Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton

Area of Science:

• Evolutionary biology
• Developmental biology
• Comparative anatomy

Background:

• The branchial skeleton in fish is crucial for food processing and its morphology is adapted to specific diets.
• Threespine sticklebacks (Gasterosteus aculeatus) are a model organism for studying evolutionary adaptations, particularly craniofacial changes in freshwater populations.
• Freshwater colonization by marine sticklebacks has led to repeated evolution of craniofacial traits, including changes to the branchial skeleton.

Purpose of the Study:

• To describe a detailed and efficient protocol for dissecting and flat-mounting the internal branchial skeleton of threespine stickleback fish.
• To enable easy visualization and quantification of branchial skeleton morphology for evolutionary and genetic studies.

Main Methods:

• A protocol for dissecting the three-dimensional branchial skeleton and mounting it flat into a two-dimensional preparation.
• The method is described as inexpensive, fast, relatively easy, and applicable to various fish species.

Main Results:

• The described method allows for straightforward visualization and quantification of branchial skeleton morphology.
• This technique facilitates the study of skeletal variations in genetic crosses to map genes controlling craniofacial development.

Conclusions:

• The developed dissection and mounting protocol provides an efficient tool for studying branchial skeleton morphology in threespine sticklebacks.
• This method supports research into the genetic architecture underlying adaptive craniofacial evolution in response to dietary changes.