Abstract

Euphausia mucronata abundance and distribution of the developmental stages (calyptopis, furciliae, juveniles, and adults) was analyzed as a function of seawater temperature and chlorophyll-a concentration between Paposo (25 degrees S) and Coquimbo (30 degrees S), Chile. Zooplankton samples were obtained using bongo nets during February of three consecutive years (2014-2016). The Q coefficient was used to explore the relationship between the distribution and abundance of the development stages of E. mucronata with the temperature recorded throughout the water column. The adults were considerably more abundant than the rest of the ontogenetic development stages during the study period. The abundance of adults decreased from February 2014 to 2016, having a negative correlation with temperature. Relative abundance of juveniles and larvae increased positively related to the total euphausiid abundance. The Q coefficient showed a significant association of all development states concerning the low-temperature intervals recorded throughout the seawater column. Q coefficient showed no association with chlorophyll- a concentration through the recorded intervals throughout the water column and neither with the vertical abundance and distribution of E. mucronata specimens.