Among
fishery biologists and even ichthyologists, maturation and spawning of
fish are viewed as processes that use “energy” that would otherwise be
applied to somatic growth, which is supposed to explain why
post-maturity growth in length tends to decline. This widespread
conceptualization may be called the “reproductive drain hypothesis”
(RDH). However, when growth is correctly viewed as involving body mass,
and is thus expressed in weight, post-maturity turns out (in
iteroparous bony fish whose maximum length exceeds 10 cm) to accelerate
after first maturity, despite its energy cost. This, and other common
observations flatly contradict the RDH, and the time has come to
withdraw this hypothesis. As a contribution towards this task, we
propose an alternative reconceptualization of fish spawning consistent
with what is known about fish biology. |