Scientists stumble upon a 12-foot long male tiger shark | Sharks of the Bermuda Triangle
This one looks good. Oh boy! Then, after nearly an hour swimming like a tiger, it's a tiger! There's a bite—got a beautiful tiger shark! Oh my God! Dr. Austin Gallagher caught a tiger shark in the Bermuda Triangle, but it's not Mabel; it's a 12-foot long sexually mature male.
“Hold it! Don’t let it run! Don’t let it run!”
“Not let it run, guys! This is a really strong shark.”
Okay, finding a male tiger shark may mean one thing: it's mating season. It's rare that you see a large male shark of any species in an area where there's a lot of females. When we saw him, it only supported our theory that they might be mating here in the Bahamas. Female tiger sharks seem to prefer the company of their own gender.
Some scientists speculate that as a group, it's easier for female tiger sharks to fend off unwanted sexual advances from males.
“Is this good?”
“Yeah, that's fine. Tie it off and then come in, Mom, and like hold...”
When you look at the distribution of sharks, we have what's called sexual segregation, which means that you find males and females in different areas. One popular explanation is that females are avoiding males outside of these mating periods. So, it makes sense that if she doesn't want to reproduce at that point, that she avoids that sort of mating behavior altogether.
That may explain why you see females in separate areas from where you find the males. With pregnancies that last up to 16 months, the female tiger sharks only mate once every three years. When females are ready to mate, it's believed that they let the male tiger sharks know by releasing pheromones.
If so, this male has likely caught a scent and is on the search for a receptive female.
“That shark is definitely one of the breeding males. There's few of them. Here we go, boys!”
“Ah, yeah, all right!”
Dr. Gallagher attaches a satellite tag to the shark's dorsal fin.
“Nice! Satellite tags are awesome! One of my favorite tools! These offer scientists like us the chance to collect high-resolution data on the sharks without us having to follow them. The tag remains attached to the shark, recording vital information including location, depth, and water temperatures. After several weeks, the tag will pop off, float to the surface, and transmit all the data to a satellite.”
“Being able to get a male with tag on it that will actually reveal its depth preferences and locations could actually help us pinpoint exactly where these animals are going too. So, that's really valuable for our larger questions here about mating, vertical habitat use, and interactions between males and females. So getting a male is actually huge for us.”
“Tags in, fin clip!”
“Hey, I'm taking a little think up here—a fin clip! Study the genetic diversity of these tiger sharks in the Bermuda Triangle.”
Dr. Gallagher clips the dorsal fin for blood and tissue samples.
“These are going to provide invaluable insights into the genetics, hormones, and stress levels of these animals. Oh, he's ready to go! These are pieces of the puzzle that we're going to put together to understand how valuable the Bermuda Triangle is for sharks. Nicely done, guys! Wow, that's a huge shark!”