Paphies subtriangulata porrecta

Taxobox
name = "Paphies subtriangulata porrecta"
regnum = Animalia
phylum = Mollusca
classis = Bivalvia
ordo = Veneroida
superfamilia = Mactroidea
familia = Mesodesmatidae
genus = "Paphies"
species = "P. subtriangulata"
subspecies = "P. subtriangulata porrecta"
trinomial = "Paphies subtriangulata porrecta"
trinomial_authority = (Marwick, 1928)

"Paphies subtriangulata porrecta" is one of three subspecies of the bivalve clam known as tuatua in the Māori language, a member of the family Mesodesmatidae and endemic to New Zealand. It is found only on the Chatham Islands of New Zealand, buried in fine clean sand on ocean beaches.

The large shell is asymmetrical, with the hinge at one side. It is thick, solid, and wedge-shaped, coloured white under a thin layer of yellow periostracum which is usually worn off. It differs from the mainland subspecies "Paphies subtriangulata subtriangulata" in its greatly elongated anterior end and short strongly convex posterior end, the latter with a very weakly defined ridge.

It is an edible delicacy, made into fritters or boiled and served on the shell. Historically it has been used as a food source by the Māori, its shell a common component of excavated Māori middens.

The clam burrows beneath the sand, and does so very quickly, making it a challenge to dig for at times. It also squirts water when threatened. All tuatua are protected with legal limits on their capture. In some areas one digger may bag no more than 50 to 150 tuatuas per day, depending on location.

Maximum length is 93 mm, and height 57 mm.

The other two subspecies are:

* "Paphies subtriangulata subtriangulata" (Wood, 1828)
* "Paphies subtriangulata quoyii" (Deshayes, 1832)

References

* Powell A. W. B., "New Zealand Mollusca", William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1