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| Freitas,Tiago Magalhães da Silva; Almeida,Vitor Hudson da Consolação; Montag,Luciano Fogaça de Assis; Rocha,Rossineide Martins da; Fontoura,Nelson Ferreira. |
| The aim of the present study was to evaluate the seasonal pattern of the gonadosomatic index (GSI), condition factor (K), and sex ratio in the catfish Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) as an approach to identify its reproductive period. A total of 589 A. longimanus specimens (251 males and 338 females) were captured in the rivers of the Caxiuanã National Forest, in the Brazilian state of Pará, between July, 2008 and July, 2009. Among the male specimens, 171 were classified as adults and 80 as juveniles, while there were 249 adults and 89 juvenile females. Using a sinusoidal equation, analysis of the GSI revealed a reproductive asynchrony between the genders, with males attaining their highest GSI values in January, while females... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Auchenipterichthys longimanus; Hydrological seasons; Reproduction; Siluriformes. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000400015 |
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| Freitas,Tiago Magalhães da Silva; Almeida,Vitor Hudson da Consolação; Valente,Roberta de Melo; Montag,Luciano Fogaça de Assis. |
| Feeding habits of the midnight catfish Auchenipterichthys longimanus collected in rivers of the Caxiuanã National Forest (Eastern Amazonia, Brazil) were investigated through the different hydrological periods (dry, filing, flood and drawdown). A total of 589 specimens were collected throughout seven samplings between July 2008 and July 2009, of which 74 were young males, 177 adult males, 89 young females and 249 adult females. The diet composition (Alimentary index - Ai%) was analyzed by a non-metric multidimensional scaling (nMDS) and by the analysis of similarity (ANOSIM), which included 37 items grouped into nine categories (Aquatic insects, Other aquatic invertebrates, Arthropods fragment, Fish, Plant fragment, Seeds, Terrestrial insects, Other... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Catfish; Hydrological seasons; Trophic ecology. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000300016 |
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| Freitas,Tiago Magalhães da Silva; Montag,Luciano Fogaça de Assis. |
| ABSTRACT A field study of the sex ratio, length-weight ratio, body size at first gonadal maturation, and the breeding season of the red-tailed catfish, Phractocephalus hemioliopterus, was carried out in the region of the middle Xingu River in the eastern Amazon basin. The fish were sampled quarterly from September 2012 to January 2014 using gillnets and long lines. The sex ratio was balanced, and while males and females were similar in standard length, the females were heavier than the males, on average. The males presented negative allometric growth, and the females, isometric growth. The estimated size at first maturity was 77.8 cm. The variation in the gonadosomatic index and the greater frequencies of mature specimens indicated a reproductive peak at... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon basin; Breeding season; Fishery; Gonadal maturity; Growth pattern. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000200216 |
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| Montag,Luciano Fogaça de Assis; Albuquerque,Adna Almeida de; Freitas,Tiago Magalhães da Silva; Barthem,Ronaldo Borges. |
| Os campos alagados ou savanas da ilha do Marajó é uma área disjunta do bioma Cerrado na Amazônia, e é considerada de grande importância para planos de manejo, conservação e preservação ambiental. A fim de ampliar o conhecimento ictiofaunístico da região, o presente estudo reuniu informações coletadas em campo, compiladas da literatura e selecionadas de coleções ictiológicas sobre a fauna de peixes da eco-região savana do Marajó. As coletas de campo ocorreram entre os anos de 2003 e 2005, e apresentaram como métodos a rede de mão, rede de arrasto, rede de tapagem e captura manual por técnica de mergulho, sendo que durante esse período foram amostrados os municípios de Ponta de Pedras, Chaves e Muaná. Além desses, outros quatro municípios também foram... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Peixes; Biodiversidade; Savana; Bacia Amazônica. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032009000300024 |
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| Montag,Luciano Fogaça de Assis; Freitas,Tiago Magalhães da Silva; Raiol,Roberta Dannyele de Oliveira; Silva,Marlene Vasconcelos da. |
| This paper describes the length-weight relationship, size at first maturation (L), and breeding season of Poecilia reticulata found in drainage channels on the campus of the Federal University of Pará (UFPA) in the Brazilian city of Belém. A total of 1.936 specimens (942 males and 994 females) were collected in monthly samples of the study area between June, 2006, and March, 2007. Females were significantly longer and heavier than males. The length-weight relationship for males was established by the equation Pt = 5 × 10-5 × Ct2.397 and for females by Pt = 3 × 10-6 × Ct3.419. The estimated value of L was 17.5 mm for males and 20.4 mm for females, suggesting that males initiate reproductive activity at a smaller size than females. The abundance of mature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish ecology; Urban environments; Breeding; Amazon; Poecilia reticulata. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032011000300007 |
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