There are 2 results of your search for blue swimmer1.
blue swimmer1
an edible Australian crab, Portunus pelagicus, of blue-green colour and capable of powerful sustained swimming; sand crab. Compare blue manna. Also, blue swimmer crab.
Contributor's comments: Also used in SE Queelsland. I've crabbed near Bribie Island for years and have always heard sand crabs referred to as "blue swimmers".
Contributor's comments: Also used in South Australia.
Contributor's comments: Also [means] a 10 dollar note (it's blue). See also "lobster" ($20 note) and "banana" ($50 note).
Contributor's comments: Also used in Western Australia.
blue swimmer2
a ten dollar note. [so called from the blue colour]