Though, "C. australe" can only produce viable eggs from within the pinniped host. C". australe" can survive perfectly well within the penguins as its host, with female worms growing bigger within the guts of Magellanic penguins. In addition, though "C. australe" can survive well within Magellanic penguins, egg viability is lessened within this non-native host. Likewise, the sex ratio of the parasitic worm is highly skewed toward females within the gut of the penguins as the host. Though Magellanic penguins are not the definitive host of "C. australe", they serve well as a suitable candidate.