Sealife guideFrom lobsters to krill: why crustaceans matterThe marine arthropods

Last updated on 09/02/2025 at 12:22 AM
Crustaceans such as lobster, spiny lobster, edible crab and shrimp are well known to the public because they are featured on seaside restaurant menus.
The spiny lobster, a crustacean well known to the public
The spiny lobster, a crustacean well known to the public
But in the end, how well do you really know them outside of your plate ? Let's rediscover them from a new perspective !
The diversity of marine crustaceans is astounding, ranging from tiny planktonic species to large lobsters, crabs and spiny lobsters. This diversity is reflected not only in their size but also in their forms, behaviors and ecological roles, making them essential components of marine food webs and ecosystems.
Crustaceans are to the marine world what insects are to the terrestrial world, totaling around 40,000 species.
Morphology
Crustaceans are equipped with an external skeleton called an exoskeleton or more commonly a shell, which protects them either partially or completely.
The body is divided into segments, each bearing a pair of appendages. Over time, these appendages have become specialized to fulfill essential functions such as locomotion, feeding or reproduction and in some cases have disappeared entirely.
Furthermore, the head has fused with several segments to form the cephalothorax. The remaining segments make up the abdomen.
Crustaceans have two pairs of antennae that serve as sensory organs.
Habitat
Marine crustaceans inhabit a wide range of ocean environments. Many live in shallow coastal waters, coral reefs and estuaries, while others are adapted to deep-sea trenches. Their ability to occupy such diverse marine habitats demonstrates their remarkable ecological adaptability.
Geographical range
Marine crustaceans are found in all the world's oceans, from tropical waters to polar regions. Some species thrive in coral reefs, while others, like Antarctic krill, dominate the southern oceans. Their distribution is influenced by temperature, salinity and ocean currents.
Discover crustaceans
Calling fiddler crab (Uca vocans)
Calling fiddler crab
(Uca vocans)
European spiny lobster (Palinurus elephas)
European spiny lobster
(Palinurus elephas)
Japanese crayfish (Panulirus japonicus)
Japanese crayfish
(Panulirus japonicus)
Panther crab (Parathelphusa pantherina)
Panther crab
(Parathelphusa pantherina)
Red hermit crab (Dardanus calidus)
Red hermit crab
(Dardanus calidus)
Seven-eleven crab (Carpilius maculatus)
Seven-eleven crab
(Carpilius maculatus)
Velvet swimming crab (Necora puber)
Velvet swimming crab
(Necora puber)
Warty crab (Eriphia verrucosa)
Warty crab
(Eriphia verrucosa)

Our latestUpdates

The dugong
Friday, January 30th 2026
The dugong
Discover the dugong, a gentle “sea cow” of tropical waters. Learn about its habitat, diet, reproduction, morphology, and the threats facing this unique marine mammal.
Dolphins: ocean's smartest creatures
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.
Hvar island
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.
Photo of the Day
Requin bouledogue (Carcharhinus leucas)
Requin bouledogue
(Carcharhinus leucas)