Navigation Links
Unheard of life history for a vertebrate
Date:6/30/2008

There is a newly discovered life history among the 28,300 species of known tetrapods, or four-legged animals with backbones. A chameleon from arid southwestern Madagascar spends up to three-quarters of its life in an egg. Even more unusual, life after hatching is a mere 4 to 5 months. No other known four-legged animal has such a rapid growth rate and such a short life span. The new research is reported in the current issue of Proceedings of the National Academy of Sciences.

"It really is a huge surprise," says Christopher Raxworthy, Associate Curator in the Department of Herpetology at the American Museum of Natural History. "Adding to that, until now, the short life span of chameleons in captivity has always been considered as a failure to thrive. We need to rethink this."

Most mammals, reptiles, birds, and amphibians (all tetrapods) typically live 2 to 10 years, an average bracketed at the upper end by some long-lived animals (for example, turtles and humans that can live for a century) and at the lower end by a handful of animals that only live for about a year. The males in nine species of marsupials die off after a year, for example, as do most adults in about twelve species of lizards. But the chameleon described here, Furcifer labordi, not only has a brief, yearly life cycle, but the bulk of that time is spent incubating inside an egg. Once outside of the egg, all individuals in the population die within 4 to 5 months.

Kristopher Karsten, a graduate student from the Department of Zoology at Oklahoma State University, discovered the unusual life cycle almost by accident. "I showed up late in the season and found something weird," recalls Karsten. "There were no juveniles. But by February, I found carcasses all over with no signs of mutilation or predation. The population plummetedwe've never seen this with other lizards."

Now, after five seasons of data and sightings of nearly 400 individuals, the life cycle of F. labordi can be described. Hatching begins with the rains in November, and, once emerged, the chameleons develop rapidly, growing up to 2.6 mm (0.1 inches) a dayup to two orders of magnitude greater than other known lizard growth rate. In less than 60 days, for example, there can be a 300%-400% increase in body size for males to reach adulthood. After reaching maturity, the population reproduces, and females burrow through about 138 mm (5.4 inches) of sand to lay their eggs. Once covered, the eggs wait out the dry season for the next 8 to 9 months, and all adults die.

"It is amazing to think that for most of the year, this chameleon species is represented only by developing eggs buried in the ground," says Raxworthy. "This species really illustrates just how much there is still to discover about the natural history of Madagascar." Karsten agrees, adding: "We've identified a species that does something really different from the others, but what is driving this system? One bad year could wipe out these chameleons."


'/>"/>

Contact: Kristin Phillips
kphillips@amnh.org
212-496-3419
American Museum of Natural History
Source:Eurekalert  

Related biology news :

1. Geology and biology meet in the history of US southwestern desert surface waters
2. Smithsonian scientists find evidence that could rewrite Hawaiis botanical history
3. Ancient DNA: reconstruction of the biological history of Aldaieta necropolis
4. Jeremy Jackson honored by Harvard Museum of Natural History
5. Smithsonians National Museum of Natural History reveals ants as fungus farmers
6. Lemurs evolutionary history may shed light on our own
7. Man-made changes bring about new epoch in Earths history
8. Journal Sleep: Insomniacs are more likely to report a family history of the sleep disorder
9. Rebuilding the evolutionary history of HIV-1 unravels a complex loop
10. Microfossils disclose geologic history of eastern California
11. New study sheds light on Galápagos hawk evolutionary history
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Unheard of life history for a vertebrate
(Date:4/28/2016)... Sweden , April 28, 2016 First ... M (139.9), up 966% compared with the first quarter of 2015 ... profit totaled SEK 589.1 M (loss: 18.8) and the operating margin ... 7.12 (loss: 0.32) Cash flow from operations was SEK ... The 2016 revenue guidance is unchanged, SEK 7,000-8,500 M. ...
(Date:4/26/2016)... -- Research and Markets has announced the ...  report to their offering.  , ,     (Logo: ... forecast the global multimodal biometrics market to grow ... 2016-2020.  Multimodal biometrics is being implemented ... healthcare, BFSI, transportation, automotive, and government for controlling ...
(Date:4/15/2016)... , April 15, 2016  A new ... make more accurate underwriting decisions in a fraction ... timely, competitively priced and high-value life insurance policies ... screenings. With Force Diagnostics, rapid testing ... lifestyle data readings (blood pressure, weight, pulse, BMI, ...
Breaking Biology News(10 mins):
(Date:6/27/2016)...  Liquid Biotech USA , ... Sponsored Research Agreement with The University of Pennsylvania ... cancer patients.  The funding will be used to ... clinical outcomes in cancer patients undergoing a variety ... employed to support the design of a therapeutic, ...
(Date:6/24/2016)... ... 2016 , ... While the majority of commercial spectrophotometers and fluorometers use the ... models are higher end machines that use the more unconventional z-dimension of 20mm. ... the bottom of the cuvette holder. , FireflySci has developed several Agilent flow ...
(Date:6/23/2016)... CAMBRIDGE, Mass. , June 23, 2016 /PRNewswire/ ... the development of novel compounds designed to target ... compound, napabucasin, has been granted Orphan Drug Designation ... in the treatment of gastric cancer, including gastroesophageal ... cancer stemness inhibitor designed to inhibit cancer stemness ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... (Yeast and Mold) microbial test has received AOAC Research Institute approval 061601. , ... tests introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial ...
Breaking Biology Technology: