Taste Organ in the Bullhead (Teleostei)

ISBN-13: 9783540088806 / Angielski / Miękka / 1978 / 100 str.

Klaus Reutter

Opis

In fish, the sense of taste is extraordinarily highly developed and essentially more sensitive than that of mammals. This is due to chemoreception, which offers suf- ficient possibilities for animals living in water to orient and maintain themselves suc- cessfully in individual and social life. Therefore, at least within the vertebrates the chemical senses have developed to their highest standard in water. Chemoreception is evidently present in land-dwelling mammals and is still dependent on moist surfaces, but the optical sense, in its highest stage of development, takes priority. In contrast, in aquatic animals vision generally plays only a subordinate role (c. f. Grant & Mackie, 1974). Although the high sensitivity of the sense of taste in fish has been extensively shown in physiological experiments, corresponding detailed morphological data are lacking. Due to their similarity the taste organs of fish and mammals have been regard- ed equally or rather the results taken from fish have been interpreted on the basis of the known morphology of the mammalian taste bud (TB). However, the high efficien- cy of the sense of taste in fish requires a corresponding morphological basis, and mor- phological and histochemical particularities can indeed be cited as examples: firstly, TB in fish are not only located in the mouth and throat area, but in many species also in the outer skin of the body.

Spis treści

I. Introduction.- II. Material.- A. Test Animals.- B. Technique of Obtaining Barbels and Barbel Regenerates.- C. Pharmacological Treatment of the Animals.- III. Methods.- A. Light Microscopical Investigations.- 1. Histological Procedures.- 2. Histochemical Investigations.- B. Electron Microscopical Investigations.- 1. Scanning Electron Microscopy.- 2. Transmission Electron Microscopy.- IV. Results.- A. Barbels and Taste Buds in Differentiated State.- 1. Morphological Observations.- a) Macroscopical Findings.- b) Light Microscopical Findings.- c) Scanning Electron Microscopical Findings.- d) Transmission Electron Microscopical Findings.- 2. Histochemical Experiments.- a) Untreated Animals.- b) Treated Animals.- B. Barbels and Taste Buds in Development.- 1. Morphological Experiments.- a) Light Microscopical Findings.- b) Scanning Electron Microscopical Findings.- c) Transmission Electron Microscopical Findings.- 2. Histochemical Investigations.- a) Barbel Regenerates of Untreated Animals.- b) Barbel Regenerates of Treated Animals.- 3. Electron Microscope-Histochemical Investigations After 5,7-DHT Treatment of the Animals.- a) Changes on Differentiated Taste Buds.- b) Changes on the Barbel Regenerate.- V. Discussion.- A. The Differentiated Barbel.- B. Regeneration of the Barbel.- C. Histochemistry of the Barbel and the Barbel Regenerate.- D. Differentiated Taste Bud.- E. Development of the Taste Buds.- F. Histochemistry of the Taste Buds and Their Developmental Stages.- G. Influence of False Transmitter Substances on Differentiated Taste Buds and the Development of the Taste Buds.- VI. Summary.- A. Differentiated Barbels and Taste Buds.- B. Development of Barbel Regenerates and Taste Buds.- VII. References.- VIII. Subject Index.