Ba. Henderson et al., REPRODUCTION OF WALLEYE IN LAKE-ERIE - ALLOCATION OF ENERGY, Canadian journal of fisheries and aquatic sciences, 53(1), 1996, pp. 127-133
An energetics mechanism is proposed to explain the trade-off between c
urrent and future reproduction. Surplus energy can be used for reprodu
ctive tissue (current reproduction) or somatic tissue (needed for futu
re reproduction); therefore, we needed to determine first, when does g
rowth of somatic and reproductive tissues occur, and second, how and w
hen is energy allocated to reproduction. Walleye were sampled monthly
from the commercial fishery in Lake Erie. Morphological attributes wer
e recorded from these walleye, as well as the lipid composition of a s
maller subsample. Energy for reproduction is acquired in the winter, s
pring, and summer before spawning and stored as visceral lipids. Ovari
an lipids are largely derived from visceral fat deposits; thus, female
s appear to be capital breeders. Females elaborate gonadal tissue only
if there is sufficient visceral fat. The circannual endocrine switch
to reproduction may occur in midsummer (August) and in October. Female
s may discontinue ovarian development during the early winter if there
is insufficient surplus energy (visceral fat). Year-class variation m
ay be partly explained by the energy condition of the females and the
proportion of the stock able to spawn successfully each year.