Formation and structure of scales in the Australian lungfish, neoceratodus forsteri (Osteichthyes: Dipnoi)
Article first published online: 21 DEC 2011
Copyright © 2011 Wiley Periodicals, Inc.
Journal of Morphology
Volume 273, Issue 5, pages 530–540, May 2012
How to Cite
Kemp, A. (2012), Formation and structure of scales in the Australian lungfish, neoceratodus forsteri (Osteichthyes: Dipnoi). J. Morphol., 273: 530–540. doi: 10.1002/jmor.11039
- Issue published online: 21 MAR 2012
- Article first published online: 21 DEC 2011
- Manuscript Accepted: 2 NOV 2011
- Manuscript Revised: 17 OCT 2011
- Manuscript Received: 5 JUL 2011
- Adelphi Australia Science Foundation
- lungfish scales;
The large elasmoid scales of the Australian lungfish, Neoceratodusforsteri, 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 littleresemblance to typical bone. J.Morphol., 2012. © 2011 Wiley Periodicals, Inc.