''Porcellanopagurus edwardsi'' is a species of

hermit crab Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit crab, most of which possess an a ...

that lives in the waters around

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 ...

and its subantarctic islands.

Distribution

''Porcellanopagurus edwardsi'' is found around the

Auckland Islands The Auckland Islands (Māori: ''Motu Maha'' "Many islands" or ''Maungahuka'' "Snowy mountains") are an archipelago of New Zealand, lying south of the South Island. The main Auckland Island, occupying , is surrounded by smaller Adams Island, ...

Campbell Islands The Campbell Islands (or Campbell Island Group) are a group of subantarctic islands, belonging to New Zealand. They lie about 600 km south of Stewart Island. The islands have a total area of , consisting of one big island, Campbell Isla ...

Snares Islands The Snares Islands / Tini Heke, known colloquially as The Snares, is a group of uninhabited islands lying about 200 km south of New Zealand's South Island and to the south-southwest of Stewart Island / Rakiura. The Snares consist of the m ...

Stewart Island Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar ...

and along the coast of New Zealand's

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 ...

. The closely related species '' P. filholi'' has a more northerly distribution, overlapping with that of ''P. edwardsi'' only in the region of the

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 ...

. pp. 110–114
''P. edwardsi''
pp. 114–117
''P. filholi''

Taxonomy

''Porcellanopagurus edwardsi'' was described by

Henri Filhol Henri Filhol Henri Filhol (13 May 1843 – 28 April 1902) was a French medical doctor, malacologist and naturalist born in Toulouse. He was the son of Édouard Filhol (1814-1883), curator of the Muséum de Toulouse. After receiving his early e ...

in 1885 as the only species in a new genus '' Porcellanopagurus''; 12 further species have since been described.

Description

Unlike most hermit crabs, ''Porcellanopagurus edwardsi'' is almost

symmetrical Symmetry (from grc, συμμετρία "agreement in dimensions, due proportion, arrangement") in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, "symmetry" has a more precise definiti ...

, but its abdomen is bent back over the carapace, so that the

pleopod The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

s are dorsally situated. The abdomen is "grossly distorted", and is usually covered by the shell of a

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

limpet Limpets are a group of aquatic snails that exhibit a conical shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" descended indep ...

, in contrast to the

gastropod shell The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium s ...

used by most hermit crabs. The

cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

is flattened and extends outwards in a number of lobes, the largest of which is the

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

at the front of the animal.PDF
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Distribution

Taxonomy

Description

References

Further reading