Sealife guideBivalves: shellfish wonders of the oceanThe marine mollusks

Last updated on 09/02/2025 at 12:22 AM

The class of bivalves is characterized by a shell composed of two parts, called valves, which are hinged and more or less symmetrical.

The noble pen shell is a type of bivalve

The most well-known bivalves include oysters, mussels, scallops and clams.

Bivalves have a calcium carbonate shell equipped with strong muscles that can close the two valves tightly in response to external threats.

Bivalves feed by filtering water through their gills. The water current is generated by the action of tiny cilia.

Discover marine bivalves

Giant rock scallop
(Crassadoma gigantea)

Great Atlantic scallop
(Pecten maximus)

Noble pen shell
(Pinna nobilis)

Spiny pink scallop
(Chlamys hastata)

Discover marine mollusks

Chamberlain's sea slug
(Nembrotha chamberlaini)

Curled octopus
(Eledone cirrhosa)

Dotted sea slug
(Peltodoris atromaculata)

Heron ardeadoris
(Ardeadoris egretta)

Leech sea slug
(Chelidonura hirundinina)

Lettuce sea slug
(Elysia crispata)

North Pacific giant octopus
(Enteroctopus dofleini)

Ocellated sea slug
(Plakobranchus ocellatus)

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Blennie d'Aron
(Ecsenius aroni)