Mutual sabotage in parasites
Some parasites have only one goal: to develop completely in their intermediate host, await the right time to infect their definitive host and procreate there. Many parasites manipulate their intermediate host's behaviour. This causes the host to act differently and, depending on the parasite's requirements, be more or less evident to its natural predator. But what happens when parasites in different developmental stages or even different species of parasites with contradictory goals infect the same host? Researchers from the Max Planck Institute for Evolutionary Biology in Plön, Germany, have discovered that two different species of parasites in different developmental stages in the same copepod will mutually sabotage each other's efforts and disable the other's manipulation. According to the researchers, the parasite in the infective stage always retains the upper hand in cases of conflicts of interest.