Papers by Tacyana Oliveira
… of Ethnobiology and …, Jan 1, 2005
From a conservationist perspective, seahorses are threatened fishes. Concomitantly, from a socioe... more From a conservationist perspective, seahorses are threatened fishes. Concomitantly, from a socioeconomic perspective, they represent a source of income to many fishing communities in developing countries. An integration between these two views requires, among other things, the recognition that seahorse fishers have knowledge and abilities that can assist the implementation of conservation strategies and of management plans for seahorses and their habitats. This paper documents the knowledge held by Brazilian fishers on the biology and ecology of the longsnout seahorse Hippocampus reidi. Its aims were to explore collaborative approaches to seahorse conservation and management in Brazil; to assess fishers' perception of seahorse biology and ecology, in the context evaluating potential management options; to increase fishers' involvement with seahorse conservation in Brazil. Data were obtained through questionnaires and interviews made during field surveys conducted in fishing villages located in the States of Piauí, Ceará, Paraíba, Maranhão, Pernambuco and Pará. We consider the following aspects as positive for the conservation of seahorses and their habitats in Brazil: fishers were willing to dialogue with researchers; although captures and/or trade of brooding seahorses occurred, most interviewees recognized the importance of reproduction to the maintenance of seahorses in the wild (and therefore of their source of income), and expressed concern over population declines; fishers associated the presence of a ventral pouch with reproduction in seahorses (regardless of them knowing which sex bears the pouch), and this may facilitate the construction of collaborative management options designed to eliminate captures of brooding specimens; fishers recognized microhabitats of importance to the maintenance of seahorse wild populations; fishers who kept seahorses in captivity tended to recognize the condtions as poor, and as being a cause of seahorse mortality.
Regional Environmental Change, 2015
Evidence-Based Complementary and Alternative Medicine, 2013
The connection between eating and healing is common in traditional folk medical systems, and the ... more 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.
Neotropical Ichthyology, 2007
This paper provides a case study of a threatened seahorse species, Hippocampus reidi, highlightin... more This paper provides a case study of a threatened seahorse species, Hippocampus reidi, highlighting the importance of using ecological information to assist conservation and management initiatives. Underwater visual sighting data (50 x 2m transect) gathered along the NE, SE and S portions of the Brazilian coast revealed an unequal distribution across localities, perhaps related to harvesting pressure, and a mean density of 0.026 ind.m -2 . Our findings suggest some restricted spatial use by H. reidi, which was consistent with its estimated home range, and with re-sighting of specimens. Reproduction was recorded year-round, however productive peaks may exist. Components of habitat structure mostly used as anchoring points were mangrove plants, macroalgae, cnidarians, seagrass, sponges, and bryozoans. Conservation recommendations include: further characterization and mapping of habitats; assessment of availability and condition of microhabitats in selected areas, and studies on dispersal routes during initial life stages.
Seahorses are known to produce sounds in different behavioural contexts, but information on the s... more Seahorses are known to produce sounds in different behavioural contexts, but information on the sound production in this fish group is scarce. Here we examined the acoustic behaviour of the longsnout seahorse Hippocampus reidi by analysing sound production when fish were introduced to a new environment and during feeding, handling and courtship. We show that males and females produce two distinct sound types: 'clicks' (main energy between 50 and 800 Hz) during feeding and courtship, and previously undescribed 'growls' (main energy concentrated below 200 Hz). The latter consists of series of sound pulses uttered in stress situations when the animals were handheld. Growls were accompanied by body vibrations, and may constitute an additional escape mechanism in seahorses, which might startle predators. During reproductive behaviour, clicks were most abundant on the third (last) day of courtship; they were particularly associated with the males' pouch-pumping behaviour, suggesting synchronization between sound production and courtship behaviour. This is consistent with the biology of Hippocampus species, which are mostly monogamous and form pair bonds. Thus, a courtship call may be used to signal readiness to mate.
Journal of Zoology
Seahorses are known to produce sounds in different behavioural contexts, but information on the s... more Seahorses are known to produce sounds in different behavioural contexts, but information on the sound production in this fish group is scarce. Here we examined the acoustic behaviour of the longsnout seahorse Hippocampus reidi by analysing sound production when fish were introduced to a new environment and during feeding, handling and courtship. We show that males and females produce two distinct sound types: ‘clicks’ (main energy between 50 and 800 Hz) during feeding and courtship, and previously undescribed ‘growls’ (main energy concentrated below 200 Hz). The latter consists of series of sound pulses uttered in stress situations when the animals were handheld. Growls were accompanied by body vibrations, and may constitute an additional escape mechanism in seahorses, which might startle predators. During reproductive behaviour, clicks were most abundant on the third (last) day of courtship; they were particularly associated with the males’ pouch-pumping behaviour, suggesting synchronization between sound production and courtship behaviour. This is consistent with the biology of Hippocampus species, which are mostly monogamous and form pair bonds. Thus, a courtship call may be used to signal readiness to mate.
Neotropical Ichthyology, Jan 1, 2010
This paper presents novel sex-related characteristics in Hippocampus reidi, expressed as a promin... more This paper presents novel sex-related characteristics in Hippocampus reidi, expressed as a prominent and pigmented keel (males only), and by a row of dorsolateral spots mostly (97.4%) found in males. While the keel was found even in the smallest males sampled, the dorsolateral spots appear to be associated with body size. Ex situ observations revealed that during courtship males highlighted both characters by turning pale their background body colour. Understanding such colour and behavioural patterns is relevant to increase our knowledge about sexual selection in a morphologically and biologically unique group of fishes.
Animals in Traditional …, Jan 1, 2012
This chapter reviews the uses of marine invertebrates for medicinal purposes, based on an extensi... more This chapter reviews the uses of marine invertebrates for medicinal purposes, based on an extensive literature survey. We identified at least 266 species which are prescribed to treat a number of diseases and conditions categories, especially those of the digestive and ...
Animals in Traditional Folk …, Jan 1, 2012
Seahorses (Hippocampus spp.) are under threat worldwide because of the global demand for them and... more Seahorses (Hippocampus spp.) are under threat worldwide because of the global demand for them and products arising from them, and by destruction of their habitats. A landmark report published in 1996 exposed the massive trade in seahorses, involving at least 32 ...
Biodiversity and …, Jan 1, 2011
Seahorses (Hippocampus spp.) are globally threatened by overexploitation and habitat destruction;... more Seahorses (Hippocampus spp.) are globally threatened by overexploitation and habitat destruction; they are also regarded as susceptible to heavy exploitation due to some of their life-history traits. From an economic perspective, they are fishes with high monetary value and marketability. Seahorses are now listed in Appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), to ensure that the international trade is not detrimental to the survival of wild populations; the effectiveness evaluation of these international controls needs comparable monitoring data, including evaluation of spatial and temporal trends. This study assesses the seahorse trade in Brazil, aiming to detect trends in catch levels, volumes and prices. Our main findings were: the dried trade was unregulated, without formal records, and primarily domestic, although records of unreported exports existed; it was primarily sustained by incidental captures in trawl nets. The live seahorse trade was mainly destined for exports, and regulated through national quotas. Between 2002 and 2009, mean prices for dried seahorses ranged from US$1.06 ± 0.46 (level 1 traders) to US$2.78 ± 0.68 (end-sellers) each, while mean prices for each live seahorse traded on the domestic market (
Neotropical …, Jan 1, 2008
This paper presents the results of the first analysis of the natural diet of Hippocampus reidi, o... more 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.
Neotropical …, Jan 1, 2007
This paper provides a case study of a threatened seahorse species, Hippocampus reidi, highlightin... more This paper provides a case study of a threatened seahorse species, Hippocampus reidi, highlighting the importance of using ecological information to assist conservation and management initiatives. Underwater visual sighting data (50 x 2m transect) gathered along the NE, SE and S portions of the Brazilian coast revealed an unequal distribution across localities, perhaps related to harvesting pressure, and a mean density of 0.026 ind.m-2. Our findings suggest some restricted spatial use by H. reidi, which was consistent with its estimated home range, and with re-sighting of specimens. Reproduction was recorded year-round, however productive peaks may exist. Components of habitat structure mostly used as anchoring points were mangrove plants, macroalgae, cnidarians, seagrass, sponges, and bryozoans. Conservation recommendations include: further characterization and mapping of habitats; assessment of availability and condition of microhabitats in selected areas, and studies on dispersal routes during initial life stages.
… of Ethnobiology and …, Jan 1, 2005
From a conservationist perspective, seahorses are threatened fishes. Concomitantly, from a socioe... more From a conservationist perspective, seahorses are threatened fishes. Concomitantly, from a socioeconomic perspective, they represent a source of income to many fishing communities in developing countries. An integration between these two views requires, among other things, the recognition that seahorse fishers have knowledge and abilities that can assist the implementation of conservation strategies and of management plans for seahorses and their habitats. This paper documents the knowledge held by Brazilian fishers on the biology and ecology of the longsnout seahorse Hippocampus reidi. Its aims were to explore collaborative approaches to seahorse conservation and management in Brazil; to assess fishers' perception of seahorse biology and ecology, in the context evaluating potential management options; to increase fishers' involvement with seahorse conservation in Brazil. Data were obtained through questionnaires and interviews made during field surveys conducted in fishing villages located in the States of Piauí, Ceará, Paraíba, Maranhão, Pernambuco and Pará. We consider the following aspects as positive for the conservation of seahorses and their habitats in Brazil: fishers were willing to dialogue with researchers; although captures and/or trade of brooding seahorses occurred, most interviewees recognized the importance of reproduction to the maintenance of seahorses in the wild (and therefore of their source of income), and expressed concern over population declines; fishers associated the presence of a ventral pouch with reproduction in seahorses (regardless of them knowing which sex bears the pouch), and this may facilitate the construction of collaborative management options designed to eliminate captures of brooding specimens; fishers recognized microhabitats of importance to the maintenance of seahorse wild populations; fishers who kept seahorses in captivity tended to recognize the condtions as poor, and as being a cause of seahorse mortality.
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Papers by Tacyana Oliveira