36
WORLD ATLAS OF CORAL REEFS
Maxillopoda contains the abundant copepods which are
usually very small, and includes many planktonic species
which are found in the coral reef environment. It also
includes the barnacles which are commonly observed
on reefs and intertidal areas. The class Ostracoda is another
highly diverse group, often showing a bivalved appearance.
These again are very small, mostly filter feeders or
detritivores. The most important and widely recognized
group on coral reefs is the class Malacostraca, and in
particular, within this, the Decapoda and the Stomatopoda.
Decapoda
These are the shrimps, lobsters and crabs, with some
10 000 species worldwide, including numerous species
found on the reef A brief list of the major groups is
provided below.
Penaeidea - these are the commercially important
prawns, often associated with inshore lagoon and mangrove areas, but not well represented on the reef.
Stenopodidea (boxing or coral shrimps) - a small
but well known group usually found in pairs and living
in "cleaning stations" where they regularly remove parasites from fish or other crustaceans. They have a highly
enlarged third pair of thoracic legs, with pincers on the tips.
Caridea - a large group of shrimps with a number of
sub-groups:
Palaemonidae - on reefs, the palaemonid shrimps
are well represented by commensal species which live in
facultative or obligate partnerships with corals, anemones,
molluscs and echinoderms. The genus Periclimenes is particularly widespread. Many species have striking colors
which they are capable of adapting to suit their hosts.
Alpheidae (snapping shrimps) - also known as pistol
shrimps, these are perhaps the commonest crustacean
family on reefs. They are able to make a cracking sound
with their pincers and are largely responsible for the
almost constant background snapping noises heard on
many reefs. Most are detrital feeders. Some of the best
known snapping shrimps are those which share their
burrows with certain species of goby: the former maintain
a burrow in which they both live, while the latter provide
warning when predators approach.
Other caridean shrimps are the hump-backed or cleaner
shrimps (Hippolytidae) which include more colorful commensal and cleaner species, and the harlequin shrimps
(Gnathophyllidae), also very colorful, which include some
species that prey on starfish such as crown-of-thorns.
Palinura (spiny lobsters) - although not a diverse
group this includes the familiar crayfish, which are a
large, colorful and commercially important group of
species found on reefs around the world. The group also
includes the less commonly observed slipper lobsters.
Anomura (hermit crabs, squat lobsters and
porcelain crabs) - the hermit crabs are widespread on
reefs and nearby intertidal areas. They are well known for
their habit of utilizing discarded mollusc shells as a form
of protection. They have an extended and soft abdomen
which fits well into the coiled whorls of these shells, and
they regularly exchange shells as they grow. Most are
scavengers or detrital feeders. Porcelain crabs are less
diverse and less obvious on the reef, but are often found
living in association with anemones. They resemble true
crabs, but only have three pairs of walking legs, and have
elongated antennae.
Brachyura (true crabs) - one of the most diverse
crustacean groups on coral reefs, with more than 2 000
species described from the tropical and sub-tropical
waters of the Indo-Pacific. The true crabs are recognizable
by their strong and usually broad thoracic carapace and
their greatly reduced abdomen which remains tucked up
Left: A banded coral shrimp Stenopus hispidus. These play an important role as "cleaners" on the reef. Right: The
peacocl< mantis shrimp Odontodactylus scyllarus, a powerful predator in the Indo-Pacific.
WORLD ATLAS OF CORAL REEFS
Maxillopoda contains the abundant copepods which are
usually very small, and includes many planktonic species
which are found in the coral reef environment. It also
includes the barnacles which are commonly observed
on reefs and intertidal areas. The class Ostracoda is another
highly diverse group, often showing a bivalved appearance.
These again are very small, mostly filter feeders or
detritivores. The most important and widely recognized
group on coral reefs is the class Malacostraca, and in
particular, within this, the Decapoda and the Stomatopoda.
Decapoda
These are the shrimps, lobsters and crabs, with some
10 000 species worldwide, including numerous species
found on the reef A brief list of the major groups is
provided below.
Penaeidea - these are the commercially important
prawns, often associated with inshore lagoon and mangrove areas, but not well represented on the reef.
Stenopodidea (boxing or coral shrimps) - a small
but well known group usually found in pairs and living
in "cleaning stations" where they regularly remove parasites from fish or other crustaceans. They have a highly
enlarged third pair of thoracic legs, with pincers on the tips.
Caridea - a large group of shrimps with a number of
sub-groups:
Palaemonidae - on reefs, the palaemonid shrimps
are well represented by commensal species which live in
facultative or obligate partnerships with corals, anemones,
molluscs and echinoderms. The genus Periclimenes is particularly widespread. Many species have striking colors
which they are capable of adapting to suit their hosts.
Alpheidae (snapping shrimps) - also known as pistol
shrimps, these are perhaps the commonest crustacean
family on reefs. They are able to make a cracking sound
with their pincers and are largely responsible for the
almost constant background snapping noises heard on
many reefs. Most are detrital feeders. Some of the best
known snapping shrimps are those which share their
burrows with certain species of goby: the former maintain
a burrow in which they both live, while the latter provide
warning when predators approach.
Other caridean shrimps are the hump-backed or cleaner
shrimps (Hippolytidae) which include more colorful commensal and cleaner species, and the harlequin shrimps
(Gnathophyllidae), also very colorful, which include some
species that prey on starfish such as crown-of-thorns.
Palinura (spiny lobsters) - although not a diverse
group this includes the familiar crayfish, which are a
large, colorful and commercially important group of
species found on reefs around the world. The group also
includes the less commonly observed slipper lobsters.
Anomura (hermit crabs, squat lobsters and
porcelain crabs) - the hermit crabs are widespread on
reefs and nearby intertidal areas. They are well known for
their habit of utilizing discarded mollusc shells as a form
of protection. They have an extended and soft abdomen
which fits well into the coiled whorls of these shells, and
they regularly exchange shells as they grow. Most are
scavengers or detrital feeders. Porcelain crabs are less
diverse and less obvious on the reef, but are often found
living in association with anemones. They resemble true
crabs, but only have three pairs of walking legs, and have
elongated antennae.
Brachyura (true crabs) - one of the most diverse
crustacean groups on coral reefs, with more than 2 000
species described from the tropical and sub-tropical
waters of the Indo-Pacific. The true crabs are recognizable
by their strong and usually broad thoracic carapace and
their greatly reduced abdomen which remains tucked up
Left: A banded coral shrimp Stenopus hispidus. These play an important role as "cleaners" on the reef. Right: The
peacocl< mantis shrimp Odontodactylus scyllarus, a powerful predator in the Indo-Pacific.