Abstract
Parasites of invading species undergoing range advance may be exposed to powerful new selective forces. Low host density in range-edge populations hampers parasite transmission, requiring the parasite to survive longer periods in the external environment before encountering a potential host. These conditions should favour evolutionary shifts in offspring size to maximise parasite transmission. We conducted a common-garden experiment to compare life history traits among seven populations of the nematode lungworm (Rhabdias pseudosphaerocephala) spanning from the parasite population core to the expanding range-edge in invasive cane toads (Rhinella marina) in tropical Australia. Compared to conspecifics from the population core, nematodes from the range-edge exhibited larger eggs, larger free-living adults and larger infective larvae, and reduced age at maturity in parasitic adults. These results support a priori predictions regarding adaptive changes in offspring size as a function of invasion history, and suggest that parasite life history traits can evolve rapidly in response to the selective forces exerted by a biological invasion.
| Original language | English |
|---|---|
| Pages (from-to) | 329-337 |
| Number of pages | 9 |
| Journal | Ecology Letters |
| Volume | 15 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2012 |
| Externally published | Yes |
Keywords
- body size
- Bufo marinus
- egg size
- fecundity
- free-living larva
- infective larva
- lung nematode
- Rhabdias pseudosphaerocephala
- Rhinella marina
- trade-off