Irrigation dams threaten Brazilian biodiversity.

Brazil is among the main contributors to global biodiversity, which, in turn, provides extensive ecosystem services. Agriculture is an activity that benefits greatly from these ecosystem services, but at the same time is degrading aquatic and terrestrial ecosystems and eroding Brazilian biodiversity. This conflict is growing, as emerging unsustainable legislative proposals that will benefit the agricultural sector are likely to accelerate the decline of biodiversity. One such initiative (Bill 1282/2019) would change Brazil's "Forest Code" (Law 12,651/2012) to facilitate construction of irrigation dams in Permanent Preservation Areas, a category that includes strips (with or without vegetation) along the edges of watercourses. Two other similar bills are advancing through committees in the Chamber of Deputies. Here we provide details of these three bills and discuss their consequences for Brazil's biodiversity if they are approved. Expected negative impacts with changes in the legislation include: increased deforestation; siltation; habitat fragmentation; introduction of non-native species; reduction in the availability of aquatic habitats; and changes in biogeochemical process. These proposals jeopardize biodiversity and may compromise the negotiations for an agreement between Mercosur and the European Union.

Notes on some type specimens of the Natural History Museum of Pirassununga, São Paulo, Brazil.

Professor Manuel Pereira de Godoy idealized the Natural History Museum of Pirassununga (MHNP, in Portuguese), State of São Paulo, Brazil, in 1938. In 1962, the MHNP was constructed in the backyard of his house. In 1977, the museum also received the type specimens of fishes from the defunct Estação Experimental de Biologia e Piscicultura de Pirassununga (EEBP). Here we provide notes (including photographs) of 11 type specimens (holotypes, paratypes, and syntypes) of the following 10 species belonging to four families and two orders: Leporinus amae, Astyanax (Astyanax) trierythropterus, Hyphessobrycon flammeus guabirubae, Plecostomus fluviatilis, Plecostomus luteus, Plecostomus topavae, Cetopsorhamdia iheringi, Chasmocranus brachynema, Nannorhamdia schubarti, Pimelodella insignis. Our study provides unprecedented photographic records of several type specimens deposited in MHNP. We expect this study will help in species identification and also assist future taxonomic studies of Neotropical freshwater fishes.

First record of plastic ingestion by a freshwater stingray.

The abundance and dispersion of plastic particles in aquatic ecosystems has become pervasive resulting in the incorporation of these materials into food webs. Here we describe the first record of plastic ingestion by the freshwater white-blotched river stingray Potamotrygon leopoldi (Potamotrygonidae), an endemic and threatened species in the Xingu River, Amazon basin. Potamotrygonidae stingrays inhabit exclusively Neotropical rivers, occupying rocky substrate habitats and feeding mainly on benthic macroinvertebrates. The gastrointestinal tract of 24 stingrays were analyzed, 16 (66.6 %) of which contained plastic particles. In total, 81 plastic particles were recorded and consisted of microplastics (< 5 mm, n = 57) and mesoplastics (5-25 mm, n = 24). The plastic particles found were classified into fibers (64.2 %, n = 52) and fragments (35.8 %, n = 29). The predominant color was blue (33.3 %, n = 27), followed by yellow (18.5 %, n = 15), white (14.8 %, n = 12), black (13.6 %, n = 11), green (6.2 %, n = 5), transparent (4.9 %, n = 4), pink, grey and brown (2.5 %, n = 2, each) and orange (1.2 %, n = 1). No significant correlation was observed between the number of plastic particles and the body size. Eight types of polymers were identified in the plastic particles analyzed using 2D FTIR Imaging. The most frequent polymer was artificial cellulose fiber. This is the first report of plastic ingestion by freshwater elasmobranchs in the world. Plastic waste has become an emerging problem in aquatic ecosystems globally and our results provide an important datapoint for freshwater stingrays in the Neotropics.

Association between Ichthyocladius (Diptera: Chironomidae) and armored catfishes in the Guareí River basin, São Paulo State, Brazil.

Ichthyocladius is a genus of chironomid (Diptera, Insecta) whose immature forms live attached to the bodies of some species of freshwater fishes. Here we investigate the association between Ichthyocladius spp. and armored catfish in streams of the Guareí River basin, Paraná River system, Brazil. We provide the first record of I. lilianae associated with fish in the São Paulo State and the Paraná River basin. In addition, this is the first report of Ichthyocladius associated with the armored catfishes Hypostomus iheringii and H. tietensis. Lastly, we record two undescribed species of Chironomidae (i.e., Ichthyocladius sp. 1 and Ichthyocladius sp. 2) associated with fishes.

Ghost nets: A poorly known threat to Brazilian freshwater biodiversity.

Ghost nets constitute a serious threat to aquatic biodiversity, because they entangle animals as long as they persist in the environment. However, scientific literature in Brazil is virtually silent about this issue in inland ecosystems. Concerned with this gap, we conducted searches on YouTube BR to gather information about ghost nets in Brazilian freshwaters. Through our search, we compiled 33 independent videos showing ghost nets in different aquatic environments. In several cases, we identified entangled animals (i.e., fishes, reptiles, and birds). In this work we also provide recommendations to better understand and mitigate this problem in Brazilian freshwater ecosystems.

Digital media reveal negative impacts of ghost nets on Brazilian marine biodiversity.

Abandoned, lost, or otherwise discarded fishing gear (ALDFG) is responsible for the entanglement of several marine species. Based on a search of digital media (i.e., Google and YouTubeBR), we assessed the negative impacts of ghost nets-a type of ALDFG-on Brazilian marine biodiversity. We found that ghost nets negatively affected crustaceans, fishes, reptiles, birds, and mammals in different parts of the Brazilian coast. Our reports include marine megafauna, such as the Bryde's whale and Guiana dolphin. In addition, we found that ghost nets impacted seven threatened species and had negative effects on animals within marine protected areas. Here, we provide an update on the negative impacts of ghost nets on Brazilian marine biota, but the real situation remains underestimated and somewhat obscure.

Large-scale Degradation of the Tocantins-Araguaia River Basin.

The Tocantins-Araguaia Basin is one of the largest river systems in South America, located entirely within Brazilian territory. In the last decades, capital-concentrating activities such as agribusiness, mining, and hydropower promoted extensive changes in land cover, hydrology, and environmental conditions. These changes are jeopardizing the basin's biodiversity and ecosystem services. Threats are escalating as poor environmental policies continue to be formulated, such as environmentally unsustainable hydropower plants, large-scale agriculture for commodity production, and aquaculture with non-native fish. If the current model persists, it will deepen the environmental crisis in the basin, compromising broad conservation goals and social development in the long term. Better policies will require thought and planning to minimize growing threats and ensure the basin's sustainability for future generations.

Plastic pollution: A focus on freshwater biodiversity.

Plastics are dominant pollutants in freshwater ecosystems worldwide. Scientific studies that investigated the interaction between plastics and freshwater biodiversity are incipient, especially if compared to the marine realm. In this review, we provide a brief overview of plastic pollution in freshwater ecosystems around the world. We found evidence of plastic ingestion by 206 freshwater species, from invertebrates to mammals, in natural or semi-natural ecosystems. In addition, we reported other consequences of synthetic polymers in freshwater ecosystems-including, for instance, the entanglement of animals of different groups (e.g., birds). The problem of plastic pollution is complex and will need coordinated actions, such as recycling programs, correct disposal, stringent legislation, regular inspection, replacement of synthetic polymers with other materials, and ecological restoration. Current information indicates that the situation in freshwater ecosystems may be as detrimental as the pollution found in the ocean, although highly underappreciated.

Negative impacts of mining on Neotropical freshwater fishes

Mining activities have significantly affected the Neotropical freshwater ichthyofauna, the most diverse in the world. However, no study has systematized knowledge on the subject. In this review, we assembled information on the main impacts of mining of crude oil, gold, iron, copper, and bauxite on aquatic ecosystems, emphasizing Neotropical freshwater fishes. The information obtained shows that mining activities generate several different disturbances, mainly via input of crude oil, metals and other pollutants, erosion and siltation, deforestation, and road construction. Mining has resulted in direct and indirect losses of fish diversity in several Neotropical waterbodies. The negative impacts on the ichthyofauna may change the structure of communities, compromise entire food chains, and erode ecosystem services provided by freshwater fishes. Particularly noteworthy is that mining activities (legal and illegal) are widespread in the Neotropics, and often located within or near protected areas. Actions to prevent and mitigate impacts, such as inspection, monitoring, management, and restoration plans, have been cursory or absent. In addition, there is strong political pressure to expand mining; if - or when - this happens, it will increase the potential of the activity to further diminish the diversity of Neotropical freshwater fishes.(AU)

As atividades de mineração têm impactado significativamente a ictiofauna de água doce Neotropical, a mais diversa do mundo. Porém, nenhum estudo sistematizou o conhecimento sobre o assunto. Nesta revisão, reunimos informações sobre os principais impactos da mineração de petróleo, ouro, ferro, cobre, e bauxita sobre os ecossistemas aquáticos, com ênfase nos peixes de água doce Neotropicais. As informações obtidas mostram que as atividades de mineração geram diferentes distúrbios, principalmente por meio de petróleo bruto, metais e outros poluentes, erosão e assoreamento, desmatamento e construção de estradas. A mineração resultou em perda direta e indireta de diversidade de peixes de vários corpos d'água Neotropicais. Os impactos negativos sobre a ictiofauna podem alterar a estrutura das comunidades, comprometer cadeias alimentares inteiras, bem como degradar os serviços ecossistêmicos fornecidos pelos peixes de água doce. Particularmente importante é que as atividades de mineração (legais e ilegais) são generalizadas na região Neotropical, e frequentemente estão localizadas dentro ou perto de áreas protegidas. Ações de prevenção e mitigação de impactos, como planos de fiscalização, monitoramento, manejo e restauração, têm sido precárias ou ausentes. Além disso, há forte pressão política para expandir a mineração; se - ou quando - isso acontecer, aumentará o potencial da atividade em diminuir ainda mais a diversidade de peixes de água doce Neotropicais.(AU)

Length-weight relationship and diet of the catfish Cambeva guareiensis (Siluriformes; Trichomycteridae) / Relação peso-comprimento e dieta do bagre Cambeva guareiensis (Siluriformes; Trichomycteridae)

Abstract: The length-weight relationship (LWR) and diet of a small trichomycterid catfish, Cambeva guareiensis, was studied based on 58 specimens captured in Corrente stream, Guareí River basin, São Paulo, Brazil. LWR analyses showed values of a ranged from 0.0097 to 0.0149 and b from 2.858 to 3.250. The analysis of the diet showed that high amounts of aquatic insects (93.75% of total items) were consumed by the species. In addition, we found no statistically significant differences when comparing the diet between the dry and rainy periods. Our study contributes to the knowledge on populational biology and feeding ecology of trichomycterid fishes in Brazilian streams.

Resumo: A relação peso-comprimento (RPC) e dieta de um pequeno bagre trichomycterídeo, Cambeva guareiensis, foi estudada com base em 58 espécimes capturados no riacho Corrente, bacia do rio Guareí, São Paulo, Brasil. As análises de RPC mostraram valores de a variando entre 0,0097-0,0149 e de b entre 2,858-3,250. A análise da dieta mostrou que altas quantidades de insetos aquáticos (93,75% do total de itens) foram consumidas pela espécie. Além disso, não encontramos diferenças estatisticamente significativas quando comparamos a dieta entre os períodos seco e chuvoso. Nosso estudo contribui para o conhecimento da biologia populacional e ecologia alimentar de peixes trichomicterídeos em riachos brasileiros.

Drifting in a free-flowing river: Distribution of fish eggs and larvae in a small tributary of a Neotropical reservoir / À deriva em um rio de fluxo livre: Distribuição de ovos e larvas de peixes em um pequeno afluente de um reservatório Neotropical

Abstract: We investigated spatial and temporal variations in the distribution of fish eggs and larvae in the Guareí River, a free-flowing tributary located in the upper section of the Jurumirim Reservoir, Paranapanema River, Brazil. Fish eggs and larvae were sampled ~ fortnightly from November 2017 to March 2018 (Cycle 1), and from November 2018 to March 2019 (Cycle 2), at three sites distributed along the entire course of the Guareí River. We collected 859 fish eggs and 1,340 larvae, comprising 19 taxa. We found reproductive activity of several fish species in the Guareí River, including long-distance migrants. However, there was no spatial differences in the assemblage structure and densities of fish eggs and larvae along the channel of Guareí River. We recorded temporal differences in larvae density only in Cycle 2. The consistent capture of fish eggs and larvae in two reproductive cycles is strong evidence that this river is a spawning site for a variety of fish species. Thus, we recommend maintaining its natural flow regime.

Resumo: Investigamos as variações espaciais e temporais na distribuição de ovos e larvas de peixes no rio Guareí, um afluente de fluxo livre localizado na parte superior do Reservatório de Jurumirim, bacia do rio Paranapanema, Brasil. Ovos e larvas de peixes foram amostrados ~ quinzenalmente de novembro de 2017 a março de 2018 (Ciclo 1), e de novembro de 2018 a março de 2019 (Ciclo 2), em três locais distribuídos ao longo de todo o curso do rio Guareí. Foram coletados 859 ovos de peixes e 1.340 larvas, compreendendo 19 táxons. Nós encontramos atividade reprodutiva de várias espécies no rio Guareí, incluindo espécies migradoras de longa distância. Contudo, não houve diferenças espaciais na estrutura das assembleias e nas densidades de ovos e larvas e ao longo do canal do rio Guareí. Diferenças temporais foram significativas apenas para densidade de larvas no Ciclo 2. A captura consistente de ovos e larvas de peixes em dois ciclos reprodutivos é uma forte evidência de que este rio é um local para a reprodução de várias espécies de peixes. Assim, recomendamos a manutenção do seu regime de fluxo natural.

Water diversion in Brazil threatens biodiversity.

Construction of water diversions is a common response to the increasing demands for freshwater, often resulting in benefits to communities but with the risk of multiple environmental, economic, and social impacts. Water-diversion projects can favor massive introductions and accelerate biotic homogenization. This study provides empirical evidence on the consequences of a proposed law intended to divert water from two large and historically isolated river basins in Brazil: Tocantins to São Francisco. Compositional similarity (CS) and ß-diversity were quantified encompassing aquatic organisms: mollusks, zooplankton, crustaceans, insects, fishes, amphibians, reptiles, mammals, and plants. For CS we (i) considered only native species, and (ii) simulated the introduction of non-natives and assumed the extinction of threatened species due to this water-diversion project. We highlight the environmental risks of such large-scale projects, which are expected to cause impacts on biodiversity linked to bioinvasion and homogenization, and we recommend alternatives in order to solve water-demand conflicts.

Knowing biodiversity: Fishes from the Guareí River basin, a tributary of the Jurumirim reservoir, Paranapanema River, Brazil / Conhecendo a biodiversidade: Peixes da bacia do Rio Guareí, um afluente do reservatório de Jurumirim, Rio Paranapanema, Brasil

Abstract: The Guareí River is a tributary of the Paranapanema River (Brazil), located in the upper portion of the Jurumirim Reservoir. Fish fauna studies in this watershed began in the 2000s, but they were restricted to a few waterbodies. This work conducted a broad survey of the fish fauna in tributary streams and the main channel of the Guareí River. Sampling occurred between February 2017 and November 2018 at 36 sites and using different collection methods. We captured 2,169 specimens belonging to 50 species, 16 families and 6 orders. The species accumulation curve tended to stabilize but indicated that species richness is underestimated. Almost all species are native (46); only three were non-native (Hyphessobrycon eques, Oreochromis niloticus and Poecilia reticulata) and one was undefined (Gymnotus pantanal). Among the native species, two are unknown to science (Bryconamericus aff. iheringii and Hypostomus sp. n.) and three are migratory (Leporinus friderici, Megaleporinus obtusidens and Pimelodus maculatus). In this paper, we provide images of species collected. Results indicate that the Guareí River basin is a hotspot of fish diversity in the Upper Paranapanema River, stressing the need for adequate management and conservation actions.

Resumo: O Rio Guareí é um afluente do Rio Paranapanema (Brasil), localizado na parte superior do reservatório de Jurumirim. Os estudos da fauna de peixes nesta bacia hidrográfica começaram nos anos 2000, mas estão restritos a poucos corpos d'água. Este trabalho realizou um amplo levantamento da ictiofauna em tributários e no canal principal do Rio Guareí. As amostragens ocorreram entre Fevereiro de 2017 e Novembro de 2018 em 36 sítios e utilizando diferentes métodos de coleta. Capturamos 2.169 espécimes pertencentes a 50 espécies, 16 famílias e 6 ordens. A curva de acumulação de espécies tendeu a se estabilizar, mas indicou que a riqueza de espécies está subestimada. Quase todas as espécies são nativas (46); apenas três não nativas (Hyphessobrycon eques, Oreochromis niloticus, e Poecilia reticulata) e uma não definida (Gymnotus pantanal). Entre as espécies nativas, duas são desconhecidas da ciência (Bryconamericus aff. iheringii e Hypostomus sp. n.) e três migradoras (Leporinus friderici, Megaleporinus obtusidens e Pimelodus maculatus). Neste artigo, fornecemos imagens das espécies coletadas. Os resultados indicam que a bacia do Rio Guareí é uma região importante em termos de diversidade de peixes no alto Rio Paranapanema, enfatizando a necessidade de ações adequadas de manejo e conservação.

A case of complete albinism in the catfish Cambeva guareiensis (Siluriformes: Trichomycteridae) / Um caso de albinismo completo no bagrinho Cambeva guareiensis (Siluriformes: Trichomycteridae)

Abstract: Albinism has been recorded in Neotropical freshwater fishes, mostly for nocturnal or cryptobiotic species. We report herein a case of albinism in the catfish Cambeva guareiensis (Trichomycteridae) from the Guareí River basin, Upper Paraná River basin, southeastern Brazil. The albino fish was caught with seven individuals with typical color pattern of the species. The features of the albino fish in life and shortly after preservation are described and illustrated.

Resumo: Albinismo tem sido registrado em peixes de água doce Neotropicais, principalmente em espécies noturnas ou criptobióticas. Relatamos aqui um caso de albinismo no bagrinho Cambeva guareiensis (Trichomycteridae) da bacia do Rio Guareí, bacia do Alto Rio Paraná, sudeste do Brasil. O peixe albino foi capturado juntamente com sete indivíduos com padrão de cor típico da espécie. As caracteristicas do peixe albino em vida e logo após a preservação são descritas e ilustradas.

Ichthyofauna of streams of the Rio Sapucaí basin, upper Rio Paraná system, Minas Gerais, Brazil / Ictiofauna de riachos da bacia do Rio Sapucaí, sistema do alto Rio Paraná, Minas Gerais, Brasil

Abstract: The Rio Sapucaí basin, in Minas Gerais State, Brazil, is one of the many watersheds of the upper Rio Paraná system. Ichthyofauna surveys in this basin, in general, are scarce. In addition, small rivers and streams of the region have been targets of anthropogenic actions (e.g., pollution) - which suggest that more ichthyological studies must be performed within the watershed. In this study we provide a survey of species that occur within three streams of the lower Rio Sapucaí basin. Samples were collected in April, July, and November 2017 and in May 2018. Collections resulted in 349 individuals belonging to 28 species, five orders, and 12 families. Among our findings are three putatively undescribed species and the first record of Oligosarcus argenteus and Pareiorhina hyptiorhachis within the Rio Paraná system.

Resumo: A bacia do Rio Sapucaí, no Estado de Minas Gerais, Brasil, é uma das muitas bacias hidrográficas do sistema do alto Rio Paraná. Levantamentos de ictiofauna nessa bacia, em geral, são escassos. Além disso, rios de pequeno porte e córregos da região têm sido alvos de ações antrópicas (e.g., poluição) - o que sugere que mais estudos ictiológicos devem ser realizados na bacia. Neste trabalho nós fornecemos um levantamento de espécies que ocorrem em três riachos da porção baixa da bacia do Rio Sapucaí. As amostras foram coletadas em Abril, Julho, e Novembro de 2017 e em Maio de 2018. As coletas resultaram em 349 indivíduos pertencentes a 28 espécies, cinco ordens e 12 famílias. Dentre os nossos achados estão três espécies possivelmente não descritas e o primeiro registro de Oligosarcus argenteus e Pareiorhina hyptiorhachis no sistema do Rio Paraná.