Whale sharks (Rhincodon typus) are often thought to be solitary behemoths that live and feed in the open ocean. Scientists at the Smithsonian Institution and colleagues, however, have found that this is not necessarily the case, finding that whale sharks can be gregarious and amass in the hundreds to feed in coastal waters.
Aggregations, or schools, of whale sharks have been witnessed in the past, ranging from several individual sharks to a few dozen. However this new research, which involved both surface and aerial surveys, has revealed an enormous aggregation of whale sharksthe largest ever reportedwith up to 420 individuals off the coast of the Yucatn Peninsula in Mexico. What brings them together is food.
"Whale sharks are the largest species of fish in the world, yet they mostly feed on the smallest organisms in the ocean, such as zooplankton," said Mike Maslanka, biologist at the Smithsonian Conservation Biology Institute and head of the Department of Nutrition Sciences. "Our research revealed that in this case, the hundreds of whale sharks had gathered to feed on dense patches of fish eggs."
While whale sharks may seem conspicuous as the heaviest and longest of all fishes, growing more than 40 feet long, there is still much that is unknown about them. They have a very widespread distribution, occurring in all tropical and sub-tropical regions of the ocean around the world. Understanding this filter-feeder's diet is especially important since food sources determine much of the whale shark's movement and location.
During the dozens of surface trips that team members made to the aggregation, called the "Afuera" aggregation, they used fine nets to collect food samples inside and immediately outside the school of feeding whale sharks. Scientists then used DNA barcoding analysis to examine the collected fish eggs and determine the species. They found that the eggs were from little tunny (Euthynnus alletteratus'/>"/>
| Contact: John Gibbons gibbonsjp@si.edu 202-633-5187 Smithsonian Source:Eurekalert |
Related biology news :
1. Jefferson scientists deliver toxic genes to effectively kill pancreatic cancer cells
2. Scientists identify novel inhibitor of human microRNA
3. Argonne scientists peer into heart of compound that may detect chemical, biological weapons
4. MU scientists go green with gold, distribute environmentally friendly nanoparticles
5. Scientists identify gene that may contribute to improved rice yield
6. Scientists discover why a mothers high-fat diet contributes to obesity in her children
7. MU scientists see how HIV matures into an infection
8. Earth scientists keep an eye on Texas
9. Thinking it through: Scientists call for policy to guide biofuels industry toward sustainability
10. Scientists identify a molecule that coordinates the movement of cells
11. Scientists Find new migratory patterns for Mediterranean and Western Atlantic bluefin tuna
 |
| Copyright © 2003-2012 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |