Foreign stingers: South American freshwater river stingrays Potamotrygon spp. established in Indonesia.

The pet trade is known to be one of the most important pathways of aquatic non-native species introduction and Indonesia is a significant trade partner. Popular ornamental South American river stingrays (Potamotrygon spp.) were introduced to Indonesia in the 1980s and the culture was established. Here we present a detailed Indonesian market and aquaculture survey, the volume of trade between January 2020 and June 2022, and the list of customer countries with the total amount of imported stingrays. Climate similarities between the native range of P. motoro and P. jabuti and Indonesia were analysed. A significant number of areas of Indonesian islands were identified as suitable for the establishment of this species. This was confirmed by the first record of probably established populations in the Brantas River (Java). In total 13 individuals including newborns were captured. The culture of potamotrygonid stingrays is unregulated in Indonesia, and the risk of the establishment of this predator and its potential spread is alarming for wildlife. Moreover, the first case of envenomation caused by Potamotrygon spp. in the wild outside of South America was recorded. The current condition is predicted as the 'tip of the iceberg' and continuous monitoring and mitigation of risks are strongly recommended.

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.

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.

Aquaculture expansion in Brazilian freshwaters against the Aichi Biodiversity Targets.

The Convention on Biological Diversity proposed the Aichi Biodiversity Targets to improve conservation policies and to balance economic development, social welfare, and the maintenance of biodiversity/ecosystem services. Brazil is a signatory of the Aichi Biodiversity Targets and is the most diverse country in terms of freshwater fish, but its national policies have supported the development of unsustainable commercial and ornamental aquaculture, which has led to serious disturbances to inland ecosystems and natural resources. We analyzed the development of Brazilian aquaculture to show how current aquaculture expansion conflicts with all 20 Aichi Targets. This case suggests that Brazil and many other megadiverse developing countries will not meet international conservation targets, stressing the need for new strategies, such as the environmental management system, to improve biodiversity conservation.

Colorful invasion in permissive Neotropical ecosystems: establishment of ornamental non-native poeciliids of the genera Poecilia/Xiphophorus (Cyprinodontiformes: Poeciliidae) and management alternatives

Headwater creeks are environments susceptible to invasion by non-native fishes. We evaluated the reproduction of 22 populations of the non-native livebearers guppy Poecilia reticulata, black molly Poecilia sphenops, Yucatan molly Poecilia velifera, green swordtail Xiphophorus hellerii, southern platyfish Xiphophorus maculatus, and variable platyfish Xiphophorus variatus during an annual cycle in five headwater creeks located in the largest South American ornamental aquaculture center, Paraíba do Sul River basin, southeastern Brazil. With few exceptions, females of most species were found reproducing (stages 2, 3, 4) all year round in the creeks and gravid females of all species showed small sizes indicating stunting. Juveniles were frequent in all sites. The fecundity of the six poeciliids was always low in all periods. The sex ratio was biased for females in most species, both bimonthly as for the whole period. Water temperature, water level and rainfall were not significantly correlated with reproduction in any species. Therefore, most populations appeared well established. The pertinence of different management actions, such as devices to prevent fish escape, eradication with rotenone and research about negative effects on native species, is discussed in the light of current aquaculture practices in the region.(AU)

Riachos de cabeceira são ambientes susceptíveis à invasão por peixes não-nativos. Neste trabalho, avaliou-se a reprodução de 22 populações dos poecilídeos não-nativos guppy Poecilia reticulata, molinésia preta Poecilia sphenops, molinésia Poecilia velifera, espadinha Xiphophorus hellerii, plati Xiphophorus maculatus e plati variado Xiphophorus variatus durante diferentes anos em cinco riachos de cabeceira localizados no maior polo de piscicultura ornamental da América do Sul, bacia do rio Paraíba do Sul, sudeste do Brasil. Foram encontradas fêmeas da maioria das espécies em reprodução (estágios 2, 3, 4), durante todos os anos nos riachos e fêmeas grávidas de todas as espécies apresentaram pequeno tamanho indicando nanismo. Juvenis de todas as espécies foram frequentes em todos os locais. A fecundidade das seis espécies sempre foi baixa em todos os períodos. Para os períodos bimestrais e totais, encontrou-se mais fêmeas que machos na maioria das espécies. Temperatura e nível de água dos riachos, bem como precipitação pluviométrica não foram correlacionadas com a reprodução. Todas as populações estão estabelecidas nos locais e ações de gerenciamento como dispositivos para impedir a fuga de peixes, erradicação com rotenona e pesquisa científica sobre os efeitos negativos nas espécies nativas são discutidas em relação às práticas de piscicultura na região.(AU)

Influence of a large dam and importance of an undammed tributary on the reproductive ecology of the threatened fish matrinxã Brycon orthotaenia Günther, 1864 (Characiformes: Bryconidae) in southeastern Brazil

A total of 312 adults of matrinxã were captured bimonthly, between 2011-2012, in two sites of the rio São Francisco: immediately downstream of the Três Marias Dam (site 1) and in the confluence with the rio Abaeté (site 2). Specimens of Brycon orthotaenia from site 2 presented higher values of total length (32.24 ± 5.70 cm for females and 26.64 ± 3.79 cm for males) and body weight (506.66 ± 332.17 g for females and 267.36 ± 145.84 g for males), when compared with the site 1. In site 2 was registered the highest GSI means (9.97 ± 2.96 for females and 0.93 ± 0.52 for males), compared with the site 1 means. Reproduction period occurred from October to February. Unlike site 2, no spawned females or spent males were captured in site 1. Significant differences were found between females and males in site 2 (χ2 = 26.84, df = 1, P < 0.05). Physical-chemical parameters of the water presented higher values in site 2. The canonical correlation test indicated that the reproduction of males is less susceptible to environmental factors than that of females. These results show that B. orthotaenia finds favourable conditions to reproduction just in site 2.

Um total de 312 adultos de matrinxã foram capturados bimestralmente entre 2011-2012, em dois pontos do rio São Francisco: imediatamente a jusante da barragem de Três Marias (ponto 1) e na confluência com o rio Abaeté (ponto 2). Exemplares de Brycon orthotaenia do ponto 2 apresentaram maiores valores de comprimento total (32,24 ± 5,70 cm para fêmeas e 26,64 ± 3,79 cm para machos) e peso corporal (506,66 ± 332,17 g para fêmeas e 267,36 ± 145,84 g para machos) quando comparado com peixes do ponto 1. No ponto 2, foi registrado as maiores médias de IGS (9,97 ± 2,96 para fêmeas e 0,93 ± 0,52 para machos) em comparação com o ponto 1. O período reprodutivo ocorreu de outubro a fevereiro. Ao contrário do ponto 2, fêmeas desovadas e machos espermiados não foram capturados no ponto 1. Foram encontradas diferenças significativas entre fêmeas e machos no ponto 2 (χ2 = 26,84, gl = 1, P < 0,05). Parâmetros físico-químicos da água apresentaram maiores valores no ponto 2. A análise de correlação canônica indicou que a reprodução de machos é menos susceptível a fatores ambientais do que de fêmeas. Estes resultados mostram que B. orthotaenia encontra condições favoráveis para a reprodução apenas no ponto 2.

Invasion risks posed by ornamental freshwater fish trade to southeastern Brazilian rivers

A model was developed to assess the risk of invasion of ornamental non-native fishes to six rivers in the state of Minas Gerais, southeastern Brazil, with focus on species popularity. Thirty-nine aquarium shops, in six cities, were visited monthly from January to December 2007. In each city, fish species were identified, and their biology and invasion history information was obtained from the literature. We calculated the annual frequency of occurrence and average number of specimens monthly available in stores. Quarterly water temperature and dissolved oxygen data from 1997 to 2007 were obtained for the Velhas, Muriaé, Uberabinha, Sapucaí-Mirim, Doce and Todos os Santos Rivers from public databases. The invasion risk of each species was assessed through a model comprising nine parameters grouped in four variables: (i) Invasiveness (thermal and dissolved oxygen ranges, diet, parental care or fecundity), (ii) History of invasions (establishment), (iii) Propagule pressure (commercial success, comprising annual frequency of occurrence and number of specimens available monthly at stores), and (iv) Invasibility (water temperature and dissolved oxygen in the target river compatible with the species ranges). Of the 345 ornamental fish species for sale, 332 are non-native to either Minas Gerais (n = 151) or Brazil (n = 194). Based on the proposed cutting values, in particular the compatibility between species and recipient thermal ranges, five ornamental non-native species (Cyprinus rubrofuscus, Carassius auratus, Xiphophorus hellerii, Poecilia reticulata, and P. latipinna) can potentially invade the Velhas and Muriaé Rivers, four species (Cyprinus rubrofuscus, Carassius auratus, X. helleri, and P. reticulata) the Uberabinha River, four species (Cyprinus rubrofuscus, Carassius auratus, X. maculatus, and P. reticulata) the Sapucaí-Mirim River, three species (Carassius auratus, X. hellerii, and P. reticulata) the Doce River, and three species (Cyprinus rubrofuscus, P. reticulata, and Amatitlania nigrofasciata) can potentially invade the Todos os Santos River. Six recommendations are suggested to reduce the invasion risk of non-native fish on the rivers surveyed posed by aquarium trade.

Um modelo foi desenvolvido para avaliar o risco de invasão de peixes ornamentais não-nativos em seis rios do estado de Minas Gerais, sudeste do Brasil, com foco na popularidade das espécies. Trinta e nove lojas de aquário em seis cidades foram visitadas mensalmente de janeiro a dezembro de 2007. Em cada cidade, as espécies foram identificadas e suas biologias e histórias de invasão foram obtidas da literatura. Calculou-se a frequência de ocorrência anual e quantidade média mensal de exemplares disponíveis nas lojas. Foram obtidas temperaturas trimestrais da água e dados de oxigênio dissolvido de 1997 a 2007 dos rios Velhas, Muriaé, Uberabinha, Sapucaí-Mirim, Doce e Todos os Santos a partir de bases de dados públicas. O risco de invasão de cada espécie foi avaliado através de um modelo composto por nove parâmetros agrupados em quatro variáveis: (i) Invasividade (limite de alcance térmico/oxigênio dissolvido, dieta, cuidado parental ou fecundidade), (ii) Histórico de invasões (estabelecimento), (iii) Pressão de propágulos (sucesso comercial, composto pela frequência de ocorrência anual e número de exemplares disponíveis mensalmente nas lojas), e (iv) Invasibilidade (temperatura da água/oxigênio dissolvido dos rios compatível com o limite de alcance térmico/ oxigênio dissolvido das espécies). Das 345 espécies de peixes ornamentais para venda, 332 são não-nativos para Minas Gerais (n = 151) ou Brasil (n = 194). Com base nos valores de corte propostos, cinco espécies de peixes ornamentais não-nativos (Cyprinus rubrofuscus, Carassius auratus, Xiphophorus hellerii, Poecilia reticulata e P. latipinna) podem potencialmente invadir os rios Velhas e Muriaé, quatro espécies (C. rubrofuscus, C. auratus, X. helleri, P. reticulata) podem ...

E-commerce of freshwater aquarium fishes: potential disseminator of exotic species in Brazil / Comércio eletrônico de peixes ornamentais de água doce: potencial dispersor de espécies exóticas no Brasil

The availability of freshwater aquarium fish species for sale was surveyed from July 2005 to June 2006 in Brazilian electronic commerce and the Orkut website. São Paulo was the leading state regarding virtual shops, auctions on Arremate/Mercado Livre, and hobbyists on Orkut, with 52, 44 and 46%, respectively. The Southeast and South regions led the offer of pest species such as C. carpio, C. auratus and P. reticulata. Among the 207 species for sale, 14 species considered potential pests were identified, contrasting with only one page that warned about the dangers of aquarium dumping. The easy access to fish (especially the potential pest species) through e-commerce and Orkut, together with the low total price (unitary value + shipping and handling ranging from US$ 17.67 to 30.39), and fast interstate delivery (two-four days on average) confirm the widespread e-commerce accessibility and its high dispersal potential via postal services and home hobbyists trade. It is imperative to enforce the use of warnings or alert messages in e-commerce about the dangers of biological invasions.

A disponibilidade para venda de espécies de peixes ornamentais de água doce foi pesquisada de julho/2005 a junho/2006 no comércio eletrônico brasileiro e no site de relacionamentos Orkut. O Estado de São Paulo foi o principal em lojas virtuais, leilões no Arremate/Mercado Livre e aquaristas vendendo peixes no Orkut, com 52, 44 e 46%, respectivamente. As regiões Sudeste e Sul são as que mais anunciaram espécies como C. carpio, C. auratus e P. reticulata. Entre as 207 espécies disponíveis para venda, 14 foram identificadas como potenciais praga, contrastando com apenas uma página eletrônica que alertava sobre os perigos do descarte de espécies ornamentais exóticas em novos ambientes. O fácil acesso aos peixes (notadamente espécies consideradas potenciais praga) pelo comércio eletrônico e Orkut, aliado a um preço acessível (valor unitário + embalagem + frete entre US$ 17,67 a 30,39) e rápido transporte interestadual (média de dois a quatro dias), confirma a ampla acessibilidade do comércio eletrônico e seu alto potencial de dispersão via correios e aquaristas amadores. É obrigação do comércio eletrônico por em execução o uso de avisos ou mensagens de alerta sobre os perigos das invasões biológicas.