Life Science

he (, toads, except Europe and Antarctica, and currently Genetic data provides a clearer belongs to another distantly-related group, newts, salamanders and consists of over 600 known species. understanding of relationships than Elachistocleis. caecilians) are one of the phylogenies built using morphological The hidden least-understood groups of Like all Neotropical narrow-mouthed frogs, characteristics, which provide conflicting Dr de Sá has officially renamed these vertebrates on earth, and one of Chiasmocleis live in burrows, emerging from evidence as similar features seem to have species according to their correct affiliations, the most vulnerable. In the Neotropics – a their underground hideaways only during evolved repeatedly in unrelated species as leaving him with a neat collection of 33 Tpoorly-explored region extending from the breeding season. According to Dr de a result of their similar burrowing lifestyles currently known species of Chiasmocleis, all Mexico and the Caribbean to the southern Sá, this is the best time to catch and study in this group of frogs. The final phylogeny descendants of a single common ancestor. history of the tip of South America – urgent conservation the elusive little creatures. He listens for the will track the evolutionary history of He will now focus in on the relationships efforts are required to protect amphibians males breeding calls, follows the sound to its Chiasmocleis, providing a framework to within this group, producing a revisionary and their rapidly disappearing . source and then catches the culprit. understand the evolution of humming frogs up-to-date description of them all, known as However, the species cannot be protected both genetically and morphologically. a ‘monograph’. unless we know that they exist, how to A FAMILY TREE humming frogs identify them, and where to find them. The foundation of Dr de Sá’s current Previously, Dr de Sá built a family tree for CRYPTIC CREATURES research will be a ‘family tree' – known as the narrow-mouthed frogs as a whole, One of the first things Dr de Sá noticed while In the depths of Brazil’s Atlantic Forest, researchers Dr de Sá’s research aims to fill the gaps in a ‘phylogeny’ – of all the frogs considered to work out where within this extended working on Chiasmocleis was that there are battling to identify species before they are lost for our knowledge surrounding one particularly to belong in the Chiasmocleis group, built family Chiasmocleis fits. Already, that tree were certain clusters of individuals with DNA enigmatic group of amphibians – the using genetic data. By examining the has shown that not all species thought similar to each other and distinctly different good. Dr Rafael O de Sá, Professor of Biology at the ‘humming frogs,’ technically known as similarities and differences in the DNA of to belong to Chiasmocleis actually fit to the DNA of other groups. These clusters University of Richmond, Virginia, USA, specialises in a Chiasmocleis. Chiasmocleis is the largest individual frogs from right across the range together in the same part of the family would suggest new species, yet they had group known as the ‘narrow-mouthed frogs’ and has genus of the narrow-mouthed frog family of the group, Dr de Sá can determine which tree: three species posing as Chiasmocleis not previously been identified as such based already found four species new to science. found in the Neotropics. The family are most closely related and which are more were really members of a nearby group on their appearance. Dr de Sá calls these has a worldwide distribution, distantly related. called Syncope, and one further imposter ‘cryptic species.’

Species cannot be protected unless we know that they exist, how to identify them, and where to find them

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The yellow line indicates the Remarkably, once the cryptic species had future biodiversity research. So far, Dr de border of Brazil's been identified from their DNA, a careful Sá’s team have formally described four new Detail Atlantic Forest analysis of morphological characteristics species of Chiasmocleis but Dr de Sá says did reveal some distinguishing his team have identified other potential new RESEARCH OBJECTIVES features, which had been overlooked cryptic species, almost indistinguishable Dr de Sa’s research focuses on the in previous studies. This included a from one another to the naked eye. For Dr What is so special about working in the speciation by the identification evolutionary biology of frogs. Within this, small difference in size, foot webbing de Sá, this highlights the importance of Neotropics? of ‘clusters’ of populations in a he utilises molecular and morphological and skin pigmentation. As Dr de Sá using genetic data in biological studies: Ecologically, i.e., variety of habitats, phylogenetic tree. Those clusters may approaches to phylogenetics, says: “The molecular data guided “The diversity [i.e., number of species] of the Neotropics are extremely diverse. represent new species. Subsequently, systematics, , and development us to reexamine … the variation Neotropical frogs goes beyond what we can The three major groups of amphibians, taxonomists explore other sources to understand the species diversity of of external morphology … and identify through traditional morphological (frogs and toads, caecilians, and of data, e.g., detailed examination frogs. identified the characteristics that approaches.” It is highly likely that the salmanders) occur in the Neotropics. of external morphology, internal would allow us to recognise those number of species of humming frogs will The region is home to 49% of the world’s characters (e.g., bones, muscles), FUNDING populations as new species.” This continue to grow. species and, of them, 39% reproductive signals (e.g., calls, National Science Foundation (NSF) means that the new species can are considered threatened, representing courtship patterns), developmental be recognised, not only in the lab, A FOUNDATION FOR CONSERVATION about 60% of the globally threatened and life history traits (e.g., larval stages, COLLABORATORS but in the field – a crucial factor for Dr de Sá’s monograph will not only list amphibians. Consequently, it is critical egg lying sites), ecology (e.g., adult João F. R. Tonini finding out more about them and the species of Chiasmocleis – cryptic or that researchers and funding agencies and larval environments, feeding), ultimately saving them from extinction. otherwise – it will also provide crucial allocate resources for research, training, patterns of distribution and possible BIO information for their conservation. Firstly, a and education focus to decipher the boundaries (e.g., rivers, valleys), Humans, for the first time in Taxonomists are the scientists that fully diagnostic description of each species biodiversity of amphibians in the to determine if those clusters our history, are witnessing the describe and name new species; this is how and how it differs from the others, will Neotropical realm and to understand the represent new species. extinction of an entire group species become “known” and is key to all enable future researchers to identify the status of more than 120 species which are of : amphibians. Dr frogs they come across. considered Critically Endangered and are How many more undiscovered Rafael O. de Sá works with possible extinct. species do you think are out there? undergraduates at the University Secondly, based on records of all the places Undoubtedly each group of organisms of Richmond and researchers the frogs have been found over the years, Why are amphibians so vulnerable to has undiscovered species. Currently, and students around the world to Dr de Sá will be able to estimate the range human activity? Chiasmocleis consists of 33 known document new species of frogs before of each species. The humming frogs can destruction and loss is the species; half of the known species have they disappear. These scientists use be found throughout the lowlands of South major threat to all wildlife; recovery been described since 2003. Further interdisciplinary approaches to assess America to the east of the Andes Mountains. programmes can be effective if analyses of Chiasmocleis will likely result cryptic diversity in frogs. However, like most animals and plants of the researchers have suitable habitat in an increase of about 25-40% of the Neotropics, little is known about the area to reintroduce species in the wild. total number of species. Fieldwork is CONTACT each individual species extends to cover. Amphibians have a ‘naked’ skin, a critical to document this disappearing Professor Rafael O. de Sá, PhD Combined with information on the extent difference from other vertebrates biodiversity as well as to enhance our Department of Biology of suitable habitat, this provides essential with some protection such as scales, knowledge of the described species – University of Richmond data for estimating the level of threat each feathers, or hair. Furthermore, the skin of information such as calls, larval stages, B115 Gottwald Science Center species may face. At present, almost a third amphibians is a major site for respiration. etc. 28 Westhampton Way of species of humming frog are recorded Consequently, amphibians are University of Richmond, VA 23173 as simply ‘data deficient’ on the IUCN’s Red particularly vulnerable to environmental How does a monograph help in the USA List of Threatened Species – because not pollution (e.g., pesticides, herbicides). conservation of species? enough is known about the species and their Over the last 30 years, the spread of A monograph provides a summary of T: +1 (804) 289 8542 distribution. a pathogenic fungus has decimated the information known for all species E: [email protected] amphibian populations. These threats reported in a particular group (genus, W: biology.richmond.edu/faculty/rdesa/ Given the rate of habitat destruction in the compounded with human-caused climate family, order, etc.) of organisms. Then, Neotropics, Dr de Sá fears that even where change are driving the current amphibian this type of work provides a place More info: frog species have been assigned a Red List mass extinction. where the non-taxonomist, students, news.mongabay.com/2017/03/three-new- status, this may be dangerously out of date. and early researchers, as well as frog-species- Many of the newly-described Chiasmocleis Can you describe how you first find a conservation efforts and policy decision found-in-disappearing-atlantic-forest/ species are restricted to the Atlantic Forest cryptic species from genetic data? making agencies can quickly refer to the of Brazil – an ecosystem under severe The analyses of genetic data from available information for that particular threat from habitat degradation and loss sampling of individuals across the group, including distribution, similar caused mainly by agriculture, such as cattle distribution of a species provide a species, etc. ranches and soybean plantations. Some first approach to understand cryptic estimates suggest that only 3.5% of the The new species can be recognised, natural vegetation of the Atlantic Forest R. de Sá's research now remains. Dr de Sá’s new monograph was funded by not only in the lab, but in the field – will provide invaluable information for The Neotropics are home to 60% of NSF-DEB Systematics researchers seeking to conserve these and Biodiversity Science globally threatened amphibians Cluster, Award 1144692 a crucial factor for finding out more fascinating animals. Hopefully for the about them humming frogs, it will not come too late.

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