Sealife guideFrom lobsters to krill: why crustaceans matterMarine Arthropods

Last updated on 08/12/2026 at 10:34 PM

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

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

Banded cleaner shrimp
(Stenopus hispidus)

Batwing coral crab
(Carpilius corallinus)

Harlequin crab
(Lissocarcinus orbicularis)

Red-eyed reef crab
(Eriphia ferox)

Red-spotted guard crab
(Trapezia tigrina)

Red sea ghost crab
(Ocypode saratan)

Skunk cleaner shrimp
(Lysmata amboinensis)

Spinous squat lobster
(Galathea strigosa)

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