Survival of the fittest
The process of evolution through natural selection or global events (i.e. ice ages, volcanic eruptions, asteroid strikes, and human driven extinctions) has claimed the fates of many species and species groups over the millennia. Sharks, however, stand out as one of the few families to survive both cataclysmic events and the slower genetic process of natural selection. Sharks are one of evolutions most classic and enduring success stories. The earliest ancestors of modern sharks can be traced back about 425 million years, which is 200 million years before the earliest known dinosaurs! However, don’t confuse ancient with being primitive. Sharks have gone through the process of adaptation and evolutionary experimentation as well. The modern descendants of ancient sharks have incorporated many of the successful traits of the past. They have changed over time, but the changes have not been too extreme, only nature perfecting an originally near-perfect design.
Below is a list of a few of the characteristics that the great white shark was been equipped with by nature. Some of the traits are unique to sharks, others unique to specifically the great white shark.
– Their skin colour represents a type of camouflage called counter-shading. Great whites are dark grey on top and white on the bottom, which not only breaks up their outline in the water making them difficult to see, but they blend in with the darker sea-floor when viewed from above and the lighter surface when viewed from below.
– The upper jaw of sharks, including the great white, is not fused to the skull as it is with other vertebrates, but is held in place by flexible connective tissue. This allows the jaw to protrude outward from the head, extending its reach and bite radius!
– The great white is a highly visual hunter and it is believed they have acute colour vision
– Great whites have electroreceptors, which are sensory organs that allow them to detect hidden prey by means of sensing the minute electrical signals they give off.
– Great whites are unique among sharks in the sense that they are endothermic, which means they can regulate their blood temperature. Networks of arteries and veins on either side of the shark keep the blood warm allowing them to retain metabolic heat. This process allows them to conserve energy for hunting, allowing the sudden bursts of speed that propels them into the air when hunting seals (such spectacular breaching events can be witness with African Shark Eco-Charters on our trips in False Bay!!)
These adaptations, along with many others give these seemingly prehistoric predators an edge, especially when it comes to hunting cape fur seals. Sharks, and specifically great whites, are fascinating representations of a perfect predator and have been for millions of years.
Come witness these spectacular animals in action in their natural environment with Africa n Shark Eco Charters in False Bay!