Feeding habits and reproductive biology of Astyanax abramis/Hábito alimentar e biologia reprodutiva de Astyanax abramis

The species of the genus Astyanax, popularly known as ‘lambaris’, are important ecologically since they can be used as environmental bioindicators. However, knowledge about the feeding habit and reproduction of species of this genus is scarce. Therefore, the aim of the study was to characterize the feeding habit and the spawning period of Astyanax abramis (Jenyns, 1842) collected from Queima-Pé River subbasin (Tangará da Serra/MT/Brazil) throughout the local hydrological cycle. Sampling was performed in April (rainy season), July and October 2016 (dry season) and January 2017 (rainy season), in six different sites from Queima-Pé River subbasin. A total of 92 A. abramis specimens were collected for evaluation of biometry (standard length, height and length of the intestine), degree of repletion of stomach, feeding habit, and gonadal maturation. The greatest lengths and height were observed in April (5.94 ± 0.23; 2.20 ± 0.08 cm, respectively) and October (4.89 ± 0.28; 1.73 ± 0.09 cm, respectively). The degree of repletion of stomach was approximately 2 (½ full) in all sampling months. The feeding habit of A. abramis species collected from Queima-Pé River subbasin was classified as unspecialized carnivore, consuming insects and fishes. Preference for fish occurs in the rainy season and for insects in the dry season. Feed of allochthonous origin were more significant in A. abramis diet from July to January. The species has a split spawning season, with greater reproduction activity in April and October, which corresponds to period to higher water temperature and pluviosity