Head to head
Noble Pen Shell vs European Flat Oyster
Noble Pen Shell
VS European Flat Oyster
The noble pen shell and the European flat oyster are two European bivalves that have suffered dramatic declines, one from a recent epidemic and the other from centuries of exploitation.
| Noble Pen Shell | European Flat Oyster | |
|---|---|---|
| Scientific name | Pinna nobilis | Ostrea edulis |
| Relationship | A bivalve that filters food from the water | A bivalve that filters food from the water |
| Size and shape | A giant, fan-shaped shell that can reach about a metre, though most are around 40 to 60 cm | A flat, rounded, rough shell, usually 6 to 11 cm across |
| Attachment | Stands upright with its narrow end buried in sand or mud among seagrass, held by tough byssus threads | The lower valve is cemented to a hard surface |
| Habitat | Seagrass meadows and sandy and muddy bottoms of the Mediterranean | Sheltered coastal waters, estuaries, and shallow seabeds of the north-eastern Atlantic and the Mediterranean |
| Special feature | Its fine byssus threads were once woven into a rare, golden fabric called sea silk | Females brood fertilised eggs in the mantle cavity and release larvae after about ten days, and individuals can change sex |
| Cause of decline | A mass-mortality epidemic since 2016, caused by a parasite, has killed most of the population | Overfishing, disease, pollution, and invasive species have drastically reduced its beds across Europe |
| Conservation status | Critically Endangered, with only scattered survivors | Not Evaluated, with restoration projects under way around Britain and Europe |
Noble Pen Shell vs European Flat Oyster: common questions
Which one is critically endangered?
The noble pen shell, because a parasite-driven epidemic since 2016 has killed most of the Mediterranean population.
What is sea silk?
It is a rare, golden fabric that was once woven from the fine byssus threads of the noble pen shell.
Why restore oyster reefs?
Reefs filter and clean the water and provide shelter and food for many other animals, so restoration helps whole ecosystems.