So I asked leading shark ethologist and behaviourist, Professor Samuel 'doc' Gruber to elaborate. After pointing out how much pain women feel when they give birth, making the point that suffering has no effect on reproduction, he reminded me that sharks evolved their mating behaviours and the physical structures involved, separately from other animals.
Research has revealed that bull sharks bite with almost 6,000N, a force that is greater than what is required to kill and eat prey. In a study published in the journal Zoology, Maria Habegger from Tampa’s University of South Florida, along with colleagues in the US and Germany, examined bite forces produced by 13 shark species and their close relatives, ranging from 1m-long ratfish to the great white shark.
The PhD study bt Dr. Susan Theiss showed that the wobbegong visual system contains only a single class of cone photoreceptor. Cone photoreceptors are the retinal cells that are used for vision under bright light conditions, whereas as rod photoreceptors are used in dim light.
These previous studies looked at opsins, which are light-sensitive proteins found in the photoreceptor cells of the retina. Rod opsins are used in low light and produce a black and white image, while cone opsins are used in bright light, and often to see colours.
One of the dreams of any naturalist is to be the first to find and detail the life of a hidden or unknown animal first hand. Since 2003, scientific divers with the Greenland Shark and Elasmobranch Education and Research Group (GEERG) have begun to unravel the mysterious life of the Greenland shark, which at over seven meters in maximum body length and exceeding a ton in weight, is the second largest carnivorous shark after the great white.
To gain a better understanding of how sharks manage to keep their teeth in such pristine condition, a team of German researchers looked at two species that eat in very different ways
The researchers looked at Isurus oxyrinchus and Galeocerdo cuvier (mako and tiger sharks) and found, as they explain in their paper published in the Journal of Structural Biology, after very close examination, that the outer coating of the shark teeth contained one hundred percent fluoride.
Scientists identified two distinct populations of white shark at the east and west of Bass Strait in Australian waters, prompting researchers to suggest the huge fish may need a regional conservation plan.
The study examined tissue samples from 97 sharks collected around Australia since 1989 which were caught in beach safety programs, as fishery bycatch and during Commonwealth Scientific and Industrial Research Organisation (CSIRO) field research. Its findings are broadly consistent with satellite and acoustic tracking research led by CSIRO’s Barry Bruce.
Announcements in June, 2006 reported the discovery of a possible new species of hammerhead off the US eastern seaboard.
Nearly seven years ago, scientists from Nova Southeastern University Oceanographic Center sampling sharks caught on charter boats off Fort Lauderdale and South Carolina stumbled on a startling discovery: some of the sharks that looked like scalloped hammerheads were actually a different, unidentified species.
Maybe the concept of ‘responsible shark diving’ sounds a little oxymoronic, but there are many things that you can do to protect yourself and the sharks during your interaction. First and foremost, I can’t stress enough the need to gain as much knowledge as possible about the animals and their environment. To go into the water without at least a basic idea of how the sharks are likely to react is foolhardy to say the least.
Just their name, their size, and their menacing looks can evoke feelings of terror, fear and instinctive rejection. However, if you have the privilege to be able to dive with big tiger sharks, as I have, you might fall in love with them, at least you will bond with them in a mysterious way.
Have you always wanted to dive with sharks? Hug a dolphin? Explore shipwrecks, caves and colorful coral reefs? What if you wanted to have all of these adventures wrapped into one destination? Then, it is time to visit the Caribbean island of Grand Bahama.
Valerie Taylor, along with her husband Ron, are two of the true pioneers of underwater photo and video, since their debut in the 1960s.
