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.Neste artigo apresenta-se um estudo de caso de uma espécie ameaçada de cavalo-marinho, Hippocampus reidi, enfatizando a importância de utilizar informações ecológicas nas ações de conservação e manejo. Dados de censo visual (transectos de 50 x 2m) obtidos nas porções NE, SE e S da costa brasileira revelaram uma distribuição heterogênea entre as localidades, talvez relacionada à pressão de coleta, e uma densidade média de 0.026 ind.m -2. Os resultados sugerem limitação no uso do espaço por H. reidi (consistente com a área vital estimada e com a re-avistagem de exemplares) e que a reprodução ocorre o ano inteiro, embora com possíveis picos. Os componentes da estrutura do habitat mais freqüentemente utilizados como pontos de ancoragem pelos cavalos-marinhos foram vegetação de mangue, macroalgas, cnidários, capim marinho e briozoários. Recomendações conservacionistas incluem caracterização adicional e mapeamento de habitats; avaliação da disponibilidade e condição dos microhabitats em áreas selecionadas, e estudos sobre rotas de dispersão durante as fases iniciais de vida.

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.

Temporal and spatial variations and environmental factors influencing the structure of tidepool fish assemblages were quantitatively investigated at Iparana beach, northeast Brazilian coast. The majority of the tidepool fishes sampled were suprabenthic juvenile individuals of great mobility. We recorded during monthly diurnal underwater visual censuses a total of 4,750 fish from 26 species, represented mainly by partial residents from the families Scaridae, Haemulidae, Gerreidae and Pomacentridae. The number of species and individuals showed significant variability among tidepools as a response to variations in their volume and type of substrate cover. The greatest species abundance and richness associated with rocks covered with algae suggested that substrate complexity is one of the main factors defining the spatial structure of the tidepool ichthyofauna. Temporal variability in species abundance and richness was associated with changes in salinity levels due to seasonal rainfalls. A higher number of juvenile fishes from December to May in our samples corroborate the hypothesis that the tidepools act as nursery sites. Therefore, the species associations found in this study and their relation to seasonal and spatial discontinuities may be partly explained according to their habitat requirements and reproductive cycles.

This paper described aspects of feeding behavior of Myrichthys ocellatus in the Western Atlantic, using diving observations and additional data from literature. The feeding behavior of M. ocellatus was characterized by scanning the sand surface and searching for buried preys, using its head and tail as a searching tool. Twelve species of reef fish were detected as followers of M. ocellatus, including three new records of follower species. The food overlap index between M. ocellatus and most follower species was low.O presente estudo descreveu aspectos do comportamento alimentar de Myrichthys ocellatus no Atlântico ocidental, através de observações subaquáticas, complementadas com dados compilados da literatura. Myrichthys ocellatus caracteriza-se por buscar presas entocadas ou enterradas no substrato não consolidados e por usar a cauda e a cabeça como ferramentas de busca. Doze espécies de peixes recifais foram observadas como seguidoras de M. ocellatus, incluindo três novas ocorrências. O índice de sobreposição alimentar entre M. ocellatus e a maioria das espécies seguidoras foi baixo.

No abstract