To Measure Is to Know: Examples of Variable or Revised Spawning Rates By Four Species from Boreal to Tropical Marine Systems

Entrenched views about static reproductive traits have given way to acceptance of phenotypic plasticity in terms of maturation rates, spawning rates, and egg batch size. Here, I provide four recent examples of either intraspecific or unexpected variation in spawning rates for species in boreal, temperate, subtropical, and tropical marine systems. A poster child for skip spawning, Winter Flounder, has high skipping rates for Canadian but not U.S. stocks. A number of goosefish species, including unpublished data for the American Goosefish, have been shown to produce more than one egg veil per year. Spatial variation in spawning rates exists for inshore versus offshore contingents of Hogfish, in the eastern Gulf of Mexico. Examination of gonad histology changed estimates of spawning rates for Dolphinfish from twice per year to approximately 180 days per year. In each case, intraspecific plasticity or re-evaluated estimates either increase or decrease the resilience of a fish stock or contingent, depending on the type, direction, and magnitude of the variation. Incorporating this information into stock assessments  has happened with two of these examples, so far; the process depends on the type of assessment (i.e. data poor vs. data rich).