Clownfish and their associated sea anemones are icons of tropical and
subtropical coastal ecosystems, but bleaching and collecting for the
aquarium trade has reduced their population densities in several
Indo-Pacific locations. We surveyed four Entacmaea
quadricolor populations and their associated clownfish
Amphiprion clarkii in Hong Kong. These assemblages
represented a combination of exposed and sheltered, flat bottomed and sloped
conditions. Different from tropical areas, where E.
quadricolor is usually found in sheltered shallow waters, the
four populations in Hong Kong were distributed in 4–10 m depths, being
densest on a 40 × 80 m slope of volcanic rocks (34.2–76.6% substrate cover
and 48.7–102.1 ind m−2) at an exposed site. This distribution
pattern could be explained by the high turbidities associated with river
discharge and sedimentation rates in local waters, which discourage the
establishment of E. quadricolor populations in sheltered bays; shallow
habitats might not be suitable for E. quadricolor in Hong
Kong due to strong wave actions generated by typhoons. Amphiprion
clarkii was present at low densities
(0.07–0.26 fish m−2) across the sites. Our data provide a
baseline for monitoring the changes of these conspicuous members of shallow
water communities in Hong Kong.