bivalves text index | photo index
Phylum Mollusca > Class Bivalvia > Family Mytilidae
Green mussel
Perna viridis
Family Mytilidae
updated May 2020
if you learn only 3 things about them ...
It is among our favourite seafood. But be careful about eating wild caught mussels.
It attaches itself to a hard surface by producing threads!
It is considered a pest outside its natural range.

Where seen? This edible clam is sometimes very common on our Northern shores, forming dense clusters on hard surfaces like rocks, pilings, floats. It is well adapted to waters that are murky and sediment laden.

Features: 5-8cm. The two-part shell is thin, smooth. Young clams often all bright green, older clams usually brownish edged in green. The animal attaches to hard surfaces with byssus threads, usually in clusters of many individuals. It has a large mobile foot and can 'climb' to another position, e.g., to avoid being buried in sediments. It grows very rapidly, compared to other encrusting animals in its preferred habitat, thus can sometimes take over a location.

Growing on a large boulder.
Changi, Jan 04

Growing on a large boulder.
Changi, Jan 04

Growing in cracks of boulder.
Punggol, Jun 12
What does it eat? Like most other bivalves, it is a filter feeder. At high tide, it opens its shell a little. It then generates a current of water through the shell and sieves out the food particles with enlarged gills. When the tide goes out, it clamps up its shells tightly to prevent water loss.

Chek Jawa, Dec 03

When submerged, filter feeds.
Punggol, Jun 12

It has a large mobile foot.
From the Lee Kong Chian Natural History Museum
What eats it? Besides humans, other animals that relish them include fishes, crabs and octopuses.

Human uses:
Green mussels are considered the economically most important mussel in our region. They are farmed in many parts of Southeast Asia as seafood. They grow fast and in dense numbers. Like other filter-feeding clams, however, mussels may be affected by red tide and other harmful algal blooms. During such times, the mussels concentrate toxins and people who eat them may get seriously ill.

Outside its natural range of the Asia-Pacific region, the Green mussel is considered an introduced pest and an unwelcome invasive species. There, unchecked by natural predators, the mussels multiply rapidly and clog industrial pipes, foul aquaculture and disturb local ecosystems.

Green mussels on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

Coney Island, Nov 20
Photo shared by Richard Kuah on facebook.

Tuas, Mar 09
Photo shared by Loh Kok Sheng on flickr.

Berlayar Creek, Mar 20
Photo shared by Loh Kok Sheng on facebook.



  • Stephane Bayen, Gareth Owen Thomas, Hian Kee Lee, Jeffrey Philip Obbard. June 2004. Organochlorine Pesticides and Heavy Metals in Green Mussel, Perna viridis in Singapore. Water, Air, and Soil Pollution, Volume 155, Issue 1, pp 103–116T
  • Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist of The Molluscs of Singapore (pdf), Raffles Museum of Biodiversity Research, National University of Singapore.
  • Tan, K. S. & L. M. Chou, 2000. A Guide to the Common Seashells of Singapore. Singapore Science Centre. 160 pp.
  • Abbott, R. Tucker, 1991. Seashells of South East Asia. Graham Brash, Singapore. 145 pp.
links | references | about | email Ria
Spot errors? Have a question? Want to share your sightings? email Ria I'll be glad to hear from you!
wildfactsheets website©ria tan 2008