Blue Carbon in Faunal Community - Blue Carbon Reservoir of the Blue Planet - page 216

Fig. 6.20 Cluster of coral
polyps

The polyps feed actively at night by extending
their tentacles for catching the zooplankton, but
during the day, their tentacles are contracted,
exposing their outer layer of cells containing
zooxanthellae to the sunlight. The reef-building
corals of tropical regions have specialized
requirements like warm, shallow, clean water and
a

of any taxa are found in both the Indo-Paci c

coral reef area and Caribbean reef area. It has
been reported that the coral species richness of
Indian Ocean rim countries is very similar to
those in the Paci c Ocean with both of these

regions having signi cantly greater coral diver-

sity than the Atlantic. Countries with large coral
diversities such as Indonesia (443), Australia
(428) and Thailand (238) border both the Indian
and Paci

rm substratum to which they can attach. The
growth of the corals is restricted to tropical waters
between 30 S where the temperature

usually ranges between 20 and 25

° N and 30 ° c Oceans, thus increasing the apparent

diversity of both. The contribution of the Indian
Ocean to this diversity is signi

° C. Waters at

depths greater than 50 100 m are too cold for

considerable secretion of calcium carbonate. Per-
haps because of this reason, most of the Caribbean
corals are found in the upper 50 m of lighted zone,
whereas Indian and Paci

cant with six

-

Table 6.8 Species richness of coral reef-associated

faunas
Taxon

c corals are found at
depths of 150 m in the more transparent water of
these oceans.
Coral reefs are ecologically important eco-
systems with rich biodiversity (Table 6.8 ). They
support complex assemblages of many different
types of plants and animals having intense
competition for space and food. Globally, coral
reefs comprise little more than 1 % of total
continental shelf area, but they are among the
most diverse of the world ' s ecosystems. It is
estimated that about 793 species of scleractinian
corals are present worldwide, of which 719 occur
in the Indo-West Paci

Number of
species

References

General Indo - Paci c reef faunas

Fishes >2,200 Sale ( 1980 )

Corals 390 Sebens ( 1994 )

Nudibranchs >500 Gosliner ( 1993 )

Estimates of faunas of single reefs
Fishes

860 Sale et al.

( 1994 )

Molluscs 150 - 500 Sorokin ( 1993 )

Crustaceans 100 250 Sorokin ( 1993 )

-

Polychaetes 100 - 200 Sorokin ( 1993 )

Echinoderms 50 100 Sorokin ( 1993 )

-

c region. Very few species

Sponges >50 Sorokin ( 1993 )