Patterns in Reproductive Life History Traits Among Marine Batch Spawning Fishes Across a Wide Range in Body Size and Latitude

In this review and meta-analysis we summarize size-dependent relationships for batch fecundity (f_b), spawning frequency (p), spawning season duration (d), and batch number (n_b) in marine batch spawning fishes.  Within species, increases in f_b with body size were nearly ubiquitous, and length and weight explained roughly the same variation in f_b.  Across species, both f_b and p were strongly size-dependent.  There was a negative relationship between d and length and n_b was not significantly size-dependent across species.  Annual fecundity (f_A) showed a strong positive relationship with size across species.  No significant correlations were evident between d and p, or between n_b and size-adjusted f_b.  The size-dependence of batch fecundity proved similar to the analogous relationship for total spawners, but the f_A-length relationship was much higher, confirming that batch-spawning fishes produce far more eggs per year than total spawners.

Length-adjusted f_b decreased significantly with (absolute) latitude.  While p was not significantly related to latitude, d and n_b showed a steep decrease with latitude.  Size-adjusted f_A also showed a decrease at higher latitudes.  Thus, populations of batch spawning fishes closer to the equator spawn for longer periods each year, producing more batches, leading to the production of more eggs than poleward populations.