The future of biotic indices in the ecogenomic era: Integrating (e)DNA metabarcoding in biological assessment of aquatic ecosystems

The bioassessment of aquatic ecosystems is currently based on various biotic indices that use the occurrence and/or abundance of selected taxonomic groups to define ecological status. These conventional indices have some limitations, often related to difficulties in morphological identification of bioindicator taxa. Recent development of DNA barcoding and metabarcoding could potentially alleviate some of these limitations, by using DNA sequences instead of morphology to identify organisms and to characterize a given ecosystem. In this paper, we review the structure of conventional biotic indices, and we present the results of pilot metabarcoding studies using environmental DNA to infer biotic indices. We discuss the main advantages and pitfalls of metabarcoding approaches to assess parameters such as richness, abundance, taxonomic composition and species ecological values, to be used for calculation of biotic indices. We present some future developments to fully exploit the potential of metabarcoding data and improve the accuracy and precision of their analysis. We also propose some recommendations for the future integration of DNA metabarcoding to routine biomonitoring programs.info:eu-repo/semantics/publishedVersio

Discussions about the Relation between Limit and Continuity of a Function: investigating Concept Images

This paper presents the results of an investigation that was made with university students enrolled in the 3rd and 4 th semester of graduation in mathematics at two public universities in the state of Pará (Brazil). We aimed to investigate the concept image of these subjects about the relation between limit and continuity of a function, through an exploratory study done in two stages. The results were related to the researches of Tall and Vinner (1981), Vinner (1991) that composed our theoretical framework. Among the evoked concept images, we emphasize the idea that when a function is not defined in one point of the domain implies, necessarily, in the non-existence of the limit of that function in that point. That is, according to them, the limit’s existence depends on the continuity of the function.Este trabalho apresenta resultados de uma investigação realizada junto a estudantes universitários que cursavam o 3º e o 4º semestre de licenciatura em matemática de duas universidades públicas do estado do Pará (Brasil). Objetivamos investigar as imagens conceituais desses sujeitos acerca da relação entre limite e continuidade de uma função, por meio de um estudo exploratório realizado em duas etapas, cujos resultados foram relacionados às pesquisas de Tall e Vinner (1981), Vinner (1991) que, por sua vez, compuseram a base da fundamentação teórica de nosso estudo. Dentre as imagens conceituais evocadas pelos sujeitos investigados, ressaltamos aquelas voltadas para a ideia de que o fato de uma função não estar definida em determinado ponto do domínio implica, necessariamente, na não existência do limite da função naquele ponto. Ou seja, de acordo com os sujeitos, a existência do limite depende da continuidade da função

Advances in the use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems

Conservation and sustainable management of aquatic ecosystems is a priority in environmental programs worldwide. However, these aims are highly dependent on the efficiency, accuracy and cost of existent methods for the detection of keystone species and monitoring of biological communities. Rapid advances in eDNA, barcoding and metabarcoding promoted by high-throughput sequencing technologies are generating millions of sequences in a fast way, with a promising cost reduction, and overcoming some difficulties of the traditional taxonomic approaches. This paper provides an updated broad perspective of the current developments in this dynamic field presented in the special session (SS) "The use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems" of the XIX Congress of the Iberian Association of Limnology (AIL2018), held in Coimbra, Portugal.Developments presented are mainly focused on the Iberian Peninsula (Portugal and Spain, including Atlantic Macaronesian islands) but include studies in France, Germany, Finland, Russia (Siberia) and South America. The networks within which these researchers are involved are yet even broader, profiting from existing molecular facilities, and traditional taxonomic expertise, which can be viewed as a characteristic of this new research area. It was evident in the SS that the use of molecular tools is widespread, being used to study a diversity of aquatic systems, from rivers' headwaters to estuaries and coastal lagoons, and volcanic, mountain and frozen lakes to hot springs. The organisms targeted are likewise varied and include fish, macroinvertebrates, meiofauna, microalgae such as diatoms and dinoflagellates, other protists, fungi, and bacteria (cyanobacteria and other). Some studies address the whole biodiversity (i.e., all species present independently of the taxonomic group) from environmental samples of water, biofilms and preservative solution from field samples (e.g., ethanol from macroinvertebrate samples). Great advances were acknowledged inWe are grateful to all participants of the special session "The use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems" for the productive discussions during the AIL 2018 meeting (XIX Iberian Association of Limnology meeting in Coimbra (Portugal, June 2018). M.J. Feio is supported by MARE strategic program (UID/MAR/04292/2013); SFP Almeida is supported by GeoBioTec strategic program UID/GEO/04035/2019. R. Cordeiro was supported by a Ph.D. Grant (M3.1.a/F/017/2011) from Fundo Regional da Ciencia e Tecnologia (FRCT); A.F. Filipe and A. Garcia-Raventos were supported by FRESHING Project "Next-generation biomonitoring: freshwater bioassessment and species conservation improved with metagenomics" funded by the Portuguese Foundation for Science and Technology (FCT) and COMPETE (PTDC/AAG-MAA/2261/2014 -POCI-01-0145-FEDER-356 016824); F.M.S. Martins was supported by a FCT PhD grant (SFRH/BD/104703/2014); A.R. Calapez was supported by a grant from the FCT-PhD programme FLUVIO (PD\BD\52510\2014); A.M. Pujante acknowledges the BIOWAT-KIT_E!11892 Eurostars project; Maria Fais and Sofia Duarte were supported, respectively, by a PhD (SFRH/BD/113547/2015) and a post-doc fellowship (SFRH/BPD/109842/2015), from FCT; and C. Murria acknowledges the Fundacio Aigues de Barcelona for funding his research

The global EPTO database : Worldwide occurrences of aquatic insects

Motivation: Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo-referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO).Main type of variables contained: A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub-catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location.Spatial location and grain: The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system.Time period and grain: Sampling years span from 1951 to 2021. Ninety-nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub-datasets, exact dates can be retrieved upon communication with the data contributors.Major taxa and level of measurement: Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification.Software format: The entire tab-separated value (.csv) database can be downloaded and visualized at . Fifty individual datasets are also available at , while six datasets have restricted access. For the latter, we share metadata and the contact details of the authors.Peer reviewe