Publisher :
Place of publication :
Publication year : 2007
Thematic : Climate Change and Biodiversity
Language : English
Note
Coral reefs are under threat due to climatemediated
coral mortality, which affects some reef coral
genera more severely than others. The impact this has on
coral reef fish is receiving increasing attention, with one
focal area assessing impacts on fish that feed directly on live
coral. It appears that the more specialised a species of
corallivore, the more susceptible it is to coral declines.
However data are sparse for the Indian Ocean, and little is
known about why some corals are preferentially fed upon
over others. Here I assess feeding specialisation in three
species of coral feeding butterflyfish in the Chagos Archipelago,
central Indian Ocean, assess the food quality of the
coral genera they target and document patterns of decline in
the Seychelles following a severe coral mortality event.
Cheatodon trifascialis was the most specialised coral feeder,
preferentially selecting for Acropora corals, however, when
Acropora was scarce, individuals showed considerable
feeding plasticity, particularly for the dominant Pocillopora
corals. C. trifasciatus also preferentially fed on Acropora
corals, but fed on a much more diverse suite of corals and also
displayed some selectivity for Porites. C. auriga is a facultative
corallivore and consumed*55% live coral, which lies
within the wide range of coral dependence reported for this
species. C:N ratio analysis indicated Lobophyllia and
Acropora have the highest food quality, with Pocillopora
having the lowest, which conforms with diet selection of
corallivores and helps explain preferential feeding. Obligate
specialist feeders displayed the greatest declines through
coral mortality in the Seychelles with obligate generalists
also declining substantially, but facultative feeders showing
little change. Clearly a greater understanding of the species
most vulnerable to disturbance, their habitat requirements
and the functional roles they play will greatly assist biodiversity
conservation in a changing climate.
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Keywords : Sphenomorphus wrighti
Encoded by : Pauline Carmel Joy Eje
