''Munida gregaria,'' commonly known as the gregarious squat lobster, is a species of squat lobster found along the eastern seaboard of the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

of New Zealand, around the southern coast of Tasmania and in a few locations around the southern parts of South America and Tierra del Fuego.

Taxonomy and nomenclature

The species was first described from Patagonia by Johan Christian Fabricius in 1793. A study of population samples from New Zealand and from the Tierra del Fuego region indicate they are the same species, despite the large distance and deep ocean between these locations. Its specific epithet (''gregaria'') derives from its behaviour in the immature phase to form very large shoals or swarms of many tens of thousands of individuals in shallow coastal waters. This can result in mass strandings. ''Munida gregaria'' is sometimes referred to as lobster krill because it looks like a baby lobster and is found in swarms near the surface like krill.

Habitat and distribution

In South America, the species has been identified in Chile, and the

Strait of Magellan The Strait of Magellan (), also called the Straits of Magellan, is a navigable sea route in southern Chile separating mainland South America to the north and Tierra del Fuego to the south. The strait is considered the most important natural pass ...

. During his voyage with

James Cook James Cook (7 November 1728 Old Style date: 27 October – 14 February 1779) was a British explorer, navigator, cartographer, and captain in the British Royal Navy, famous for his three voyages between 1768 and 1779 in the Pacific Ocean an ...

on in 1769,

Joseph Banks Sir Joseph Banks, 1st Baronet, (19 June 1820) was an English naturalist, botanist, and patron of the natural sciences. Banks made his name on the 1766 natural-history expedition to Newfoundland and Labrador. He took part in Captain James ...

described small shoals near Cape Horn. Shoal gregarious squat lobster

In New Zealand, ''Munida gregaria'' is most commonly found along the east coast of the South Island, particularly around

Banks Peninsula Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately and encompasses two large harbours and many smaller bays and coves. The South Island's largest cit ...

and

Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...

. However, they have also been observed in Milford Sound, are occasionally seen around the southern parts of Cook Strait and the beaches of Nelson. They generally live along coastlines where there is a mixing of coastal and oceanic waters to provide a sufficiently rich supply of food. There are many species of squat lobster, but ''M. gregaria'' is unusual in that it is only one of a very few of the ''Munida'' species that aggregate in large swarms. Adult ''M. gregaria'' live on the sea floor and grow to around long. They have been found on the sea floor in the outer Marlborough Sounds and along the coastline from Cook Strait south to Campbell Island, where they have been observed at depths of . In New Zealand waters, the larvae of ''M. gregaria'' undergo 5 stages of larval development from mid-winter until the postlarval metamorphosis in spring, when they form large swarms on the surface and heaped up on beaches. They come inshore in large numbers during this phase of their life-cycle, seeking suitable habitat. Some aggregations seen from the air have been in bands up to wide but long; formation of shoals varies from year to year, with little or no shoaling observed every 3 to 5 years. The post-larval stage typically lasts until February when the animals begin the

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

phase of their life-cycle and settle on the sea floor. Adults that settle on the bottom may live for 2 or 3 years.

References

External links

* * ''Munida gregaria'' discussed on

RNZ Radio New Zealand ( mi, Te Reo Irirangi o Aotearoa), commonly known as Radio NZ or simply RNZ, is a New Zealand public-service radio broadcaster and Crown entity that was established under the Radio New Zealand Act 1995. It operates news and cu ...

'' Critter of the Week''
15 July 2022
{{Taxonbar, from=Q3327924 Squat lobsters Crustaceans of the Atlantic Ocean Crustaceans of the Indian Ocean Crustaceans of the Pacific Ocean Crustaceans described in 1793 Taxa named by Johan Christian Fabricius