Size at first reproduction and reproductive periods of the hybrids were also closer to those of the inherited parental mitochondrial type.
However, for iteroparous species, T cannot be fully described by age at first reproduction, because reproductive events may continue to occur long after the first event.
However, the timing of metamorphosis affects phenotype, survival, age at first reproduction and reproductive success, and shorter larval periods may lead to decreased lifetime fecundity [ 5, 18, 20].
We found no overall evidence to suggest that middleborns in a family are disadvantaged in terms of their survival, age at first reproduction or lifetime reproductive success.
For example, age at first reproduction influenced the amount of reproductive effort invested in offspring production and defense in Sockeye salmon, Oncorhynchus nerka[ 25- 27].
However, individual fish can differ in life-history traits [13] such as age at first reproduction, number and size of offspring, reproductive lifespan and ageing [14].
Fourth, we tested whether important proxies of reproductive fitness (offspring number, offspring size, age at first reproduction) are affected by brain size evolution.
For semelparous species, age at first reproduction (b) accurately represents T, because all of the offspring are produced in the first reproductive event.
Fecundity, reproductive days, reproductive effort (= number of eggs per reproductive day), eggs produced till 10-d-old, age at the first reproduction, and longevity are reported.
First, reproduction must increase the chance of a phenotypic switch.
Cereal crops such as wheat are semelparous, meaning that they die after their first reproduction.
