999 resultados para Food fishes
Resumo:
v.1:no.8(1897)
Resumo:
v.1:no.4(1896)
Resumo:
n.s. no.100(2002)
Resumo:
v.11:no.5(1951)
Resumo:
v.21(1936)
Resumo:
v.36:no.2(1956)
Resumo:
v.15:pt.3(1928)
Resumo:
v.31:no.53(1951)
Resumo:
v.32:no.3(1947)
Resumo:
The effects of hydrological disturbances by flooding and drought on the diversity and stability in a temporary river fish community in the Brazilian semiarid region were analyzed over the 1996 hydrological cycle. Twelve collections of fishes were made during the wet and dry phases, and 789 individuals of 16 species were collected. Diversity was measured using Simpson's Index (S) and community stability was analyzed by the variation in abundance using Kendall's W concordance test. Fish diversity in the Taperoá river was subjected to hydrological disturbances by flooding and drought. During the wet phase the diversity was higher (S = 0.855) than during the dry phase (S = 0.771). The community was considered stable during the whole annual hydrological cycle (W = 0.418 p < 0.001), but a higher stability in the community was found during the dry phase. During the dry phase the number of dominant species was smaller than during the wet phase.
Resumo:
v.34:no.7(1952)
Resumo:
v.37:no.9(1955)
Resumo:
v.15:pt.1(1923)
Resumo:
n.s. no.8(1981)
Resumo:
The effect of intraspecific competition for food on larvae and of food deprivation for 24 h on 2nd and 4th instars of Ascia monuste orseis (Godart, 1819) was investigated. Intraspecific competition for food during the immature phase leads to long pupation time, high larval mortality, reduced adult weight, and reduced number of eggs per female. In food deprivation experiments, the major differences in A. monuste orseis performance were long pupation time in the group that was deprived during the 2nd instar; and a negative effect on reproduction in the group that was deprived during the 4th instar, with reduced adult weight. Both food deprived periods tested are critical, and deprivation during the 2nd instar seems to have an effect as drastic as during the 4th instar because it directly affects larvae survival. Immatures can resist food deprivation for 24 h during the 2nd and 4th instars (low mortality), have a compensatory behaviour (high ingestion and biomass gain) during the 5th instar, and do not demonstrate cannibalistic behaviour during food deprivation.