Chondroid bone and secondary cartilage contribute to apical dentary growth in juvenile Atlantic salmon

The microstructure and tissue composition of the dentary bone in Atlantic salmon salmo salar parr were examined using a variety of histological and whole-mount techniques. Proximally, the dentary is composed of typical cellular lamellar bone with Sharpey's fibres extending dorsally, proximally...

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Bibliographic Details
Published in:Journal of Fish Biology
Main Authors: Gillis, J. A., Witten, Paul Eckhard, Hall, B. K.
Format: Article in Journal/Newspaper
Language:English
Published: 2006
Subjects:
Online Access:https://biblio.ugent.be/publication/8646032
http://hdl.handle.net/1854/LU-8646032
https://doi.org/10.1111/j.0022-1112.2006.00998.x
https://biblio.ugent.be/publication/8646032/file/8646033
Description
Summary:The microstructure and tissue composition of the dentary bone in Atlantic salmon salmo salar parr were examined using a variety of histological and whole-mount techniques. Proximally, the dentary is composed of typical cellular lamellar bone with Sharpey's fibres extending dorsally, proximally and ventrally. Meckel's cartilage is located medially through the entire length of the dentary, and degrades distally resulting in a short transitional zone between hyaline cartilage and connective tissue. At the distal tip of the dentary, isogenic clusters of chondrocytes of periosteal origin were observed secreting small amounts of pericellular cartilage matrix within the bone matrix. These characteristics are highly indicative of secondary chondrogenesis, and suggest that the apical part of the dentary bone in Atlantic salmon does not grow via'pure' intramembranous ossification, but rather via a modified mode of periosteal ossification involving secondary cartilage and chondroid bone. Furthermore, the unusual mode of gender-related dentary growth (kype formation) in adult male Atlantic salmon could be the continuation of a general mode of salmonid apical dentary growth.