Electroreceptors and Other Specialized Receptors in Lower Vertrebrates

The originality of this volume is to reveal to the reader the fascination of some unfamiliar sensory organs that are sometimes ignored and often misunderstood. These receptors have only recently been identified and their functional specificity is in some cases still a matter for discussion. The four classes of sensory organs considered here differ widely from one another in many respects. One might even say that the only thing they have in common is that they belong to cold-blooded vertebrates. These classes are: 1. the directionally sensitive lateral-line mechanoreceptors of fishes and amphi­ bians (Chapter 7); 2. the pseudobranchial organs of some teleosts, equipped with pressoreceptors and at least three other types of receptors (osmo- and chemoreceptors) (Chapter 8); 3. the infrared-sensitive pit organs of some snake families (Chapter 9) ; 4. the various kinds of electroreceptors found in several marine and freshwater fish families (Chapters 2 to 6). The first three classes of receptors mentioned above thus rate only one chapter each, whereas five chapters are devoted to the electroreceptors. Electroreception has aroused enormous interest among physiologists in specialties ranging from molecular biology to animal behavior. The resulting quantity of research and discussion fully justifies this disproportion. However, it cannot be denied that the contents of the volume must appear unbalanced and heterogeneous, yet it should not be perceived as a mere juxtaposition of particular and unrelated cases.

1 General Introduction.- Electroreceptors in the Teleost.- 2 Anatomy of the Specialized Lateral Line Organs of Electroreception.- 3 Physiology of Electroreceptors.- Electroreceptors in the Elasmobranch.- 4 The Ampullae of Lorenzini.- The Role of Electroreceptors in Animal's Life.- 5 The Detection of Electric Fields from Inanimate and Animate Sources Other Than Electric Organs.- 6 The Detection of Electric Fields from Electric Organs.- Other Specialized Receptors.- 7 Lateral-Line Mechano-Receptors in Fishes and Amphibians.- 8 Pseudobranchial Receptors in Teleosts.- 9 Thermoreceptors in Snakes.- Author Index.