Emeritus Professor Howard Choat

Adjunct Professor

Emeritus Professor Howard Choat

Adjunct Professor (2001 - present)

Head of School, School of Marine Biology and Aquaculture, JCU (1997- 2000)

Professor and Head of Department, Marine Biology, JCU (1986-97)

Senior Lecturer, Department of Zoology, University of Auckland, New Zealand (1978-85)

Lecturer, Department of Zoology, University of Auckland (1969-71)

Commonwealth Postgraduate Award, University of Queensland, Brisbane (1968-69).

BSc Wellington, MSc Wellington, PhD Queensland.

Member of the: Ecological Society of America, James Cook University Research Funding Panel

Sigma Xi Scientific Society, Leader, Education Program CRC Reef.


Contact Details

Campus:

Townsville

Phone:

+61 7 4781 6383

Fax:

+61 7 4725 1570

Email:

John.Choat@jcu.edu.au

Note: Please direct all student enquiries through the School Secretary.

Research Interests

  • Biology of Herbivorous Fishes, Including Development and Growth from Larval Stages

  • Demography and Life Cycles in Reef Fishes and Cephalopods

  • Evolutionary biology of reef fishes

Recent and Current Projects Include

My current research is focused on two areas of reef fish biology; feeding in nominally herbivorous fishes and their significance in coral reef ecosystems and the population evolutionary biology of labroid and acanthuroid fishes. The studies on herbivorous reef fishes are being carried out in collaboration with Dr K.D. Clements, University of Auckland and has focused on the resources used by herbivorous fishes and the manner in which they are harvested and processed. The primary goal is to is to evaluate the ecological consequences of different modes of herbivory on coral reefs. The most recent applications of this work include comparative feeding studies in acanthurid fishes linked to a phylogenetic analysis of species relationships using molecular analyses in association with Lynne van Herwerden.

The most interesting aspect of this work is the suggestion that many nominal herbivores among the parrot and surgeon fishes harvest and process very small amount of plant material. This has important implications for reef trophodynamics.

This work is also associated with a study of the population biology of different groups of reef fishes based on an analysis of growth rates and age structures through examination of annuli in saggital otoliths. One unexpected finding has been the very different growth rates and longevities in various groups of reef fishes. Labrid fishes including wrasses and parrot fishes are relatively short-lived rarely exceeding 20 yrs of age. Acanthurid fishes are long-lived with individuals of smaller species commonly exceeding 40 years of age. A similar variation in age distribution is also seen in serranid fishes. The goal of this research is to provide material for age-based rather than size-based analyses of reef fish population dynamics.

Recent and Currently Supervised Projects

  • Population biology and dynamics of lutjanid and serranid fishes

  • Temporal dynamics of reef fish assemblages

  • Growth, demography and genetics of reef sharks

  • Biogeographical trends in reef fish growth and recruitment patterns

Future PhD Directions

  • Evolutionary patterns in reef fish feeding patterns

  • Demographic comparisons of Caribbean and Indo-Pacific reef fishes

Selected Publications

Choat J.H., Robbins W.D. and Clements K.D. 2004. The trophic status of herbivorous fishes on coral reefs II: Food processing modes and trophodynamics. Marine Biology 145 (3) 445-454.

Choat, J.H., Clements, K.D. and Robbins, W.D. 2002. The trophic status of herbivorous fishes on coral reefs 1: Dietary analyses. Marine Biology. 140(3): 613-623.

Gust, N., Choat, J.H., Ackerman, J.L. (2002). "Demographic plasticity in tropical reef fishes." Marine Biology 140(5): 1039-1051.

Choat, J.H. and Clements, K.D. 1998. Vertebrate herbivores in marine and terrestrial environments: a nutritional ecology perspective. Annu. Rev. Ecol. Syst. 29, 375-403.

Craig, P., Choat, J.H., Axe, L. and Saucerman, S. 1997. Population biology and harvest of the coral reef surgeonfish Acanthurus lineatus in American Samoa. Fishery Bulletin 95, 680-693.

Meekan, M.G. and Choat, J.H. 1997. Latitudinal variation in abundance of herbivorous fishes: a comparison of temperate and tropical reefs. Marine Biology 128, 373-383.

Choat, J.H. and Axe, L.M. 1996. Growth and longevity in acanthurid fishes; an analysis of otolith increments. Marine Ecology Progress Series 134, 15-26.

Clements, K.D. and Choat, J.H. 1995. Fermentation in tropical marine herbivorous fishes. Physiological Zoology 68(3), 355-378.