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Place of publication :
Publication year : 0
Thematic : Coral Reef
Language : English
Note
New information on the presence and relative
abundances of 41 reef-building (zooxanthellate) coral
species at 11 eastern PaciRc and 3 central PaciRc local-
ities is examined in a biogeographic analysis and review
of the eastern PaciRc coral reef region. The composition
and origin of the coral fauna and other reef-associated
taxa are assessed in the context of dispersal and vicar-
iance hypotheses. A minimum variance cluster analysis
using coral species presenceÂ}absence classiRcation data
at the 14 localities revealed three eastern PaciRc reef-
coral provinces: (1) equatorial Â} mainland Ecuador to
Costa Rica, including the GalaApagos and Cocos Islands;
(2) northern Â} mainland MeAxico and the Revillagigedo
Islands; (3) island group Â} eastern PaciRc Malpelo Island
and Clipperton Atoll, and central PaciRc Hawaiian,
Johnston and Fanning Islands. Coral species richness is
relatively high in the equatorial (17Â}26 species per lo-
cality) and northern (18Â}24 species) provinces, and low
at two small o€shore island localities (7Â}10 species). A
high proportion (36.6%, 15 species) of eastern PaciRc
coral species occurs at only one or two localities; of
these, three disappeared following the 1982Â}83 ENSO
event, three occur as death assemblages at several lo-
calities, and Rve are endangered with known populations
of ten or fewer colonies. Principal component analysis
using ordinal relative density data for the 41 species at
the 14 localities indicated three main species groupings,
i.e., those with high, mid, and narrow spatial distri-
butions. These groupings correlated with species pop-
ulation-dynamic characteristics. These results were
compared with data for riverine discharges, ocean cir-
culation patterns, shoreline habitat characteristics, and
regional sea surface temperature data to help clarify the
analyses as these measures of environmental variability
a€ect coral community composition. Local richness was
highest at localities with the highest environmental
variability. Recent information regarding the strong af-
Rnity between eastern and central PaciRc coral faunas,
abundance of teleplanic larvae in oceanic currents, high
genetic similarity of numerous reef-associated species,
and appearances of numerous Indo-west PaciRc species
in the east PaciRc following ENSO activity, suggest the
bridging of the east PaciRc Rlter bridge (formerly east
PaciRc barrier).
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Keywords : Taphozous melanopogon
Encoded by : Pauline Carmel Joy Eje
