page_title: Portunus armatus
section_title: Behaviour
hierarchical_section_title: Portunus armatus / Behaviour
caption_attribution_description: English: Portunus pelagicus feeding, Qatif, Saudi Arabia.
context_page_description: Portunus armatus, also known as the flower crab, blue crab, blue swimmer crab, blue manna crab or sand crab, rajungan in Indonesian, and alimasag in Tagalog, Kapampangan, and Pangasinan, is a large crab found in the intertidal estuaries around most of Australia and east to New Caledonia.
context_section_description: They stay buried under sand or mud most of the time, particularly during the daytime and winter, which may explain their high tolerance to ammonium (NH₄⁺) and ammonia (NH₃). They come out to feed during high tide on various organisms such as bivalves, fish and, to a lesser extent, macroalgae. They are excellent swimmers, largely due to a pair of flattened legs that resemble paddles. However, in contrast to another portunid crab (Scylla serrata), they cannot survive for long periods out of the water.
caption: Portunus pelagicus feeding, Qatif, Saudi Arabia.
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