The scales of primitive living actinopterygians

Kerr, T. W.

doi:10.1111/j.1469-7998.1952.tb06313.x

Cited by 59 publications

(68 citation statements)

References 5 publications

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“…The existence of such a dermal space was the main reason to suppose that the epithelial layer, which deposits ganoine matrix, was of dermal origin (e.g., Nickerson, 1893;Kerr, 1952;Thomson and McCune, 1984).…”

Section: In Lepisosteus Scales Ganoine Is Enamelmentioning

confidence: 98%

Light and TEM study of nonregenerated and experimentally regenerated scales of Lepisosteus oculatus (holostei) with particular attention to ganoine formation

Sire

1994

Anat. Rec.

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Section: In Lepisosteus Scales Ganoine Is Enamelmentioning

confidence: 98%

Light and TEM study of nonregenerated and experimentally regenerated scales of Lepisosteus oculatus (holostei) with particular attention to ganoine formation

Sire

1994

Anat. Rec.

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“…Two fiber systems cause the coherence of the scale-jacket in polypterids as well as lepisosteids. One system (the Sharpey's fibers of Kerr [1952] and Schultze [1977]) interconnects scales of a single scale row, i.e., its short fibers run from the dorsal margin of a scale to the ventral margin of the adjacent scale. Attachment of these fibers is confined to a narrow strip on the dorsal and ventral margin of the scales and between the peg and socket (Fig.…”

Section: Architecture Of the Stratum Compactummentioning

confidence: 99%

“…Kerr (1952) described some aspects of the microscopic anatomy of the interconnection between individual ganoid scales and the stratum compactum in polypterids and lepisosteids. Functional studies of the ganoid squamation have addressed several issues.…”

mentioning

confidence: 99%

Architecture of the integument in lower teleostomes: Functional morphology and evolutionary implications

Gemballa

Bärtsch

2002

Journal of Morphology

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A bony ganoid squamation is the plesiomorphic type in actinopterygians. During evolution, it was replaced by weak and more flexible elasmoid scales. We provide a comparative description of the integument of "ganoid" fishes and "nonganoid" fishes that considers all dermal components of mechanical significance (stratum compactum, morphology of ganoid scales, and their regional differences) in order to develop a functional understanding of the ganoid integument as a whole. Data were obtained for the extant "ganoid" fishes (Polypteridae and Lepisosteidae) and for closely related "lower" actinopterygians (Acipenser ruthenus, Amia calva) and "lower" sarcopterygians (Latimeria chalumnae, Neoceratodus forsteri). Body curvatures during steady undulatory locomotion, sharp turns, prey-strikes, and fast starts in "ganoid" fishes were measured from videotapes. Extreme body curvatures as measured in anesthetized specimens are never reached during steady swimming, but are sometimes closely approached in certain situations (sharp turns, prey-strike). During extreme body curvatures we measured high values of lateral strain on the convex and on the concave side of the body. Scale overlap changes considerably (66-127% in Lepisosteus, 42-140% in Polypterus). The ganoid squamation forms a protective coat, but at the same time it permits extreme body curvatures. This is reflected in characteristic morphological features of the ganoid scales, such as an anterior process, concave anterior margin, and peg-and-socket articulation. These characters are most pronounced in the anterior body region, where maximum changes in scale overlap are required. The anterior processes and anterior concave margin, together with the attached stratum compactum, guide movements in a horizontal plane during bending. Displacements of scales relative to each other are possible for scales of different scale rows, but are impeded in scales of the same scale row due to the peg-and-socket articulation. Furthermore, ganoid scale rows, fibers of collagen layers of the stratum compactum, and the lateral myoseptal structures follow the same oblique orientation, which is needed to achieve extreme body curvatures. There is no evidence that body curvatures are limited by the ganoid squamation in Polypterus or Lepisosteus to any larger extent than by a type of integument devoid of ganoid scales in teleostomes of similar body shape. Our results essentially contradict former functional interpretations: 1) Ganoid scales do not especially limit body curvature during steady undulatory locomotion; 2) They do not act as torsion-resisting devices, but may be able to damp torsion together with the stratum compactum and internal body pressure.

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“…Such scales, called ganoid scales (Goodrich, 1907), are still present in two families of living Actinopterygii, the Polypteridae (Hertwig, 1879;Sewertzoff, 1932;Kerr, 1952;Meunier, 1980) and the Lepisosteidae (Hertwig, 1879;Nickerson, 1893;Meunier et al, 1978;Thomson and McCune, 1984).…”

Section: Introductionmentioning

confidence: 96%

On the origin of ganoine: Histological and ultrastructural data on the experimental regeneration of the scales of Calamolchthys calabaricus (osteichthyes, brachyopterygii, polypteridae)

Géraudie

et al. 1987

Am. J. Anat.

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In order to understand the process of ganoine formation on the ganoid scales, scale regeneration has been studied to overcome the lack of a growth series of scale ontogeny. Seven stages of ganoid scale regeneration have been defined over a period of five months in the polypterid fish Calamoichthys calabaricus. The study has been carried out using transmission electron microscopic techniques. After wound healing and differentiation of the osseous basal plate, a layer of vascular dentin is deposited at the upper surface of the basal plate owing to the presence there of odontoblasts closely applied to the dentin. When these cells move away, a close contact is then established between the stratified epidermis and the regenerating scale. Numerous alterations of the epidermal-dermal boundary occur until its disappearance and a thick layer of pre-ganoine is formed. This layer is progressively mineralized; and finally an organic intermediate layer differentiates between the ganoine, which is a hyper-mineralized tissue, and the overlying epidermis. This ultrastructural study demonstrates rather unequivocally the involvement of the inner epidermal layer (IEL) in the appearance and growth of the ganoine. It is suggested that these epidermal cells can be compared functionally to the inner dental epithelium (IDE) described during mammal tooth morphogenesis. Consequently, our results allow us to propose that ganoine can be identified as true enamel, although additional data are necessary to analyze the proteinaceous component or its organic matrix.

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The scales of primitive living actinopterygians

Cited by 59 publications

References 5 publications

Light and TEM study of nonregenerated and experimentally regenerated scales of Lepisosteus oculatus (holostei) with particular attention to ganoine formation

Light and TEM study of nonregenerated and experimentally regenerated scales of Lepisosteus oculatus (holostei) with particular attention to ganoine formation

Architecture of the integument in lower teleostomes: Functional morphology and evolutionary implications

On the origin of ganoine: Histological and ultrastructural data on the experimental regeneration of the scales of Calamolchthys calabaricus (osteichthyes, brachyopterygii, polypteridae)

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