NEOTROPICAL FRESHWATER FISHES: A dataset of occurrence and abundance of freshwater fishes in the Neotropics.

The Neotropical region hosts 4225 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 southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications.

Community stability and seasonal biotic homogenisation emphasize the effect of the invasive tropical tanner grass on macrophytes from a highly dynamic neotropical tidal river.

We described the spatial and temporal dynamics of aquatic macrophytes in a Neotropical coastal estuarine river, and identified the negative effects associated to the presence and dominance of the invasive tanner grass. We compared macrophyte beds along the Guaraguaçu River (South Brazil) over four years, using taxonomic and functional dimensions. Biodiversity descriptors were higher in the driest periods compared to the rainiest, although this difference seems to be decreasing over the studied years. Moreover, the spatial organization of biodiversity and community structure slightly changed over time. Such spatial community stability was highlighted by the dominance of the highly invasive tanner grass. In beds dominated by the invasive species, the biodiversity was reduced. As aquatic macrophytes represent an important group in water bodies, the long-term loss of seasonal differences in community structuring is of concern, mainly regarding its potential to impact other groups and ecosystem functioning. By analysing data from standardized monitoring, we were able to identify a poorly discussed facet of biotic homogenisation-the seasonal homogenisation. We also discussed the impact of massive development of invasive species and its consequences for biodiversity in a Neotropical river of outmost importance for biological conservation. Supplementary Information: The online version contains supplementary material available at 10.1007/s00027-022-00858-3.

Metazoan parasites of Micropterus salmoides (Lacépède 1802) (Perciformes, Centrarchidae): a review with evidences of spillover and spillback.

Among the topics related to invasion science, the least studied are parasite co-introduction and spillback. This leads to an uncertainty in invasion ecology theories and applications to management. Therefore, the present study brings a systematic review of published information on the metazoan parasite fauna of Micropterus salmoides, a widely introduced fish, with the aim of comparing information about the composition and richness of the associated parasite communities in its native and introduced regions. This review demonstrates that there were twice as many studies of M. salmoides in its native region in comparison with introduced regions, although most of the studies focused on the analysis of a single species or taxon of parasite. This bias impacts the number of parasite species observed and, consequently, the apparent importance of enemy release in introduced regions. The composition of the parasite community in the two regions showed high similarity, which indicates the introduction and acquisition of parasites in introduced regions. Otherwise, there was no pattern related to the geographic distance, highlighting the influence of the propagule pressure and vector strength on the introduction of novel parasites. This illustrates the importance of vector strength on fish-parasite co-introduction and the necessity of new research examining host-parasite interactions with the parasite community of the invaded ecosystems. We still do not know the major influences of the composition of the parasite fauna of M. salmoides or how we can manage to develop a more restrictive vector pathway of introduction. The future of our ecosystems depends on how to account for current and future interactions among novel interactions, habitat, and climate change.