Navigation Links
Study: Lizards bask for more than warmth
Date:4/20/2009

Keeping warm isn't the only reason lizards and other cold-blooded critters bask in the sun. According to a study published in the May/June issue of Physiological and Biochemical Zoology, chameleons alter their sunbathing behavior based on their need for vitamin D.

"It's a longstanding assumption that thermoregulation is the only reason that lizards bask," says Kristopher Karsten, a biologist at Texas Christian University who led the study. "Our results suggest that in addition to thermoregulation, vitamin D regulation appears to have a significant impact on basking behavior as well."

Chameleons, like humans and most other vertebrates, get vitamin D in two ways: They can absorb it from food, and they can produce it in their skin. In order to produce vitamin D, however, the skin must be exposed to UV radiation.

To test whether chameleons alter their sunning behavior based on dietary vitamin D intake, Karsten observed the behavior of two different groups of chameleons. One group had high internal vitamin D levels, thanks to a diet of crickets dusted with a vitamin D powder. The other group ate regular crickets and had low vitamin D. The chameleons were then placed in individual outdoor enclosures that offered open area for direct sun, and a tree to offer filtered sun and shade.

Chameleons generally move from sun to shade throughout the day. But Karsten found that chameleons fed the low vitamin D diet compensated by increasing their exposure to the sun's UV rays. Chameleons with high vitamin D diets, on the other hand, limited their UV exposure.

"It appears that panther chameleons have the ability to gauge their internal vitamin D levels and alter their basking behavior accordingly," Karsten says.

And they do it with remarkable accuracy.

"The chameleons were as effective as mathematically possible by our methods at regulating toward optimal UV exposure for their vitamin D profile," he says. "We thought they were probably pretty good at regulating their UV exposure; we just didn't think they'd be this good."

It's not clear, however, by what mechanism they are able to sense their internal vitamin D levels, but Karsten thinks there may be a brain receptor sensitive to the vitamin.

"Given the ability for panther chameleons to precisely, accurately and effectively adjust basking behavior as a direct result of vitamin D3, [a brain vitamin D receptor] seems likely to occur in panther chameleons."


'/>"/>

Contact: Kevin Stacey
kstacey@press.uchicago.edu
773-834-0386
University of Chicago Press Journals
Source:Eurekalert

Related medicine news :

1. National Physicians Study: Nearly One Third Would Choose Different Career Today
2. Ex-White House Drug Czar McCaffrey, U.S. Congress Drug Caucus Chair Cummings, CRC Health CEO Karlin Join Hopkins Researchers at News Conference April 17 on Breakthrough Study: Internet Video Drug Treatment as Effective as Traditional Counseling
3. Study: Every 1.7 minutes a Medicare beneficiary experiences a patient safety event
4. Study: Doctor-patient conversations at end of life associated with lower medical expenses
5. UCF study: Hyperactivity enables children with ADHD to stay alert
6. Newly Published Menopause Study: Bioidentical and FDA-Approved Divigel(R) (estradiol gel) 0.1 Percent Safe and Effective Treatment for Moderate to Severe Hot Flashes Associated With Menopause
7. Study: Genetic Risk for Substance Use Can be Neutralized by Good Parenting
8. Study: Genetic risk for substance use can be neutralized by good parenting
9. Pediatrics study: Involve adolescents in end-of-life medical decisions
10. U-M Study: 19% of Breast Cancer Patients Dont Receive Recommended Radiation After Mastectomy
11. New Study: Protein in the Morning Helps Dieters Stay on Track and Keep Weight Off
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/2/2016)... ... December 02, 2016 , ... On Dec. 2, 2016, ... Rock Hotel San Diego honoring the 2016 MPN Heroes—eight individuals who have made a ... going above and beyond the standard of care, demonstrating leadership within the MPN community ...
(Date:12/2/2016)... ... December 02, 2016 , ... Advanced Inc., a leading provider ... Jason Bice, CPA, MBA to serve as Advanced Inc.’s Chief Financial Officer, effective December ... , Jason brings extensive financial and operational leadership experience to Advanced Inc. He began ...
(Date:12/2/2016)... , ... December 02, 2016 , ... The annual time ... Period (or Annual Election Period), is ending December 7th. Currently-enrolled Medicare beneficiaries who are ... or prescription drug plan (Part D) need to make changes during this period order ...
(Date:12/2/2016)... (PRWEB) , ... December 02, 2016 , ... ... inspirational interview of two ostomy patients, standing as living proof that attitude and ... from digestive diseases and issues that spike around the holidays. This campaign will ...
(Date:12/2/2016)... ... December 02, 2016 , ... Mediaplanet is proud to ... which covers the innovative treatments, therapeutic technologies, and revolutionized nutrition that are helping ... prolonging life 6 years in the last 3 decades,” says Dr. Valentine Fuster, ...
Breaking Medicine News(10 mins):
(Date:12/2/2016)... largest share in the ECG Cables And ECG Leadwires Market ... monitoring ECG devices. On the other hand, the ... highest growth rate during the forecast period. The ... (U.S.), Medtronic plc ( Ireland ), Koninklijke Philips ... International Limited ( China ), held major share ...
(Date:12/2/2016)... -- Quantum Radiology,s Mobile Breast Center (QR MBC) brings ... women at the workplace, thereby maximizing convenience and compliance.  ... Lines and SunTrust Bank, and community health groups to ... initiatives. "I think it,s a great service ... have a mammogram without taking a large amount of ...
(Date:12/2/2016)... , Dec. 2, 2016  Eli Lilly and ... financial guidance for 2017 and provide updated financial guidance ... also conduct a conference call on that day with ... company,s financial guidance. The conference call will ... general public can access a live webcast of the ...
Breaking Medicine Technology: