James Cook University Subject Handbook - 2000

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MB3250:03

The Marine Megafauna: Implications of Body Size in the Marine Environment

Townsville

36 lectures, 12 tutorials, 36 hours practicals. Second semester.

Staff: Professor H Choat.

The implications of body size in aquatic animals. Very large body size (length ›10m; mass ›1 tonne) is rare in marine environments but has evolved a number of times in many different taxonomic groups. The subject will initially review the implications of body size in terms of metabolism, size-specific metabolic scaling, functional design and the associated demographic and behavioural consequences of size. This will include the consequences of endothermy, ectothermy aquatic and terrestrial existence. Size spectra in a number of marine groups including vertebrates and invertebrates will be reviewed and those lineages in which large size has evolved and the points in geological time that this has occurred will be identified. A more detailed analysis of this will focus on specific groups including cephalopods, elasmobranchs, teleost fishes, marine reptiles and mammals. This will include the ecological and behavioural consequences of size including movement through a liquid medium, the costs of locomotion, resource harvesting growth and demography.

This subject is designed to assist in the development of a complementary subject on the management of large marine organisms.

Learning Objectives:

  1. insights into the fundamental relationships between size, resource harvesting and metabolic rate in aquatic and terrestrial assemblages;
  2. an overview of patterns of animal evolution in aquatic environments and the implications of large size in different phyletic lineages;
  3. the influence of size and habitat on the functional design of respiratory, vascular muscular and digestive systems;
  4. confirmation of the importance of physical properties of liquids in the support and locomotion of marine organisms of different sizes; biophysics for biologists.

Assessment by final examination (60%); laboratory assignments (20%); written assignment (20%).

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