Population Dynamics, Numerical Production, and Potential Predation Impact on a Meiobenthic Copepod

From the fecundity and temperature-dependent development times of the life stages of Microarthridion littorale and long-term measurements of the densities of copepodites and female and male adults in subtidal sediments at North Inlet, South Carolina, we calculated maximum and minimum productivity limits of this meiobenthic copepod. The potential production of numbers of nauplii (10 002 × 103∙m−2∙yr−1) exceeds the population density and production of copepodites and adults by about 2 orders of magnitude; observed populations of copepodites and adults can be supported even with a 98% mortality of nauplii. This suggests that predation or other causes of nauplii mortality limits the population density of M. littorale at North Inlet. The potential dry biomass production of nauplii is about 2.0 g∙m−2∙yr−1and greatly exceeds the combined biomass production of copepodites and adults. Because the minimum numerical productivity (that required to explain the temporal changes in population size) of adults (38 × 103∙m−2∙yr−1) is 26% of the maximum potential adult productivity (derived from the maturation of copepodites), it is likely that adult densities are regulated by recruitment. A time series of population data indicates large interannual variations in production of the different developmental stages, with potential naupliar recruitment showing the greatest variability.