Mapping seahorses in a Brazilian estuary: mangrove structures as key predictors for distribution and habitat preference.

Planning for effective conservation demands an accurate understanding of the ecological aspects of species, particularly their distribution and habitat preferences. This is even more critical in the case of data-poor, rare, and threatened species, such as seahorses, mainly when they inhabit vulnerable ecosystems like estuaries. Given the importance of better understanding these parameters to design seahorse conservation strategies, we mapped the distribution and assessed habitat preferences of longsnout seahorses (Hippocampus reidi) in a mangrove estuary in a Brazilian protected area. Using generalised linear mixed-effects models we found that dense mangrove cover macro-habitats and shallow depths predicted seahorse sightings and higher densities. Furthermore, the selective index of micro-habitats used by seahorses showed that seahorses exhibited a preference for mangrove structures as holdfasts (i.e., fallen branches). Due to the significant importance of mangroves in providing suitable habitats for H. reidi in estuaries, it is crucial to enforce the protection of these ecosystems in conservation and management strategies for the species.

Marine or freshwater: the role of ornamental fish keeper's preferences in the conservation of aquatic organisms in Brazil.

Background: The use of ornamental fish as pets has important implications for the conservation of the species used in fish keeping, particularly in relation to overexploitation. Understanding ornamental fish keepers' relationship with the hobby can provide important information for assessing the potential impacts of the activity. Here, we analyzed the profile of Brazilian ornamental fish keepers and evaluated their preferences and the implications of their choices. Methods: Information was obtained by applying questionnaires to 906 ornamental fish keepers participating in fish keeping groups in a social network. The questionnaire contained questions about the species of fish kept (freshwater and marine), techniques used, socio-economic aspects, and associated conservation perspectives. Results: Most ornamental fish keepers were young men (20-40 years old), with higher education and monthly income above US$ 530.00. Participants predominantly kept freshwater fish (86%), but marine fish only (5%) or both marine and freshwater hobbyists (9%) were also recorded. A total of 523 species of ornamental fish were kept, most of which comprised freshwater (76% of the total) and exotic species (73%). About a third of the fish species recorded were under national trade restrictions. In addition, about a third of ornamental fish keepers declared that they also had invertebrates. Marine aquariums require a greater financial investment, especially at the beginning, than freshwater aquariums and are also almost entirely based on exotic species. The aesthetic factor is the main motivation associated with practicing this hobby, being color and behavior key factors in choosing fish. A total of 10% of hobbyists have already released fish into the wild, highlighting concerns about potential biological invasions. There is an urgent need to enforce regulations towards restricting ornamental fish keepers' access to threatened native species and potentially invasive species, as well as measures aimed at informing and raising hobbyists' awareness of conservation measures related to the hobby.

Trends in Medicinal Uses of Edible Wild Vertebrates in Brazil.

The use of food medicines is a widespread practice worldwide. In Brazil, such use is often associated with wild animals, mostly focusing on vertebrate species. Here we assessed taxonomic and ecological trends in traditional uses of wild edible vertebrates in the country, through an extensive ethnobiological database analysis. Our results showed that at least 165 health conditions are reportedly treated by edible vertebrate species (n = 204), mostly fishes and mammals. However, reptiles stand out presenting a higher plasticity in the treatment of multiple health conditions. Considering the 20 disease categories recorded, treatment prescriptions were similar within continental (i.e., terrestrial and freshwater) and also within coastal and marine habitats, which may reflect locally related trends in occurrence and use of the medicinal fauna. The comprehension of the multiplicity and trends in the therapeutic uses of Brazilian vertebrates is of particular interest from a conservation perspective, as several threatened species were recorded.

Wild animals used as food medicine in Brazil.

The connection between eating and healing is common in traditional folk medical systems, and the multiple possibilities resulting from the combination of biodiversity and culture confer a wealth and complexity in terms of knowledge of the flora and fauna as to their potential as food medicine. The growing awareness of the links between traditional therapeutic-alimentary uses of wildlife and conservation has drawn attention to the gaps in knowledge on the social, economic, and biological contexts in which different forms of traditional wildlife uses take place, particularly with regard to zootherapeutic resources. In this study we interviewed 124 merchants and 203 traditional users of animal-derived remedies in Brazil, aiming at documenting the animal species used as foods and medicines in urban and rural areas of the country. At least 354 wild animal species are used in Brazilian traditional medicine, of which 157 are also used as food. The high degree of overlap between medicinal and alimentary uses of wild animals highlights the importance of understanding the socioeconomic, cultural, and ecological contexts in which those traditional uses take place for elucidating their potential impact on public health and biodiversity conservation.

Assessing diet composition of seahorses in the wild using a non destructive method: Hippocampus reidi (Teleostei: Syngnathidae) as a study-case

This paper presents the results of the first analysis of the natural diet of Hippocampus reidi, one of the most sought after seahorse species in the international aquarium trade. Its main goals were to investigate food items and prey categories consumed by the species, and to discuss feeding strategy and inter and intra-individual components of niche breadth. Data were gathered from October 2005 to September 2006 at the Mamanguape estuary, State of Paraíba, NE Brazil. Food items from seahorses anaesthetized with clove oil were obtained by using a modified version of the flushing method, and were counted and identified to the lowest possible taxonomic level. Specimens were marked and had their height, sex, life and reproductive stage recorded, and then returned to the same place where they were found for the further assessment of anaesthetization/gut flushing on seahorses. Food items were analyzed using frequency of occurrence, relative abundance, index of preponderance and prey-specific abundance using the points method. The graphic method of Amundsen et al. (1996) was used to interpret the feeding strategy and contribution to niche breadth. Nematodes and crustaceans were the most important items found, the latter item usually being the most commonly found in the gut contents of syngnathids. No significant differences in diet composition were found between reproductive stages, however, a higher proportion of large items were consumed by the larger seahorses. The feeding strategy and niche breadth analysis suggests that H. reidi has a generalist feeding strategy, with high variation between phenotypes. Our results suggest that the anaesthetization-flushing technique has the potential to be a useful tool in seahorse research.

Este artigo apresenta os resultados do primeiro estudo sobre a alimentação natural de Hippocampus reidi, uma das espécies de cavalos-marinhos mais intensamente comercializadas pelo mercado aquarista. Seus principais objetivos foram descrever os itens alimentares e categorias de presas consumidos pela espécie e fornecer informações acerca da estratégia alimentar e dos componentes inter e intra-individuais para a largura de nicho. As amostragens foram realizadas mensalmente por meio de busca intensiva, entre outubro de 2005 e setembro de 2006, no estuário do rio Mamanguape, Paraíba, onde os cavalos marinhos foram marcados, anestesiados com óleo de cravo e submetidos à técnica da lavagem estomacal. Para cada cavalo-marinho registrou-se a altura, sexo, estágio de vida e estado reprodutivo. Após a coleta de dados, todos os cavalos-marinhos foram devolvidos ao mesmo local onde haviam sido encontrados e o material obtido através da lavagem foi identificado, em laboratório, até o menor nível taxonômico possível, com o auxílio de especialistas. Os itens alimentares foram descritos através de freqüência de ocorrência, abundância relativa, índice de preponderância e abundância específica; já a estratégia alimentar e contribuição para a largura de nicho foram descritos através do método de Amundsen. Os principais itens encontrados foram nematodos e crustáceos, não tendo sido encontradas diferenças entre os itens consumidos e o estado reprodutivo dos cavalos marinhos. Entretanto, verificou-se que exemplares de maior porte consumiram uma maior proporção de itens grandes. Os resultados sugerem que H. reidi apresenta uma estratégia alimentar generalista e com alta variação entre os fenótipos. Nossos resultados sugerem que a técnica da lavagem estomacal pode vir a representar uma ferramenta útil em estudos acerca de cavalos-marinhos.