''Meridiastra mortenseni'' 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 ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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: ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. Described as ''Patiriella mortenseni'' in 2002, it is named after T. Mortensen, who recorded it as distinct from ''

Patiriella regularis __NOTOC__ ''Patiriella regularis'', the New Zealand common cushion star, is a sea star of the family Asterinidae, native to New Zealand. It has an arm spread of up to . It is one of New Zealand's most common rocky shore starfish. It is abundant i ...

'', the New Zealand common cushion star, in 1925.Mortensen, T. 1925: Echinoderms of New Zealand and the Auckland-Campbell Islands. III-V. Asteroidea, Holothurioidea, Crinoidea. ''Videnskabelige Meddelelser fra Dansk naturhistorisk Forening i København'' 79: 261–420. According to genetic evidence, ''P. mortenseni'' was moved from the ''

Patiriella ''Patiriella'' is a genus of sea stars of the family (biology), family Asterinidae. Many species formerly included in this genus have been transferred to other genera (''Cryptasterina'', ''Meridiastra'', and ''Parvulastra''). They are commonly kn ...

'' genus to ''

Meridiastra ''Meridiastra'' is a genus of star fish in the family Asterinidae. The genus is found in the Indian and Pacific Oceans, with most records from the waters around Australia. They occur in shallow waters down to a depth of about . ''Meridiastra'' ar ...

'' in 2004. Reciprocal transplant experiments in

Fiordland Fiordland (, "The Pit of Tattooing", and also translated as "the Shadowlands"), is a non-administrative geographical region of New Zealand in the south-western corner of the South Island, comprising the western third of Southland. Most of F ...

have shown it is less tolerant of hyposaline conditions than the sympatric (but distantly related) ''P. regularis''. This is reflected in its

distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

: it lives in deeper waters (at depths of roughly 10±3 m in

Milford Milford may refer to: Place names Canada * Milford (Annapolis), Nova Scotia * Milford (Halifax), Nova Scotia * Milford, Ontario England * Milford, Derbyshire * Milford, Devon, a place in Devon * Milford on Sea, Hampshire * Milford, Shro ...

and

Doubtful Sound Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Ze ...

s), below the low salinity layer. In

laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratories are found in a variety of settings such as schools ...

conditions, they die after 24-hour exposure to water with salinities below 25

‰ The phrase per mille () indicates parts per thousand. The associated symbol is , similar to a per cent sign but with an extra zero in the divisor. Major dictionaries do not agree on the spelling, giving other options of per mil, per mill, pe ...

References

Asterinidae Echinoderms of New Zealand Endemic fauna of New Zealand Echinoderms of the Pacific Ocean Animals described in 2002 {{Asteroidea-stub