Seasonal, Physiological and Genetic Functions in Antarctic Krill, Euphausia superba, at Different Latitudes in the Southern Ocean

• Main Author: Höring, Flavia
• Format: Thesis
• Language: unknown
• Published: 2019
• Subjects: Life sciences; biology; Antarctic; Southern Ocean; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: http://oops.uni-oldenburg.de/4112/; http://oops.uni-oldenburg.de/4112/1/hoesea19.pdf

Light regime and the endogenous timing system of Antarctic krill, Euphausia superba, are known to play important roles in the regulation of its seasonal cycles of growth, maturity, metabolic activity and gene expression. This dissertation aimed to investigate the effect of different latitudinal light regimes on the seasonal cycle of Antarctic krill. It comprised two main parts: a) a field study with the goal to characterize seasonal processes on the molecular level in Antarctic krill in different latitudinal regions (Publication 1), and b) a two-year laboratory study under constant food and temperature conditions that tested the effect of the latitudinal light regimes 52¡S, and 66¡S, and constant darkness on the seasonal cycle of Antarctic krill (Publication 2 & 3). Our results suggest that the seasonal timing system of Antarctic krill is highly plastic, thereby promoting regional acclimatization to different latitudinal light regimes. We further discuss that the internal 'photoperiodic-controlled' seasonal cycles in Antarctic krill may be adjusted by other environmental cues like temperature and food supply in the field.