![Page 1: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/1.jpg)
Early Life and Spawning
![Page 2: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/2.jpg)
GOALS
Background on an important part of fish ecology that is often overlooked
Generalizations of early life history of fish
Spawning strategies
![Page 3: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/3.jpg)
Basic Background
![Page 4: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/4.jpg)
Life History
Embryo/Egg
Larvae
Adult
![Page 5: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/5.jpg)
Early Life History Stages
• Embryonic period
• Larval Period
• Juvenile Period
![Page 6: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/6.jpg)
What do Fish Larvae Look Like?
![Page 7: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/7.jpg)
Diversity of Larvae
Lake Sturgeon
Yellow Perch
Lake Trout
![Page 8: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/8.jpg)
Diversity of Larvae
Brown Bullhead
Northern Pike
Largemouth Bass
![Page 9: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/9.jpg)
How we sample larvae
Bongo Nets
![Page 10: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/10.jpg)
Opening Discussion
Why are early life histories important to fish ecology?
![Page 11: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/11.jpg)
Key Reason
1. Survivorship of young influence future generation’s abundance (year class strength)
a. Majority of mortality occurs early in life
b. Boatloads of things affect early survivorship
![Page 12: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/12.jpg)
Factors that influence early life survival
Temperature-How quickly adult fish mature and spawn-How quickly eggs hatch-Growth rate of larvae and YOY
![Page 13: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/13.jpg)
Factors that influence early life survival
Food availability-Is the right food available once yolk sac is used up?
-As they grow does the food out grow them? Do they outgrow the food?
![Page 14: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/14.jpg)
Factors that influence early life survivalSpawning Site -Water Level: Eggs can be left high and dry or smothered?
-Refugia: Egg survival can depend on size of substrate or degree to which they are hidden
-Flow: Too fast and eggs are swept away. Too slow and not enough oxygen
![Page 15: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/15.jpg)
Factors that influence early life survival
Predation-Do larvae face a predator gauntlet?
![Page 16: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/16.jpg)
Predation
Lake trout eat alewives…right?
What about larval lake trout?
Great lakes LT spawning reefs
Must fill swim bladder at surface (physoclistous )
![Page 17: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/17.jpg)
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
![Page 18: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/18.jpg)
Match/Mismatch Hypothesis
Yellow perch hatch
Yellow perch hatch
Eat small copepods, then switch to Daphnia
Eat small copepods but Daphnia show up too late
Conditions match what is needed
Conditions don’t match what is needed
![Page 19: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/19.jpg)
Timing is everything…Figure from Cargnelli and Gross 1996
Evolution at work!
![Page 20: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/20.jpg)
Egg Size (r vs K strategist)
• 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)
![Page 21: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/21.jpg)
Yolk Size of Various Fishes
![Page 22: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/22.jpg)
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!
![Page 23: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/23.jpg)
Lentic vs. Lotic Patterns
• Lentic Fish often have pelagic larvae
• Lotic Fish often have benthic larvae
![Page 24: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/24.jpg)
How often: Semelparous = once, Iteroparous = more then once
Common Spawning Strategies
![Page 25: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/25.jpg)
Life history strategies
Multiple strategies: Bluegill – parental care or Cuckolder
http://publish.uwo.ca/~bneff/research_beea.htm
Female mimic
![Page 26: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/26.jpg)
Common Spawning Strategies
Non-guarding vs. guarding
Pelagic vs. Benthic
Fine vs. Coarse substrate
Vegetation
Livebearers
![Page 27: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/27.jpg)
Non-gaurding , Pelagic
Alewife - inshore waters, eggs settle
Gizzard shad - Often move up rivers, eggs drift down
High fecundity
High early stage mortality
![Page 28: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/28.jpg)
Non-gaurding , Pelagic
Freshwater drum eggs float on surface until hatch
Paddlefish eggs are sticky when fertilized, adhere to the first thing they touch
![Page 29: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/29.jpg)
Non-gaurding , Benthic – fine substrate
Spottail shiners spawn on gravel and silt substrates
![Page 30: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/30.jpg)
Non-gaurding , Benthic - Crevice
Spotfin shiners use rock crevices to hold eggs
![Page 31: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/31.jpg)
Non-gaurding , Benthic – stream
Pacific salmon and brown trout dig redds – clean gravel where stream water upwells
![Page 32: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/32.jpg)
Non-gaurding , Benthic –vegetation
Northern pike prefer flooded vegetation in backwaters
![Page 33: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/33.jpg)
Sticklebacks make nests of algae and macrophytes and then lay eggs inside the nests
Guarding , Nests – nests of plants
Guarding means higher survival
![Page 34: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/34.jpg)
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
![Page 35: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/35.jpg)
Gaurding , Nests – gravel
Common in centrachids also lamprey, nests are often fanned to increase water flow and remove sediments
Smallmouth bass
American brook lamprey
![Page 36: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/36.jpg)
Gaurding , Nest – fine sedimentBluegill nests associated with fine sediments
![Page 37: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/37.jpg)
Gaurding , Nests – Holes and burrows
Catfish and bullheads make burrows or use existing holes
![Page 38: Early Life and Spawning. GOALS Background on an important part of fish ecology that is often overlooked Generalizations of early life history of fish](https://reader036.vdocument.in/reader036/viewer/2022070400/56649e605503460f94b5ac2e/html5/thumbnails/38.jpg)
Livebearers , (none native) Mosquitofish
60 -100 progeny per brood, born live, male has modified anal fin to impregnate female