Lateral migration of fish between an oxbow lake and an Amazonian headwater river

Abstract

– We report on lateral movements of fish between an Amazonian headwater river (Manu River in Manu National Park, Perú) and a 24‐ha oxbow lake (Cocha Cashu) in the adjacent floodplain. During wet season flood pulses, or ‘crecientes,’ fish can enter and exit the lake through a connecting channel that is normally dry. To investigate fish movements, we operated a bi‐directional funnel trap in the connecting channel during high water interludes. We captured 4090 fish of 60 species during the 2005 and 2006 rainy seasons and sub‐sampled the adults for gonadal state and stomach contents. We found that most exiting fish were gravid and that most entering fish had recently spawned, suggesting that fish were leaving the lake to spawn in the river or elsewhere. Entering fish had full stomachs more often than exiting fish and entering and exiting individuals of most species were of similar size.

Diversity in migratory patterns among Neotropical fishes in a highly regulated river basin

“…Although less studied than longitudinal migrations in tropical river floodplain systems (Osório et al , 2011), lateral migrations are at least as important as long‐distance longitudinal migrations in terms of fish production. In the Amazon floodplain, the lateral migration of the pirarucu Arapaima gigas (Schinz 1822) is reportedly a very cost‐effective strategy for optimizing the spatial and temporal heterogeneity of resources of the várzea (Castello, 2008).…”

The spatial pattern of larval fish assemblages in the lower reach of the Yangtze River: potential influences of river–lake connectivity and tidal intrusion

“…We suggest that the larger number of species and higher abundance of larval fish at AQ than at NJ reflect an influence of the connectivity of the Poyang Lake with the Yangtze River upstream of AQ, and the delayed bloom of larval fish and the occurrence of estuarine species at JJ reflect the influence of tidal intrusion from the estuary. Life histories of many fish species have evolved to adapt to the hydrological regimes of river-floodplain system by spawning in the river and nursing in the floodplain habitats (Fernandes, 1997;Balcombe et al, 2007;Osorio et al, 2011). Lateral connectivity between river and the floodplain habitats is essential for these fishes to complete their life cycles (Junk et al, 1989;Bayley, 1991).…”

“…Landscape pattern plays an important role in structuring larval fish assemblages in large river basins (Balcombe et al, 2007;Osorio et al, 2011).…”

Modelling growth in fish with complex life histories

“…Ontogenetic shifts in habitat may be lateral (Kahilainen et al 2003;Osorio et al 2011), or longitudinal (Lin et al 2012, and are frequently cyclic in nature. Ontogenetic migration is a phenomenon most frequently associated with anadromous fish and reef fish but examples have also been reported from pelagic habitats (e.g.…”