Proximate Composition and Overwintering Strategies of Antarctic Micronektonic Crustacea
Proximate (protein, lipid, carbohydrate and chitin) and elemental (carbon and nitrogen) composition were determined for 18 species of Antarctic micronektonic Crustacea, representing the majority of species found in the Antarctic water column. Individuals used in the analyses were captured during fall and winter; for 8 species data were collected in both seasons. Seven of the 8 species showed some evidence that combustion of body stores were an aid to surviving the winter months; comparison with data from other investigators suggests that most of the species inhabiting shallow and mid-depths exhibit some degree of combustion of body stores during winter. Three types of overwintering strategies are proposed for Antarctic zooplankton and micronekton. Type 1, exhibited by some calanoid copepods, is characterized by accumulation of large lipid deposits and a true dormancy, or diapause, during winter. Type 2, exhibited by euphausiids and hyperiid amphipods, is characterized by a marked reduction in metabolic rate, combustion of body substance, opportunistic feeding, but no true dormancy. Type 3, 'business as usual' is exhibited by decapods and gammarid amphipods; it is characterized by an absence of a winter reduction in metabolic rate, combustion of body stores in some species but a lack of combustion or accumulation of energy in others, and opportunistic feeding. Over-wintering scenarios computed for Euphausia superba suggest that the impact of the winter season is most severe in the smaller size classes.
Joseph J. Torres, J. Donnelly, Thomas L. Hopkins, T. M. Lancraft, A. V. Aarset, and D. G. Ainley. "Proximate Composition and Overwintering Strategies of Antarctic Micronektonic Crustacea" Marine Ecology - Progress Series 113.3 (1994): 221-232.
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