Tiostrea chilensis

Tiostrea chilensis the Bluff oyster
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Subclass:	Pteriomorphia
Order:	Ostreoida
Family:	Ostreidae
Genus:	Tiostrea
Species:	T. chilensis
Binomial name
Tiostrea chilensis
Synonyms
Ostrea chilensis Tiostrea lutaria

Tiostrea chilensis, known in Chile as Ostra chilena and in New Zealand as the Bluff oyster,^[1] is a species of marine bivalve mollusc in the family Ostreidae.

Distribution

Tiostrea chilensis is endemic to Chile and New Zealand.

There is also a self-sustaining population in the Menai Strait which was accidentally introduced from the Fisheries Laboratory, Conwy, in 1965 or 1966 (sources disagree).

Habitat

This bivalve is found from low tide to depths of up to 35 m.

Description

Height is up to 105 mm, width up to 70 mm, and inflation up to 33 mm.

Commercial importance

Bluff oysters at a restaurant

In New Zealand they are a prized delicacy, and harvested from March to August from the Foveaux Strait oyster fishery based around the town of Bluff (hence the local name).^[1] From the early 1980s the fishery went into serious decline, due to the outbreak of an oyster parasite Bonamia exitiosa, the disease killing an estimated billion oysters between 2000 and 2003.^[1] The population has been recovering since 2003, with fishermen voluntarily limiting the catch to half the allowable to aid the revival.^[1]

Other

There is some speculation that with the change in river flows in Southland due to farming and especially power generation, this has amounted to lower flows of fresh water carrying limestone deposits into the Strait. This therefore is believed by some to have amounted to increase of susceptibility to Bonamia as well as lower growth rates for some seasons in the past. As of yet there is little evidence to support it and as such only seems coincidental.

References

1. ^ ^{a b c d} "High demand for recession-proof oysters". New Zealand Herald. 2 March 2009. http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10559582. Retrieved 2009-03-02. 

External links

• The National Centre for Fisheries & Aquaculture's page on Bluff oysters
• JNCC
• ZipCodeZoo