Yellow Lampmussel

Scientific name: Lampsilis cariosa
Mi’kmaq name:


The Yellow Lampmussel is an oval bivalve mollusc that reaches lengths of 110 mm, but is generally closer to 75 mm. It has a bright yellow to reddish-brown tinge to the outer surface of its glossy shell, and iridescent white to pink on the inside. Several fine, radiating lines circle the long slope of the outer shell. The soft living parts (mantle) are visible between the shell valves.


Found large, fast flowing, alkaline rivers, with sand and gravel bottoms. In Sydney River, it also occurs in a lake with vegetated, wave-washed shorelines, and in a dammed reservoir. Water depths range from 0.5 – 6.0 metres, and it prefers sandy substrate.

Interesting Points

  • They are an integral part of the Sydney River ecosystem, playing an important role in nutrient cycling, and serving as a food source for other animals.
  • The dark rings that form around their shell are added one per year, like trees.
  • They increase the clarity and quality of the waters in which they live by filtering out algae and bacteria.
  • Adults have a unique modified “lure” that looks like a little fish, which they dangle out to attract potential fish hosts. When one comes nearby, they spew out little parasitic larvae that attach to the fish’s gills.


  • The population in the Sydney River is large and apparently stable, but since it is isolated and only found in a small geographic area, it is extremely vulnerable to pollution and habitats destruction at a local level.

Courtesy of Species at Risk in Nova Scotia: Identification & Information Guide


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