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.
Giant basking sharks like to take tropical vacations too.
Previously thought to inhabit only temperate waters, a new study, just published in Current Biology, shows that the giant sharks make long, make vast migrations to deep, warm-water hideouts. Before the annual winter disappearance, scientists tagged 25 basking sharks off New England with floating, timed-release satellite transmitters, which showed that, like humans, the giant basking sharks like to take tropical vacations too.
Dr Jonathan Cox from the University’s Department of Chemistry has been working with researchers from the University of Cambridge and the Natural History Museum in London, testing a scale model of a hammerhead shark in a flow tank to see how the water flows around the nasal cavity of its strange flattened head.
Weighing in at up to 3,000 pounds and attaining lengths of 18 feet, Great White sharks are among the ocean’s most feared yet revered inhabitants. Having a face-to-face encounter with the ocean’s apex predator is a bona-fide adrenaline rush, with divers worldwide shelling out mega bucks and travelling great distances for the privilege.
Boasting pristine blue water with 100-foot visibility, Guadalupe Island situated west of Baja California, Mexico, is one of the world’s premier Great White destinations.
A team of researchers led by Jason Blackburn of the University of Florida sampled and tested 134 fish living in coastal waters of the Gulf of Mexico, Belize, and Massachusetts for signs of drug-resistant bacteria, using a suite of twelve common antibiotics. Resistance was found everywhere they looked, to varying degrees. Pronounced resistance to an array of drugs was found in sharks in Dry Tortugas National Park in the Florida Keys, for example.
Hopes that shark cartilage would prove to be a useful treatment for cancer were not borne out in one of the most rigorously designed and executed studies of an alternative therapy ever conducted. Adding a drug derived from shark cartilage to standard cancer treatments did not improve survival among patients with late-stage lung cancer in the study.
While using the liver as an energy store and for buoyancy is well documented in adult sharks, this study provides the first evidence of a decline in liver mass of newborn sharks, from 20% of body weight at birth to 6% when they start to feed themselves.
Research by a Bangor University-led international team found that during the critical period after birth, shark pups lose weight by consuming their liver reserves. This weight loss is not necessarily an indicaton that the sharks are in a poor nutritional state, as has been previously thought.
A new 4-million-year-old fossil from Peru described in this month’s issue of the Journal of Vertebrate Paleontology provides important evidence suggesting the shark’s origins may be more humble than previously believed.
Dana Ehret, Gordon Hubbell and Bruce MacFadden studied an exceptionally well-preserved fossil of a species of white shark (Carcharodon sp.) from Peru (estimated to be about 5 m long by the authors), consisting of a complete jaw with 222 teeth, and 45 vertebrae, in their paper.
Researchers believe this quality could be harnessed to help slow the spread of diseases such as cancer.
Potentially, it could lead to a new generation of drug treatments.
The Australian team found that shark antibodies can withstand high temperatures as well as extremely acidic or alkaline conditions.
The minute scales, which are just 200 micrometres long, are made from tough enamel, such as that found on teeth, giving the skin a rough texture like sandpaper. Lying flat, they had previously been found to reduce drag as the shark swims. Some reports had also suggested that sharks can bristle their scales, causing them to stand up on end.
Experiments have now revealed that tiny vortices or whirlpools formed within the cavities between the scales.
