Some of us know all about our own family tree. Some of us have a very extensive one and so does the tuna. There are many branches on the tuna family tree. There are cousins aplenty.  We can start with a general overview where we find a class of fish known as scrombridea in which there are 55 species each known as a scrombrid. The tuna is a scrombrid. But then so too is a mackerel, a pilchard, a sardine, a herring, a salmon and about 50 other fish.  A scrombrid has certain common characteristics throughout their 55 species. These common characteristics include

• Streamlined bodies packed with muscle
• Retractable fins which reduce drag
• Two dorsal fins
• A powerful and rigid caudal fin and
• Extensive tiny fins called finlets