Invertebrate Vision

Publisher description

Invertebrate Photoreceptors: A Comparative Analysis covers the structure and pigment chemistry of invertebrate photoreceptors. The book discusses the photobehavior and photoreceptor systems of invertebrate animals; the protozoan photoreceptor; and the compound eye. The text also describes the crustacean and mollusc eyes; the vertebrate retinal photoreceptors; and the invertebrate eye and its visual pigments. The book concludes with discussions on primitive photoreceptors; spectral sensitivity, pigments, and color vision; and polarized light analysis. Biologists and people involved in the study of invertebrate photobiology will find the text invaluable.

I see a man's life is a tedious one. Cymbeline, Act III, Sc. 6. It is well known that the best way to learn a subject is to teach it! Along the same lines one might also say that a pleasant way of learning a subject and at the same time getting to know quite a few of the workers active in it, is to arrange and to attend an Advanced Study Institute (ASI) or a workshop lasting about two weeks. This was and is the wisdom behind the NA TO-ASI programme and much as people fear that a fortnight may be too long, before it is over everyone feels that it was too short, especially if the weather had cooperated. Organising this ASI which resulted in this volume has been a very good learning experience. I started my career in research with invertebrates and retained an interest in them over the years due to my teaching a course and working sporadically on various aspects of photoreception in Polychaetes, Crustaceans and Insects. Thus, the thought of organising an ASI on photoreception and vision in invertebrates had been brewing in my mind for the past half a dozen years or so. It was felt that it will be desirable to do a bit of stock taking and discuss possible new approaches to the study of this matter.

In the comparative physiology of photoreception by the Protista and the invertebrates two aspects are emphasized: (1) the diversity of visual processes in these groups and (2) their bearing upon general mechanisms of photoreception. Invertebrates have evolved a far greater variety of adaptations than vertebrates modifications aiding survival in the remarkably different biotopes they occupy. The number of species in itself suggests this multiformity; each of them has peculiarities of its own, in morphology as well as in physiology and behavior. But these special adaptations are variations on a few great themes. Although the catalogue of invertebrate species is immense, the literature concerning them nearly rivals it in extent-even if one considers only that fraction dealing with visual physiology. Taxonomy proceeds by grouping the species, categorizing them in genera, families, orders, and progressively larger units. Similarly, comparative physiology aims at an analogous, more or less compre hensive, classification. This Part A of Volume VII/6, like Part B that follows it, emphasizes the broad questions that concern groups larger than the individual species; in some cases these questions have general applicability. The middle course between approaches that are too specialized and those that are too general is often elusive, but here we attempt to follow it. The vast number of special adaptations-probably, as we have said, as large as the number of species-is beyond the range even of a handbook.

This detailed 1990 book describes the light and dark adaptation of receptoral and post-receptoral mechanisms from a number of perspectives. The authors emphasise the importance of the study of achromatopsia, a rare congenital condition in which the visual mechanisms that mediate day vision are absent whilst those that mediate night vision remain intact.

This textbook is intended for use in a course for undergraduate students in biology, neuroscience or psychology who have had an introductory course on the structure and function of the nervous system. Its primary purpose is to provide a working vocabulary and knowledge of the biology of vision and to acquaint students with the major themes in biological vision research. Part I treats the eye as an image-forming organ and provides an overview of the projections from the retina to key visual structures of the brain. Part II examines the functions of the retina and its central projections in greater detail, building on the introductory material of Part I. Part III treats certain special topics in vision that require this detailed knowledge of the structure and properties of the retina and visual projections.