The characins living in Trinidad show considerable variation in the shape of male sex ornaments, and the researchers suspected that those differences might have something to do with what they eat.
Kolm's team has now confirmed that characins that mainly eat ants also carry sex ornaments that look more like ants.
interruptum feeding habits were related to changes in the abundance of consumed prey within the insects, agreeing with the conclusions of Barreto and Aranha (2006) about the importance of environmental alterations, such as floods as the main cause for diet shifts of four characins
from an Atlantic Rain Forest stream in Brazil.
in the collection of the Carnegie Museum.
Five new species of genus Astyanax Baird & Girard, 1854 from Rio Iguacu, Parana, Brazil (Ostariophysi, Characiformes, Characidae)/ Cinco novas especies do genero Astyanax Baird & Girard, 1854 do Rio Iguacu, Parana, Brasil (Ostariophysi, Characiformes, Characidae)
Its fish fauna is mostly composed of traira (Hoplias malabaricus), curimbata (Prochilodus lineatus), tabarana (Salminus hilarii), armoured fish and characins. Just for holding so many species, this site presents low degradation and seems to possess several habitats.
Sites like so01 are predominantly lentic, exihibiting high saguirus abundance and characins; ta01 and so03 present high abundance of Hoplosternum litoralle, typical fish of still waters.
This conclusion should allow us to classify the species as a diurnal feeder like many other Characins
Such species are less dependent on the rheophilic behavior and may complete the entire life cycle within the impounded area, e.g., cichlid species, small-sized characins
The baits used by the sport fishers were earthworm, dough (prepared with flour and water), orange bug, live bait (characins
or other small fish captured in the reservoir) and artificial bait.