__NOTOC__ ''Patiriella regularis'', or New Zealand common cushion star, is a

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

of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Asterinidae The Asterinidae are a large family of sea stars in the order Valvatida. Description and characteristics These are generally small sea stars, flattened dorsally and bearing very short arms, often giving a pentagonal shape in the body ;example: ...

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. It has an arm spread of up to . It is one of New Zealand's most common rocky shore starfish. It is abundant in shallow water around both mainland islands. They come in a large range of colours and have 4–6 arms. They feed on algae, barnacles and invertebrates. To catch their food the cushion star inflates its cushion and then deflates on top of its prey. They were introduced into waters in south east

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, where they have become well established. Concern exists that they may be an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

. They breed in January to March. Once fertilised, 9–10 weeks are needed for them to grow from larvae.

Research

A genetic variance is found in ''P. regularis'' from the North and South of New Zealand. Geographic barriers, and coastal

upwelling Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutr ...

s might keep various types of ''P. regularis'' from being able to spread or comingle.

References

Patiriella Echinoderms of New Zealand Taxa named by Addison Emery Verrill Animals described in 1867 {{Asteroidea-stub