurding , Nests – gravel
Common in centrachids also lamprey, nests are often fanned to increase water flow and remove sediments
Smallmouth bass
American brook lamprey
Gaurding , Nests – Holes and burrows
Catfish and bullheads make burrows or use existing holesNoodling Time:
http://www.youtube.com/watch?v=zOjA8Puh1BM
Gaurding , Nest – fine sediment
Crappie nests associated with vertical vegetation in fine sediments
Livebearers , (none native) Mosquitofish
60 -100 progeny per brood, born live, male has modified anal fin to impregnate female
Why bear live young?
Spawning variants
Multiple strategies: Bluegill – parental care or Cuckolder
http://publish.uwo.ca/~bneff/research_beea.htm
Female mimic
Spawning variants
How often: Semelparous = once, Iteroparous = more then once
Fish evolve to spawn in different locations
Temiscamie – strain
Tributary spawner
Assinica- strain
Outlet spawner
Little Tupper strain
Shoal spawner
Why...think about the emerged fry!
Embryonic Development
What do you mean “larval fish”?
Embryo
Larvae
Adult
Diversity of Larvae
American Eel
Diversity of Larvae
Lake Sturgeon
Yellow Perch
Lake Trout
Diversity of Larvae
Brown Bullhead
Northern Pike
Largemouth Bass
Theories of Development
• Saltational: Gradual punctuated by stages of rapid, distinct change
• Gradual: All distinct stages are arbitrary
• Truth?
People are not fishYolk
Early Life History Stages
• Embryonic period
• Larval Period
• Juvenile Period
See Photo
Embryonic Period
Embryonic Period: Cleavage Phase
• From fertilization to recognizable predecessors of the neural plate and other organ systems.
Zebrafish embryo stages
Embryonic Period: Embryonic Phase
• Embryo recognizable as a vertebrate
• Major organ systems appear
• Ends at hatching
Embryonic Period: Free Embryo Phase
• Embryo is free of egg membranes, but still depends on yolk for nourishment
• No longer curled up, starts to resemble adult fish
• Ends when capable of capturing food
Some Ecology
Temperature and Development of Fish at Hatch
Lake Trout (Coldwater) Pygmy Sunfish (Warm water)
Temperature also effects how long egg stage lasts
Egg Size
• Larger eggs more developed at hatching
Herring: eggs, newly hatched, and 7-10 months
Newly Hatched Steelhead
Altricial: Mouths just formed at yolk depletion (Long Larvae)
Precocial: Good predators at yolk depletion (Short Larvae)
Substrate Size and Egg Survival
Yolk Size of Various Fishes
Larval Stage
Bongo Nets
Lentic vs. Lotic
• Lentic Fish often have pelagic larvae– Major period of dispersal – Major period of mortality
• Lotic Fish often have benthic larvae– Avoid being swept away– Exist for short periods, under heavy cover
Strength of Year Class
• Match/Mismatch Hypothesis– Food and other conditions are good for
survival = strong year class• Food is abundant• Predators are not abundant• Temperature is appropriate
– Cues for Spawning– Several factors can disrupt matching and
result in weak year classes
Match/Mismatch
Plankton Peak
Ideal Match
Match/Mismatch
Food Abundance
• Nutrient levels
• Temperature
• Lower-level match/mismatch dynamics
• Number of competitors
• Water chemistry
Food Abundance Fluctuations
Water Temperature
• Thermal cues for spawning
• Weather: Shallow areas variable
• Varies from system to system
• Upwelling a large cause of fluctuations in lakes
Temperature and Recruitment
Temperature and Food
0
50
100
150
200
250
300
0 5 10 15 20 25
Water Temperature (Degrees Celsius)
Nu
mb
er o
f M
idg
es
Co
llect
ed
Predator Abundance
• More predators = more mortality
• Location, location, location!
• Temperature also
Wind Effects on Temperature, Food, and Predators
Esocidae (Pikes)Grass pickerel
Northern pike
Muskellunge
Identification
Identify with pores and or branchiostegal rays
PoresPickerel – 4Pike – 5Muskie – 6-9
Branchial. RaysPickerel – 12Pike – 14-16Muskie – 16-19
Umbridae (Mudminnows)
Central mudminnow
Homocercal tail
Fin placement
Lottidae (Burbot)
Long continuous anal and dorsal fins
Homocercal tail
Single chin barbel
Aphredoderidae (Pirate perch)
"Migrating anus"
Starts here
Ends here
Big dorsal
Percopsidae (Trout-perch)
Big head and big eye
Centrarchidae – 4 genera, 8 species
MicropterusAmbloplites
PomoxisLepomis
Micropterus
Largemouth bass
Smallmouth bass
Lepomis Bluegill
Pumpkinseed
Green Sunfish
Ambloplites – rock bass
Rounded pectoral
Percidae – 5 genera, 8 species
PercaSander
Crystallaria
Etheostoma
Percina
Sander
Walleye
Sauger
Wh
ite tip
No-W
hite
tip
Brian's childhood friend Matt Sander
Rainbow darter
Johnny darter
Fantail darter
Crystal darter
Moronidae (Temperate Basses)
White bass
Yellow bass
Sciaenidae (Drums)
Gobiidae (Gobies)
Gasterosteidae (Sticklebacks)
Fundulidae (Killifishes & Topminnows)
Ictaluridae (Bullhead Catfishes)
Bullheads
Catfishes
Madtoms
Poeciliidae (Livebearers)
Osmeridae (Smelts)