Pablo Tedesco

Institute of Research for Development | IRD · Laboratoire Evolution et Diversité Biologique (EDB)

The Amazon Basin features a vast network of healthy, free-flowing rivers, which provides habitat for the most biodiverse freshwater fauna of any basin globally. However, existing and future infrastructure developments, including dams, threaten its integrity by diminishing river connectivity, altering flows, or changing sediment regimes, which can i...

Global ecosystems are facing a deepening biodiversity crisis, necessitating robust approaches to quantifying species extinction risk. The lower limit of the macroecological relationship between species range and body size has long been hypothesized as an estimate of the relationship between the minimum viable range size (MVRS) needed for species pe...

A primary goal of community ecology is to understand the mechanisms that drive species' spatial distribution and habitat associations. Species' geographic distribution can be influenced by the distribution of their prey partly because consumers' behaviour is oriented to optimal energy use during foraging. We analysed how differences in dietary pref...

The Neotropical region hosts 4,225 freshwater fish species, ranking first among the world’s most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north, to the sout...

Background Population dynamics are driven by a number of biotic ( e.g. , density-dependence) and abiotic ( e.g. , climate) factors whose contribution can greatly vary across study systems ( i.e. , populations). Yet, the extent to which the contribution of these factors varies across populations and between species and whether spatial patterns can b...

Regional taxonomic diversity (species richness) is strongly influenced by a joint effect of the current processes (habitat and energy availability) and historical legacies (past climate and geography), but it is still unclear how those historical and current environmental drivers have shaped the functional diversity of species assemblages. Freshwat...

The human alteration of habitats is a major driver in the decline of biodiversity worldwide. However, the relationships between different forms of rarity, including both taxonomic and functional aspects, are poorly known. Two relationships were examined in this study: (i) between the different forms of taxonomic rarity and functional originality of...

Aim Phylogenetic relatedness among species can provide useful information on the diversification history and past dispersal events that may have shaped contemporary assemblages. Here, using of the most comprehensive fish occurrence database currently available and a global molecular phylogeny of ray-finned fishes, we evaluate the respective roles o...

The regional extent and transboundary nature of the world largest rivers accentuate the difficulty to characterize river forms and processes at a whole basin scale. We developed a framework to define a river classification protocol adapted to large rivers and further applied this protocol to elaborate a geomorphological classification of Amazonian...

Motivation Global freshwater fish biodiversity and the responses of fishes to global changes have been explored intensively using taxonomic data, whereas functional aspects remain understudied owing to the lack of knowledge for most species. To fill this gap, we compiled morphological traits related to locomotion and feeding for the world freshwate...

Aim: Community phylogenetics provides important information about the evolutionary and ecological factors help structure regional species assemblages. Here, we analyze phylogenetic diversity (phylodiversity) patterns among fish species in 97 sub-drainages of the Amazon basin, to evaluate the roles of historical and contemporary processes in generat...

Significance Understanding the mechanisms by which biological communities are reorganized by environmental change is a key question facing ecologists. Using a global database of fish abundance time series spanning recent decades, together with community-level indices describing species temperature and flow affinities, we show that two important asp...

Aim Geographical gradients of vertebrate species richness are determined jointly by evolutionary and environmental factors. Support for these factors comes mostly from tetrapods and, recently, marine fishes, but their validity and relative importance in freshwater fishes is not well understood. Here, we describe the species richness gradient for th...

The sustained development of hydropower energy in the last century has caused important ecological impacts, promoting recent advances in efficient mitigation measures to be implemented in existing and future hydropower plants. Although upstream fish migration has been largely addressed with the development of fish-pass infrastructures, downstream p...

Dendritic habitats, such as river ecosystems, promote the persistence of species by favouring spatial asynchronous dynamics among branches. Yet, our understanding of how network topology influences metapopulation synchrony in these ecosystems remains limited. Here, we introduce the concept of fluvial synchrogram to formulate and test expectations r...

• The Amazon basin has been subjected to extreme climatic events and according to climate change projections this hydrosystem could face changes in the natural dynamic of flood cycles that support the feeding and reproduction of many fish species, threatening aquatic biodiversity. • Protected areas (PAs) are the main tools used to safeguard the bio...

Motivation: We compiled a global database of long-term riverine fish surveys from 46 regional and national monitoring programmes and from individual academic research efforts, with which numerous basic and applied questions in ecology and global change research can be explored. Such spatially and temporally extensive datasets have been lacking for...

Upstream range shifts of freshwater fishes have been documented in recent years due to ongoing climate change. River fragmentation by dams, presenting physical barriers, can limit the climatically induced spatial redistribution of fishes. Andean freshwater ecosystems in the Neotropical region are expected to be highly affected by these future distu...

Aim We examined the diversity–biomass relationship in stream fish communities and quantified direct and indirect effects of abiotic variables on this relationship. Location France. Time period 1992–2012. Major taxa studied Stream fishes. Methods We analysed the relationship between biodiversity (species richness and functional diversity) and fi...

Despite the increasing ubiquity of biological invasions worldwide, little is known about the scale‐dependent effects of nonnative species on real‐world ecological dynamics. Here, using an extensive time series dataset of riverine fish communities across different biogeographic regions of the world, we assessed the effects of nonnative species on th...

Undetected extinctions constitute a portion of biodiversity loss that is often ignored. We compared the performance of two models of undetected extinctions – Tedesco and SEUX – when estimating undetected extinctions with both simulated and real‐world data. We generated simulated data by considering a birth‐death process where less abundant species...

The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-div...

The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-div...

Conserving freshwater habitats and their biodiversity in the Amazon Basin is a growing challenge in the face of rapid anthropogenic changes. We used the most comprehensive fish-occurrence database available (2355 valid species; 21,248 sampling points) and 3 ecological criteria (irreplaceability, representativeness, and vulnerability) to identify bi...

Change in species' climatic niches is a key mechanism influencing species distribution patterns. The question of which factors impact niche change remains a highly debated topic in evolutionary biology. Previous studies have proposed that rates of climatic niche change might be correlated with climatic oscillations at high latitude or adaptation to...

Using the most comprehensive fish occurrence database, we evaluated the importance of ecological and historical drivers in diversity patterns of subdrainage basins across the Amazon system. Linear models reveal the influence of climatic conditions, habitat size and sub-basin isolation on species diversity. Unexpectedly, the species richness model a...

Using the most comprehensive fish occurrence database, we evaluated the importance of ecological and historical drivers in diversity patterns of subdrainage basins across the Amazon system. Linear models reveal the influence of climatic conditions, habitat size and sub-basin isolation on species diversity. Unexpectedly, the species richness model a...

To define the major biogeographical regions and transition zones for freshwater fish species. Strictly freshwater species of actinopterygian fish (i.e. excluding marine and amphidromous fish families). We based our bioregionalization on a global database of freshwater fish species occurrences in drainage basins, which, after filtering, includes 11,...

Significance Species’ geographic range size is a fundamental aspect of understanding and predicting changes in biodiversity patterns. Investigating the global drivers of geographic range size variation in freshwater fishes, we found clear evidence that current and historical connectivity are, by far, the main determinants of range size. More specif...

The title "AMAZON FISH database" is a working title for the Amazonian Freshwater Fish Biodiversity database that was constructed in the framework of the AMAZON FISH (ERANetLAC/DCC-0210) project. In order to construct the AMAZON FISH database, which aims to become a high quality freshwater fish biodiversity database covering the entire Amazon draina...

Built infrastructure, such as dams and weirs, are some of the most impactful stressors affecting aquatic ecosystems. However, data on the distribution and characteristics of small built infrastructure that often restrict fish movement, impede flows, and retain sediments and materials, remain limited. Collection of this necessary information is chal...

Global spread of non‐native species profoundly changed the world biodiversity patterns, but how it translates into functional changes remains unanswered at the world scale. We here show that while in two centuries the number of fish species per river increased on average by 15% in 1569 basins worldwide, the diversity of their functional attributes...

The hierarchical branching nature of river networks can have a strong influence on the assembly of freshwater communities. This unique structure has spurred the development of the network position hypothesis (NPH), which states that the strength of different assembly processes depends on the community position in the river network. Specifically, it...

Aim To define the major biogeographical regions and transition zones for freshwater fish species. Taxon Strictly freshwater species of actinopterygian fish (i.e., excluding marine and amphidromous fish families). Methods We based our bioregionalisation on a global database of freshwater fish species occurrences in drainage basins, which, after fi...

The hierarchical branching nature of river networks can have a strong influence on the assembly of freshwater communities. This unique structure has spurred the development of the network position hypothesis (NPH), which states that the strength of different assembly processes depends on the community position in the river network. Specifically, it...

Andes-to-Amazon river connectivity controls numerous natural and human systems in the greater Amazon. However, it is being rapidly altered by a wave of new hydropower development, the impacts of which have been previously underestimated. We document 142 dams existing or under construction and 160 proposed dams for rivers draining the Andean headwat...

Intermittent rivers and ephemeral streams (IRES) are strong drivers of evolution because they experience spatially variable and recurrent disturbances and succession processes. Alternating wet and dry phases exert strong selection that imposes trade-offs and leads to multiple strategies for spreading risk through space and time. IRES populations ra...

A growing interest is devoted to global-scale approaches in ecology and evolution that examine patterns and determinants of species diversity and the threats resulting from global change. These analyses obviously require global datasets of species distribution. Freshwater systems house a disproportionately high fraction of the global fish diversity...

Human activities are often implicated in the contemporary extinction of contemporary species. Concerning riverine fishes, the major biotic and abiotic threats widely cited include introduction of non-native species, habitat fragmentation and homogenization in stream flow dynamics due to the damming of rivers, dumping of organic loadings, degradatio...

Initial Data Management Plan for the Amazonian Freshwater Fish Biodiversity database that will be constructed in the framework of the AMAZONFISH (ERANetLAC/DCC-0210) project.

Tropical rivers are experiencing an unprecedented boom in dam construction. Despite rapid dam expansion, knowledge about the ecology of tropical rivers and the implications of existing and planned dams on freshwater-dependent species remains limited. Here we evaluate fragmentation of fish species ranges, considering current and planned dams of the...

Factors that isolate populations and reduce gene flow are considered key drivers of speciation and possibly diversification. Here we analyse the diversification rates of nearly 80% of the actinopterygian fish families in relation to biological traits and habitat factors associated with isolation and fragmentation levels. Global. Net diversification...

Studies about fish assemblages in Brazilian streams have grown in recent years, however, it remains unclear whether this increase is followed by increments in the diversity of addressed topics and theoretical frameworks adopted by researchers. We performed a systematic search for Brazilian studies on stream fish assemblages recording study region,...

With around 15% of all described freshwater fish species in the world, the Amazon Basin is by far the most fish species-rich freshwater ecosystem on the planet. In this opinion paper, a rough evaluation is given on just how vulnerable Amazonian freshwater fishes are to ongoing climate change. And to argue that current anthropogenic threats through...

The bushmeat trade in tropical Africa represents illegal, unsustainable off-takes of millions of tons of wild game –mostly mammals – per year. We sequenced four mitochondrial gene fragments (cyt b, COI, 12S, 16S) in >300 bushmeat items representing nine mammalian orders and 59 morphological species from five western and central African countries (G...

With around 15% of all described freshwater fish species in the world, the Amazon Basin is by far the most fish species-rich freshwater ecosystem on the planet. In this opinion paper, a rough evaluation is given on just how vulnerable Amazonian freshwater fishes are to ongoing climate change. And to argue that current anthropogenic threats through...

AimTo examine the pattern and cumulative curve of descriptions of freshwater fishes world-wide, the geographical biases in the available information on that fauna, the relationship between species richness and geographical rarity of such fishes, as well as to assess the relative contributions of different environmental factors on these variables.Lo...

The pattern of increasing species body size with increasing latitude has been noticed in different groups of animals. Here, we used seven key environmental factors and independent contrasts to assess body size latitudinal clines in Cyprinidae at two phylogenetic levels (inter- and intragenera), which were defined using a genus-level supertree. Mode...

Most ecosystems undergo substantial variation over the seasons, ranging from changes in abiotic features, such as temperature, light and precipitation, to changes in species abundance and composition. How seasonality varies along latitudinal gradients is not well known in freshwater ecosystems, despite being very important in predicting the effects...

Human activities are often linked to contemporary species extinctions. For riverine fishes, a highly studied and emblematic taxon, introduction of non-native species, damming of rivers, increasing water pollution and sediment loads, eutrophication, habitat degradation and water abstraction for human and agricultural consumption are believed to be a...

The relative importance of contemporary and historical processes is central for understanding biodiversity patterns. While several studies show that past conditions can partly explain the current biodiversity patterns, the role of history remains elusive. We reconstructed palaeo-drainage basins under lower sea level conditions (Last Glacial Maximum...

Because both descriptions of species and modern human-driven extinctions started around the same time (i.e., eighteenth century), a logical expectation is that a large proportion of species may have gone extinct without ever having been recorded. Despite this evident and widely recognized assumption, the loss of undescribed species has never been e...

Con el 15% de todos los peces de agua dulce descritos en el mundo, la cuenca amazónica es el sistema de agua dulce más biodiverso del planeta. Hoy en día, losfactores principalesde degradaciónde los ecosistemas deagua dulceen la regiónamazónica son la rápida expansión de las infraestructuras y actividades económicas. Estas perturbaciones provocan i...

Compared with small rivers and streams, the study of fish communities in large rivers remains challenging as spatial and temporal data variability can be greatly influenced by sampling strategy and operator choice. In an attempt to limit this variability, a new sampling protocol for fish communities in medium- to large-sized rivers was developed, b...

High-level phylogenies are very common in evolutionary analyses, although they are often treated as incomplete data. Here, we provide statistical tools to analyze what we name "clade data," which are the ages of clades together with their numbers of species. We develop a general approach for the statistical modeling of variation in speciation and e...

* Current models estimating impact of habitat loss on biodiversity in the face of global climate change usually project only percentages of species ‘committed to extinction’ on an uncertain time-scale. Here, we show that this limitation can be overcome using an empirically derived ‘background extinction rate–area’ curve to estimate natural rates an...

Although habitat fragmentation fosters extinctions, it also increases the probability of speciation by promoting and maintaining divergence among isolated populations. Here we test for the effects of two isolation factors that may reduce population dispersal within river networks as potential drivers of freshwater fish speciation: 1) the position o...

Whereas global patterns and predictors of species diversity are well known for numerous terrestrial taxa, our understanding of freshwater diversity patterns and their predictors is much more limited. Here, we examine spatial concordance in global diversity patterns for five freshwater taxa (i.e. aquatic mammals, aquatic birds, fishes, crayfish and...

There is growing interest in large-scale approaches to ecology, for both plants and animals. In particular, macroecological studies enable examination of the patterns and determinants of species richness of a variety of groups of organism throughout the world, which might have important implications for prediction and mitigation of the consequences...

The Fish-SPRICH database