LAUSR

The co-occurrence patterns of fish communities in the littorals of three lagoons of the Orinoco River floodplain in Venezuela were studied during four hydrological phases: low, rising, high and falling waters, from 2008–2009, using null models.  The analyses were made separately for each floodplain lake and for each habitat type within them.  During low waters only one lake showed a segregated pattern in beaches covered with leaf litter, whereas in the other floodplain lakes the communities were randomly assembled in all habitats during the four hydrological phases.  Despite the absence of a significant overall structure, several significantly aggregated and segregated species pairs were observed in the three lakes.  The temporal variation might be the main factor responsible for the co-occurrence patterns observed in these floodplain lakes due to the periodic reshuffling of littoral habitats.