''Luidia australiae'', the southern sand star, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...

in the family Luidiidae. It is found in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

around Australia and New Zealand.

Description

''Luidia australiae'' has a variable number of long, slim, tapering arms but seven is the most common number. The central disc and the arms are a dull yellow colour, irregularly blotched with dark green or black. It can grow to in diameter.

Distribution and habitat

''Luidia australiae'' is native to the waters around southern Australia and New Zealand. It is found on reefs, in

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s, and semi-buried in sand at depths of up to . It is sometimes washed ashore after storms.

Biology

''Luidia australiae'' is a

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

and is often found half-buried in the sediment in seagrass beds where its colouring provides camouflage. It is likely to be an opportunist

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

of macrofauna, and possibly also a

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

References

{{Taxonbar, from=Q2676469 Luidia Animals described in 1920 Fauna of the Pacific Ocean Taxa named by Ludwig Heinrich Philipp Döderlein