The stickleback has very well developed bone tissue. Bones perform an important protective function in this species. At the same time, they are a convenient structure for studying morphological variability, since they do not change their shape depending on external conditions, as soft tissues do. This is especially important in the case when a high measurement accuracy is required, as, for example, in the case of studying fluctuating asymmetry – small deviations from complete bilateral symmetry.
These scans show several bilaterally symmetric stickleback bones, for which we used a 2% alkali solution – sodium hydroxide. It dissolves soft tissue while leaving bone tissue. This allows you to obtain very clean preparations, which clearly show the structure of the bones. Here are four versions of the same picture processed with different Adobe Photoshop filters. The names of the bones (top to bottom, then from the inside to the outside) are: Coracoideum, Hyomandibulare, Cleithrum, Praeoperclum, Pelvic gridle, Operculum.