Lecture 14/15 Life History Flashcards
The Nature of Life History Traits (3)
-age specific
-influence reproductive contribution to future generations
-including specific aspects of reproduction
Life history traits: Mortality (2)
-Stage (or age) specific (i.e. larval, juvenile, adult)
-Maximum lifespan
Life history traits: Reproduction (5)
-age at maturity
-fecundity (eggs laid per spawning)
-egg/offspring size
-reproductive strategy (spawning behavior , parental care, embryonic development)
-frequency of spawning
Types of reproductive strategies (2)
-iteroparity (multiple) vs semelparity (single) LIFETIME reproductive cycles
-parental strategies: guarders (substrate and nest) vs non-guarders vs bearers (internal and external)
Anadromy
Type of migration where fish is born in freshwater, matures in the ocean and returns to freshwater to spawn
Catadromy
Type of migration where a fish is born in the ocean, matures in freshwater and returns to the ocean to spawn
Types of migration (5)
Ocean to Freshwater
Freshwater to Ocean
lake to river
onshore to offshore
within different areas of lakes and oceans
Atlantic Salmon (Salmo salar) Migration (6)
-Born and grow in freshwater
-alvin→fry→parr→smolt
-To Open Ocean (Salmon)
-Return to Stream
-Spawning
-Back To Ocean or die
Trade Offs in Life history
Energy from food is used for general maintenance of the body, with excess being stored for growth and reproduction. The trade off is usually “do i grow more or reproduce more”
Trade off examples (2)
Alewife (Alosa pseudoharengus)
- Age at Maturity and growth rate are greater in migratory populations
- growth-survival tradeoff
American Shad (Alosa sapidissima)
- Semelparous (reproduces once) with high fecundity (lots of kids) in southern streams (reliable incubation)
-Iteroparous (reproduces multiple times) and lower fecundity in northern streams
-fecundity-survival tradeoff
