Crustaceans are among the most abundant, diverse and commonly found creatures in the sea, and are regularly encountered in freshwater ecosystems as well as on land.

Shrimps from Uluru

Crustaceans are among the most abundant, diverse and commonly found creatures in the sea, and are regularly encountered in freshwater ecosystems as well as on land. Crustaceans are rare in arid environments because they need moisture to breathe and reproduce. However, the Australian Museum crustacean collection contains shrimp found in temporary pools near the summit of Uluru (Ayers Rock), 360 m above the Gibson Desert of central Australia.

The crustaceans found at Uluru are commonly known as fairy or brine shrimp (Anostraca), shield or tadpole shrimp (Notostraca) and clam shrimp (Conchostraca). Together they form a group called Branchiopoda. Branchiopoda means 'gill foot' and refers to structures on the animals' limbs through which they breathe. Branchiopods have an unusual adaptation which allows them to live in temporary water bodies such as pools or small lakes and areas with low rainfall. Their eggs tolerate drying and can therefore survive periods of drought. The eggs lie dormant until rainfall triggers them to hatch. The branchiopods then grow rapidly, resulting in population explosions, which allow more eggs to be produced before the water dries up. The presence of shrimp at Uluru may be due to the dispersal of their drought resistant eggs by wind.

Dry branchiopoda eggs are sometimes sold in pet stores as a powder that can be added to water to 'miraculously' produce animals marketed as 'sea monkeys'.