Fisheries Behavioral Ecology - Abstracts
Hurst, T.P. and D.O. Conover. 2003. Seasonal and interannual variation in the allometry of energy allocation in juvenile striped bass. Ecology 84(12):3360-3369.
Abstract
Survival rates during the first winter of life are strongly size dependent and
variable in many temperate fish populations. Starvation is often implicated as the cause of
size-dependent first-winter mortality, and interannual variation in energy accumulation and
the allocation between growth and storage is a likely source of variability. We examined
these processes in young-of-the-year Hudson River striped bass Morone saxatilis, which
are known to experience size-selective winter mortality and a winter energy deficit. Neutral-lipid
and lean-tissue masses were determined for fish of five consecutive year classes
collected through the first year of life. Differences in scaling relationships between body
length and neutral-lipid and lean-tissue mass were used to infer patterns of resource allocation.
Lipid reserves scaled isometrically with body length in summer but increased at
a greater rate than did body length in autumn and winter. Lean-tissue allometries were less
variable but followed a similar seasonal cycle. Allometric slopes were homogeneous across years, but significant interannual variation in length-specific lipid content and lean-tissue
mass in the later half of the growing season indicated variable allocation patterns. During
winter, up to 21% of total energy content and 50% of neutral-lipid stores were depleted.
The results indicate that energy allocation patterns result from interactions among season,
ontogenetic stage, and body size. The variation in growth, allocation, and severity of the
winter energy deficit likely interact to determine first-winter survival.
Last updated
26 April, 2007
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