Venus flytrap seedlings show growth-related prey size specificity

Abstract

Venus flytrap (Dionaea muscipula) has had a conservation status of vulnerable since the 1970s. Little research has focussed on the ecology and even less has examined its juvenile stages. For the first time, reliance on invertebrate prey for growth was assessed in seedling Venus flytrap by systematic elimination of invertebrates from the growing environment. Prey were experimentally removed from a subset of Venus flytrap seedlings within a laboratory environment. The amount of growth was measured by measuring trap midrib length as a function of overall growth as well as prey spectrum. There was significantly lower growth in prey-eliminated plants than those utilising prey. This finding, although initially unsurprising, is actually contrary to the consensus that seedlings (traps < 5 mm) do not catch prey. Furthermore, flytrap was shown to have prey specificity at its different growth stages; the dominant prey size for seedlings did not trigger mature traps. Seedlings are capturing and utilising prey for nutrients to increase their overall trap size. These novel findings show Venus flytrap to have a much more complex evolutionary ecology than previously thought. © 2014 Christopher R. Hatcher and Adam G. Hart.