The scales of modern lungfish.

Kerr, T. W.

doi:10.1111/j.1096-3642.1955.tb00603.x

Cited by 20 publications

(27 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cosmine nodules may also be found buried by subsequent growth of additional elements (Denison, 1968). It is not present in the scales and epidermis of living lungfish (Kemp, 2012b;Kerr, 1955;Zylberberg, 1988). Cosmine is located between the pore canals and flask organs where the tubules terminate in fossils.…”

Section: Discussionmentioning

confidence: 95%

Skin structure in the snout of the Australian lungfish, Neoceratodus forsteri (Osteichthyes: Dipnoi)

Kemp¹

2014

Tissue and Cell

View full text Add to dashboard Cite

Many fossil lungfish have a system of mineralised tubules in the dermis of the snout, branching extensively and radiating towards the epidermis. The tubules anastomose in the superficial layer of the dermis, forming a plexus consisting of two layers of vessels, with branches that expand into pore canals and flask organs, flanked by cosmine nodules where these are present. Traces of this system are found in the Australian lungfish, Neoceratodus forsteri, consisting of branching tubules in the dermis, a double plexus below the epidermis and dermal papillae entering the epidermis without reaching the surface. In N. forsteri, the tubules, the plexus and the dermal papillae consist of thick, unmineralised connective tissue, enclosing fine blood vessels packed with lymphocytes. Tissues in the epidermis and the dermis of N. forsteri are not associated with deposits of calcium, which is below detectable limits in the skin of the snout at all stages of the life cycle. Canals of the sensory line system, with mechanoreceptors, are separate from the tubules, the plexus and the dermal papillae, as are the electroreceptors in the epidermis. The system of tubules, plexus, dermal papillae and lymphatic capillaries may function to protect the tissues of the snout from infection.

show abstract

Section: Discussionmentioning

confidence: 95%

Skin structure in the snout of the Australian lungfish, Neoceratodus forsteri (Osteichthyes: Dipnoi)

Kemp¹

2014

Tissue and Cell

View full text Add to dashboard Cite

show abstract

“…Lungfish have, in common with some other vertebrates, large elasmoid scales containing squamulae and elasmodin (Bertin,1944; Kerr,1955; Brien,1962; Zylberberg et al,1980; Meunier,1983,1984; Zylberberg,1988; Sirè,1989a; Schultze,1996; Meunier and Zylberberg,1999). Lungfish scales have been preserved in the fossil record since the group first appeared in the Devonian (Denison,1968), and there has been a progressive simplification in structure since that time (Chapman,1912; Forster‐Cooper,1937; Kerr,1955; Zylberberg,1988; Pridmore and Barwick,1993; Schultze and Chorn,1996). In the living Australian lungfish, Neoceratodus forsteri , scales have a base of elasmodin, made up of layers of collagen fibre bundles, surmounted by a loose fibrous connective tissue and by mineralised squamulae (Kerr,1955).…”

Section: Introductionmentioning

confidence: 99%

“…Lungfish scales have been preserved in the fossil record since the group first appeared in the Devonian (Denison,1968), and there has been a progressive simplification in structure since that time (Chapman,1912; Forster‐Cooper,1937; Kerr,1955; Zylberberg,1988; Pridmore and Barwick,1993; Schultze and Chorn,1996). In the living Australian lungfish, Neoceratodus forsteri , scales have a base of elasmodin, made up of layers of collagen fibre bundles, surmounted by a loose fibrous connective tissue and by mineralised squamulae (Kerr,1955). Unlike the condition of scales in cladistians (Sirè et al, 1987; Sirè, 1994; Zylberberg et al,1997) and certain teleost fish (Sirè et al,1997), there is no external layer of ganoin (enamel), and apparently no epithelial contribution to the cells that secrete and maintain the scale (Kerr,1955).…”

Section: Introductionmentioning

confidence: 99%

“…In the living Australian lungfish, Neoceratodus forsteri , scales have a base of elasmodin, made up of layers of collagen fibre bundles, surmounted by a loose fibrous connective tissue and by mineralised squamulae (Kerr,1955). Unlike the condition of scales in cladistians (Sirè et al, 1987; Sirè, 1994; Zylberberg et al,1997) and certain teleost fish (Sirè et al,1997), there is no external layer of ganoin (enamel), and apparently no epithelial contribution to the cells that secrete and maintain the scale (Kerr,1955). Cosmine (dentine), found in early fossil dipnoans (Forster‐Cooper,1937; Denison,1968; Pridmore and Barwick,1993) and present in the coelacanth (Meunier and Zylberberg,1999), is absent from the scales of living lungfish, as is enameloid, also found in early dipnoans and in the living coelacanth.…”

Section: Introductionmentioning

confidence: 99%

“…Structural details differ among scales of the three extant lungfish, N . forsteri in Australia, Lepidosiren paradoxa in South America, and Protopterus species in Africa (Kerr,1955; Brien,1962; Zylberberg,1988). All three have mineralised plates, or squamulae, on a basal layer of elasmodin, as do scales of osteoglossids such as Osteoglossum and Arapaima (Meunier,1984).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Formation and structure of scales in the Australian lungfish, neoceratodus forsteri (Osteichthyes: Dipnoi)

Kemp

2011

Journal of Morphology

View full text Add to dashboard Cite

The large elasmoid scales of the Australian lungfish, Neoceratodus forsteri, are formed within the dermis by unpigmented scleroblasts, growing within a collagenous dermal pocket below a thick glandular epidermis. The first row of scales, on the trunk of the juvenile lungfish, appears below the lateral line of the trunk, single in this species, at around stage 53. The scales, initially circular in outline, develop anteriorly and posteriorly from the point of initiation in the mid-trunk region, and rows are added alternately below the line, and above the line, until they reach the dorsal or ventral midline, or the margins of the fins. Scales develop later on the ventral surface of the head, from a separate centre of initiation. Scales consist of three layers, all produced by scleroblasts of dermal origin. The outermost layer of interlocking plates, or squamulae, consists of a mineralised matrix of fine collagen fibrils, covered by unmineralised collagen and a single layer of cells. Squamulae of the anterior and lateral surfaces are ornamented with short spines, and the mineralised tissue of the posterior surface is linked to the pouch by collagen fibrils. The innermost layer, known as elasmodin, consists of bundles of thick collagen fibrils and cells arranged in layers. An intermediate layer, made up of collagen fibrils, links the outer and inner layers. The elasmoid scales of N. forsteri can be compared with scale types among other osteichthyan groups, although the cellsand canaliculi in the mineralised squamulae bear little resemblance to typical bone.

show abstract

Structure of the dermal scales in gymnophiona (Amphibia)

Zylberberg

Castanet

Ricqlès

1980

Journal of Morphology

View full text Add to dashboard Cite

Histology and cytology of dermal scales of the gymnophionans Ichthyophis kohtaoensis and Hypogeophis rostratus reveal their structure and the nature of their mineralization. Dermal scales are small flat disks set in pockets in the transverse ridges of the skin. Each pocket contains several scales of various sizes. A ring of "hypomineralization" of varying diameter may occur on scales of a particular dermal pocket but bears no relation to the diameter of these scales. Three different layers form the scales and are seen on sections perpendicular to the surface. The cells of the basal layer lie deepest. Each of the two or three more superficial fibrous layers is composed of bundles of fibres that are oriented in parallel. The orientation varies among layers. The striation of the fiber scales has a periodicity comparable to that of the surrounding dermal fibers. Squamulae form a discontinuous layer on the scale surface and are the only mineralized part of the scale. The minerals are deposited both on the collagen fibers passing from the fibrous layers into the squamulae, and in the interfibrillar spaces. Spherical concretions, either isolated or coalescent, reaching up to 1 μm, are found on the surface of the squamulae. The dermal scales of Gymnophiona present some analogies with those of evolved bony fishes. Their characteristics could make them an original model for the study of mineralization.

show abstract

The scales of modern lungfish.

Cited by 20 publications

References 11 publications

Skin structure in the snout of the Australian lungfish, Neoceratodus forsteri (Osteichthyes: Dipnoi)

Skin structure in the snout of the Australian lungfish, Neoceratodus forsteri (Osteichthyes: Dipnoi)

Formation and structure of scales in the Australian lungfish, neoceratodus forsteri (Osteichthyes: Dipnoi)

Structure of the dermal scales in gymnophiona (Amphibia)

Contact Info

Product

Resources

About