Extremely diverse in size, structure and habit, crustaceans exhibit fascinating lifestyles and live in unusual places. Some crabs are very large while other crustaceans scale down in size to water fleas and copepods so minute that their intricate structures can only be revealed
through the use of microscopes. The Crustacea is the only large class of arthropods that is primarily aquatic. There are more than 30,000 species of crustaceans.
Most are marine, some freshwater, others terrestrial.
Within our bountiful coral reefs dwell numerous colourful crustaceans. The conspicuous crustaceans in the coral reefs are shrimps, prawns, crabs and lonsters, collectively referred to as decapods. There are two pairs of feelers in a crustacean and the exoskeleton comprises a series of segmented hard shells. The name “crustaces” is derived from the Latin for shell.
Most of us have personal knowledge of the value of crustaceans as food; we are familiar with crabs, shrimps and lobster which habe graced our dining table. But the exotic crustaceans that inhabit the coral reefs are truly amazing in their way of life. Many reef crustaceans live in hiding to escape from predation, only to come out in the open to feed during the night. Others live symbiotically with sea-anemones, corals, gorgonians, molluscs, sponges, echinoderm and sea-squirts.
Mimicry and camouflage are common. While some seek empty seashells for use as homes, others create loud noises with their claws. Even some can stick their heads on the surface, kicking food into their mouths with their legs.
Tretalia nigrolineata, Neopetrolisthes maculatus
Periclemenes holthuisi, Synalpheus neomeris