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
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)
Banded cleaner shrimp
(Stenopus hispidus)
Blue swimmer crab (Portunus pelagicus)
Blue swimmer crab
(Portunus pelagicus)
Caribbean spiny lobster (Panulirus argus)
Caribbean spiny lobster
(Panulirus argus)
Ghost crab (Ocypode gaudichaudii)
Ghost crab
(Ocypode gaudichaudii)
Mediterranean slipper lobster (Scyllarides latus)
Mediterranean slipper lobster
(Scyllarides latus)
Red sea ghost crab (Ocypode saratan)
Red sea ghost crab
(Ocypode saratan)
Spinous squat lobster (Galathea strigosa)
Spinous squat lobster
(Galathea strigosa)
Weak shelled rock crab (Grapsus tenuicrustatus)
Weak shelled rock crab
(Grapsus tenuicrustatus)

Our latestUpdates

The Caribbean king crab
Saturday, September 12th 2026
The Caribbean king crab
Discover the Caribbean king crab (Maguimithrax spinosissimus), an impressive reef crab found throughout the Caribbean and western Atlantic.
The reticulated sandperch
Thursday, September 10th 2026
The reticulated sandperch
Discover the reticulated sandperch (Parapercis tetracantha), a small Indo-Pacific fish known for its elongated body and distinctive brown and white pattern.
The wedgetail triggerfish
Monday, September 7th 2026
The wedgetail triggerfish
Discover the wedgetail triggerfish, Hawaii's famous state fish. Learn about its vibrant colors, coral reef habitat, unique behavior, and cultural significance in Hawaii.
Photo of the Day
Mérou céleste (Cephalopholis argus)
Mérou céleste
(Cephalopholis argus)