260
Phytoplankton diversity in the Indian Sundarbans is extremely rich and in some
pockets like Lothian Island, the Shannon Weiner Index (H) has shown a high value.
A total of 64 species has been documented from the brackish water system of Indian
Sundarbans (Banerjee et al. 2000), among which some species are abundant almost
in all the season of the year. Now the number of phytoplankton species has exceeded
150 (Mitra and Zaman 2016).
Faunal Biodiversity
The mangrove ecosystems of the north-east coast of Bay of Bengal in the Indian
sub-continent also sustain a wide range of faunal diversity. Although, the faunal
exploration of Sundarbans can be traced back to mid-eighteenth century (Stolicza
1869) and extensive studies have been carried out by the workers of the Zoological
Survey of India (Annandale 1907; Kemp 1917; Hora 1934), but the works of Mandal
and Nandi (1989) and Chaudhuri and Chaudhuri (1994) provide an excellent data
base of macrofaunal diversity of the ecosystem, although the two data sets are somewhat mismatching (Table 8.11).
It is a fact that Sundarban ecosystem is still one of the most biologically productive and taxonomically diverse ecosystems of the Indian sub-continent, although
about 6 vertebrates have disappeared from this ecosystem since the last 200 years
and about 20 species are in the endangered species list (Table 8.12).
Mangrove swamps of Indian Sundarbans also invites two species of horseshoe
crabs (Fig. 8.9) namely Carcinoscorpius rotundicauda and Tachypleus gigas during
the premonsoon period of high salinity. These crabs have excellent biomedical values and have recently been established as potential source of bioactive substance,
the Carcinoscorpius Amoebocyte Lysate (CAL) and Tachypleus Amoebocyte Lysate
(TAL). These reagents are highly sensitive and useful for the rapid and accurate
assay of Gram negative bacteria even if they are present in a very minute quantity
up to the level of 10
−10
gm. Hence, these reagents have wide application in the medical sphere as they have immense role in detecting endotoxins in several pharmaceutical products and other life saving drugs like interferon, insulin etc.
The list of macro-invertebrate species found in this deltaic ecosystem exhibits
unique species diversity although the magnitude of diversity (as reflected through
Shannon Weiner index or index of dominance) varies markedly with season (Mitra
2000). The invertebrate phyla act as magnificent “conveyer belts” in this ecosystem
for the transferring energy to the higher vertebrates. The scat analysis of Indian
Tiger (Panthera tigris tigris) revealed the presence of Toxocara carti, which proves
the direct dependency of higher vertebrates on invertebrate species.
Apart from sustaining a wide spectrum of invertebrate species in the benthic
substratum, this deltaic region also houses some marvellous beds of minor phyla. A
relatively small phylum of marine worms, often overlooked by biologists, the
Sipunculus, (number slightly more than 300 species in the globe with 16 recongnised genera) is also a representative of Indian Sundardans. The benthic substratum
8 Mangroves: A Reservoir of Biodiversity
Phytoplankton diversity in the Indian Sundarbans is extremely rich and in some
pockets like Lothian Island, the Shannon Weiner Index (H) has shown a high value.
A total of 64 species has been documented from the brackish water system of Indian
Sundarbans (Banerjee et al. 2000), among which some species are abundant almost
in all the season of the year. Now the number of phytoplankton species has exceeded
150 (Mitra and Zaman 2016).
Faunal Biodiversity
The mangrove ecosystems of the north-east coast of Bay of Bengal in the Indian
sub-continent also sustain a wide range of faunal diversity. Although, the faunal
exploration of Sundarbans can be traced back to mid-eighteenth century (Stolicza
1869) and extensive studies have been carried out by the workers of the Zoological
Survey of India (Annandale 1907; Kemp 1917; Hora 1934), but the works of Mandal
and Nandi (1989) and Chaudhuri and Chaudhuri (1994) provide an excellent data
base of macrofaunal diversity of the ecosystem, although the two data sets are somewhat mismatching (Table 8.11).
It is a fact that Sundarban ecosystem is still one of the most biologically productive and taxonomically diverse ecosystems of the Indian sub-continent, although
about 6 vertebrates have disappeared from this ecosystem since the last 200 years
and about 20 species are in the endangered species list (Table 8.12).
Mangrove swamps of Indian Sundarbans also invites two species of horseshoe
crabs (Fig. 8.9) namely Carcinoscorpius rotundicauda and Tachypleus gigas during
the premonsoon period of high salinity. These crabs have excellent biomedical values and have recently been established as potential source of bioactive substance,
the Carcinoscorpius Amoebocyte Lysate (CAL) and Tachypleus Amoebocyte Lysate
(TAL). These reagents are highly sensitive and useful for the rapid and accurate
assay of Gram negative bacteria even if they are present in a very minute quantity
up to the level of 10
−10
gm. Hence, these reagents have wide application in the medical sphere as they have immense role in detecting endotoxins in several pharmaceutical products and other life saving drugs like interferon, insulin etc.
The list of macro-invertebrate species found in this deltaic ecosystem exhibits
unique species diversity although the magnitude of diversity (as reflected through
Shannon Weiner index or index of dominance) varies markedly with season (Mitra
2000). The invertebrate phyla act as magnificent “conveyer belts” in this ecosystem
for the transferring energy to the higher vertebrates. The scat analysis of Indian
Tiger (Panthera tigris tigris) revealed the presence of Toxocara carti, which proves
the direct dependency of higher vertebrates on invertebrate species.
Apart from sustaining a wide spectrum of invertebrate species in the benthic
substratum, this deltaic region also houses some marvellous beds of minor phyla. A
relatively small phylum of marine worms, often overlooked by biologists, the
Sipunculus, (number slightly more than 300 species in the globe with 16 recongnised genera) is also a representative of Indian Sundardans. The benthic substratum
8 Mangroves: A Reservoir of Biodiversity