Abstract: Attainment of adulthood by a young fish is a function of environment, competition, starvation, cannibalism and predation amongst other factors. Predators do not exhibit predatory qualities from birth, it has to grow over time before the qualities are expressed. Thus, the aim of this study was to determine minimum size of dragonfly (Palpopleura lucia (Drury, 1773)) nymphs (Naiads) that can predate on guppy (Poecilia reticulata) (Peters, 1859)) with a view to understanding predation in aquaculture. Guppies of 5-12 mm total length were introduced to naiads of varying lengths ranging from 2.00-10.00 mm over a 48 h period. Results obtained showed that naiads ≥6.00 mm were able to predate on guppies while those ≤5.5 mm co-habited with guppies without predation. This study thus concludes that aquaculture management practices can be geared towards eliminating naiads ≥6.00 mm, this will hopefully assist farmers to optimize human and material resources expended in the control of naiads in aquaculture.