Data/hora: 10/06/2024 18:27:30

Provedor de dados: | Zoologia
País: | Brazil
Título: | Abundância relativa e distribuição de Loricariichthys spixii (Steindachner) (Siluriformes, Loricariidae) no reservatório de Lajes, Estado do Rio de Janeiro, Brasil
Autores: | Duarte,Silvana; Araújo,Francisco Gerson.
Data: | 2001-06-01
Ano: | 2001
Palavras-chave: | Lajes; Reservoir; Loricariidae; Distribution; Environmental parameters.
Resumo: | The armored catfish Loricariichthys spixii (Steindachner, 1882) is the most abundant member of the Loricariidae family in the Lajes reservoir (22º42'-22º50'S 43º53' -44º05'W), the largest dam in the State of Rio de Janeiro State, but little is known about its biology and life cycle. A standardized fish sampling program in three zones of the reservoir (lower, middle and upper reaches), during three annual cycles: monthly in 1994/1996 and bi-monthly in 1997 was conducted out aiming to assess and add knowledge of the population structure of this species. Fishes were caught using gill nets (50 m long, 3 m depth and 25 to 45 mm meshes), amounting 160 samples. Water temperature, pH and transparency were registered at each sample to correlate with fish abundance. Loricariichthys spixii (Steindachner, 1882) was the most abundant fish species in the reservoir, contributing about on third of the total number and half of the total weight of the catches, but a decreasing trend was observed over the three year of the study, with number and biomass being significantly more abundant in 1994, followed by 1996 and 1997. There is no clear dependence between environmental parameters and fish occurrence, except for the coincidence of decreasing fish abundance and decreasing levels of water of the reservoir over the three year. Fishes were more abundant in the high and intermediate reaches of the reservoir, near to mouth of the tributaries. Seasonally, there is no clear variation in relative abundance. The success of use of the reservoir by L. spixii could be attributed to availability of muddy and sandy substrate associated with its k-strategy by carrying eggs, which could allow this species faces the environmental changes of the reservoir, mainly the variations in level of water, by hydroelectric power demand.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Português
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752001000200017
Editor: | Sociedade Brasileira de Zoologia
Relação: | 10.1590/S0101-81752001000200017
Formato: | text/html
Fonte: | Revista Brasileira de Zoologia  v.18 n.2 2001
Fonte: | info:eu-repo/semantics/openAccess