Benthic Crustaceans
189
escaping grazing (mysids, cumaceans, copepods); (2) crustaceans, which
inhabit soft sediments and rubble, covered with seagrasses and macrophytes;
(3) the criptofaunal crustaceans; (4) commensals and symbiotic crustaceans
of varions sedentary and vagi Ie benthic animals and (Thomassin 1974; Haig
1976; Patton 1976; Tsareva 1980; Peyrot-Clausade 1981; Galkin 1982).
The lower meiobenthic vagUe crustaceans are represented on reefs by
small adults and by larvae, which have sizes of 0.05 to 3 mm (Thomassin et
al. 1976, 1982). They are mostly cyclopids, harpacticids, ostracods, and the
cyclopid nauplii. The most numerous of these crustaceans are found in coral
sands, in rubble, and in the thickets of macrophytes. The number of
cyclopids in coral sands of the barrier reef of Tulear was 4-15 x 10 3 dm - 3 ,
and their biomass 1-5gm- 2 . The numbers of ostracods varied there within
40 to 400 sp. dm- 3 . In the same biotopes off Moorea Island the density of
these groups was and by an order less. Most of the bottom cyclopids are the
demersal predators, which at night migrate up to the water column and
catch small zooplankters. But some of cyclopids are symbionts and parasites
of corals. For example, cyclopids from the family Lichmolgidae are the
symbionts of the scleractinian corals. They live on their surface and feed on
their mucus and on their zooxanthellae, accomplishing thus the function of
cleaners. The copepods Anthessius, Astroxynus, Nanaspis are the symbionts
of some molluscs and echinoderms. The highly specialized parasitic
copepods Xarfia live inside the coral polyps. They have worm-like bodies
with the reduced legs (Patton 1976). The copepods Pandarus, Dentigryps,
Caligus, and Lepeophtheris are parasites of fish. The ostracods inlude
several tens of species, most of which belong to the genera Sarsiella,
Xestoleberis, Paradoxostoma, and Anscottiella (Hartmann 1964; Herriott
and Immerman 1979; Shornikov 1980; Jones 1984). The ostracods feed on
microphytobenthos and on detritus.
The sedementary lower crustacean barnacles belong mostly to the order
Cirripedia. The ordinary barnacles attach to the surfaces of the flat and of
the littoral rocks, to bivalves or to turtles shells. The boring barnacle
Lithotria bores into the lime rocks. The corallobiont barnacles grow into the
living coral colonies so that their shells are hidden completely inside them.
On the surface remains only a small hole with elevated edge, through which
the animal sticks out its filtering apparatus composed by its modified legs.
Most of specialized corallobiont cyrripedians belong to the family
Pyrgomatidae, which list about 35 of their species. Among them there are
also several species of real balanid barnacles (Balanus cardin us , B.
durhamy, Kachloria floridana). The corallobionts are merely the
commensals. But some of them lost the ability for filter-feeding and feed on
the mucus and - even on the polyps of their coral hosts (Hoekia).
The higher reef crustaceans (class Malacostraca) such as mysids,
stomatopods, cumaceans, isopods, and amphipods inhabit mostly the
biotopes of soft sediments as well as the rubble and the solid reef-flat
biotopes covered with macrophytes (Jones 1984). Most of them are demersal
189
escaping grazing (mysids, cumaceans, copepods); (2) crustaceans, which
inhabit soft sediments and rubble, covered with seagrasses and macrophytes;
(3) the criptofaunal crustaceans; (4) commensals and symbiotic crustaceans
of varions sedentary and vagi Ie benthic animals and (Thomassin 1974; Haig
1976; Patton 1976; Tsareva 1980; Peyrot-Clausade 1981; Galkin 1982).
The lower meiobenthic vagUe crustaceans are represented on reefs by
small adults and by larvae, which have sizes of 0.05 to 3 mm (Thomassin et
al. 1976, 1982). They are mostly cyclopids, harpacticids, ostracods, and the
cyclopid nauplii. The most numerous of these crustaceans are found in coral
sands, in rubble, and in the thickets of macrophytes. The number of
cyclopids in coral sands of the barrier reef of Tulear was 4-15 x 10 3 dm - 3 ,
and their biomass 1-5gm- 2 . The numbers of ostracods varied there within
40 to 400 sp. dm- 3 . In the same biotopes off Moorea Island the density of
these groups was and by an order less. Most of the bottom cyclopids are the
demersal predators, which at night migrate up to the water column and
catch small zooplankters. But some of cyclopids are symbionts and parasites
of corals. For example, cyclopids from the family Lichmolgidae are the
symbionts of the scleractinian corals. They live on their surface and feed on
their mucus and on their zooxanthellae, accomplishing thus the function of
cleaners. The copepods Anthessius, Astroxynus, Nanaspis are the symbionts
of some molluscs and echinoderms. The highly specialized parasitic
copepods Xarfia live inside the coral polyps. They have worm-like bodies
with the reduced legs (Patton 1976). The copepods Pandarus, Dentigryps,
Caligus, and Lepeophtheris are parasites of fish. The ostracods inlude
several tens of species, most of which belong to the genera Sarsiella,
Xestoleberis, Paradoxostoma, and Anscottiella (Hartmann 1964; Herriott
and Immerman 1979; Shornikov 1980; Jones 1984). The ostracods feed on
microphytobenthos and on detritus.
The sedementary lower crustacean barnacles belong mostly to the order
Cirripedia. The ordinary barnacles attach to the surfaces of the flat and of
the littoral rocks, to bivalves or to turtles shells. The boring barnacle
Lithotria bores into the lime rocks. The corallobiont barnacles grow into the
living coral colonies so that their shells are hidden completely inside them.
On the surface remains only a small hole with elevated edge, through which
the animal sticks out its filtering apparatus composed by its modified legs.
Most of specialized corallobiont cyrripedians belong to the family
Pyrgomatidae, which list about 35 of their species. Among them there are
also several species of real balanid barnacles (Balanus cardin us , B.
durhamy, Kachloria floridana). The corallobionts are merely the
commensals. But some of them lost the ability for filter-feeding and feed on
the mucus and - even on the polyps of their coral hosts (Hoekia).
The higher reef crustaceans (class Malacostraca) such as mysids,
stomatopods, cumaceans, isopods, and amphipods inhabit mostly the
biotopes of soft sediments as well as the rubble and the solid reef-flat
biotopes covered with macrophytes (Jones 1984). Most of them are demersal