“Meet the Locals” is a 3-part blog series in honor of our local elasmobranchs (sharks and rays) and Shark Summer 2014. This is the second post. Part 1: Sevengill sharks
With Shark Summer in full swing, by now we are all pretty familiar with our local leopard sharks, which aggregate in the warm shallow waters of La Jolla Shores each summer. Did you know that one of the leopard shark’s closest relatives is also a local? The soupfin shark (Galeorhinus galeus) is a member of the family Triakidae, which includes the leopard shark and the smooth hound shark. Soupfin sharks are similar in size and shape to the leopard shark, topping out at just over six feet long. However, soupfin sharks have a dark gray back, lacking the distinctive saddle patches that the leopard sharks have. Soupfin sharks frequent both shallow inshore waters and pelagic habitats, and they feed on a variety of prey, including fish and invertebrates such as lobster, crabs, octopus, and worms. An interesting study found that soupfin sharks separate themselves by gender- and not just by a few miles. Most of the soupfin sharks in Southern California are females, while the males range from British Columbia to Northern California. Their range overlaps in Central California, where the male to female ratio is about equal.
Wondering how this shark received its unique name? The soupfin shark was heavily fished in the 1930s and 1940s in California, as its fins were used to make traditional sharkfin soups. The soupfin shark was also known as the vitamin shark because the oil in its liver was so rich in vitamin A that it was used to make Vitamin A supplements. The heavy fishing pressures placed on this species took a toll on its population size.
However, this story has a happy ending. Synthetic Vitamin A was developed in the late 1940s, eliminating the need to harvest it from the soupfin shark’s liver oil. And more recently, California has become a safer place for sharks due to a 2011 law that banned the sale or possession of any shark-fin products throughout the state.
Sharks are amazing, vital, and often misunderstood animals. By participating in Birch Aquarium’s Shark Summer activities, you can take an active role in learning more about all of our local sharks in order to advocate for and protect them.
Shark Summer 2014 at Birch Aquarium is sponsored by ESET. http://www.eset.com/us/protection/goexplore-birch/