A comparison of the establishment success, response to competition, and community impact of invasive and non-invasive Gambusia species
- 8 Downloads
How an invader responds to the novel biotic elements of a new community will affect its ability to invade. Species that are able to cope well with novel competitors might be expected to achieve greater establishment success. We compared the population-level responses of two mosquitofish species, the widespread invader Gambusia affinis and non-invasive G. geiseri to competition from each other and a non-invasive competitor. We simulated the invasion of a simplified pond community by introducing different combinations of the Gambusia spp. into communities already inhabited by a novel competitor, the red shiner Cyprenella lutrensis. We measured the effect of competition on establishment success by comparing population abundances achieved by each Gambusia species in all treatments, and examined whether the invasive and non-invasive Gambusia differed in their community impact by comparing their effects on the abundances of pond fauna. We also used N and C stable isotope analysis to compare their trophic roles. Both novel and intrageneric competition negatively affected both Gambusia spp.’s abundances, but the invasive G. affinis managed to remain more abundant than G. geiseri regardless of competition treatment. Stable isotope analysis revealed the Gambusia spp. to have similar trophic placement and showed competition to cause significant trophic shifts only in G. geiseri. A cascading effect (reduced phytoplankton abundances) was detected only when G. affinis was present. These results suggest that a higher vulnerability to novel competition along with life history traits contributes to the limited spread of G. geiseri in comparison to the widespread G. affinis.
KeywordsInvasive species Gambusia Competition Trophic impact Cyprenella lutrensis
This work was supported by an NSF graduate research fellowship to JSR, NSF DDIG DEB-0206542 to J.S.R, A.S. and an Australia Awards Endeavour fellowship to L.K.L.
- Fuller PL, Nico LG, Williams JD (1999) Nonindigenous fishes introduced into inlands waters of the United States. American Fisheries Society, BethesdaGoogle Scholar
- Hubbs C (1996) Geographic variation in life history traits of Gambusia species. Proc Desert Fishes Counc 27:1–21Google Scholar
- Hubbs C (1998) Large spring Gambusia (Gambusia geiseri) produces young in all seasons. Tex J Sci 50:343–344Google Scholar
- Hubbs C, Springer VG (1957) A revision of the Gambusia nobilis species group, with descriptions of three new species, and notes on their variation, ecology and evolution. Tex J Sci 9:299–326Google Scholar
- ISSG (2000) 100 of the world’s worst invasive alien species: a selection from the global invasive species database. Global Invasive Species Programme, University of Auckland, AucklandGoogle Scholar
- MacArthur RH (1972) Geographical ecology. Harper and Row, New YorkGoogle Scholar
- Miller JT, Hui C, Thornhill AH et al (2017) Is invasion success of Australian trees mediated by their native biogeography, phylogenetic history, or both? AoB Plants 9:8Google Scholar
- Moyle PB (2002) Inland fishes of California. University of California, BerkeleyGoogle Scholar
- Werner EE (1986) Species interactions in freshwater fish communities. In: Diamond J, Case TJ (eds) Community ecology. Princeton University Press, Princeton, pp 344–357Google Scholar
- Williamson MH (1996) Biological invasions. Population and community biology series, vol 15. Chapman and Hall, LondonGoogle Scholar