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

Abe's polycera nudibranch
(Polycera abei)

Brown edge glossodorid
(Glossodoris hikuerensis)

Chamberlain's sea slug
(Nembrotha chamberlaini)

Lettuce sea slug
(Elysia crispata)

Little leaf sheep
(Costasiella kuroshimae)

Pustulose wart slug
(Phyllidiella pustulosa)

Spanish dancer
(Hexabranchus sanguineus)

White lined dirona
(Dirona albolineata)

Our latestUpdates

Friday, January 23rd 2026

Dolphins: ocean's smartest creatures

Discover dolphins, the ocean's geniuses: explore their intelligence, social behavior, sophisticated communication, species diversity and vital role in marine ecosystems.

Friday, January 9th 2026

Hvar island

Hvar, a jewel of the Adriatic, captivates with its turquoise waters, wild coves and fragrant lavender fields. Between medieval villages, lively ports, and lush hills, Hvar island offers the perfect mix of relaxation, culture and breathtaking landscapes. Ideal for sun, sea and authentic experiences.

Thursday, January 8th 2026

The lemonpeel angelfish

The lemonpeel angelfish is a small, brightly colored reef fish found in the tropical waters of the Indo-Pacific ocean. It inhabits shallow coral reefs, sheltering among corals and rocky crevices.

Photo of the Day

Labre échiquier
(Halichoeres hortulanus)