Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NUS Researchers Discover for the First Time That a Rare Bush Frog Breeds in Bamboo

29.10.2014

Scientists observed this new reproductive mode in critically endangered white spotted bush frogs in South India’s Western Ghats

Researchers from the National University of Singapore (NUS) have discovered a new reproductive mode in frogs and toads - breeding and laying direct developing eggs in live bamboo with narrow openings - which was observed in the white spotted bush frog (Raorchestes chalazodes). This critically endangered frog is currently only one of two species known to adopt this novel reproductive strategy. The findings were published in The Linnean Society of London’s Biological Journal of the Linnean Society, in October 2014.


Seshadri K S

Researchers from the National University of Singapore have discovered a new reproductive mode in frogs and toads - breeding and laying direct developing eggs in live bamboo with narrow openings - which was observed in the white spotted bush frog (Raorchestes chalazodes).

Life history strategies to increase reproductive success are termed as reproductive modes. Frogs and toads currently exhibit 40 known reproductive modes, including 17 aquatic modes and 23 terrestrial modes. This study reports the discovery of the 41st reproductive mode which is different from all other known modes – breeding in live bamboo with narrow slits through which adults enter and deposit direct developing eggs and provide parental care. Direct-developing eggs are eggs that hatch as frogs directly.

The species of frogs that exhibit this behaviour, R. chalazodes, was thought to be extinct for over 100 years until it was rediscovered recently in the wet evergreen forests of the Kalakad Mundanthurai Tiger Reserve in the Western Ghats. This biodiversity hotspot of India is listed as a UNESCO World Heritage Site.

In this study, Mr Seshadri K S, a PhD student, and Assistant Professor David Bickford from the Department of Biological Sciences at the NUS Faculty of Science, discovered the reproductive strategy of R. chalazodes. Mr Seshadri observed that adult male frogs enter hollow internodes of the flute bamboo Ochlandra travancorica where they vocalise to attract mates.

They make their way into the bamboo through a small opening, possibly made by insects. Female frogs are attracted to the calls and follow suit, laying about 5 to 8 eggs inside the bamboo. Other females may also choose to mate with the male frog and deposit egg clutches in the bamboo. The male stays in the bamboo to take care of the eggs, which develop directly into froglets.

Although the adult frog is small, under 25 millimetres in length, it enters the bamboo with considerable resistance as the narrow openings are often less than 5 to 10 millimetres long and 3 to 4 millimetres wide. The researchers observed that R. chalazodes only breeds in bamboo that have openings at the base of the internode as those with openings at the top would result in collection of water, possibly flooding the eggs or drowning the froglets.

The adult males actively search for openings in bamboo and possibly defend territories. They leave the bamboo for a few hours in the evening to feed and return to look after the eggs. The researchers made these findings after conducting field observations over a period of six months between 2009 and 2012.

Asst Prof Bickford said, “This is a significant discovery in two ways. First, it reiterates that natural history observations, often ignored, are fundamental for understanding evolutionary ecology. Second, it sets a theoretical foundation to ask several interesting questions about the diversity of reproductive modes and the evolutionary pathways behind such amazing amphibian behaviors.”

The second author of the paper, Dr Gururaja K V from the Centre for Infrastructure, Sustainable Transportation and Urban Planning at the Institute of Science, Bangalore, India, had observed that another species of frogs, known as the Ochlandra reed frog (Raorchestes ochlandrae), breeds in internodes of bamboo. While the geographic ranges of these two species do not overlap and nesting occurs inside different species of bamboo, the reproductive mode is comparable.

R. ochlandrae was previously ascribed to a reproductive mode characterised by direct developing eggs deposited in a nest above ground or in the trees. In this study, the researchers did not observe any nest-making behaviour and thus, the mode was reclassified to be the same as R. chalazodes.

The study is timely as R. chalazodes is currently critically endangered with small populations occurring in fewer than five localities. As this species only breeds in bamboo, unregulated overharvesting of bamboo for paper and pulp may destroy breeding habitats and have a negative impact on the long-term viability of populations. It is critical to conduct more studies on these unique frogs, in particular, those that look into developing frog-friendly harvesting techniques in order to conserve them.

Mr Seshadri, the lead author, said, “Amphibians are among the most threatened creatures on earth and yet, we know very little about them. I was enthralled when we observed this behavior and it opened a whole new world for me. There are several evolutionary questions that could be answered by studying this fascinating group of frogs. For example, what transpires inside the bamboo internodes is still a mystery. The Western Ghats is a well-known hotspot for amphibian diversity which is facing threats primarily from habitat loss. If we do not initiate conservation efforts, we may lose everything before we even document anything.”

Dr Gururaja said, “While species diversity has increased, very little ecological information has been added. The recent discoveries of interesting behaviour such as foot-flagging in the dancing frog (Micrixalus kottigeharensis), and clay nest-building in the potter frog (Nyctibatrachus kumbara) are a case in point that there is much more to be discovered in India and Southeast Asia.”

Contact Information
Kimberley WANG
Assistant Manager, Media Relations
Office of Corporate Relations
National University of Singapore
Email: kimberley.wang@nus.edu.sg

Kimberley WANG | newswise
Further information:
http://www.nus.edu.sg

Further reports about: Bamboo NUS behaviour breeding discovered diversity eggs frogs reproductive

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>