A presenting a dominance of d = 0.28; during the period of receding water, a predominance of Characidae (92 fish sampled) was observed, with Hemigrammus
ureyi presenting d = 0.19; in low water, Loricariidae were more abundant, with 184 individuals, all of the species Hypoptopoma inexspectatum (d = 0.82).
Axis 1 was characterized by the species variation, Hyphessobrycon diastatos, Hisonotus vespuccii, and Hemigrammus
gracilis, which were related to higher altitudes, greater water superficial velocity and large substrates.
Eigenmannia macrops Eigenmannia virescens Gymnotus carapo Hypoptopoma guiare Det Det Hoplias malabaricus Ins Hemigrammus
marginatus Inv Inv Lar Hemigrammus
neptunus Heros severus Inv Hypoptopoma cf.
pertensis, Taeniacara candidi, Mesonauta festivus, Mesonauta sp., Laetacara curviceps, and Crenicara maculatum; the gymnotoid Eigenmannia virescens; the characoids Charax condei, Capella sp., Hemigrammus
(1998) reported a similar feeding habit for Cichla orinocensis Humboldt, 1821 in Guri Reservoir, which foraged mostly in shallow, structured habitats within littoral zone where Crenicichla wallacii Regan, 1905, other cichlids, and the characid Hemigrammus
micropterus Meek, 1907 were the dominant preys.
pulcher Iguanodectes spilurus Knodus sp.
These macrohabitats shared 37 species comprising the largest assemblage of ornamental and relatively smaller species (<120mm standard length), such as those in the Astyanax, Ancistrus, Apareiodon, Apistogramma, Bujurquina, Characidium, Cheirodon, Corydoras, Hemigrammus
, Holoshesthes, Moenkhausia, Otocinclus, Odontostilbe and Xenurobrycon genera.
imbecillis in 3 days on silver tip tetra (Hemigrammus
nanus) is one of the shortest glochidial parasitic durations recorded.
Spatial and temporal variation in population structure of Hemigrammus
marginatus (Characiformes: Characidae) in streams of the Ivinhema