The unique life cycle strategy of Antarctic krill: Adaptation to a high latitude environment

The polar pelagic environment is characterized by the extreme seasonal cycle of its environments such as day length, light intensity, sea ice extent and food availability. Possessing biological timing that guarantees regulation of their physiology and behaviour in response to seasonal cycles of environment is of particular advantage, and not surprisingly, many polar pelagic organisms have evolved endogenous rhythmic physiological and behavioural functions, which are synchronized with these cyclic changes. The polar environment is currently subject to the fastest warming on the planet affecting patterns of the polar marine environment (e.g. sea ice decline) as well as causing changes in water properties such as temperature rise and ocean acidification. In order to predict effects of these changes on ecosystems at species and community levels, it is of paramount importance to understand the basic principles of how the life cycle of key species is synchronized with their seasonal environment. The mechanisms leading to these rhythms, however, are far from clear. In this respect it is of fundamental scientific interest to understand the molecular basis of biological rhythms and clocks in polar pelagic organisms that have a central importance in polar pelagic food webs. This talk aims to give an overview of daily and seasonal pattern in physiological and behaviour functions of the polar key species Antarctic krill, Euphausia superba, the drivers behind these patterns and their ecological consequences in general and in a changing environment in particular

Condition of larval (furcilia VI) and one year old juvenile Euphausia superba during the winter–spring transition in East Antarctica

Antarctic krill, Euphausia superba, is an important species in the Southern Ocean ecosystem. Information on krill condition during winter and earlyspring is slowly evolving with our enhanced ability to sample at this time of year. However,because of the limited spatial and temporal data, our understanding of fundamental biological parameters for krill during winter is limited. Our study assessed the condition of Larval (furciliaVI) and one year old juvenile krill collected in East Antarctica (115°E–130°E and 64°S–66°S) from September to October 2012. Krill condition was assessed using morphometric, elemental and biochemical body composition, growth rates,oxygen uptake and lipid content and composition. Diet was assessed using fatty acid biomarkers analysed in the krill. The growth rate of larvae was 0.0038 mm day with an inter moult period of 14 days. The average oxygen uptake of juvenile krill was 0.3070.02 μl Oxygen consumed per mg dry weight per hour. Although protein was not significantly different amongst the krill analysed, the lipid content of krill was highly variable ranging from 9% to 27% dry weight in juveniles and from 4% to 13% dry weight in larvae. Specific algal biomarkers, fatty acids ratios, levels of both long-chain(ZC20) monounsaturated fatty acids and bacterial fatty acids found in krill were in di-Cative of the mixed nature of dietary sources and the opportunistic feeding capabilityof larval and juvenile krill at the end of winter

Marco Polo: A Sample Return Mission to a Primitive Near-Earth Object in Assessment Study in the ESA Program Cosmic Vision 2015-2025

Meteoritics and Planetary Science Supplement, 72, p. 5261 (2009)International audienc

MARCO POLO: near earth object sample return mission

MARCO POLO is a joint European--Japanese sample return mission to a Near-Earth Object. This Euro-Asian mission will go to a primitive Near-Earth Object (NEO), which we anticipate will contain primitive materials without any known meteorite analogue, scientifically characterize it at multiple scales, and bring samples back to Earth for detailed scientific investigation. Small bodies, as primitive leftover building blocks of the Solar System formation process, offer important clues to the chemical mixture from which the planets formed some 4.6 billion years ago. Current exobiological scenarios for the origin of Life invoke an exogenous delivery of organic matter to the early Earth: it has been proposed that primitive bodies could have brought these complex organic molecules capable of triggering the pre-biotic synthesis of biochemical compounds. Moreover, collisions of NEOs with the Earth pose a finite hazard to life. For all these reasons, the exploration of such objects is particularly interesting and urgent. The scientific objectives of MARCO POLO will therefore contribute to a better understanding of the origin and evolution of the Solar System, the Earth, and possibly Life itself. Moreover, MARCO POLO provides important information on the volatile-rich (e.g. water) nature of primitive NEOs, which may be particularly important for future space resource utilization as well as providing critical information for the security of Earth. MARCO POLO is a proposal offering several options, leading to great flexibility in the actual implementation. The baseline mission scenario is based on a launch with a Soyuz-type launcher and consists of a Mother Spacecraft (MSC) carrying a possible Lander named SIFNOS, small hoppers, sampling devices, a re-entry capsule and scientific payloads. The MSC leaves Earth orbit, cruises toward the target with ion engines, rendezvous with the target, conducts a global characterization of the target to select a sampling site, and delivers small hoppers (MINERVA type, JAXA) and SIFNOS. The latter, if added, will perform a soft landing, anchor to the target surface, and make various in situ measurements of surface/subsurface materials near the sampling site. Two surface samples will be collected by the MSC using ``touch and go'' manoeuvres. Two complementary sample collection devices will be used in this phase: one developed by ESA and another provided by JAXA, mounted on a retractable extension arm. After the completion of the sampling and ascent of the MSC, the arm will be retracted to transfer the sample containers into the MSC. The MSC will then make its journey back to Earth and release the re-entry capsule into the Earth's atmosphere