Concerning the form of asexual reproduction termed gynogenesis, the offspring are formed parthenogenetically but egg development is induced by sperm of the same or closely-related sexual species.
The negative relationship found between female fecundity and longevity supports the hypothesis that cyprinid fish pay for an increased investment in reproduction in term of adult survival [ 9].
This differential access can be understood as 'stratified reproduction' (a term coined by Ginsburg and Rapp) [ 2], an unequal power equation by which some categories of people are encouraged or empowered to reproduce, while reproduction in others is devalued.
Resource allocation to reproduction in terms of proportional biomass allocated to reproductive structures had been measured previously in C. ernesti-augusti, by Bullock [9], and in C. alternans, by Oyama and Dirzo [10].
Alternatively, they may reflect differences in reproductive effort in yearling females and a cost of reproduction in terms of subsequent survival.
In long-lived species with late ages at first reproduction, long-term weight gain may be closely linked to reproductive strategy, though little is currently known of the social structure of males or their reproductive success, making it difficult to assess the influence of weight in dominance interactions and mating success.
Finally, different life-history traits such as fecundity and survival should also be considered and compared with early reproduction in terms of trade-offs [32, 33].
We also allow for two different types of reproduction methods termed "Equal Opportunity" in which the parents to be paired for mating are selected with equal opportunity and a second based on always choosing the best string in the current generation as one of the parents which is referred to as the "Queen bee", while the other parent is randomly selected from the set of parent strings.
In the sea urchin Lytechinus variegatus the xanthophylls lutein and zeaxanthin were found to be more important for reproduction in terms of the number of juveniles produced and their survival rates than had previously been thought [73].
However, reproduction, in terms of weaning-to-oestrus interval and percentage of re-breedings, was negatively affected in the group-housed compared with the stalled sows.
