The Amphibians of the Gulf of Guinea Oceanic Islands

Abstract

This chapter reviews the diversity, evolutionary relationships, ecology, and conservation of the Gulf of Guinea oceanic islands’ endemic caecilian and anuran fauna. A total of nine amphibian species (representing five families) are known from São Tomé and Príncipe islands, all of which are endemic. No amphibians have been reported from Annobón. Taxonomic research on this group of animals began in the second half of the nineteenth century with subsequent refinement following the advent of molecular techniques. The presence of several amphibians from distinct evolutionary lineages is unexpected for oceanic islands and has motivated several biogeographic studies to reconstruct the evolutionary histories of these enigmatic species. Yet, the continental source for many of the islands’ amphibians remains unknown. The amphibians of São Tomé and Príncipe also exhibit intriguing phenotypic diversity for addressing long-standing hypotheses in evolutionary biology, including body size evolution and gigantism on islands, intraspecific variation and interspecific divergence in coloration, and reproductive and dietary niche partitioning. Recent studies have confirmed the presence of the fungal pathogen Batrachochytrium dendrobatidis in amphibian communities on both São Tomé and Príncipe, but it is unclear whether this pathogen is negatively impacting local populations. Most of the Gulf of Guinea oceanic island endemic amphibians are incredibly abundant and widespread, occurring in primary forest, secondary forest, and agricultural habitats across the islands. Three anuran species (Hyperolius thomensis, Leptopelis palmatus, Ptychadena newtoni) have more limited distributions and/or more specialized ecologies; consequently, additional land-use change poses a threat to the long-term persistence of these taxa.

Biodiversity in the Gulf of Guinea Oceanic Islands: A Synthesis

“…Chapter 17 (Costa et al 2022) lists and discusses the more than 1000 species of fishes that potentially occur in the fresh and marine waters of the islands. Chapter 18 (Bell et al 2022) deals with amphibians, which include three species on Príncipe and six on São Tomé, all of which are endemic (Annobón has no amphibians). The chapter provides a detailed overview of species biology, ecology, and biogeography.…”

“…Chapter 25 (Ayres et al 2022) assesses recent strategies of formal and non-formal environmental education on São Tomé and Príncipe, which are vital to augment local capacity for conservation and scientific research. Chapter 26 (Bell et al 2022) proposes a path toward biodiversity resilience for future naturalists, biologists, conservationists, and educators.…”

The Terrestrial Reptiles of the Gulf of Guinea Oceanic Islands

“…This project, which has made a total of 12 expeditions to the islands as of 2020, is still ongoing and has been one of the most comprehensive efforts to study the biodiversity of São Tomé and Príncipe islands since Francisco Newton's expedition in the nineteenth century. Due to Drewes' herpetological background, the project has always had a strong emphasis on the study of the amphibians and reptiles of these islands (see Bell et al 2022). The reptile collections resulting from these expeditions are currently the largest in the world (Table 19.1), with a total of 449 specimens (Scheinberg and Fong 2019).…”

“…The genus Afrotyphlops is represented by the Príncipe endemic Afrotyphlops elegans (Peters, 1868), locally known as "Cobra-bobô" (Fig. 19.2, 5), which is the same name used on São Tomé to refer to the endemic caecilians of the genus Schistometopum Parker, 1941 (Bell et al 2022). Not much is known about the ecology of this fossorial species, however, in multi-locus and morphological phylogenetic analyses of typhlopid snakes, Kornilios et al (2013) and Hedges et al (2014) showed that it is closely related to the Central African Afrotyphlops angolensis (Bocage, 1866).…”

The History of Biological Research in the Gulf of Guinea Oceanic Islands

“…One fundamental difference in the research carried out in the twenty-first century is the use of molecular methods to study the taxonomy, phylogenety, and biogeography of the biodiversity of the islands. While this has not yet been applied to all taxonomic groups, the use of molecular methods has been widely applied to the study of the island's herpetofauna (Bell et al 2022;Ceríaco et al 2022), birds (Melo et al 2022) and, to a lesser extent, plants (Plana et al 2004;Soares et al 2010). The growing importance of ecological and conservation studies has also marked the research landscape in the oceanic islands of the Gulf of Guinea, with dozens of works and theses produced on the topic, especially at the University of Lisbon (see , Soares et al 2022), but also the seminal works on marine turtles (see Ferreira-Airaud et al 2022), plants (see Stevart et al 2022, and even land molluscs (see Panisi et al 2022).…”