The course discusses the ecology and biology (with emphasis on feeding and reproduction) of the Porifera, Coelenterata, Annelida, Mollusca, Arthropoda (excluding Insects) and Echinodermata. The following phenomena are also highlighted: cellular aggregation and division of labour as demonstrated by the Porifera;

polymorphism as demonstrated by the Coelenterata; significance of hydrostatic skeleton; coral formation; locomotory habits; metamerism as providing a degree of plasticity in the annelids; segmental locomotor appendages as shown by selected classes of the Arthropoda, adaptive radiation in the Mollusca; and dermal endoskeleton of the Echinodermata.