''Triops australiensis'', sometimes referred to as a shield shrimp, is an Australian species of the tadpole shrimp ''

Triops ''Triops'', from Ancient Greek τρία (''tría''), meaning "three", and ὄψ (''óps''), meaning "face" or "eye", is a genus of small crustaceans in the order Notostraca (tadpole shrimp). The long-lasting resting eggs of several species of '' ...

''.

Distribution

''Triops australiensis'' has a wide distribution across

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, excluding the northernmost parts of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

, and

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

. It is also absent from

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

in the south, where it is replaced by ''

Lepidurus apus ''Lepidurus apus'', commonly known as a tadpole shrimp, is a notostracan in the family Triopsidae, one of a lineage of shrimp-like crustaceans that have had a similar form since the Triassic period and are considered living fossils. This species ...

''. The two species can be distinguished by the presence of a supra-anal plate between the caudal rami at the end of the

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

in ''L. apus'', which is lacking in ''T. australiensis''.

Biology

''T. australiensis'' inhabits temporary pools of water in the arid regions of the Australian outback. When desiccated pools fill with water, the resting eggs hatch into nauplii, and rapidly develop to adulthood. Reproduction succeeds within a few weeks of hatching. Adults achieve a maximum size of around , which is considered large for a tadpole shrimp.

Water chemistry

''Triops australiensis'' can tolerate a pH of 7–9, and can live in both hard and

soft water Hard water is water that has a high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium and magnesium carbonates, ...

, but the eggs of ''T. australiensis'' are more likely to hatch in water with a low mineral content.

References

External links

* {{Taxonbar, from=Q3313727 Notostraca Freshwater crustaceans of Australia Endemic fauna of Australia Crustaceans described in 1895 Taxa named by Walter Baldwin Spencer