Episode 269 – Bull Shark: Huck Fin

“…and today we’re talking about the sea bull to the manatee’s sea cow, but much more scary. But more on later.”

If Huck Finn knew what might have been lurking in the waters of the ol Missisip, he may have thought twice about rafting down it for as long as he did. The bull shark has the uncanny ability to travel very far from home to menace the fair river folk. In fact, finding a full-grown shark in your local freshwater fishin spot is so alarming, people have taken to naming it after wherever they happened to find it. But how can this deadly predator leave the comforting salt of the sea? Like a master chef, it’s all about managing your salt levels here in Life, Death, and Taxonomy.

Description of the Bull Shark

  • The bull shark is a typical shark form, with some distinctives. 
  • They are shaped like a football and less like a torpedo, making them look stocky.
  • They have long and broad pectoral and dorsal fins.
  • Bull sharks have gray backs and cream colored bellies. Countershading. 

Measure Up

Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We don’t have a new Measure Up intro!


  • Bull sharks are around 7 feet long. Females can reach as long as 13 feet.
  • Formula one driver Romain Grosjean clipped an opponent and crashed into metal guardrails at the Bahrain Grand Prix in 2020, slicing the car in half and immediately setting the front half of the vehicle on fire. How many sharks per hour was Grosjean going when he struck the barrier?
  • Hint: Grosjean was in the flaming vehicle for 28 seconds, and onlookers were basically accepting that he was not going to make it out. But, like a phoenix, he climbed out of the car after slipping out of his trapped boot. He miraculously escaped with burns on his hands and a minor ankle or foot injury.
  • 89,760 sharks per hour. He hit the barrier at 119 mph (73.9 kmph)


  • 130 kg (290 lb)
  • How many bull sharks go into the largest bulldozer ever made?
  • Hint: The Acco Super Bulldozer was made by the Umberto Acco company in Italy. It has a 23 foot (7 m) wide blade.
  • 1,391 bull sharks. The dozer is 183 tonnes (403,446 pounds).

Fast Facts about the Bull Shark

The attacks that inspired Jaws were more likely to have been perpetuated by a bull shark than a Great White.

They are generalists and they can eat fish, crustaceans, sea birds, and anything else that they can get their jaws around. 

Bull sharks give birth to live young and gestation takes 13 months. They can live up to 30 years old.

Major Fact – He’s climbin in yo rivers, he snatchin yo fishies up tryna chomp em so y’all better hide yo trout, hide yo bass, and hide yo sturgeon cause they chompin everybody out here.

  • The bull shark takes the bronze in therms of most recorded attacks
  • 117 recorded attacks – 25 fatalities
    • Tiger – 138 attacks: 36 fatalities
    • Great White – 333 attacks: 52 fatalities
  • Third most dangerous shark and it lives in your backyard
  • Bull sharks have been found as far north as Alton, Illinois, a small city 700 miles up the mighty Mississip!
  • The Bull shark is diadromous, which means it has no issue swimming in either salt water, fresh water, or everything in between – like a salmon filled with teeth and testosterone
  • Most cartilaginous fish (namely sharks, skates, and rays) can’t live in freshwater
    • This is because a fish’s blood typically needs to be as salty as the water around it. 
    • Sharks and othe cartiliginous fish have glands that secrete urea and other chemicals that keep the salt content up if they ever find themselves in fresh water, so they can survive but not for long
    • The glands in bull sharks are able to turn off when in a freshwater environment. They can even recycle salt in the bloodstream and make slight adjustments based on the salinity in the water. 
    • The older the shark, the higher its tolerance for extremes in salinity. Young sharks are actually born in fresh and brackish estuaries so that other sharks that might eat their young can’t get to them. The can tolerate higher salt levels as they get older.
    • This can allow it to live in fresh water forever if it weren’t for the fact that bull sharks mate in the ocean.
    • Also, they did some studies on bull sharks in fresh water and found that they didn’t make it more than four years. They figured it might be starvation since there is a lot more food in the ocean.
  • The reality is that bull sharks spend most of their time growing up in their brackish estuaries before heading out to sea to mate. 
  • Most recorded attacks actually don’t take place in fresh water but rather near the shore 

Ending: So hang out in rivers, practice your osmoregulation, and don’t let anyone tell you where you can and can’t kill things like the bull shark here in LDT.