Trypaea

Trypaea australiensis, known as the (marine) yabby or ghost nipper in Australia, or as the one-arm bandit due to their occasional abnormally large arm, and as the Australian ghost shrimp elsewhere, is a common species of mud shrimp in south-eastern Australia, and may be the only extant species in the genus Trypaea. T. australiensis is a popular bait used live or frozen by Australians targeting a range of species. It grows to a length of 6 cm and lives in burrows in mudflats or sandbanks, especially in or near estuaries.

Species
One extant and two extinct species belong to the genus Trypaea:
 * Trypaea australiensis Dana, 1852 (Australian ghost shrimp) (Indo-West Pacific and Australia)
 * † Trypaea inornata (Nagao & Huzioka, 1938)
 * † Trypaea mizunamiensis Karasawa, 1993 (temperate Asia)