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juvenile survivorship (small eggs). They inhabit predictable and seasonal
environments (Winemiller and Rose, 1992; McCann and Shuter, 1997).
The opportunistic life-history strategy shows most of the classical traits of the
r strategy, with small body size, early maturation, low juvenile survivorship and short
lifespan, although it differs in that fecundity per spawning event is low. The
opportunistic strategists maximize population growth through a reduction in the mean
time of generation (Ramirez-Llodra, 2002). Early maturation results in a short lifespan
and high population yield but diminishes their capability to produce a large quantity
of offspring per event and large eggs. However, because of their multiple spawning
frequencies, annual fecundity is high and allows for colonization of new habitats.
These organisms inhabit highly disturbed and unpredictable environments
(Winemiller and Rose, 1992; McCann and Shuter, 1997).
In the Winemiller-Rose model, K strategy is redefined as the equilibrium
strategy and its boundaries are constrained. The equilibrium strategists have moderate
age at maturity, low fecundity and high juvenile survivorship determined by a large
egg size. They differ from the classical K strategists in that they have small to
medium body sizes (Ramirez-Llodra, 2002). The species that evolve in the
equilibrium strategy maximize juvenile survivorship at the expense of fecundity. They
inhabit constant environments ((Winemiller and Rose, 1992; McCann and Shuter,
1997).
The production of eggs is a high energy-demanding process. Therefore, the
accessibility of food plays an essential role before and during the process of egg
production (Eckelbarger, 1986; Chia and Walker, 1991). The process of vitellogenesis
consumes a large proportion of the energy intake of an organism, and this requirement
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