Daphnia, a water flea. Photo via Nothing in Biology Makes Sense!.

This week at Nothing in Biology Makes Sense!, the still shiny new collaborative science blog, contributor Devin Drown describes what happens when two different parasite species infect the same water flea.

Octosporea bayeri needs the host to produce offspring for vertical transmission, that is the host and parasite have an aligned interest in producing offspring. On the other hand, Pasteuria ramosa is using host resources, including the reproductive tissues, to produce spores for infecting other hosts. Because of the alignment of interests between host and the vertically transmitting parasite, the question becomes: does infection by O. bayeri provide host protection from future infection by P. ramosa?

The answer, of course, is in the full post. ◼