190
Reef Zoobenthos
animals feeding as filterers or as planktonovorous predators. They go up to
the water column at night for feeding. In the samples of botton sediments
the mysids and the young or the small adult isopods form a significant part
of meiobenthos, especially in daytime (Thomassin et al. 1982). The mysids
in such samples include usually demersal species from the genera Euchalina,
Gastrosaccus, Erythrops, and Doxomysis. Some isopods live permanently on
the thallus of macrophytes, in sands (Exosphaeroma), in the rubble
(Cirolana), or under stones (Orbinus). Their other common genera are:
Apanthura, Leptautura, and Mesanthura. Isopods feed on periphyton, on
detritus and graze thalli of macrophytes. Some isopods live at the base of
colonies of corals and gorgonaceans and feed on the mucus which they shed
(Kensley 1982). Many isopod species are exoparasites of fish.
The cumaceans inhabit mostly the soft sediments. Some of them are
demersal as the mysids. They are predators and feed on smaller crustaceans
and on nematods. The most common cumacean species belong to the
genera Bodotria, Discoides, and Sheardia. The stomatods are relatively
large benthic crustaceans, being 2-8 cm long. They live in sediments,
digging in, constructing permanent holes, or hiding in seaweeds. They are
also predators. Some of their species are demersal. Their most common
species in reef biotopes are: Pseudosquilla ciliata, Astrosquilla littoralis,
Alima clorida, Lysisquilla sp. Leptosquilla sp., and Nanosquilla sp.
(Thomassin 1974). The amphipods, gammerids and caprellids, comprise the
bulk of benthic communities in different reef biocopes enriched with
decaying plant material and detritus. Some of them live on thalli of
seaweeds. Others build there a kind of nest (Hyale, Maera, Mallacota). The
amphipods Lembos, Gammaropsis, Amphithoe, Cymadusa construct the
tubes from a mucous substance hardening in water, and fasten them in
trenches or in branches of dead corals. The amphipod Cyparus constructs its
tube home with which he can move about like the trichopteran larvae
(Bernard 1976), and the Lysianassa lives under stones. The young
amphipods feed on detritus, but the adult become more specialized. Among
them there are filterers (Urothoe, Albunea), phytophages on benthic
microalgae (Siphonoecetes), predators and a lot of commensals and
parasites which live on hydroids and feed on their polyps (Podocerus), in
ascidians or in sponges (Leucothoe), in the mantle of some molluscs
(Cyprodinius), or in holes with polychaetes or crabs (Lizistriella). The most
common reef gammarides belong to the genera Ampelisca, Cymadusa,
Gammaropsis, Dexamine Leucothoe, Listriella, Lysianassa, Lembos,
Cerapus, Melita, and Photus, and the common caprellids to the genera
Metaprotella, Dodecadina, and Phthilisca.
The reef decapods include prawns and shrimps (suborder Natantia), crabs
and lobsters (both from the suborder Reptantia). They include hundreds of
species and comprise a major portion of crustaceans in any reef biotope by
number of taxa and by their biomass. Many decapods are commensals or
Reef Zoobenthos
animals feeding as filterers or as planktonovorous predators. They go up to
the water column at night for feeding. In the samples of botton sediments
the mysids and the young or the small adult isopods form a significant part
of meiobenthos, especially in daytime (Thomassin et al. 1982). The mysids
in such samples include usually demersal species from the genera Euchalina,
Gastrosaccus, Erythrops, and Doxomysis. Some isopods live permanently on
the thallus of macrophytes, in sands (Exosphaeroma), in the rubble
(Cirolana), or under stones (Orbinus). Their other common genera are:
Apanthura, Leptautura, and Mesanthura. Isopods feed on periphyton, on
detritus and graze thalli of macrophytes. Some isopods live at the base of
colonies of corals and gorgonaceans and feed on the mucus which they shed
(Kensley 1982). Many isopod species are exoparasites of fish.
The cumaceans inhabit mostly the soft sediments. Some of them are
demersal as the mysids. They are predators and feed on smaller crustaceans
and on nematods. The most common cumacean species belong to the
genera Bodotria, Discoides, and Sheardia. The stomatods are relatively
large benthic crustaceans, being 2-8 cm long. They live in sediments,
digging in, constructing permanent holes, or hiding in seaweeds. They are
also predators. Some of their species are demersal. Their most common
species in reef biotopes are: Pseudosquilla ciliata, Astrosquilla littoralis,
Alima clorida, Lysisquilla sp. Leptosquilla sp., and Nanosquilla sp.
(Thomassin 1974). The amphipods, gammerids and caprellids, comprise the
bulk of benthic communities in different reef biocopes enriched with
decaying plant material and detritus. Some of them live on thalli of
seaweeds. Others build there a kind of nest (Hyale, Maera, Mallacota). The
amphipods Lembos, Gammaropsis, Amphithoe, Cymadusa construct the
tubes from a mucous substance hardening in water, and fasten them in
trenches or in branches of dead corals. The amphipod Cyparus constructs its
tube home with which he can move about like the trichopteran larvae
(Bernard 1976), and the Lysianassa lives under stones. The young
amphipods feed on detritus, but the adult become more specialized. Among
them there are filterers (Urothoe, Albunea), phytophages on benthic
microalgae (Siphonoecetes), predators and a lot of commensals and
parasites which live on hydroids and feed on their polyps (Podocerus), in
ascidians or in sponges (Leucothoe), in the mantle of some molluscs
(Cyprodinius), or in holes with polychaetes or crabs (Lizistriella). The most
common reef gammarides belong to the genera Ampelisca, Cymadusa,
Gammaropsis, Dexamine Leucothoe, Listriella, Lysianassa, Lembos,
Cerapus, Melita, and Photus, and the common caprellids to the genera
Metaprotella, Dodecadina, and Phthilisca.
The reef decapods include prawns and shrimps (suborder Natantia), crabs
and lobsters (both from the suborder Reptantia). They include hundreds of
species and comprise a major portion of crustaceans in any reef biotope by
number of taxa and by their biomass. Many decapods are commensals or