Can the functional response to prey predict invasiveness? A comparison of native fishes and alien poeciliids in Hong Kong

Alphonse Hin Fat TSANG*, David DUDGEON

*Corresponding author for this work

Research output: Journal PublicationsJournal Article (refereed)peer-review

1 Citation (Scopus)


Biological invasion is globally pervasive and an increasing threat to biodiversity. We need to be able to predict the ecological impacts of alien species, in order to prioritize management of those expected to be most damaging. Comparisons of functional response (FR) between invaders and trophically similar natives has been proposed as useful for predicting invader impacts, as interaction intensity tends to be reflected in higher FRs. We undertook feeding trials comparing FRs of four invasive poeciliids (mosquitofish [Gambusia affinis], guppy [Poecilia reticulata], liberty molly [P. salvatoris] and swordtail [Xiphophorus hellerii]) in Hong Kong with three similar-sized native fishes (ricefish [Oryzias curvinotus: Adrianichthyidae]; predaceous chub [Parazacco spilurus] and half-banded barb [Puntius semifasciolatus: Cyprinidae]). We tested whether FRs correctly reflected known impacts of the mosquitofish and guppy locally, and used FRs to forecast potential impacts of the molly and swordtail. Overall, the swordtail and molly consumed more prey and had higher FRs than the other five fishes, owing to their shorter prey handling time and/or higher attack rate. Mosquitofish and guppy had similar FRs to native fishes. All fishes showed type-II FRs, and had some potential to destabilize prey populations. Such results predict that the molly and swordtail could have strong ecological effects in Hong Kong freshwaters. However, FR alone was not highly predictive of known impacts of mosquitofish and guppy. It is suggested a more holistic approach incorporating estimates of field abundance and parameterization of other niche dimensions of the invader will be needed.

Original languageEnglish
Pages (from-to)2143-2154
Number of pages12
JournalBiological Invasions
Issue number7
Early online date6 Mar 2021
Publication statusPublished - Jul 2021
Externally publishedYes

Bibliographical note

Funding Information:
We thank Ms. Lily Ng for technical support and Mr. Lag Wan for field assistance. We are also grateful to Dr. Jiahuan Liew and Dr. Ken So for helpful discussions. This study complied with local laws and was conducted under license from the University of Hong Kong and local government regarding the use of animals in experiments.

Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.


  • Biological invasion
  • Comparative functional response
  • Impact prediction
  • Invasive poeciliids
  • Prey consumption rate


Dive into the research topics of 'Can the functional response to prey predict invasiveness? A comparison of native fishes and alien poeciliids in Hong Kong'. Together they form a unique fingerprint.

Cite this