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 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)
Giant rock scallop
(Crassadoma gigantea)
Great atlantic scallop (Pecten maximus)
Great atlantic scallop
(Pecten maximus)
Noble pen shell (Pinna nobilis)
Noble pen shell
(Pinna nobilis)
Spiny pink scallop (Chlamys hastata)
Spiny pink scallop
(Chlamys hastata)
Discover marine mollusks
Adorned stiliger (Stiliger ornatus)
Adorned stiliger
(Stiliger ornatus)
Flamingo tongue (Cyphoma gibbosum)
Flamingo tongue
(Cyphoma gibbosum)
Glossodoris cincta nudibranch (Glossodoris cincta)
Glossodoris cincta nudibranch
(Glossodoris cincta)
Hooded nudibranch (Melibe leonina)
Hooded nudibranch
(Melibe leonina)
Mimic octopus (Thaumoctopus mimicus)
Mimic octopus
(Thaumoctopus mimicus)
Nudibranch Trapania palmula (Trapania palmula)
Nudibranch Trapania palmula
(Trapania palmula)
Red-lined flabellina (Coryphellina rubrolineata)
Red-lined flabellina
(Coryphellina rubrolineata)
Stubby squid (Rossia pacifica)
Stubby squid
(Rossia pacifica)

Our latestUpdates

Faroe islands
Thursday, May 7th 2026
Faroe islands
Discover the Faroe islands, a remote archipelago between Iceland and Norway known for its dramatic cliffs, colorful villages, and untouched Nordic landscapes. Find travel tips, itineraries, hiking guides, local culture, and inspiration to explore this unique destination in the North Atlantic.
The short-finned pilot whale
Wednesday, May 6th 2026
The short-finned pilot whale
Discover the tropical pilot whale (Globicephala macrorhynchus), a highly social large cetacean from tropical and subtropical waters, specialized in deep dives in search of squid.
Where to see groupers in the Mediterranean ?
Thursday, April 23rd 2026
Where to see groupers in the Mediterranean ?
Discover where to see groupers in the Mediterranean: the best diving spots and protected marine areas to observe this iconic fish in its natural habitat.
Photo of the Day
Poisson papillon à bandes cuivrées (Chelmon rostratus)
Poisson papillon à bandes cuivrées
(Chelmon rostratus)