Abstract
A field and laboratory study in 1984–1985 using the foregut contents of crabs caught in Moreton Bay, Queensland, when trawling was underway, showed that animals discarded from trawls constituted about 33% of the diet. Portunus pelagicus can fill its foregut in about 8 min and clear it completely of tissues in about 6 h, except for fish bone which requires about 24 h. P. pelagicus used a zigzag search pattern to find food and moved towards it at a mean point-to-point speed of 290 m h-1 (8 cm s-1). Underwater still photography on the trawl grounds showed that P. pelagicus was the most common scavenger attracted to a bait that simulated trawl-discards, and that it was most active at dusk. Trawler-discards at periods of high food demand in summer may allow larger populations of P. pelagicus to exist than would otherwise occur.
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Communicated by G. F. Humphrey, Sydney
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Wassenberg, T.J., Hill, B.J. Feeding by the sand crab Portunus pelagicus on material discarded from prawn trawlers in Moreton Bay, Australia. Mar. Biol. 95, 387–393 (1987). https://doi.org/10.1007/BF00409569
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DOI: https://doi.org/10.1007/BF00409569