| SS4.02 Ecology and Physiology of Marine Organisms: Insights from Genes, Genomes, and Proteomes |
| Green, A, J, University of Southern California, Los Angeles, USA, allisong@usc.edu |
| Manahan, D, T, University of Southern California, Los Angeles, USA, manahan@usc.edu |
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| HIGH GROWTH EFFICIENCIES IN ANTARCTIC LARVAE |
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| Antarctic sea urchin larvae synthesize protein for 25-times less energy than any other animal. This unique, efficient metabolism might be the basis for high growth efficiency in cold ocean environments. We studied growth efficiency in larvae of the Antarctic sea urchin Sterechinus neumayeri. For five sets of independent cultures, the following series of measurements were made over a total period of larval development and growth of 2 months at 1.5C: clearance rates of algae by larvae; rates of protein growth; and metabolic rates. Clearance rates were 17 ± 1.8 (SE) algal cells/larva/hr; protein growth was 8.1 ± 1.9 ng/larva/day; metabolic rates ranged from 25 to 57 pmol oxygen/larva/hr. Gross growth efficiency for larvae was calculated for each culture – i.e., ratio of protein growth to amount of protein obtained from algae. The mean growth efficiency for five cultures was 99% ± 12. This near-perfect (100%) growth efficiency is exceptionally high for invertebrate larval forms and suggests that these Antarctic larvae, living for most of their life span in food-limited environments, can maximize growth rates by having unique macromolecular synthesis processes. |
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