Mussel
Mussel (/ˈmʌsəl/) is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.
The word "mussel" is frequently used to mean the bivalves of the marine family Mytilidae, most of which live on exposed shores in the intertidal zone, attached by means of their strong byssal threads ("beard") to a firm substrate.[1] A few species (in the genus Bathymodiolus) have colonised hydrothermal vents associated with deep ocean ridges.
In most marine mussels the shell is longer than it is wide, being wedge-shaped or asymmetrical. The external colour of the shell is often dark blue, blackish, or brown, while the interior is silvery and somewhat nacreous.
The common name "mussel" is also used for many freshwater bivalves, including the freshwater pearl mussels. Freshwater mussel species inhabit lakes, ponds, rivers, creeks, canals, and they are classified in a different subclass of bivalves, despite some very superficial similarities in appearance.
Freshwater zebra mussels and their relatives in the family Dreissenidae are not related to previously mentioned groups, even though they resemble many Mytilus species in shape, and live attached to rocks and other hard surfaces in a similar manner, using a byssus. They are classified with the Heterodonta, the taxonomic group which includes most of the bivalves commonly referred to as "clams".
On 6 February 2024, a new species of mussel named Vadumodiolus teredinicola was reported in The New York Times.[2]
Mussel-inspired materials[edit]
Byssal threads, used to anchor mussels to substrates, are now recognized as superior bonding agents. A number of studies have investigated mussel "glues" for industrial and surgical applications.[11][12] Further, mussel adhesive proteins inspired the design of peptide mimics that were well studied for surface bioengineering of medical implants.[13] Self-assembling mussel-inspired peptides were also shown to form functional nanostructures.[14][15] Also, a peptide derived from mussel foot protein-5, a key protein in mussel adhesion, displayed antibacterial properties and served as inspiration for the design of a new class of peptide-based antibacterial adhesive hydrogels, which are active against drug-resistant Gram-positive bacteria.[16]
Additionally byssal threads have provided insight into the construction of artificial tendons.[17]
Environmental applications[edit]
Mussels are widely used as bio-indicators to monitor the health of aquatic environments in both fresh water and the marine environments. They are particularly useful since they are distributed worldwide and they are sessile. These characteristics ensure that they are representative of the environment where they are sampled or placed. Their population status or structure, physiology, behaviour or the level of contamination with elements or compounds can indicate the status of the ecosystem.[18] Transplanted caged mussel were used in a study to monitor heavy metal contamination in coastal waters.[19]
Mussels and nutrient mitigation[edit]
Marine nutrient bioextraction is the practice of farming and harvesting marine organisms such as shellfish and seaweed for the purpose of reducing nutrient pollution. Mussels and other bivalve shellfish consume phytoplankton containing nutrients such as nitrogen (N) and phosphorus (P). On average, one live mussel is 1.0% N and 0.1% P.[20] When the mussels are harvested and removed, these nutrients are also removed from the system and recycled in the form of seafood or mussel biomass, which can be used as an organic fertilizer or animal feed-additive. These ecosystem services provided by mussels are of particular interest to those hoping to mitigate excess anthropogenic marine nutrients, particularly in eutrophic marine systems. While mussel aquaculture is actually promoted in some countries such as Sweden as a water management strategy to address coastal eutrophication,[20] mussel farming as a nutrient mitigation tool is still in its infancy in most parts of the world. Ongoing efforts in the Baltic Sea (Denmark, Sweden, Germany, Poland) and Long Island Sound[21] and Puget Sound[22] in the U.S. are currently examining nutrient uptake, cost-effectiveness, and potential environmental impacts of mussel farming as a means to mitigate excess nutrients and complement traditional wastewater treatment programs.
Conservation[edit]
Freshwater mussels[edit]
There are 297 known freshwater mussel taxa in the United States and Canada, which are home to the most diverse freshwater mussel fauna in the world.[23] Of the 297 known species, 213 (71.7%) taxa are listed as endangered, threatened, or of special concern.[24] The main factors contributing to the decline of freshwater mussels include destruction by dams, increased siltation, channel alteration and the introduction of invasive species such as the zebra mussel.[23]