MEPS 511:129-141 (2014)  -  DOI: https://doi.org/10.3354/meps10914

ABSTRACT: Due to growing concerns regarding ocean warming, it has become important to precisely understand the influence of temperature on the reproduction of marine organisms. This study investigated the population dynamics of the small temperate epifaunal crustaceans Caprella danilevskii and C. scaura and the boreal species C. cristibrachium, which occur sympatrically in a boreal area, and examined whether reproductive dynamics within a location and along a latitudinal gradient can be explained by seasonal temperature fluctuations. Although the 2 temperate species are known to reproduce throughout the year in their temperate habitat, the population dynamics of all 3 caprellids showed the same pattern in that active reproduction was limited to June-October. A simple simulation using a temperature-maturation function in caprellids could explain the occurrence of mature females and the timing of active reproduction in the study area. While the simulation predicted continuous reproduction at temperatures above 12°C, the caprellid densities decreased immediately after the peak temperature in the field. These results suggest that the reproductive patterns and population dynamics in caprellids within/between locations can be simply explained by maturation time, which is controlled by local temperature fluctuations, but the results also highlighted the existence of other ecological factors (e.g. food availability or predation pressure) that can cause drastic population decreases in the summer.

KEY WORDS: Epifauna · Caprella · Reproductive dynamics · Life history