Key Event Title
|Level of Biological Organization|
Key Event Components
Key Event Overview
AOPs Including This Key Event
|AOP Name||Role of event in AOP|
|DIO2i posterior swim bladder||KeyEvent|
|DIO2i anterior swim bladder||KeyEvent|
|DIO1i posterior swim bladder||KeyEvent|
|DIO1i anterior swim bladder||KeyEvent|
|TPOi anterior swim bladder||KeyEvent|
|fathead minnow||Pimephales promelas||High||NCBI|
|All life stages||High|
Key Event Description
Young of year refers to young animals (usually fish) produced in one reproductive year, which have not yet reached one year of age. Small fish, hatched from eggs spawned in the current year, are considered young of year.
Young of year survival directly impacts population structure, growth and fitness. Maintenance of sustainable fish and wildlife populations is an accepted regulatory goal upon which risk assessments and risk management decisions are based.
How It Is Measured or Detected
Young of year survival can be measured:
- in the lab by recording survival during prolonged exposure experiments
- in dedicated mesocosms, or in drainable ponds
- in the field, for example by determining age structure after one capture, or by capture-tag-recapture efforts
Domain of Applicability
Taxonomic: Young of year survival is important for all species.
Life stage: for many fish species, including the zebrafish and fathead minnow, the adult stage is reached within the first year. Young of year survival therefore applies to all life stages.
Sex: Young of year survival is important across sexes.