While the two fish are superficially very similar, they have differences in terms of diet, defense mechanisms, and anatomy. What are the key differences between an orca and a hagfish? The greatest differences between an orca and a hagfish can be found in their size and morphology. The hag...
The gill is widely accepted to have played a key role in the adaptive radiation of early vertebrates by supplanting the skin as the dominant site of gas exchange. However, in the most basal extant craniates, the hagfishes, gills play only a minor role in