par Van De Sande, Eliza 
Président du jury Dahdouh-Guebas, Farid
Promoteur Vanschoenwinkel, Bram
Publication Non publié, 2021-07-08
Président du jury Dahdouh-Guebas, Farid
Promoteur Vanschoenwinkel, Bram
Publication Non publié, 2021-07-08
Mémoire
| Résumé : | Pitcher plants of the iconic genus Nepenthes have evolved a variety of uniquemechanisms to acquire nutrients to survive on the oligotrophic soils on whichthey are found in the paleotropics. These carnivorous plants have specialisedleaves forming a pitcher that contains a water body in which prey is captured,retained, and digested. Although the pitchers secrete enzymes to digest theirinsect prey, several invertebrate species manage to survive inside the pitcherfluid without getting digested. Little is known about the nature of thissymbiosis. The main objective of this study is to explore whether the infaunathat live inside pitchers influence the digestion efficiency of the prey andwhether they should consequently be considered mutualists, commensals, orparasites. To determine this, we conducted manipulative field experiments inJambu Bongkok (Malaysia) where the food web structure of Nepenthesrafflesiana and Nepenthes gracilis was modified. We hypothesised that infaunawould improve digestion and that filtering collector mosquitoes might benefitfrom prey fragmented by midges. We found indications for a potential effect ofinfauna on digestion, but this depends on the water level in the pitchers. Midgesand mosquitoes, which have had previously been shown to be commensals inSarracenia pitchers, are likely to be competitors in Nepenthes pitchers. Weconclude that the studied Nepenthes species may not strongly rely on infauna tohelp them digest prey and that a commensal or parasitic relationship seemsmore likely than a mutualism based on the data at hand.ii |
