Thermal limits of krill species from the high-Arctic Kongsfjord (Spitsbergen)
| Autor: | Friedrich Buchholz, Kim Huenerlage |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
0106 biological sciences
Thysanoessa Krill Ecology biology 010604 marine biology & hydrobiology Nematoscelis megalops Thysanoessa raschii Aquatic Science biology.organism_classification 010603 evolutionary biology 01 natural sciences Oceanography Arctic Respiration Sexual maturity Thysanoessa inermis 14. Life underwater Ecology Evolution Behavior and Systematics |
| Zdroj: | Marine Ecology Progress Series. 535:89-98 |
| ISSN: | 1616-1599 0171-8630 |
| DOI: | 10.3354/meps11408 |
| Popis: | The high-Arctic Kongsfjord is influenced mainly by cold Arctic water but also by warmer Atlantic water masses. In recent years, the proportion of the Atlantic inflow from the south has increased. Concurrently, one temperate-boreal (Meganyctiphanes norvegica) and one subtropical-temperate (Nematoscelis megalops) krill species are now regularly found in the Kongsfjord, in addition to the previously prevailing arcto-boreal species Thysanoessa inermis and T. raschii. In view of the recent changes in these species’ biogeographic distributions, we compared their physiological tolerances. Using non-invasive optical oxygen sensors, respiration measurements served to characterize metabolic responses to temperature variations. Thysanoessa spp. appear more cold-stenotherm than the other 2 krill species: the upper level of respiratory capacity is reached at 12°C and they are less tolerant to decreasing oxygen concentrations. This finding is consistent with their arcto-boreal distribution. In contrast, M. norvegica and N. megalops showed a higher tolerance to temperature changes, a robust nutritional condition and sexual maturity. Such physiological plasticity may explain the recent northward expansion of their geographic range. |
| Databáze: | OpenAIRE |
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