Santiago Castroviejo-Fisher

Research Associate

+1 (212) 769-5734


Research Interests

As an evolutionary biologist and zoologist, my main interests are to study, describe, name, and understand the diversity of life with an emphasis on organisms and species. To study current diversity I mainly use a historical approach based on disciplines such as phylogenetic systematics and biogeography. Inferring evolutionary history allows me to understand things such as phenotypic evolution, the origin and causes of the distribution of organisms, and species boundaries. I have focused my research on amphibians and reptiles of tropical America and, to a lesser extent, Africa.

Current Research

Amazon Biodiversity

The Amazon Lowland rainforest, with more than 6 million Km2, harbors more than a quarter of Earth’s biodiversity. Nonetheless, its fauna and flora have been poorly studied even at the taxonomic level. Most studies in the region have been sporadic and based on few specimens from one or few localities. 

In this project we aim to answer a series of questions related to the amazing levels of biodiversity in the Amazon. How did this diversity originate? How much of this diversity is still unknown to science? How much diversity are we loosing with habitat destruction? How much diversity are we protecting by creating a new national park?

We are using amphibians as a study case to understand the diversity of the Amazon. We are applying a multidisciplinary approach that integrates classical disciplines such as taxonomy with recently developed techniques such as molecular phylogenetics, phylogeography and statistical bioacoustics. This multidisciplinary approach will allow us to identify areas of high species richness and endemism, evaluate the causes of the observed diversity and point out those linages that are evolutionarily unique. 

I am coordinating this project together with José Manuel Padial, Andrew J. Crawford, and Ignacio De la Riva. This project is based on a network of collaborators including scientists from: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru and Venezuela

Systematics and Evolution of Glassfrogs (Centrolenidae)

During my PhD at Uppsala University, Sweden I studied glassfrog systematics, biogeography and evolution. I am still active in this research line and work in close collaboration with other scientists. Together with Juan Manuel Guayasamín we are studying the historical biogeography of centrolenids using sequences from 10 markers with roughly 60% species coverage. I also collaborate with Marco Rada in his Ph.D. thesis on the phylogenetic relationships of glassfrogs.

Phenotypic Disparity and Concerted Evolution

Why is phenotypic variability unevenly distributed among clades? This is a long-standing question in evolutionary biology and we are using glassfrogs as a model to study this pattern.

Centrolenids are an excellent group to study the evolution of phenotypic disparity. The genus Hyalinobatrachium, 28 species, is one of the oldest clades of glassfrogs and is extremely monophormic showing little variation in its bauplan when compared to the remaining 11 genera. All Hyalinobatrachium species reproduce on the underside of leaves, i.e., males call from this side of leaves and females lay their egg clutches at or near calling sites. Thus, I hypothesize that once glassfrogs evolved the ability to reproduce on the underside of leaves, this new reproductive strategy imposed strong stabilizing selection on the morphology of these glassfrogs. Such stabilizing selection may constrain Hyalinobatrachium and other glassfrogs that have a similar reproduction strategy to be smaller, lighter, more transparent and with certain body proportions.

I am doing this project in collaboration with Dayanna L. Sánchez Martínez, Andrew J. Crawford, Juan Manuel Guayasamín,Alejandro González Voyer and Marco Rada.


Why do some groups of organisms have substantially more species than others? To try to answer this central question in biology we study diversification rates (speciation – extinction) and its relationships to intrinsic (e.g., phenotypic characters) and extrinsic (e.g., biogeographical events) variables. Currently, I am collaborating with José Manuel Padial and Alejandro González Voyer in this topic. In a first work, we are investigating the main causes behind the major amphibian radiation: Terrarana.

Species Delimitation and Integrative Taxonomy

Species is one of the most complex and debated concepts in biology. However, it is a fundamental unit of comparison in science and it is widely used by stakeholders (conservation, biomedicine, pest control, etc.). Thus I think it is very important to develop solid theoretical and practical basis to delimit species. Together with José Manuel Padial and Ignacio De la Riva, I have explored the use of multiple and independent lines of evidence under the evolutionary species concept to establish species boundaries.


Please write an email for pdf files and/or reprints


  • De la Riva I, Castroviejo-Fisher S, Chaparro JC, Boistel R & Padial JM. 2011. A new species of Atelopus (Anura: Bufonidae) from the Amazonian slopes of the Andes in south-eastern Peru. Salamandra 47, 161–168.
  • Castroviejo-Fisher S., Skoglund P., Valadez R., Vila C., Leonard J.A. 2011. Vanishing native American dog lineages. 2011.BMC Evolutionary Biology 11:73
  • Castroviejo-Fisher S., Moravec J., Aparicio J., Guerrero-Reinhard M., Calderón G. 2011. DNA taxonomy reveals two new species records of Hyalinobatrachium (Anura: Centrolenidae) for Bolivia. Zootaxa 2798, 64–68
  • Gonzalez-Voyer A., Padial J.M., Castroviejo-Fisher S., De la Riva I., Vila C. 2011. Correlates of species richness in the largest Neotropical amphibian radiation. Journal of Evolutionary Biology doi: 10.1111/j.1420-9101.2011.02243.x


  • Castroviejo-Fisher S, Guayasamin JM & Kok PJR. 2009. Species status of Centrolene lema Duellman and Señaris, 2003 (Amphibia: Centrolenidae) revealed by Integrative Taxonomy. Zootaxa 1680, 25–53.
  • *Castroviejo-Fisher S, *Guayasamin JM, Trueb L, Rada M & Vilà C. 2009. Phylogenetic systematics of Glassfrogs (Amphibia: Centrolenidae) and their sister taxon Allophryne ruthveniZootaxa 2100, 1–97. * = Equal contribution
  • Padial JM, Castroviejo-Fisher S, Köhler J, Vilá C, Chaparro JC & De la Riva I. 2009. Deciphering the products of evolution at the species level: the need for an integrative taxonomy. Zoologica Scripta 38, 431–447.
  • Castroviejo-Fisher S, Padial JM, Chaparro JC, Aguayo R & De la Riva I. 2009. A new species of Hyalinobatrachium (Anura: Centrolenidae) from the Amazonian slopes of the central Andes with comments on the diversity of the genus in the area.Zootaxa 2143, 24–44.
  • Padial JM, Castroviejo-Fisher S & De la Riva I. 2009. The phylogenetic relationships of Yunganastes revisited (Anura: Terrarana). Molecular Phylogenetics and Evolution 52, 911–915


  • Kok PJR & Castroviejo-Fisher S. 2008. Glassfrogs (Anura: Centrolenidae) of Kaieteur National Park, Guyana, with notes on the distribution and taxonomy of some species of the family in the Guiana Shield. Zootaxa 1680, 25–53.
  • Barrio-Amorós CL & Castroviejo-Fisher S. 2008. The taxonomic status of Rhaebo anderssoni (Melin, 1941) (Anura: Bufonidae). Salamandra 44, 59–67.
  • Guayasamin JM, Castroviejo-Fisher S, Ayarzagüena J, Trueb L & Vilà C. 2008. Phylogenetic relationships of glassfrogs (Centrolenidae) based on mitochondrial and nuclear genes. Molecular Phylogenetics and Evolution 48, 574–595.
  • Guayasamin JM, Cisneros-Heredia DF & Castroviejo-Fisher S. 2008. Taxonomic identity of Cochranella petersi Goin, 1961 and Centrolenella ametarsia Flores,1987. Zootaxa 1815, 25–34.
  • v, Señaris JC, Ayarzagüena J & Vilà C. 2008. Resurrection of Hyalinobatrachium orocostale and notes on theHyalinobatrachium orientale species complex (Anura: Centrolenidae). Herpetologica 64, 472–484.
  • Barrio-Amorós CL & Castroviejo-Fisher S. 2008. Comments on the distribution, taxonomy and advertisement call of the Guyanan glass frog Hyalinobatrachium ignioculus (Anura: Centrolenidae). Salamandra 44, 235–240.


  • Castroviejo-Fisher S, Ayarzagüena J & Vila C. 2007. A new species of Hyalinobatrachium (Centrolenidae: Anura) from Serranía de Perijá, Venezuela. Zootaxa 1441, 51–62.
  • Padial JM, v, Köhler J, Domic E & De la Riva I. 2007. Systematics of the Eleutherodactylus fraudator species group.Herpetological Monographs 21, 213–240.
  • Castroviejo-Fisher S, De la Riva I & Vilà C. 2007. Transparent frogs show potential of natural world. Nature 449, 972.


  • Padial JM, Castroviejo-Fisher S, Merchan M, Cabot J & Castroviejo J. 2003. The Herpetological collection from Bolivia in the “Estación Biológica de Doñana” (Spain). Graellsia 59, 5–13.


  • Padial JM, Castroviejo-Fisher S, Quintana AZ, Ávila E, Pérez-Marín J & Castroviejo J. 2002. Notes on the distribution of reptiles from NW Africa. Boletín de la Asociación Española de Herpetología 13, 2–5.