This week’s featured creature is the imposter in a case of mistaken marine identity! MSI instructors hear it all the time from students and teachers alike. When the moment comes to introduce our student groups to one of the more common species of shark in the bay, there is the inevitable call of, “Whoa it’s a tiger shark!” Au contraire, mon petit scientifique! MSI and the San Francisco Bay are home to LEOPARD sharks, not TIGER sharks! It’s your classic, big cat mix up! (so maybe that isn’t really a thing, but it’s a pretty common mix up at MSI!) Not only do tiger sharks not reside in the San Francisco bay but if they did, we sure wouldn’t have kids touch them! There are some other simple ways to distinguish tiger sharks from other species.
Visually, tiger sharks have vertical stripes and spots that seem to dissipate when maturing, similar to actual tigers. Tiger sharks like to live in sub-tropical and tropical waters. Unlike leopard sharks, which can only reach to about 6 feet in length, tiger sharks usually reach an average of 14 feet.
Let us dive in deeper (scuba pun!) to explore more about the 3rd most dangerous shark in the world, the tiger shark, also known as Galeocerdo cuvier. As you know, we don’t always like the connotations that the word “dangerous” can carry. They are not a shark that hunts for humans in particular, but there is no denying that this species has a very unique palate. Tiger sharks are known as the “garbage cans of the ocean” because they will pretty much eat anything (and I mean anything!) Dissections of deceased tiger sharks have unearthed rays, turtles, other fish, license plates, tires, fishing line and more in their stomachs. They are very curious sharks and will try a bite of anything that they can fit in their mouth. As powerful and inquisitive predators they are also not known to swim away after biting but will eat even when they are not hungry. It makes sense that they will eat whenever possible, since wild animals often have no guarantee that they will find their next meal. Tiger sharks are a solitary species and travel towards the surface of the water, heading inland to feed at night.
Like many shark species, these sharks are fished worldwide for their fins, skin, and liver (which is a hefty source of vitamin A). Considered “Near Threatened” by The World Conservation Union because the catch rate of the species have declined. While this may seem encouraging, the reason for the decreased catch rate is thought to be a decline in tiger shark populations over all.
Join us next week as we learn what the Number 2 most dangerous shark in the world is. Do you have a guess? Write it in the comments below.
Edited by KC O’Shea
Photography: Kevin Bryant and Willy Volk