Association Between Early-Stage Juveniles of Sailfin Catfish (Pterygoplichthys, Loricariidae) and Floating Hydrophytes: Behaviour Supports Species Dispersal?

The vertical distribution of early-stage juvenile sailfin catfish ( Pterygoplichthys , Loricariidae), an invasive species, were investigated in littoral habitats and the center of channel with floating hydrophytes from the Red River system in Vietnam. Sailfin catfish were sampled from the upper water column with associated floating hydrophytes of the invasive water hyacinth ( Eichhornia crassipes ) and native water spinach ( Ipomoea aquatic ) and the bottom using hand nets (2-mm mesh sizes). Significantly higher numbers of early-stage juveniles were associated with floating hydrophytes compared to bottom sampling. The association between early stages of sailfin catfishes and floating hydrophytes, especially the free-floating invasive water hyacinth, supports the potential mechanism in the dispersal of an invasive fish.