Don't let the bed bugs bite: goatfish resting aggregations on low sediment reef surfaces

Reducing benthic sediment loads on experimental 1m2 plots of algal turf on a coral reef crest (following Goatley and Bellwood 2012) repeatedly attracted a school of Indian goatfish ('Parupeneus indicus'), which settled on the benthos, appearing to rest (Fig. 1). The first goatfish arrived less than 17 minutes after sediment reduction, and while the resting aggregation exhibited high turnover, with individuals resting for 103±23 s (mean±S.E., n=20 randomly selected fish), there were 4-15 (mean 6.3±0.8, n=20) fish resting at any time, for periods of at least 2 hours. This behaviour was observed using static underwater video cameras, in two different plots on non-consecutive days and only where sediment had been removed using a compressed air gun. These resting aggregations have not previously been observed on the Great Barrier Reef.