University of Florida

Perna Species

Phylum: Mollusca
Class:
Bivalvia
Order: Mytiloida
Family: Mytilidae
Subfamily: Mytilinae
Genus: Perna

Perna Viridis

also known as "Green mussels"

Range: Indo-Pacific, from the Persian Gulf to the Philippines and Hong Kong. Introduced to Japan, Fiji, Tahiti, Queenslands (Australia), Trinidad, Venezuela, Jamaica, and Florida. This species is killed by cold water tempeatures, and occurs only in tropical and warm temperate coastal waters, and is most abundant in estuaries.

Shell: The periostracum, or shell coating, is usually green, at least at the shell margins, but intertidal specimens may be mostly brown. The periostracum may wear off in older shells, revealing a white, slightly pearly shell beneath. Some specimens have faint radial rays of brown or red, visible towards the shell margins.

The green mussel, P. viridis, is one of at least three closely related and similar species which may be confused for each other. These three other species are listed below with some characters that may be useful in distinguishing them.

Perna Viridis

Perna Perna

also known as "Brown Mussel" or "Mexilhao Mussel"

Range: Most African coastlines, Atlantic coast of South America, introduced to the southern Caribbean, Mexico, and Texas. This species occurs only in tropical and warm temperate coastal waters and is most abundant in high-salinity areas.

Shell: The periostracum is mostly brown. There may be areas of green, but rarely at the shell margin, and there are no radial rays of color. The shell beneath the periostracum is white and slightly pearly.

Perna Perna

Perna Canaliculus

also known as"Green-Lipped Mussel"

Range: New Zealand. This species does not occur in tropical waters, and is not known from outside of New Zealand except as a processed food item. This is the “green-shell” or “green-lipped” mussel often sold in American seafood markets and restaurants.

Shell: The periostracum is mostly green, like that of the green mussel, P. viridis. Most P. cancaliculus specimens, however, have distinct radial rays of brown or red, particularly visible towards the shell margins. These rays of colors are more consistent and usually more distinct than those in P. viridis. The shell beneath the periostracum is white and slightly pearly.

Perna Canaliculus

Mytilus Edulis Group

Range: Temperate and cold waters of the North Pacific and North Atlantic, Mediterranean and Black Sea. Mytilus edulis, once thought to range widely from the Mediterranean to the Pacific, has been broken into three species: M. edulis (blue mussel), M. galloprovincalis (black or Mediterranean mussel), and M. trossulus (Pacific blue mussel). These three species are so similar that molecular genetics are required to reliably distinguish them. Some of these species have been introduced to other parts of the world, including the Southern Hemisphere, and all three are widely marketed.

Shell: The periostracum is usually dark blue to nearly black, but smaller specimens may be brown or have broad radial stripes of several colors, including brown. Green color rays are rare. Beneath the periostracum, the surface of the shell is blue to purple and slightly pearly, but the internal shell layers are white.

Mytilus Edulis

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