Related Experiment Video
Updated: Jun 4, 2026

Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
Published on: May 7, 2016
Development of the osteocranium in Corydoras aeneus (Gill, 1858) Callichthyidae, Siluriformes
Frank Huysentruyt1, Tom Geerinckx, Marleen Brunain
1Evolutionary Morphology of Vertebrates, Department of Biology, Ghent University-UGent, K.L. Ledeganckstraat 35, 9000 Gent, Belgium. frank.huysentruyt@ugent.be
Abstract:
Development in the osteocranium of Corydoras aeneus was studied based on 48 cleared and stained specimens and 10 series of serial sections. Development overall follows the general trends observed in siluriform development, with ossifications appearing as a response to functional demands. Early development of the skull occurs in two distinct phases. In a first phase, several new bony elements, all of dermal origin and related to feeding, appear shortly after yolk depletion (4.4 mm SL). Between 5 and 8 mm SL, developmental priorities seem to shift to size increase of the cartilaginous skull and no new bony elements appear. Finally, a second phase of osteogenesis occurs from 8 to 18 mm SL, in which all remaining dermal and perichondral bones appear.
More Related Videos
Related Concept Videos
Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
Osmoregulation in Fishes
Overview of the Skull
The cranial vault surrounds and protects the brain and houses the middle and inner ear structures. This cavity is bounded superiorly by the rounded top of the skull, which...
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...

