Module Identifier BS20910  
Academic Year 2003/2004  
Co-ordinator Dr Iolo Ap Gwynn  
Semester Semester 2  
Other staff Dr John H R Gee, Dr Joanne V Hamilton  
Pre-Requisite BS10710 - Introduction to Invertebrate Zoology  
Course delivery Lecture   20 Hours  
  Practical   9 Hours (3 x 3 hours)  
Assessment TypeAssessment Length/DetailsProportion
Semester Exam2 Hours One 2-hour theory paper  70%
Semester Assessment Practical Exercise: Continuous assessment of practicals  30%
Supplementary Assessment2 Hours One 2-hour theory paper (plus resubmission of failed coursework or an alternative)   

Learning outcomes

On completion of the module the student will

Brief description


This module builds on Module BS10710 - Introduction to Invertebrate Zoology - by introducing the student to a range of specialist topics which draw on examples from the phyla studied in Level 1.


The module begins with lectures on excretion. Excretory organs regulate the osmotic pressure, ionic composition and volume of body fluids and, particularly in terrestrial organisams, are the main site of nitrogenous excretion. The structure and function of the excretory organs found in protozoa, platyhelminths, annelids, molluscs and crustacea are described. The physiological adaptations required for life in freshwater and life on land are discussed. Invertebrates produce a range of nitrogenous end products and there is a correlation between the type of end product produced and the ecology of the organism.
The invertebrate nervous system is considered in four lectures. The physiology, development and evolution of the system in the different phyla are investigated in relation to sense organs and effectors. The different classes of neurons are described and transmission between neurons and about the body is discussed. The development of nerve nets, ganglia and brains is considered, along with the importance of invertebrate studies in neurophysiology.
A series of lectures on invertebrate feeding mechanisms discusses structural adaptations and the behaviour employed by a range of species, with particular emphasis on foraging strategies. The four principal trophic categories considered are carnivory, herbivory, deposit and suspension feeding, and food-based mutualism.
Lectures on invertebrate locomotion consider the basic principles involved, the effect of size, and the physical properties of muscle and skeletal material. The function of hydrostatic skeletons is discussed in relation to peristaltic and serpentine locomotion in annelids and this leads to a consideration of the high pressure pseudocoelom of nematodes and their unique body wall structure. Locomotion in soft bodies invertebrates is concluded with discussion of jet propulsion, gliding and flotation in molluscs. The function of the jointed arthropod skeleton is illustrated with a comparison of the mechanisms involved in the jump of the flea and the spider.
Lectures on reproduction and life history strategies discuss the relative merits of asexual and sexual reproduction, the distribution of both patterns among invertebrate groups and mechanisms of sex determination. The lectures also describe the sequence of events leading to reproduction, the timing of reproduction and the allocation of resources to reproduction within invertebrate life histories. Other topics discussed in this section include a brief comparison of the life-history patterns of individual and colonial species of invertebrates.
The course concludes with three lectures on invertebrate phylogeny which take the form of a critical assessment of the evidence put forward to support the main theories and draws on the knowledge acquired in both Level 1 and Level 2 modules.

Practical classes are designed to develop further the main theories established in the lectures and involve a limited number of dissections.

Reading Lists

** Reference Text
Willmer, P. (1990) Invertebrate relationships Cambridge University Press
Alexandra, R.M. (1990) Animals Cambridge University Press
** Multiple Copies In Hugh Owen
Barnes, R.S.K., Calow, P. Olive, P.J.W. (1993) The invertebrates: a new synthesis Oxford: Blackwell Science
Pechenik, J.A. (1996) Biology of invertebrates 3rd. London: W.C. Brown
Ruppert, E.E. & Barnes, R.D. (1994) Invertebrate zoology 6th. Saunders college Publishing


This module is at CQFW Level 5