Image: Fish Dissection - Cutting operculum
The students of St Vincent's College also examined the gills of the Blue Mackerel. Here, the right gill cover (operculum) is being removed to expose the underlying gills.
The Blue Mackerel shares the usual bony fish character of having a single opening behind each operculum (the branchial aperture). Water passes in through the mouth, over the gills and out through the branchial aperture. In contrast, the sharks and rays have five to seven branchial apertures on each side of the head.
- Stuart Humphreys
- © Australian Museum