RESUMO
Environmental DNA (eDNA) metabarcoding is a promising tool to estimate aquatic biodiversity. It is based on the capture of DNA from a water sample. The sampled water volume, a crucial aspect for efficient species detection, has been empirically variable (ranging from few centiliters to tens of liters). This results in a high variability of sampling effort across studies, making comparisons difficult and raising uncertainties about the completeness of eDNA inventories. Our aim was to determine the sampling effort (filtered water volume) needed to get optimal inventories of fish assemblages in species-rich tropical streams and rivers using eDNA. Ten DNA replicates were collected in six Guianese sites (3 streams and 3 rivers), resulting in sampling efforts ranging from 17 to 340 liters of water. We show that sampling 34 liters of water detected more than 64% of the expected fish fauna and permitted to distinguish the fauna between sites and between ecosystem types (stream versus rivers). Above 68 liters, the number of detected species per site increased slightly, with a detection rate higher than 71%. Increasing sampling effort up to 340 liters provided little additional information, testifying that filtering 34 to 68 liters is sufficient to inventory most of the fauna in highly diverse tropical aquatic ecosystems.
Assuntos
Código de Barras de DNA Taxonômico/métodos , DNA Ambiental/análise , Monitoramento Ambiental/métodos , Peixes/genética , Rios/química , Água/química , Animais , Biodiversidade , Guiana Francesa , Tamanho da AmostraRESUMO
BACKGROUND: Environmental DNA [eDNA] metabarcoding has recently emerged as a non-destructive alternative to traditional sampling for characterising species assemblages. NEW INFORMATION: We here provide a consistent dataset synthetising all eDNA sampling sites in French Guiana to date. Field collections have been initiated in 2014 and have continued until 2019. This dataset is however a work in progress and will be updated after each collecting campaign. We also provide a taxon by site matrix for fishes presence / absence as inferred from eDNA. Our aim is to allow a transparent communication to the stakeholders and provide the foundation for a monitoring programme based on eDNA. The lastest version of the dataset is publicly and freely accessible through the CEBA geoportal (http://vmcebagn-dev.ird.fr) or through the French Guiana geographic portal (https://www.geoguyane.fr).
RESUMO
An identification key is provided for 21 larval types of Elmidae (riffle beetles) known to occur in French Guiana. Not all elmid genera known to occur in French Guiana are known in the larval stage. Nor are all the known larval types assigned to known elmid genera.(AU)
Assuntos
Animais , Besouros/anatomia & histologia , Besouros/classificação , Larva/anatomia & histologia , Larva/classificação , Guiana Francesa , BiodiversidadeRESUMO
Abstract An identification key is provided for 21 larval types of Elmidae (riffle beetles) known to occur in French Guiana. Not all elmid genera known to occur in French Guiana are known in the larval stage. Nor are all the known larval types assigned to known elmid genera.
RESUMO
An identification key is provided for 21 larval types of Elmidae (riffle beetles) known to occur in French Guiana. Not all elmid genera known to occur in French Guiana are known in the larval stage. Nor are all the known larval types assigned to known elmid genera.