Dr Alexandra Grutter (Lexa)

Position: Adjunct Senior Lecturer

Education:

  • 1995  PhD in Marine Ecology, James Cook University (JCU), Department of Marine Biology, Townsville, Australia, "Parasites in the cleaning interactions between the cleaner wrasse Labroides dimidiatus and fish" Supervisors: Professor J.H. Choat and Professor David R. Bellwood.
  • 1989  BA Honors in Aquatic Biology, University of California, Santa Barbara, CA (UCSB).
  • 1986  Kauai Community College (KCC), Hawaii.

Research Interests: Cleaning behaviour, cooperation, fish parasites, coral reef ecology

Awards:

  • 2004 UQ Foundation Research Excellence Award, University of Queensland.
  • 1999 Fresh Science Scientist, ScienceNow!, The National Science Forum, Melbourne Exhibition Centre, Australia.
  • 1989  Graduated with Highest Honours (summa cum laude), Received Distinction in Major, UCSB.

Research Projects:

  • 1. What happens to reefs without cleaner fish?
To control blood-sucking parasites, coral reef fishes rely on cleaner fish-organisms that specialize in removing and eating parasites. Recently, we showed cleaning affects the behaviour, spatial distribution, and size of client fish. The mechanisms involved in such effects, and the consequences to the rest of the community, however, are unknown. Using the longest ongoing experiment of its kind, involving the large-scale removal of cleaner fish from small reefs for over 10 years, we aim to test how cleaning affects fish health, physiology, and recruitment and other reef organisms. This will reveal the role of positive interactions in preserving coral reefs.

Investigators:

  • Lexa Grutter
  • Liz Madin
  • Redouan Bshary
  • Mark Meeken
  • Robert Warner
  • 2. Do larval fish leave the reef to avoid parasites?

Although fundamental to understanding the processes that determine the abundance and community structure of coral reef fishes, the selection pressures for why larval fish migrate to the pelagic zone remain controversial. There is little support for the traditional explanations that a pelagic phase is for dispersal and that larval fish avoid predators and obtain more food in open water. A new hypothesis for the pelagic phase has been recently proposed: that larvae leave the reef to avoid parasites when small and vulnerable. However, recent work on the Great Barrier Reef suggests that reef-based micropredatory parasites may be an even more compelling source of selection to leave the reef. In this study we investagte the role that general parasites and micropredatory parasites play in the ecology of larval fish.


    Investigators:

    • Lexa Grutter
    • Redouan Bshary
    • Armand Kuris
    • Robert Warner
    • Jennifer Pickering
    • Conor Jones

A larval apogonid Fish on the reef Juvenile fish with isopod
  • 3. Do cleaner fish control fish diseases transmitted by parasites?

Cleaner fish eat such large numbers of parasites that abundances of parasites on client fish decline daily. Recent studies, however, suggest that a second, and likely more important, benefit of cleaning behaviour may be the control of blood infections. The parasites that cleaner fish eat also harbour parasites obtained from fish blood. By removing these, cleaners may affect the spread of fish diseases. This study investigates the role of fish parasites as vectors of parasitic diseases; whether cleaner fish control these diseases; and whether cleaners themselves serve as vectors of diseases.


Investigators:

    • Lexa Grutter
    • Nico Smit
    • Bob Lester
    • Hamish McCallum
    • Rob Adlard
    • Angela Davies
    • Armand Kuris
Armand Kuris and Lexa Nico Smit and Lexa Christine Fury
  • 4. The cleaner fish-client fish symbiosis: a model multispecies mutualism

In this project we investigate cooperation among unrelated individuals and in multi-species interactions using the cleaner fish-client mutualism as a model system. Central questions to this project are determining how costs and benefits influence behavioural interactions and the role of cheating, punishment, reward, partner recognition, competition for partners, and partner choice in maintaining or affecting cooperative interactions.


Investigators:

  • Lexa Grutter
  • Redouan Bshary
  • Rufus Johnstone
Redouan Bshary Redouan and Lexa Experimental setup
  • 5. The ecological consequences of fish cleaning behaviour

Although there is evidence that cleaner fish reduce the abundance of parasites (gnathiid isopods) on a daily basis, the long-term effects of cleaners on parastie populations and fish 'health' are unknown. This study examines the long-term effect of cleaners on gnathiid populations and fish 'health' using a novel approach where the standing crop of parasites on the reef is sampled by capturing them as they emerge from the reef in search of clients.

    Investigators:

    • Lexa Grutter
    • Jan-Maree Murphy
    • Christine Fury
Loading the boat Jan-Maree Murphy Lexa with trap
  • 6. Communication between cleanerfish and their hosts: the role of colour

Here we investigate the use of colour signals involved in the interaction between cleaner fish, their mimics, and their hosts as well as between adult fish and juveniles. The aims are to determine if cleaning organisms have a unique colour, whether clients recognize cleaners by their colour, the role of colour in mimics, and the role of ontogenetic changes in fish colour.

    Investigators:

    • Lexa Grutter
    • Justin Marshall
    • Karen Cheney
    • Samantha Waller
Bignose and cleanerfish Cod and cleaner shrimp Sailfin tang and cleanerfish
  • 7. Parasite removal as the cause of cleaning behaviour in client fish (completed)

In this study I examined why client fish seek cleaner fish to engage in cleaning behaviour. I was interested in whether parasites influence the tendency of client fish to seek cleaner fish and looked at such things as client cleaning behaviour relative to the ectoparasite load. I found that parasites did affect a client's tendency to seek cleaners in the laboratory.

      Investigators:

      • Lexa Grutter
Gnathiid isopod Cod with cleanerfish Sweetip and cleanerfish
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