Diel and seasonal movements of grumatã Prochilodus lineatus (Valenciennes 1836) (Characiformes: Prochilodontidae) in the Sinos River, Southern Brazil

Abstract

Prochilodus lineatus is a reophilic migratory species of economical importance for local fisheries which is widely distributed in Brazil. The present study investigated diel and seasonal movement patterns, spawning migration and habitat use of P. lineatus in the Sinos River, Southern Brazil. Between August 2002 and March 2004, 19 grumatãs were tagged internally with digitally coded radio transmitters. Tracking was conducted weekly by boat or aircraft, and six fixed data loggers recorded movements of tagged fish. Results showed that the mean distance covered per fish and day was positively related with fish weight (p = 0.03; n = 19). Grumatã showed preference for river streches surrounded by wetlands (p < 0.001; n = 286). Their diel activity pattern displayed one peak at 7 hours, and a second at 15 hours. During the night, activity was significantly reduced (p = 0.01). The seasonal movements pattern showed increased activity in No synchronized long distance spawning migrations were observed. The mean distance covered by the individuals/ day showed a negative significant relationship with number of tracking days (p = 0.022; n = 19), indicating a higher probability of being captured for more mobile individuals. The preservation of the still existing wetlands and reduction of the fishing pressure are essential for the future conservation of the grumatã population of the Sinos River.

Fish hatchering and its effects on the morphology of Prochilodus lineatus (Actinopterygii: Prochilodontidae)

“…Its reproductive habits are migratory, swimming upriver to spawn in the breeding season. The adults inhabit the main channel of the river, showing preference for river stretches surrounded by wetlands (Pesoa and Schulz, 2010). The young inhabit the marginal lagoons of the floodplain, where they remain during the first years of life (Agostinho and Júlio-Júnior, 1999;Graça and Pavanelli, 2007;Pesoa and Schulz, 2010).…”

“…The adults inhabit the main channel of the river, showing preference for river stretches surrounded by wetlands (Pesoa and Schulz, 2010). The young inhabit the marginal lagoons of the floodplain, where they remain during the first years of life (Agostinho and Júlio-Júnior, 1999;Graça and Pavanelli, 2007;Pesoa and Schulz, 2010). Prochilodus lineatus was chosen due to its ecological relevance, importance for fishing, and because is one of the most used native fish in stocking and repopulation.…”

Reporting on the recapture of electronic tagged fish by fishers in the Xingu River, Brazilian Amazon

“…Data about recapture of electronic tagged fish and return of transmitters by fishers has been reported in other biotelemetry projects in Brazil and ranged from 13 to 54% (Godinho and Kynard, 2006;Godinho et al, 2007;Hahn et al, 2011;Pesoa and Schulz, 2010), values that are greater than observed so far in the Xingu River. The return of transmitters is important because it not only makes it possible to reuse the tags in other fish, but also because fishers will provide information on the use of habitats beyond the limits of study area and after the transmitter battery runs out.…”

Fish movement in an Atlantic Forest stream

“…In order to increase the offspring survival and to avoid intraspecific competition, some species displace kilometres and occupy specific habitats, with higher productivity and lower predator density (Schulz, Leal, 2012). Long spawning migration can occur in some fish groups, such as salmonids and large migratory fishes from Amazon and Paraná basins (Goulding, 1980;Winemiller, Jepsen, 1998;Antonio et al, 2007;Fernadez et al, 2007;Pesoa, Schulz, 2010;Tejerina-Garro, Mérona, 2010). Fish movements in streams can also be important for the fish community stability (Martin-Smith et al, 1999).…”