The aquatic Macrophytes as nursery grounds of the Amazon's Fish fauna

The present research describes the size structure and maturity of the fish that lives associated to roots of aquatic macrophytes during the high water period. The main objective was to test the hypothesis that this habitat functions as nursery ground to the fish fauna of the Amazon floodplain. Sampling summed up 3910 individuals of 91 species on four types of aquatic macrophytes (Paspalum repens, Echynocloa polystachya, Eichhornia spp. and mixed decomposing grasses) at three floodplain lakes (Camaleão, Rei and Janauacá). Most fish (90%) were shorher than 7 cm. The fish fauna was composed by 87% young individuals, which 41 species were commercialy exploited. These results indicate that this habitat is an important nursery ground and its conservation will safeguard fisheries resources.O presente estudo descreve a estrutura de tamanho e maturidade sexual das espécies de peixes que vivem associadas às raízes de macrófitas aquáticas durante o período de cheia. Foi o objetivo do trabalho demonstrar que este habitat funciona como um berçário e que a maior parte da sua fauna é composta por indivíduos jovens. Foram coletados 3910 indivíduos de 91 espécies de peixes, em quatro tipos de macrófitas aquáticas (Paspalum repens, Echynochloa polystachya, Eichhornia spp. e "mistura de capins em decomposição") em três lagos de várzea da Amazônia Central (Camaleão, Rei e Janauacá). A ictiofauna foi composta predominantemente por indivíduos menores que 7 cm. Indivíduos jovens formaram a maioria da assembléia (87%). Quarenta e uma espécies são explotadas pela frota pesqueira da região. Conclui-se que este habitat é um berçário importante e que deve ser conservado para manter o potencial dos recursos pesqueiros da Amazônia Central

Ictiofauna associada às macrófitas aquáticas Eichhornia azurea (SW.) Kunth. e Eichhornia crassipes (Mart.) Solms. no lago Camaleão, Amazônia Central, Brasil

This research describes the influence of biotic and abiotic characteristics on fish fauna structure that inhabits the stands of aquatic macrophytes Eichhornia azurea and Eichhornia crassipes. 182 individuals were sampled belonging to 27 fish species in Camaleão lake, Central Amazonia. Values of dissolved oxygen and water temperature varied from 2.11 to 4.02mgL-1 and 29.17 to 30.93°C for the stands of E. crassipes, and from 1.29 to 2.59mgL-1 and 28.32 and 29.95°C for E. azurea. The highest number of fish species (24), individuals (134), biomass of roots (1572gm-2) belonged to E. azurea. Significantly differences among the stands were obtained to emerged portions (p<0.018; F=8.891) and to the number of individuals that do not support hypoxia (p<0.035; F=6.383). Diversity, evenness and similarity indexes show that fish assemblages associated to banks of E. azurea and E. crassipes have different structure and select the Eichhornia spp stand

Aberturas del cordón de arena de la laguna costera imboassica (estado de Rio de Janeiro, Brazil) no alteran la abundancia de los peces comerciales

The coastal lagoon Imboassica (Rio de Janeiro State) had from 1993 to 2004 four openings of the sand bar that separates it from the ocean. During this period, 28 samples of fish fauna occurred; 55.6% with commercial value classified in functional guilds as: residents of coastal lagoons (RLC), marine dependent (MD), marine visitors (VM) and from freshwater (D). The catch per unit effort CPUE from the fish species with commercial value during the periods before and after the openings was availed according to exposure time and area of the gill nets. It was observed a growing trend of the individuals VM, RCL and MD with commercial interest during the periods after the openings of the sand bar. When the sand bar remained closed for at least three years, it was observed an increase on the abundance of freshwater fish, as a reduction on other guilds (VM, RCL and MD). The fish production in Imboassica lagoon is considered low and varies in function of the opening and closing of the sand bar. © 2016, Instytut Technologii Drewna. All rights reserved

Population structure of the seahorse Hippocampus reidi (Syngnathiformes: Syngnathidae) in a Brazilian semi-arid estuary

Abstract The longsnout seahorse (Hippocampus reidi) is a vulnerable species found along most of the Brazilian coastline, such as semi-arid estuaries with strong rainfall seasonality, hypersalinity, and low depth. To evaluate the population structure of H. reidi over time, we monitored the seahorse population in the Pacoti estuary (Brazil) for one year, based on 248 registered specimens. Salinity, water transparency, sex, pregnancy, body height, and holdfast use were registered. Mixed linear models revealed that sampling month, salinity, and transparency had no influence on population density in the lower zone of the estuary. Pregnant individuals were more frequent in the dry season and at higher salinities. Mean body height (12.7 cm) increased in the dry season. Bright colors were predominant. The seahorses employed nine types of holdfasts, most often mangrove roots, and were found to reproduce throughout the year, peaking in the dry season. Salinity and transparency did not impact population density. In Brazilian semi-arid estuaries, the longsnout seahorse is strongly associated with mangrove vegetation, used as holdfast. Therefore, the conservation of seahorse populations depends on the conservation of the local mangrove forests

As Macrófitas aquáticas como berçário para a Ictiofauna da Várzea do Rio Amazonas

O presente estudo descreve a estrutura de tamanho e maturidade sexual das esp&#233;cies de peixes que vivem associadas &#224;s ra&#237;zes de macr&#243;fitas aqu&#225;ticas durante o per&#237;odo de cheia. Foi o objetivo do trabalho demonstrar que este habitat funciona como um ber&#231;&#225;rio e que a maior parte da sua fauna &#233; composta por indiv&#237;duos jovens. Foram coletados 3910 indiv&#237;duos de 91 esp&#233;cies de peixes, em quatro tipos de macr&#243;fitas aqu&#225;ticas (Paspalum repens, Echynochloa polystachya, Eichhornia spp. e "mistura de capins em decomposi&#231;&#227;o") em tr&#234;s lagos de v&#225;rzea da Amaz&#244;nia Central (Camale&#227;o, Rei e Janauac&#225;). A ictiofauna foi composta predominantemente por indiv&#237;duos menores que 7 cm. Indiv&#237;duos jovens formaram a maioria da assembl&#233;ia (87%). Quarenta e uma esp&#233;cies s&#227;o explotadas pela frota pesqueira da regi&#227;o. Conclui-se que este habitat &#233; um ber&#231;&#225;rio importante e que deve ser conservado para manter o potencial dos recursos pesqueiros da Amaz&#244;nia Central

Etnotaxonomia e tabus alimentares dos pescadores artesanais nos açudes Araras e Edson Queiroz, bacia do Rio Acaraú, Ceará, Brasil

The ethnoichthyology aims to describe and enhance the knowledge of fisher-folk, through studies that prove that they are carriers of bio-ecological knowledge about the fish they catch. Thus, this study aimed to evaluate the ethnotaxonomy and food taboos of fisherfolk public weirs Araras and Edson Queiroz (Ceará, Brazil). Was selected a repre-sentative population of fishermen for each of these weirs: Ilha de Esaú, for the Araras reservoir, and Vila São Cosme, to Edson Queiroz reservoir. They were conducted participant observation, semi-structured interviews, visual stimulation and guided tours with fishermen in selected populations. Twenty fishermen inter-viewed in Vila São Cosme and twenty-four in Ilha de Esaú addressing socioeconomic aspects of fisheries and ethnoecological of the main species of fish. Twenty ethnospecies were cited of fish and shrimp to be caught in weirs. In the classification of fish populations, fishermen using morphological and ecological aspects, presenting several ethnospecies with generic and few names binomial names. In your diet, these people consume fish as the main source of animal protein, and there are restrictions on social and cultural character. Thus, the con-sistency of knowledge of the fishermen of the Ilha de Esaú and Vila São Cosme, this knowledge can be incorporated in the development of management plans and sustainable management of water and fishing resources of weirs Araras and Edson Queiroz