Some mollusks may serve as paratenic or intermediate hosts for nematodes. A paratenic host transfers a parasitic larva to another host with little or no development occurring in the process; a parasite will carry out part of its life cycle within an intermediate host (Grewal et al. 2003). Nematodes are part of the phylum Nematoda, usually <5 cm in length, and many are parasitic. V. angelicae has been found to be an intermediate host to the nematode Parelaphostrongylus odocoilei  (Grewal et al. 2003). During its juvenile stage, the nematode will enter the snail and develop into its infective stage until the snail is ingested by the definitive host. Although the presence of some species of nematodes have been reported to result in the death of the snail host, P. odocoilei has not been observed to do such (Grewal et al. 2003).