Do Not Mess With Fish 14

and you thought fish were fun!

just when you thought you were safe from shark attack upstream in freshwater, well have I got news for you! Bull sharks can swim up to 4,000 kilometers in freshwater rivers,

500 lb+ Bull shark

while bull sharks are commonly found along coastlines, bays, and harbors, they also frequent a most uncommon shark habitat—freshwater rivers. The species has been spotted 2,500 miles (4,000 kilometers) up the Amazon River in South America and dwell in Lake Nicaragua, a freshwater lake in Central America. Bull sharks have traveled up the Mississippi River as far north as Illinois and are regularly spotted in India's Ganges. Their ability to tolerate freshwater is rooted in salt retention. Sharks must retain salt inside their bodies. Without it, their cells will rupture and cause bloating and death. Given this requirement, most sharks cannot enter fresh water, because their internal salt levels would become diluted. But bull sharks have special physiological adaptations that enable them to live in fresh water. Their kidneys recycle the salt within their bodies and special glands, located near their tails, also aid in salt retention.

Perhaps the most famous Bull shark attack in freshwater occurred in Mattawan Creek which is roughly twenty miles north of Spring Lake, nestled inside Raritan Bay, the creek being the runoff point. On July 12th 1916, a retired sea captain ran into Mattawan screaming that while crossing a bridge over the creek, he had seen a large shark swimming upstream towards town, and a few swimming spots for kids. Needless to say, his words were not taken too seriously, Mattawan being some ten miles from the open ocean. He was laughed out of town. A little after noon that day, a group of kids went to an abandoned steamer pier to go for a quick swim. Among them was 10 year old Lester Stilwell. The boys played in the creek on a regular basis, coming here after work at the local factory (In those days, it was not uncommon for a ten year old boy to work in a factory). As they continued to play around in the shallows, Lester was heard to say "hey guys, watch me float!". As soon as the words came out of his mouth, one of the boys felt a hard 'bump' from some large thing in the water, and looked down to see the shark move right towards Lester. In front of the horrified eyes of the boys, the shark grabbed Lester around the chest and dragged him under the water.

Mattawan Creek

The boys ran into town screaming of the shark attack and of the disappearance on Lester Stilwell. Soon, townsfolk were running down the country road to try and help out as best they could. Stanley Fisher, a local businessman, bravely swam out to the spot the boys had seen Lester go under. Stan made a number of dives to the bottom, searching the deeper parts of the creek. Arthur Van Buskirk, the local deputy, was in his boat, searching from the surface, when there was great thrashing and an ever-widening blood stain in the waters on the far shore of the creek. No sooner did he get to the spot, Stanley Fisher appeared in the middle of the commotion.The deputy helped him into the boat, and was horrified by what he saw. Stanley's left leg was missing all the flesh and muscle from the knee to the groin. On the shore, Stanley was able to state what happened. On the bottom of Mattawan creek, He had found Lester in the jaws of the shark, and attempted to wrestle his body from the beast. Stanley Fisher died from his wounds. Lester Stilwell was never found.

So there you have it, in the Ganges and even in Brisbane Australia you will find Bull sharks, the theory is that female Bull sharks go upstream to give birth at certain times of the year to coincide with local fish populations reproducing, which brings us on to the question, how does the female know when this is and also how does that impact on the time she mates with a male at sea?