Communities Structure of Reef Corals
277
Sinularia and Parerythropodium. On the slopes expansive associations of
Xenia colonies and Lithophyton arboreum are usual. The same large
monospecific settlements are formed by the symbionic aJcyonaceans
Sinularia flexibilis, S. gibbosa, Lobophytum pauciflorum, Sarcophytum
glaucum and Litophyton viridis. They may occupy areas up to several square
meters on fiats and at slightly inclined outer slopes. Single colonies or
medium-sized associations of Cladiella, Stereonephthea, Paralemnalia
(eburnea) as well as of the stoloniferans Tubipora and Clavularia could be
met with in all reef zones at medium depths. Deeper down the reef slopes
usual are the asymbiotic octocorals Nephthya, Dendropephthya,
Stereonephthya, as well as the gorgonians Acabaria, Bebryce, Gorgonella,
Juncella, and Anthogorgia (Stiasny 1940). The deep soft bottom biotopes at
the base of reefs are occupied mostly by associations of the pennatulacians
Virgularia and Vitellum. The total number of octocoral species on the reefs
of Eilat could be evaluated at 18-20. The percentage of bottom area
covered by them varied in different zones between 2 to 17%. More than half
of this area is shared by two to three leading species. Among them, in
different zones, are usually Litophyton arboreum, Heteroxenia furcesens,
Parerythropodium fulvum, Sinularia compressa and S. leptoclados.
Benayahu (1985), during his revision of octocoral fauna in other reef
regions of the Red Sea, has recorded over 180 species, which belong to the
following taxa: family AJcyoniidae 96, Nephtheidae 56, Xeniidae 27, and
Nidaliidae (genus Siphonogorgia) 3. By number of species most abundantly
the following genera were represented: Cladiella 30, Sinularia 42,
Dendronephthea 29, Xenia 20, and Sarcophyton 20, species. Among the
most common octocorals of the Red Sea reefs there could be mentioned
Cladiella pachyclados, C. brachyclados, Sinularia leptoclados, S. polydactila,
S. gardineri, Sarcophyton glaucum, S. gemmatum, Lobophyton pauciflorum,
L. crassum, Alcyonium flaccidum, Parerythropodium fulvum, Dendronephthea curvata, D. ehrenbergi, Xenia blumi, and X. macrospiculata.
An insight into the structure and composition of octocoral communities of
the Pacific reefs is given by their description on reefs of Leing Island, New
Guinea, offered by Tursch and Tursch (1982). The octocorals inhabited on
these reefs with calm waters about a half of the rocky surfaces of the
bottom, covered by corals. Over 70% of the space covered by octocorals
was occupied by four leading species of the aJcyonacean octocorals
Lithophyton viridis, Sinularia guerciformes, S. gibberosa and Lobophytum
pauciflorum, which formed there large monospecific settlements. Other
octocorals (Xeniids, gorgonaceahs) were rare, and stoloniferans were
absent. In total, on these reefs 115 species of octocorals have been recorded,
which is by the way close to the species numbers of scleratinian corals on
most of the Pacific reefs. Among them there were 23 species of the genus
Sinnularia, 10 of Sarcophyton, 7 each of Xenia, Dendronephthea and
Lobophytum and, 7 new species of octocorals (Verseveldt and Tursch
1979).
277
Sinularia and Parerythropodium. On the slopes expansive associations of
Xenia colonies and Lithophyton arboreum are usual. The same large
monospecific settlements are formed by the symbionic aJcyonaceans
Sinularia flexibilis, S. gibbosa, Lobophytum pauciflorum, Sarcophytum
glaucum and Litophyton viridis. They may occupy areas up to several square
meters on fiats and at slightly inclined outer slopes. Single colonies or
medium-sized associations of Cladiella, Stereonephthea, Paralemnalia
(eburnea) as well as of the stoloniferans Tubipora and Clavularia could be
met with in all reef zones at medium depths. Deeper down the reef slopes
usual are the asymbiotic octocorals Nephthya, Dendropephthya,
Stereonephthya, as well as the gorgonians Acabaria, Bebryce, Gorgonella,
Juncella, and Anthogorgia (Stiasny 1940). The deep soft bottom biotopes at
the base of reefs are occupied mostly by associations of the pennatulacians
Virgularia and Vitellum. The total number of octocoral species on the reefs
of Eilat could be evaluated at 18-20. The percentage of bottom area
covered by them varied in different zones between 2 to 17%. More than half
of this area is shared by two to three leading species. Among them, in
different zones, are usually Litophyton arboreum, Heteroxenia furcesens,
Parerythropodium fulvum, Sinularia compressa and S. leptoclados.
Benayahu (1985), during his revision of octocoral fauna in other reef
regions of the Red Sea, has recorded over 180 species, which belong to the
following taxa: family AJcyoniidae 96, Nephtheidae 56, Xeniidae 27, and
Nidaliidae (genus Siphonogorgia) 3. By number of species most abundantly
the following genera were represented: Cladiella 30, Sinularia 42,
Dendronephthea 29, Xenia 20, and Sarcophyton 20, species. Among the
most common octocorals of the Red Sea reefs there could be mentioned
Cladiella pachyclados, C. brachyclados, Sinularia leptoclados, S. polydactila,
S. gardineri, Sarcophyton glaucum, S. gemmatum, Lobophyton pauciflorum,
L. crassum, Alcyonium flaccidum, Parerythropodium fulvum, Dendronephthea curvata, D. ehrenbergi, Xenia blumi, and X. macrospiculata.
An insight into the structure and composition of octocoral communities of
the Pacific reefs is given by their description on reefs of Leing Island, New
Guinea, offered by Tursch and Tursch (1982). The octocorals inhabited on
these reefs with calm waters about a half of the rocky surfaces of the
bottom, covered by corals. Over 70% of the space covered by octocorals
was occupied by four leading species of the aJcyonacean octocorals
Lithophyton viridis, Sinularia guerciformes, S. gibberosa and Lobophytum
pauciflorum, which formed there large monospecific settlements. Other
octocorals (Xeniids, gorgonaceahs) were rare, and stoloniferans were
absent. In total, on these reefs 115 species of octocorals have been recorded,
which is by the way close to the species numbers of scleratinian corals on
most of the Pacific reefs. Among them there were 23 species of the genus
Sinnularia, 10 of Sarcophyton, 7 each of Xenia, Dendronephthea and
Lobophytum and, 7 new species of octocorals (Verseveldt and Tursch
1979).