What sawfish really do with their saw
“Northern Australia is considered to be the last stronghold in the world for four species of sawfish,” says Barbara Wueringer who works at the universities of Queensland and Western Australia and with Cairns Marine (an aquarium fish collecting company). “But if we do not understand these animals, we will not be able to save them.”
Sawfish are beautiful and mystic ancient predators, Barbara says. They are regularly taken as by-catch in fisheries, and their fins and saws are traded as highly priced medicines, curios and culinary delicacies. The saws are packed with sensors known as ampullary pores which can detect electric fields, the distribution of which is influenced by how the sawfish captures its prey.
Barbara compared the distribution of ampullary pores in four species of sawfish, which all inhabit remote ecosystems in northern Australia. She found that sawfish have much more concentrated collections of pores on the upper side of the saw than their relatives the shovel-nosed rays. This indicates that they use their saw to detect prey in the three-dimensional space above the saw.
So one of the properties of seawater is that it could propagate an electric field. Sawfish use this property of seawater to hunt for prey. If form follows function then the "saw"fish should be renamed into "antenna"fish
BTW, it seems that different sharc species next to scent sensors also hunt on their prey by use of electromagnetic sensors.
Allynh, the "How Water Shapes DNA" observation is I think closely related to studies of the now controversial noble price winner Luc Montagnier:
- Electromagnetic signals are produced by aqueous nanostructures derived from bacterial DNA
- DNA between Physics and Biology - DNA waves and water
http://montagnier.net/montagnier/index. ... lications/
Bacteria on the Radio: DNA Could Act as Antenna
http://www.wired.com/wiredscience/2011/ ... ial-radio/
The claims were embraced by homeopaths, and Montagnier himself became involved in a dubiously designed clinical trial of autistic children. Eventually he left France to head a research institute at Jiaotong University in Shanghai, telling Science that he sought to escape the constrictions of intellectually fearful European scientists. “It’s not pseudoscience. It’s not quackery. These are real phenomena which deserve further study,” he said.