Georgia Aquarium Conducts First Whale Shark Exams
Findings Show Increase in Size, Larger Blood Cells Than Other Shark, Skate or Ray Species
Atlanta (November 9, 2006) – The Georgia Aquarium, the world's largest aquarium, demonstrated its continued commitment to the understanding of aquatic animals today by conducting a routine physical exam on one of their four whale sharks, the largest fish in the world. These exams, the first of their kind, will help scientists to better understand a species of which little is known. Today's exam is a follow-up exam on Ralph, one of the two male whale sharks at the Aquarium. All four of the Georgia Aquarium's whale sharks, including Norton, Alice and Trixie, have been examined at least once as part of an effort to establish a baseline of normal biology in whale sharks.
"One of the most exciting discoveries was when we first looked under a microscope at whale shark blood, no one has ever done that before," said Ray Davis, Vice President, Zoological Operations. "In a normal field of view for a smaller shark, you would see 30-40 smaller red blood cells. For whale sharks, we saw 10 huge cells."
During the physical exam, Georgia Aquarium veterinarian Tonya Clauss drew blood as part of a complete physical analysis and to read Ralph's hormone levels as a measurement of sexual maturity. The Aquarium team and Dr. Bob Hueter, shark expert from Mote Marine Laboratory, believe Ralph and Norton may be entering sexual maturity.
Fifty husbandry and veterinary staff were involved in the exam, twenty of whom were in the water to help swim Ralph into a stretcher. The Georgia Aquarium team built the world's largest fish anesthesia machine to put the animal into a relaxed state in order to conduct the physical exam at the water's surface. The exam lasted two hours, after which time Ralph swam out smoothly into the 6.2 million gallon Ocean Voyager habitat. The Aquarium's husbandry and veterinary staff say the exam demonstrates the facility's ability to care for animals and conduct cutting edge scientific research. The Georgia Aquarium was built to perform procedures of this magnitude in order to provide the best possible care for all of the animals.
Physical Exam Procedures:
- Whale shark anesthetized with largest fish anesthesia machine ever built.
- Blood drawn as part of a routine physical assessment and for hormonal reading to give scientists an idea if male whale sharks, Ralph and Norton, are reaching sexual maturity.
- Aquarium husbandry staff imaged under gill flaps and inside whale sharks mouth to study feeding mechanics.
- Whale shark given small amount of food with color-coded indigestible beads to track feeding mechanics and study digestive transit.
- DNA samples taken to increase the database being developed to understand the zoogeography of whale sharks.
- Cloacal exams performed to understand normal cytology and condition of the lower gastrointestinal tract.
- Measurements taken to track growth of animals.
Physical Exam Results:
- Ralph has grown six feet and Norton seven feet since arriving at the Georgia Aquarium in June 2005; both now measure 22 feet in length.
- Alice and Trixie have each grown 1 foot 7 inches since arriving at the Aquarium in June 2006; now both measure 14 and 15 feet in length, respectively.
- While blood work for the Georgia Aquarium's whale sharks falls within the known ranges of sharks, skates and rays, whale sharks' red blood cells and white blood cells are significantly larger than those of other sharks, skates or rays.
- Ralph and Norton may be entering sexual maturity; blood work will give scientists a better understanding of their hormonal levels.
"The whale shark physical exams are part of the Georgia Aquarium's continued commitment to a better understanding of the species we care for," said Jeff Swanagan, Executive Director, Georgia Aquarium. "More than three million people have seen our whale sharks since we opened one year ago, and these exams will help us not only to better educate our guests about whale sharks, but also to increase the knowledge base of these animals worldwide."
As part of the Georgia Aquarium's 4R Program (Rehabilitation, Relocation, Rescue and Research) and in partnership with Mote Marine Laboratory, funding is dedicated to studying whale sharks in Florida, off the coast of Mexico's Yucatan Peninsula. The Aquarium's 4R Program also funds whale shark research in Taiwan. Researchers hope these findings will develop a better understanding of nutritional needs, biology, feeding behavior, migration patterns and population of whale sharks.
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About the Georgia Aquarium
The Georgia Aquarium in Atlanta, Georgia, is the world's largest with more than eight million gallons of water and more than 100,000 animals of 500 different species. The mission of the Georgia Aquarium is to be an entertaining, educational and scientific institution featuring exhibits and programs of the highest standards, offering engaging and exciting guest experiences and promoting the conservation of aquatic biodiversity throughout the world.
For additional information on the Georgia Aquarium, visit www.georgiaaquarium.org.