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3.
J Fish Biol ; 97(5): 1393-1400, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32815164

ABSTRACT

Length at first maturity (L50 ) is an important tool for the management and conservation of fish populations. Traditional approaches based on macroscopic and microscopic maturity staging exhibit high accuracy and precision, while alternative approaches (e.g., Ig -based staging, stanza changing point) are less resource-demanding. Herein, we compare four approaches to estimate L50 in a population of the heptapterid Rhamdioglanis transfasciatus from Atlantic Forest streams. Fish were sampled monthly during a year by using electrofishing. We measured the length (cm), mass (g), and gonad mass (g) of each specimen, then classified their maturity status macroscopically and microscopically. Alternative approaches were strongly discordant from traditional ones. Logistic curves considering mature individuals as those displaying at least 1% of the maximum Ig in the sample greatly underestimated L50 for females and overestimated L50 for males. The stanza changing point derived from the polyphasic growth model underestimated L50 in both cases. Despite the increasing development of less onerous approaches, it seems that they are not suitable for all fish populations and the requirements to use such approaches demand further investigation.


Subject(s)
Body Size/physiology , Fishes/anatomy & histology , Models, Biological , Sexual Maturation/physiology , Animals , Female , Gonads/anatomy & histology , Male , Reproduction , Rivers , Seasons , Tropical Climate
4.
Neotrop. ichthyol ; 17(4): e180004, 2019. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1056801

ABSTRACT

The Paraíba do Sul River is affected by extensive water collection for supply, organic and industrial pollution, and dams. Nonetheless, the ichthyofauna maintains biodiversity and sustains artisanal fisheries. This study analyzes the composition, abundance and distribution of fish larvae, an important approach to determine the reproductive period and spawning sites. The sampling occurred from August 2011 through February 2013 in five sites at a transect between the banks on the lower reach of the Paraíba do Sul River. A total of 5,412 larvae belonging to 20 taxa was captured. The predominant order was Characiformes. Larvae of Prochilodus spp. and Leporinus spp. were the most abundant; larvae of Brycon insignis, an endangered species, were present. Fewer larvae were collected in the second reproductive cycle during a severe drought. The absence of eggs indicates that the study area is not used for spawning, and highlights the need for studies in the main channel and in the tributaries of the Paraíba do Sul River. Fish larvae need to have access to the marginal lagoons along the lower stretch of the river, an area which is the object of disputes between fishermen and farmers.(AU)


O rio Paraíba do Sul é afetado por retirada de água para abastecimento, poluição orgânica e industrial e barramentos, mas mantém a biodiversidade de peixes e sustenta a pesca artesanal. Este estudo apresenta a composição, abundância e distribuição de larvas de peixes, abordagem importante para determinar o período de reprodução e locais de desova. A amostragem ocorreu entre agosto de 2011 e fevereiro de 2013 em cinco pontos de um transecto de 500 m entre as margens no trecho inferior do rio Paraíba do Sul. Um total de 5.412 larvas de 20 táxons foi capturado. Predominaram Characiformes, sendo que larvas de Prochilodus spp. e Leporinus spp. foram as mais abundantes. Larvas de Brycon insignis, espécie em extinção, foram registradas. Larvas foram menos abundantes no segundo ciclo reprodutivo, coincidindo com o início de uma seca severa na região. A ausência de ovos nas amostras indica que a área estudada não é utilizada para desova e aponta a necessidade de estudos no canal principal a montante e nos afluentes. Ressaltamos a necessidade de acesso das larvas às lagoas marginais no trecho inferior do rio Paraíba do Sul, área objeto de desentendimentos entre pescadores e agricultores.(AU)


Subject(s)
Animals , Zooplankton/growth & development , Biodiversity , Models, Structural
5.
J Fish Biol ; 93(1): 30-39, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29882352

ABSTRACT

This study investigated the effect of hydrological periods on the feeding activity and trophic interactions of four piscivorous fishes from the middle Xingu River, Brazil: pike-characid Boulengerella cuvieri, dogtooth characin Hydrolycus armatus, dogtooth characin Hydrolycus tatauaia and South American silver croaker Plagioscion squamosissimus. Repletion Index (IR %), Alimentary Index (IAi %) and food web properties were calculated for each species. A total of 825 specimens were collected. The IR showed changes in feeding intensity of B. cuvieri, H. armatus and H. tatauaia among hydrological periods. Flood pulse showed no influence on composition and importance of food items consumed. Trophic connections showed that connectivity ranged from 0.025 to 0.038. The highest number of trophic connections (75) occurred in the high-water period, when 51 food items were recorded and the lowest number of trophic connections (43) occurred in receding water, with 31 food items. In all food webs, over 45% of food items were consumed by only one species (ultra-peripheral items), which is common in piscivorous fishes.


Subject(s)
Characiformes , Floods , Food Chain , Perciformes , Rivers , Animals , Brazil , Fishes
6.
J Ethnopharmacol ; 224: 535-540, 2018 Oct 05.
Article in English | MEDLINE | ID: mdl-29933011

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Brazilian plant species used in folk medicine have acquired several popular names related to commercial medicines in recent decades. This fact has directly effect to the medicalization process. AIM OF THE STUDY: Evaluate the rise of medicalized popular names of medicinal plants in Brazil. MATERIALS AND METHODS: Medicalized popular names of medicinal plants were recorded from 314 ethnobotanical articles in eleven scientific journals published between 1980 and 2017. RESULTS: The review included 141 ethnobotanical articles containing medicalized names from 314 articles consulted. The presence of medicalized names in Brazilian ethnobotanical studies has increased significantly since the 2000s. A total of 85 medicalized popular names were recorded according with phonetic and graphical similarity. The most cited medicalized names were Anador, Insulin, Terramycin, Vick, Novalgin and Penicillin. The prevalence of medicalized name citations in ethnobotanical surveys over non-medicalized names for several species indicates the existence of medicalized plant species. CONCLUSION: Since the 2000s, an increasing number of ethnobotanical studies revealed the appropriation of drug names by folk medicine through the changes of vernacular names of medicinal plants. This medicalization process is mostly related to the expansion of the Brazilian Unified Health System, pharmaceutical industry marketing and Non-Governmental Organizations in the last decades.


Subject(s)
Plants, Medicinal/classification , Terminology as Topic , Brazil , Ethnobotany , Medicine, Traditional , Phytotherapy
7.
Neotrop. ichthyol ; 15(2): e160144, 2017. tab, graf, mapas
Article in English | LILACS, VETINDEX | ID: biblio-841897

ABSTRACT

Fishes of the order Gymnotiformes have high diversity of oral and head morphology, which suggests trophic specializations within each clade. The aim of this study was to describe resource use patterns by two fish species (Gymnorhamphichthys rondoni and Gymnotus coropinae) in the National Forest Saracá-Taquera, Oriximiná - Pará, analyzing microhabitat use, diet composition, feeding strategies, niche breadth and niche overlap. Stomach contents of 101 individuals (41 G. rondoni and 60 G. coropinae), sampled in 23 headwater streams were analyzed and volume of food items was quantified to characterize their feeding ecology. Gymnorhamphichthys rondoni was captured mainly on sandy bottoms, whereas G. coropinae in crevices. Both species had a zoobenthivorous diet and consumed predominantly Sediment/Detritus and Diptera larvae, but also included allochthonous prey in their diet. These species had high niche overlap, with small variations related to the higher consumption of Ceratopogonidae larvae by G. rondoni and of Chironomidae larvae by G. coropinae. Both species had a generalist feeding strategy, but G. coropinae had a broader niche breadth. Our results demonstrate that G. rondoni and G. coropinae occupy different microhabitats but rely on similar food resources.(AU)


Peixes da ordem Gymnotiformes apresentam alta diversidade morfológica, o que sugere a existência de especializações tróficas dentro dos clados. O objetivo deste estudo foi analisar o uso de recursos por duas espécies de peixes elétricos (Gymnorhamphichthys rondoni e Gymnotus coropinae) na Floresta Nacional Saracá-Taquera, Oriximiná - Pará, analisando o uso de microhabitats, composição da dieta, estratégias alimentares, amplitude de nicho e sobreposição de nicho. Conteúdos estomacais de 101 indivíduos (41 G. rondoni e 60 G. coropinae), capturados em 23 igarapés de cabeceira, foram analisados e quantificados volumetricamente para a caracterização da ecologia trófica. Gymnorhamphichthys rondoni foi registrada principalmente em bancos de areia, enquanto G. coropinae em fendas. Ambas as espécies apresentaram dieta zoobentívora e consumiram predominantemente sedimento/detritos e larvas de Diptera, mas também consumiram presas alóctones. Foi observada alta sobreposição de nicho trófico e a baixa variação encontrada foi relacionada à maior utilização de larvas de Chironomidae por G. rondoni e de larvas de Ceratopogonidae por G. coropinae. Ambas as espécies apresentaram estratégia alimentar generalista, porém G. coropinae apresentou maior amplitude de nicho. Nossos resultados demonstram que G. rondoni e G. coropinae ocupam microhabitats diferentes, mas dependem de recursos alimentares similares.(AU)


Subject(s)
Animals , Ecosystem , Gymnotiformes/metabolism , Natural Resources/supply & distribution , Eating
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