The Amphibian Ear

The Amphibian Ear

Ernest Glen Wever
Copyright Date: 1985
Pages: 496
https://www.jstor.org/stable/j.ctt7zth8g
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  • Book Info
    The Amphibian Ear
    Book Description:

    Professor Wever studies the structure of the ear and its functioning as a receptor of sounds in all amphibian species (139) for which living representatives could be obtained

    Originally published in 1985.

    ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

    eISBN: 978-1-4008-5506-3
    Subjects: Zoology, General Science

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-vi)
  3. PREFACE
    (pp. vii-viii)
  4. PART I. INTRODUCTION
    • 1. NATURE AND ORIGIN OF THE AMPHIBIA
      (pp. 3-16)

      The name Amphibia literally signifies “both lives” and refers to the proclivity of many of these animals for alternating between aquatic and terrestrial habitats. This name was first used broadly by Linnaeus in reference to a wide variety of animals, including such species as seals, turtles, and crocodiles as well as frogs and salamanders, that live sometimes in the water and sometimes on land. Soon thereafter the term was applied more selectively to a particular class of vertebrates, a class including the frogs, salamanders, and caecilians among modern types, together with a number of ancient animals known only as fossils...

    • 2. EXPERIMENTAL METHODS
      (pp. 17-31)

      Three types of procedures are used in the study of the ear and its performance in response to sounds; these are anatomical methods for the examination of the receptive structures, behavioral observations of the animal’s acoustic discriminations and reactions, and electrophysiological procedures in the analysis of the ear’s internal processes. These procedures have been developed over many years in the course of studies on the ears of higher vertebrates, and with minor modifications are found applicable to the amphibians. An earlier study of the ear of reptiles (Wever, 1978b) dealt with these procedures at considerable length and should be consulted...

    • 3. GENERAL ANATOMY OF THE AMPHIBIAN EAR
      (pp. 32-98)

      A general treatment of the anatomy of the amphibian ear presents difficulties because the three orders now living, the anurans, caudates, and caecilians, exhibit many different specializations combined with what appear to be various degrees of reduction and degeneration from an earlier, more general form. Parsons and Williams (1963) in their defense of the lissamphibian hypothesis, which holds that the three existing orders of Amphibia had a common origin, tried to formulate what the primordial lissamphibian ought to be like. They listed 19 features that they considered as most probably possessed by this ancestral form, among which they emphasized the...

  5. PART II. THE ANURANS
    • 4. THE PRIMITIVE FROGS: THE ASCAPHIDAE AND DISCOGLOSSIDAE
      (pp. 101-128)

      This chapter begins a systematic examination of the anurans, with a consideration of the ear structures in all species for which specimens were available for study. This amphibian order is divided into 21 families, one of which is known only from fossil remains. It was possible to obtain representatives of all but 4 of the 20 families of living species.

      The systematic arrangement of these forms has presented a continuing problem. No one has any hesitation in identifying a given animal as a frog: the peculiar body structure and the great uniformity among members of the group insure their immediate...

    • 5. THE PRIMITIVE FROGS: THE PIPIDAE AND RHINOPHRYNIDAE
      (pp. 129-155)

      The consideration of the primitive anurans is continued in the Pipidae. These are frogs with a completely aquatic mode of life, except that they have lungs and breathe air. It is likely that they are derived from frogs with terrestrial habits and that their aquatic adaptation is secondary.

      The Pipidae constitute a single family in the suborder Aglossa (the tongueless frogs) and have a disjunct distribution in Africa and South America. Four genera are widely recognized:Pipa, containing 5 species in South America,Xenopuswith 6 species and a few subspecies in South Africa,Hymenochirus, with 4 species in west...

    • 6. THE INTERMEDIATE FROGS: THE PELOBATIDAE
      (pp. 156-177)

      The pelobatids include three principal genera,Scaphiopus, Pelobates, andMegophrys, along with a few others, widely distributed over the northern hemisphere.Scaphiopusincludes a number of species in the southern regions of the United States and Mexico that are commonly known as spadefoot toads because of the presence of a sharp tubercle on the foot that is used in digging.Pelobatesincludes a few species of Europe that are similarly equipped.Megophrysis a genus of many species without the digging instrument but otherwise similar to the spadefoot group occurring in the Orient in the region of the South China...

    • 7. THE ADVANCED FROGS: THE LEPTODACTYLIDAE AND BUFONIDAE
      (pp. 178-218)

      The advanced frogs were given the formal designation of Neobatrachia by Reig (1958) and are primarily distinguished by their vertebral structure; with a few exceptions all have holochordal centra: the original cartilage of the notochord is largely replaced by bone. In Dowling and Duellman’s classification (see Chapter 1, p. 13) this group is divided into three superfamilies, the Bufonoidea, Microhyloidea, and Ranoidea. The first of these, the Bufonoidea, includes a large number of toad-like forms in nine families as shown in Table 7-1. The second superfamily is the Microhyloidea containing the single family of Microhylidae, though sometimes thePhrynomerusspecies...

    • 8. THE ADVANCED FROGS: BRACHYCEPHALIDAE, RHINODERMATIDAE, DENDROBATIDAE, HYLIDAE, AND CENTROLENIDAE
      (pp. 219-255)

      A number of frog families generally considered to be derived from the Bufonidae, or at least closely related to these, will now be examined.

      A group of frogs to which Noble in 1931 had accorded the status of a subfamily has more recently been regarded as a full family, the Brachycephalidae, including four genera,Atelopus, Brachycephalus, Dendrophryniscus, andOreophyrnella, with a number of species distributed over South America from Guiana to Argentina. Of these generaAtelopushas by far the widest representation in terms of species, numbering about 34, whereasBrachycephalushas only one; this condition may justify the designation...

    • 9. THE MICROHYLIDAE
      (pp. 256-268)

      The second of the three superfamilies making up the group of advanced frogs (the Neobatrachia) is the Microhyloidea, which consists of only one family, the Microhylidae. This group is considered to be closely related to the ranids and probably was derived from the same early stock.

      This assembly of frogs has presented particular difficulties for the systematists. The species are highly varied in character and in earlier classifications were scattered among several families. Then Noble in 1931 proposed a new systematic scheme in which the form of the vertebral column was the principal determinant, and thus he brought together a...

    • 10. THE RANIDAE, RHACOPHORIDAE, AND HYPEROLIIDAE
      (pp. 269-286)

      Members of the Ranidae, often referred to as the “true frogs,” are worldwide in distribution. As many as ten subfamilies have been recognized, half of which occur only in Africa. Several species of the genusRanawere examined, and all showed an ear structure closely similar to that already described forRana utricularia sphenocephala(Chapters 3 and 4). Results will be presented for additionalRanaspecies that will show some of the observations made on general features and on the sensitivity to tonal stimuli, but the studies were not extensive enough to reveal species differences in full detail.

      Rana adspersa...

  6. PART III. THE URODELES
    • 11. THE SALAMANDER EAR
      (pp. 289-323)

      As was done for the anurans, a consideration of the anatomy of the ear in the urodeles will begin with the skull structures for purposes of general orientation and then will include the labyrinth as a whole. Finally, with these topographical features in mind, a series of figures will be presented to show the forms of the auditory receptor organs and their relations to other structures and especially the pathways by which these organs may be stimulated by sounds.

      First to be examined in this orienting survey are two species ofAmbystoma, which are among the more advanced of the...

    • 12. THE HYNOBIIDAE AND CRYPTOBRANCHIDAE
      (pp. 324-337)

      Now to be considered in respect to the structure of the salamander ear and its performance in the reception of sounds are the various species available for study, disposed in a series that follows the Dowling and Duellman arrangement of this group in four suborders according to their conception of a progressively increasing level of specialization.

      This series begins with the Hynobiidae in the suborder Cryptobranchoidea, which are regarded as the most primitive of salamanders and probably the best living representatives of the basal stock from which all others were derived; the series then continues with the Cryptobranchidae in this...

    • 13. THE SIRENIDAE
      (pp. 338-346)

      The family Sirenidae includes two genera,SirenandPseudobranchus, with the first of these containing two species, one of them with two subspecies; specimens were available of the greater siren,Siren lacertina, which occurs along the Atlantic coastline from Virginia through all of Florida, and of the lesser siren,Siren intermedia intermedia, which is found in the coastal half of South Carolina and southward through southern Georgia and Florida. Specimens were also obtained ofPseudobranchus striatus spheniscus, a subspecies that occurs in north central Florida and southwest Georgia.

      These salamanders are fully aquatic, eel-like in body form, and live in...

    • 14. THE SALAMANDRIDAE: THE NEWTS
      (pp. 347-373)

      The family Salamandridae is the most widespread of all the urodele groups; it includes the dominant species of Europe, Asia, and North Africa and is well represented in North America also. An important genus in this family,Salamandra, will first be examined and then the discussion will turn to a number of other genera for which specimens were available, includingTriturus(also known asTriton),Taricha, Notophthalmus(also calledDiemictylus),Salamandrina, Pleurodeles, Cynops, andEuproctus. In these last-named genera the columella has been reduced still further than in theSalamandraspecies, and the structure that remains, as seen in the...

    • 15. THE PROTEIDAE AND AMPHIUMIDAE
      (pp. 374-381)

      Of somewhat uncertain status, but generally considered to be related to the Salamandridae of the foregoing chapter, are the families Proteidae and Amphiumidae, now to be described.

      The genusNecturus, whose members are known colloquially as mudpuppies or sometimes as water dogs, includes a group of American salamanders that are thoroughly aquatic in habit and are permanent larvae; the three pairs of external gills persist through life, though these animals also possess lungs. This genus and the European genusProteus, a subterranean lake-dweller that it closely resembles, constitute the small family of Proteidae.

      Several species ofNecturusare widely distributed...

    • 16. THE AMBYSTOMATIDAE
      (pp. 382-400)

      The family Ambystomatidae contains three genera,Ambystoma, Dicamptodon, andRhyacotriton, the first with 17 species and subspecies and the others with a single species each (Bishop, 1974). All occur in North America. In this group is found the most complete form of sound-receptive mechanism along the salamanders, with important developments in the course of transformation from larval to adult stages.

      In the larva a columella is present, bearing an extended process, the stylus, that makes a connection with the squamosal, or sometimes with the palatoquadrate, or with both these elements. Also the base of the columella (the fenestral plate) connects...

    • 17. THE PLETHODONTIDAE: THE LUNGLESS SALAMANDERS
      (pp. 401-422)

      The Family Plethodontidae is not only the largest among the caudates, containing 23 genera with about 175 species, but also exhibits the greatest diversity, its members occupying a wide variety of habitats ranging from brooks and streams to forest areas and rocky regions containing water sources, and including even holes in trees and basins of bromeliads. Members of this family have gone farthest of all the salamanders in reducing the dependence on an aquatic environment, and a few have achieved complete terrestriality, laying their eggs on land in protected places such as chinks in logs or in caves where they...

  7. PART IV. THE CAECILIANS
    • 18. THE CAECILIAN EAR
      (pp. 425-440)

      Of the three kinds of amphibians now existing, by far the most poorly known are the caecilians, of the orderGymnophiona. They occur in only a few remote places around the world, mainly in tropical and subtropical regions and are exceedingly difficult to collect and study. This difficulty comes from the habit of most species of living in burrows underground, often far below the surface; the remaining few that are not fossorial but aquatic dwell almost as well concealed in bogs, pools, or streams.

      Caecilians occur in Asia and especially its adjoining islands, in the Seychelles in the Indian Ocean,...

    • 19. The Caeciliidae and Ichthyophiidae
      (pp. 441-462)

      Dermophis mexicanus. The second caecilian to be examined isDermophis mexicanus, a relatively large, heavy-bodied species occurring in southern Mexico and neighboring regions. Figure 18-1 above shows the body form, and Fig. 19-1 gives a view of the head after the removal of superficial tissues to expose the bone structures in the posterior region. The columella presents a broad footplate in the oval window and gives off an anterior process that makes a ligamentary attachment to the quadrate.

      In general form and arrangement the labyrinthine structures are much the same as described forTyphlonectes. Two auditory organs are present—the...

  8. PART V. THE EVOLUTION OF THE EAR
    • 20. THE AMPHIBIAN EAR IN EVOLUTION
      (pp. 465-472)

      The sense of hearing at the advanced stage in which it occurs in ourselves and the other higher vertebrates carries such a wealth of information about the outside world (and its loss occasions so severe a burden) that its appearance in the evolution of animal life seems almost an inevitable event. Even among the very lowly forms of life this sense appears early and plays a highly significant role in such fundamental matters as the finding of food, the choice of mates, the care of the young, and escape from dangers. An earlier treatment (Wever, 1978b) was concerned with this...

  9. GLOSSARY
    (pp. 473-476)
  10. REFERENCES
    (pp. 477-484)
  11. INDEX
    (pp. 485-488)