PETERS, KEVIN J.1*, CHARLES D. AMSLER1, MARGARET O. AMSLER1, JAMES B. MCCLINTOCK1, KATRIN B. IKEN1, and BILL J. BAKER2. 1Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294-1170 USA; 2Department of Chemistry, University of South Florida, Tampa, FL 33620 USA. - The effects of thallus toughness and nutritive quality on palatability of antarctic macroalgae.
Palatability of macroalgae can be affected by many different factors
including thallus toughness, nutritional quality (carbohydrates,
lipids, proteins, ash), and the presence of deterrent secondary
metabolites. Palatability bioassays were performed using two different
antarctic algal grazers (the antarctic rockfish Notothenia
coriiceps and the sea star Odontaster validus). These data
were then compared to toughness and chemical composition data.
Toughness was determined using a penetrometer and a wide range of
thallus toughness was observed in individuals of differing species as
well as of the same species. Some of the tougher individuals required
more than 30 N of force to cut through the thallus while others
required less than 1 N to break through. Each algal species is also
being tested for percent composition of carbohydrates, lipids,
proteins, as well as ash. It is hypothesized that the algal species
with greater nutritional quality and/or less thallus toughness are
more likely to be acceptable foods to consumers. (NSF OPP9814538,
OPP9901076)
Key words: Antarctica, chemical composition, herbivory, thallus toughness