Module Information

The module begins with a brief review of invertebrate design and classification. This is followed by the investigation of selected groups:
The phylum Porifera (sponges) is discussed covering choanocyte structure and function; the water conducting system in ascon-, sycon- and leucon-type sponges; spicules; and the absence of true nerves. The superphylum Radiata is then introduced, using examples from the phylum Cnidaria (hydroids, jellyfish, anemones etc), their cellular organisation is investigated with emphasis on polymorphism and colonial life.
The module then introduces further aspects of invertebrate design with the groups of invertebrates commonly referred to as triploblastic. Throughout these lectures examples are drawn from appropriate phyla, and at this stage of the course the phylum Annelida is discussed to illustrate diversity of form and function.
With the introduction of the phylum Arthropoda, several aspects of their biology are investigated including growth cycles, moulting, locomotion, and feeding mechanisms.
Studies on the phylum Mollusca emphasise the diversity of function that is achieved by adaptive radiation from a relatively simple body plan. Features of molluscan structure and function common to most of the major groups are explored with emphasis on the shell, respiration, digestion, circulatory and excretory systems. The form of the shell and mantle cavity of the Bivalvia is considered along with the evolution of the gills. Features distinguishing cephalopods from other molluscs and enabling them to operate as fast-moving benthic and pelagic predators in the sea are discussed.
The lecture course concludes with a study of the phylum Echinodermata. Their symmetry, diversity of body form, the endoskeleton, the uniqueness of the water-vascular system and its role in feeding, respiration, and locomotion are investigated.
Practical classes illustrate and develop the main themes introduced in lectures. Practical work involves observation of living specimens, video presentation and examination of prepared material. There are no dissections.