Perna canaliculus

Perna canaliculus occurs around all of New Zealand's mainland. It is usually found below the intertidal zone, but it can occur in the intertidal zone. P. canaliculus feeds on various types of phytoplankton. ==Description==

This shellfish is economically important to New Zealand. It differs from other mussel species in that it has dark brown/green shells with green lips around the edges, and has only one adductor muscle. It is also one of the largest mussel species, reaching in length. ==Aquaculture==

P. canaliculus is endemic to New Zealand. When grown for aquaculture there, it is marketed under the trademark name Greenshell. This industry produces over annually and in 2009 was valued in excess of NZ$250 million. Around 270 tonnes of wild spat which is attached to beach-cast seaweed are collected from Ninety Mile Beach in northern New Zealand each year to supply the aquaculture industry. Nowhere else in the country are such large quantities of mussel-covered seaweed washed ashore. This single beach provides around 80% of the seed mussels required for this aquaculture industry. Even with this industry's heavy dependency on wild spat, the biological and environmental processes by which the spat arrives on Ninety Mile Beach and on spat collection ropes are largely unknown. Initial farms were based on the 700-year-old European floating raft method of mussel cultivation which was suitable at small scales; however, methods to support larger scale production were soon needed. Once the spat have been transported from the beach to mussel farms around the country, they are transferred into a stocking that holds the spat-covered seaweed material around a "dropper rope" which is suspended in the water column hanging at regular intervals off the backbone ropes. Both the mussels and seawater around the farms are tested for biotoxins, bacteria, and heavy metals. The water quality is constantly monitored with tests carried out to the standards set by the U.S Food and Drug Administration, European Union, and NZ Food Safety Authority. The standards are in place to meet the increasing global demand for safe and healthy seafood products. The Resource Management Act 1991 and Fisheries Act 1996 have been put in place by the New Zealand government to mitigate the environmental effects of aquaculture in New Zealand. New Zealand's high aquaculture standards have been recognized by the International Conservation Organisation Blue Ocean Institute, which ranked New Zealand greenshell mussels as one of the top two 'eco-friendly seafoods' in the world. ==Parasites==

entering a green-lipped mussel hosting a female crab, infrared video the mate location behaviour of male New Zealand pea crabs, which were observed when dwelling in the mussel. Given the cryptic behaviour of the male crabs, a trapping system was developed to determine whether male crabs would exit their mussel hosts in response to an upstream female crab. Observations of the nocturnal mate-finding behaviour of male crabs were made in darkness using infrared video recordings. Male crabs were often observed stroking the mantle edge of the mussel whilst attempting to gain entry, successfully increasing mussel valve gape during entry from . ==Medicinal effects==

Perna canaliculus inhibits the 5-lipoxygenase pathway, which leads to the formation of leukotrienes. Many of the products of these pathways have inflammation-supporting properties. However, a 2006 systematic review of scientific research on supplementation with green-lipped mussel found "little consistent and compelling evidence" of any benefit for rheumatoid or osteoarthritis. However, subsequent placebo-controlled trials have shown that green-lipped mussels do show promise as an alternative therapy for joint issues. Another study on canines shows that a diet rich in green-lipped mussels yielded an improvement in pain and functioning in Osteoarthritic Dogs. A lipid extract from this shellfish is sold under the brand name Lyprinol. A 2011 literature review found weak evidence of anti-inflammatory effects similar to fish oil, but noted that clinical trials to date had been limited. TVNZ was also found to have breached broadcasting standards by publishing the claims in a news story. == See also ==