Faculdade de Ciências Naturais - FACIN/CBREVE
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/4318
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Navegando Faculdade de Ciências Naturais - FACIN/CBREVE por Periódicos "Neotropical Ichthyology"
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Item Acesso aberto (Open Access) Early Pleistocene lineages of Bagre bagre (Linnaeus, 1766) (Siluriformes: Ariidae), from the Atlantic coast of South America, with insights into the demography and biogeography of the species(Sociedade Brasileira de Ictiologia, 2016) SILVA, Wemerson Clayton da; MARCENIUK, Alexandre Pires; SALES, João Bráullio de Luna; SILVA, Juliana Araripe Gomes daCoastal and marine environments are characterized by a lack of evident physical barriers or geographic isolation, and it may be difficult to understand how divergence can arise and be sustained in marine environments. The identification of 'soft' barriers is a crucial step towards the understanding of gene flow in marine environments. The marine catfishes of the family Ariidae are a demersal group with restricted migratory behavior, no pelagic larval stages, and mechanisms of larval retention, representing a potentially useful model for the understanding of historical processes of allopatric speciation in the marine environment. In the present study, two lineages of the Coco sea catfish, Bagre bagre , were recognized from their complete segregation at both mitochondrial and morphological levels. One lineage is distributed between Venezuela and the northern coast of Brazil, including the semiarid northeast coast, while the second lineage is found on the eastern coast of Brazil, including the humid northeast coast. Based on distribution area, habitats preference, and genetic variability, inferences are made in relation to biogeography and demography of lineages in Atlantic coast of South America.Item Acesso aberto (Open Access) Population and reproductive parameters of the red-tailed catfish, Phractocephalus hemioliopterus (Pimelodidae: Siluriformes), from the Xingu River, Brazil(Universidade Federal do Pará, 2019-07) FREITAS, Tiago Magalhães da Silva; MONTAG, Luciano Fogaça de AssisA 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 the beginning of the high-water (flood) period. As P. hemioliopterus is an important commercial fish, our findings will contribute to the future development of effective conservation and management strategies, such as minimum catch size and a close season that is appropriate for the region. These data will also provide important insights for the evaluation of potential impacts on the biology of this fish resulting from the construction of Belo Monte dam.Item Acesso aberto (Open Access) Predicting size at first sexual maturity from length/weight relationship: a case study with an Amazonian catfish(Universidade Federal do Pará, 2016) FREITAS, Tiago Magalhães da Silva; ALMEIDA, Vitor Hudson da Consolação; MONTAG, Luciano Fogaça de Assis; FONTOURA, Nelson FerreiraRelationship between length and weight (LWR) is used to describe aspects concerning the life cycle of fish, but does not considers possible changes during the lifetime mainly due to the sexual maturation. Thus, this study aims to identify the size at first maturity of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) and infer if the reproductive engagement could change growth pattern, concerning the LWR. Estimates of the size at first maturity (L 50 ) were made by visual identification of gonadal development and through the gonadosomatic index (G SI ). L 50 was estimated as 12.5 cm for males and 13.0 cm for females when applied visual identification of gonads development. L 50 estimates increased to 13.05 cm for males and 13.7 cm for females when estimated from G SI values. LWR was adjusted by using a regular power function and through the polyphasic growth model, with proportionality and allometric coefficients changing in a two phases. The results indicate differences in the growth pattern concerning males and females, as well as polyphasic growth. The change in the growth pattern of the polyphasic LWR was estimated at 11.42 cm for males and 12.53 cm for females, suggesting that changes in the growth pattern can sign-out the attainment maturity in this catfish.