The shell of Mytilaster minimus has a smooth and glossy surface which is marked with faint growth rings.

The shell has an elongated shape, with the apex located at one end and a reduced hinge which has no teeth.

[2] Mytilaster minimus is distributed throughout the Mediterranean Sea[2] and is also found off Gran Canaria and Tenerife in the Canary Islands[3] It forms colonies on hard substrates in coastal waters and in brackish water such as coastal lagoons.

[4] This species can colonise rather oligotrophic areas but in more eutrophic regions the larger Mediterranean edible mussel Mytilus galloprovincialis can be found among and, in places displace M.

[6] Mytilaster minimus is threatened by the invasive Brachidontes pharaonis which is displacing it in many areas of theMediterranean.