Current Status of Freshwater Biodiversity of India: An Over View

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Chapter 1
CURRENT STATUS ON FRESHWATER
FAUNAL DIVERSITY OF INDIA
– AN OVERVIEW
KAILASH CHANDRA, K.C. GOPI, D.V. RAO, K.A. SUBRAMANIAN
AND K. VALARMATHI
INTRODUCTION
Freshwater systems form a subset of Earth’s aquatic ecosystems. They include
lakes and ponds, rivers, streams, springs, and wetlands, which can be broadly
classied into lentic and lotic systems, i.e., still and owing waters, respectively.
The freshwater ecosystems constitute the major part of the “Inland waters”, the
aquatic systems or environment that can be fresh, saline or a mix of the two
(brackish water), located within land boundaries. The estuaries are transitional
brackish-water zones between rivers and the sea. Inland waters have more focus on
fresh water mainly because of the global importance of fresh water environments,
which dominate inland waters.
All freshwater ecosystems are regulated by the hydrological cycle, ultimately
driven by the solar-energy evaporation, without which freshwater ecosystems
would not exist on Earth. Freshwater ecosystems are important for many reasons:
they help in regulating hydrological regimes, attenuating oods, recycling of
nutrients, purication of water and recharging of aquifers. They support a wide
range of biodiversity, sustaining and sheltering their living environment for
the aquatic life, besides providing congenial riparian habitats for dependent
terrestrial wildlife. Freshwater systems also provide vital ecosystem services for
humans, e.g., drinking water, ood control, climate regulation, food production,
etc. Aquatic ecosystems nowadays play a major role in the wellness industry like
tourism and recreation as many natural open waters like backwaters and lakes,
and their scenic beauties around in the coastal plains and highland or mountain
environments are tagged as important tourism destinations.
Of all the water on Earth, approximately 3% is considered “fresh water” (i.e.,
salinity < 0.5 parts per thousand). Of the 3% of global water, that is fresh water,
only an extremely small proportion is available as habitats for living organisms
on the surface of the Earth. The available freshwater ecosystems cover only
approximately 0.8% of the surface of the Earth. Thus, signicantly, much of the
Earth’s aquatic biodiversity requires the freshwater habitats, both owing (lotic)
and static (lentic), found in these rare ecosystems. It is therefore not surprising that
freshwater habitats contain some of the most endangered taxa in the biosphere.
The number of species inhabiting a given area is the species richness.
Freshwater ecosystems support innumerable organisms as they require fresh
water for survival, and the freshwater species are those which spend at least a
portion of their lives in freshwater habitats. Many hundreds of freshwater species

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of different groups, invertebrates like annelids (polychaetes, earthworms, leeches,
etc.), arthropods (insects and crustaceans), shes, amphibians, molluscs (snails and
mussels), and others have been described. The list of known diversity of freshwater
species, unlike that of terrestrial life forms, is likely to be an underestimate.
Despite the relative rarity of freshwater habitats (i.e., 0.8% of the Earth’s total
surface area), the freshwater ecosystems exhibit far more intrinsic physical and
chemical characteristics, and support a disproportionately larger share of world’s
freshwater biodiversity in relation to the habitat areas occupied. The diversity
and distribution of the well-studied taxonomic groups like shes and amphibians
provide an insight into the signicance and the global patterns of freshwater
biodiversity (Abell et al., 2008).
Another important measure of signicance for freshwater biodiversity is
the concept of species endemism—the indigenousness of a species by virtue of
its natural origin or occurrence in a given location or region and nowhere else
in the world. The global distribution of an endemic species is limited to a given
area (i.e., they occur only within a particular ecoregion or watershed). Areas of
high endemism often result from a combination of ecological forces including high
biological productivity and geographic isolation, as is evidenced in the endemism
in freshwater shes and amphibians in India.
Indian Freshwater Ecosystems and Faunal diversity
India is the seventh largest country in the world covering an area of 32, 87,590 sq.
km, the largest land mass of the Indian subcontinent, and lies to the north of the
equator between 6° 45´ (the southern-
most extremity, the Indira Point in
Great Nicobar Islands of the Indian
territory) and 37° 6´ north latitude
and 68° 7´ and 97° 25´ east longitude.
India is endowed with remarkable
biodiversity in its diverse ecosystems
and habitats that are distributed in
varied, but unique biogeographic zones.
Its biodiversity richness is well-reected in the fauna of not only the terrestrial
ecosystems, but also the aquatic ecosystems (i.e., the marine and freshwaters).
India is one among the seventeen mega biodiversity nations known from the
world, and occupies the 9th position in terms of freshwater mega biodiversity
(Mittermeier et al., 1997).
The freshwater ecosystems of India include all types of inland wetlands:
lakes, rivers, ponds, streams, groundwater, springs, cave waters, oodplains, as
well as bogs, marshes and swamps. India with 2.4% of global landmass has 4%
of the world’s freshwater resources (source: the Ministry of Water Resources,
Govt. of India). The abundant water resources include 29,000 kms of rivers, 3.15
million hectares of reservoirs, 2.35 million hectares of ponds and tanks, 0.2 million
hectares of oodplains and 33 wetlands (Ayyappan, 2007). The main freshwater
systems are 14 major rivers and their tributaries, numerous minor/ small rivers,
rivulets and streams, 44 medium reservoirs and lakes, and other small water

Current Status on Freshwater Faunal Diversity of India - An Overview
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bodies. The National Wetland Inventory and Assessment published recently by
MoEFCC, Govt. of India estimates that 10.56 million hectares of inland wetlands
exist in India, comprising of 6.62 million hectares of natural wetlands and 3.94
million hectares of manmade wetlands. The total area of Indian wetlands is only
0.03% of the geographical extent of the country.
Freshwater ecosystems and habitats of India are distributed in diverse
biogeographic regions or environments, from cold arid Trans-Himalayan to wet
Terai regions of Himalaya foot hills and Gangetic plains, extending down to the
Southern peninsula of the mainland, and beyond to the two archipelagoes of the
Andaman and Nicobar Islands in the Bay of Bengal and Lakshadweep Islands
in the Arabian Sea. The varied freshwater systems in the mainland are directly
or indirectly associated with the numerous river-drainage systems of India, such
as the major rivers like Ganges and Brahmaputra, including their tributaries, of
Himalaya’s origin, Narmada, Tapti, and their tributaries from Vindya-Satpura
Mountains, and Godavari, Krishna and Cauvery, and their tributaries as well as
many other minor, west-owing rivers of Western Ghats’ origin.

CHANDRA et al.
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Indian Wetlands
The wetlands are the most productive natural ecosystems in the world because of
their physical proximity to both water and soil, thereby supporting large number
plants and animals in their signicant diversity of characteristic species. India has
the representation of almost all types
of wetlands as dened by the Ramsar
convention. The wetland ecosystems
in India constitute the natural water
bodies, such as rivers, lakes, coastal
lagoons, mangroves, peat land, coral
reefs and man-made wetlands such
as ponds, farm ponds, irrigated elds,
sacred groves, salt pans, reservoirs,
gravel pits, sewage farms and canals.
At present, 115 wetlands (Table 1)
have been identied under the National Wetland Conservation Programme
(NWCP), and about 26 wetlands (Table 2) have been declared as Ramsar sites of
international importance under Ramsar Convention (Ramsar, 2017). According to
a study conducted by the Bombay Natural History Society (BNHS), around 160
Indian wetland sites that are home to thousands of water birds meet the criteria
to qualify them to be included in the ‘Ramsar’ category. These include already
designated ‘Ramsar Sites’. In addition, many wetlands in India are protected as
Sanctuaries and National Parks. The well known wetland protected areas are:
Keoladeo National Park, Bharatpur Bird Sanctuary, Loktak Lake, Pong Dam,
Renuka Lake, Point Calimere National Park and Chambal River Sanctuary.
Table 1. State-wise Ramsar Sites (Wetlands) in India
Sl. No. Wetland name State
1. Kolleru Lake Andhra Pradesh
2. Deepor Beel Assam
3. Nalsarovar Bird Sanctuary Gujarat
4. Chandartal Wetland
Himachal Pradesh5. Pong Dam Lake
6. Renuka Wetland
7. Hokera Wetland
Jammu & Kashmir
8. Surinsar-Mansar Lakes
9. Tsomoriri Lake
10. Wular Lake
11. Ashtamudi Wetland
Kerala12. Sasthamkotta Lake
13. Vembanad-Kol Wetland
14. Bhoj Wetland Madhya Pradesh

Current Status on Freshwater Faunal Diversity of India - An Overview
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Sl. No. Wetland name State
15. Loktak Lake Manipur
16. Bhitarkanika Mangroves Odisha
17. Chilika Lake
18. Harike Lake
Punjab19. Kanjli Wetland
20. Ropar Wetland
21. Sambhar Lake Rajasthan
22. Keoladeo National Park
23. Point Calimere Wildlife and Bird Sanctuary Tamil Nadu
24. Rudrasagar Lake Tripura
25. Upper Ganga River (Brijghat to Narora Stretch) Uttar Pradesh
26. East Calcutta Wetlands West Bengal
Table 2. State-wise list of wetlands identied under National
Wetlands Conservation Programme
Andhra Pradesh
1. Kolleru
Assam
2. Deepar Beel
3. Urpad Beel
4. Sone Beel
Bihar
5. Kabar
6. Barilla
7. Kusheshwar Asthan
Gujarat
8. Nalsarovar
9. Great Rann of Kachh
10. Thol Bird Sanctuary
11. Khijadiya Bird
Sanctuary
12. Little Rann of Kachh
13. Pariej
14. Wadhwana
15. Nanikakrad
Haryana
16. Sultanpur
17. Bhindawas
Himachal Pradesh
18. Renuka
19. Pong Dam
20. Chandratal
21. Rewalsar
22. Khajjiar
Jammu & Kashmir
23. Wullar
24. Tso Morari
25. Tisgul Tso & Chisul
Marshes
26. Hokersar
27. Mansar-Surinsar
28. Ranjitsagar
29. Pangong Tsar
30. Gharana
31. Hygam
32. Mirgund
33. Shalbugh
34. Chushul & Hanley
Jharkhand
35. Udhwa
36. Tilaiya Dam
Karnataka
37. Magadhi
38. Gudavi Bird Sanctuary
39. Bonal
40. Hidkal & Ghataprabha
41. Heggeri
42. Ranganthittu
43. K.G. Koppa wetland
Kerala
44. Ashtamudi
45. Sasthamkotta
46. Kottuli
47. Kadulandi
48. Vembanad Kol
Madhya Pradesh
49. Barna
50. Yashwant Sagar
51. Wetland of Ken River
52. National Chambal
Sanctuary
53.Ghatigaon
54. Ratapani
55. Denwa Tawa
56. Kanha Tiger Reserve
57. Pench Tiger Reserve
58. Sakhyasagar
59. Dihaila
60. Govindsagar
61. Sirpur

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Maharashtra
62. Ujni
63. Jayakawadi
64. Nalganga
Manipur
65. Loktak Lake
Meghalaya
66. Umiam lake
Mizoram
67. Tamdil
68. Palak
Odisha
69. Chilka
70. Kuanria
71. Kanjia
72. Daha
73. Anusupa
Punjab
74. Harike
75. Ropar
76. Kanjli
77. Nangal
Rajasthan
78. Sambhar
Sikkim
79. Khecheopalri
80. Tamzey
81. Tembao Wetland
Complex
82. Phendang Wetland
Complex
83. Gurudokmar
84. Tsomgo
Tamil Nadu
85. Point Calimere
86. Kaliveli
87. Pallaikarni
Tripura
88. Rudrasagar
89. Gumti reservoir
Uttar Pradesh
90. Nawabganj
91. Sandi
92. Lakh Bahoshi
93. Samaspur
94. Alwara
95. Semarai
96. Nagaria
97. Keetham
98. Shekha
99. Saman Bird Sanctuary
100. Sarsai Nawar
101. Patna Bird Sanctuary
102. Chandotal
103. Taal Bhaghel
104. Taal Gambhirvan &
Taal Salona
105. Aadi jal Jeev Jheel
Uttarakhand
106. Ban Ganga Jhilmil Tal
107. Asan
West Bengal
108. East Kolkata wetlands
109. Sunderbans
110. Ahiron Beel
111. Rasik Beel
112. Santragachi
113. Patlakhawa- Rasomati
Chandigarh (UT)
114. Sukhna
Puducherry ( UT)
115. Ousteri
The National River Conservation Directorate, under the Ministry of
Environment, Forest and Climate Change is engaged in implementing the River
and Lake Action Plans under the National River Conservation Plan (NRCP)
and National Lake Conservation Plan (NLCP).The Government of India and
the World Bank have signed three agreements, May 2011, (of which 2 deal with
biodiversity conservation) for cleaning Ganga River and to Strengthen Rural
Livelihoods and Biodiversity Conservation in India. Government of India, in
close collaboration with the State/UT Governments has been implementing the
National Wetlands Conservation Programme (NWCP), since the year 1985-
86, to prevent the degradation, ensuring the wise use for the benet of local
communities and overall conservation of biodiversity. Under the Programme, 115
wetlands (including the 26 wetlands of international importance under Ramsar
Convention) in 24 states and 2 Union Territories have been identied under the
National Wetland Policy by the Ministry which require urgent conservation and
management interventions (National Report on Wetlands, 2009). As of now there
is no specic legal framework for wetland conservation, management and their
wise use. National Forest Commission, 2006 has demanded the launch of National
Wetland Conservation Act, National Wetland Biodiversity, National Wetland
Inventory and Wetland Ecosystem Monitoring Programmes and National Wetland
information system for checking the health of the Wetlands, the transitional zones

Current Status on Freshwater Faunal Diversity of India - An Overview
7
between wetlands. Baseline information on the biodiversity of water bodies in the
form of an inventory of the fauna including birds, shes, reptiles, mammals and
invertebrates is essential to identify the wetlands that are to be designated as
Ramsar sites for inclusion in the ‘List of Wetlands of International Importance’,
and to prepare the MAPs as well as the IUCN Red List of Threatened Species.
The National River Conservation Directorate, under the Ministry of Environment,
Forest and Climate Change is engaged in implementing the River and Lake Action
Plans under the National River Conservation Plan (NRCP) and National Lake
Conservation Plan (NLCP) (MoEFCC, Annual report 2005).
Role of ZSI in Freshwater Ecosystem Conservation
Zoological Survey of India (ZSI) as a premier taxonomic research organization has
been developing baseline information on the faunal diversity of water bodies in the
form of an inventory of various fauna including birds, shes, reptiles, mammals as
well as invertebrates for monitoring and analysing the species population trends,
as well as for the evaluation of Threatened taxa. Studies on the presence of exotic/
invasive alien species and their possible impacts have also been incorporated into
the faunal documentation works. Accordingly, ZSI has developed need-based, fauna-
related reference systems such as the species inventories or faunal inventories of
selected wetlands on a priority basis to be incorporated into the information system
or its Management Action Plans for wetland conservation. ZSI has contributed
signicantly to document the fauna of Indian wetlands. The scientists of ZSI have
conducted extensive eld surveys and described many new species of different
faunal groups. Major contributions have been in molluscs, shes, amphibians,
lower invertebrates, crustaceans and various insect groups. Publications in the
form of Fauna of India, Memoires, Occassional Papers, and numerous research
articles have been published on wetland fauna of India. Exclusive publications
have been brought out on the faunal diversity of wetlands of both natural and
man-made lakes as Chilka, Renuka, Ujani, Kabar, Asan, Sambhar, Nath Sagar,
Pichhola, Kopli, Vembanad, NalSarovar, Chaurs, Khijadia, Wyra, Deepor, Palar,
Krishna Sagar, Cumbum, and Subarnarekha. Future surveys are proposed for
lakes as Chandra Tal, Gobindsagar, Sasthamkota, Narayansarovar, Deeper Beel
etc. as per Vision 2020 document of ZSI, approved by the Ministry.
ZSI has augmented its efforts in recent years to make better use of the
existing expertise and knowledge, and also engaging young and talented taxonomic
researchers to identify and catalogue, including part-by-part digitization, of the
back-log zoological collections in its central and regional faunal repositories and
museums. This ongoing task is being carried out through institutional initiatives
as well as through AICOPTAX (All India Coordinated Programme on Taxonomy)
programmes specially funded by the Ministry.
Freshwater Faunal Biodiversity in India
Global assessment on biodiversity of freshwater ecosystems demonstrates
that the biodiversity potential of these systems is very much larger than that
would be expected from the area occupied by inland waters (Balian et al. 2008).
Balian and team estimated that out of the 1.32 million species described on Earth,
126,000 lived in fresh water, contributing to almost 10% of the global total.

CHANDRA et al.
8
Freshwater habitats in India support a signicant proportion of the total
diversity of organisms, representing most of the taxonomic groups. As much as
about 9.7% of the total Indian fauna are associated with freshwater ecosystems
of India. However this estimated faunal diversity may be an underestimate due
to the inadequate exploration and identication of taxa (species) of many faunal
groups, especially invertebrates. As a result, the authentic status of the near-
absolute freshwater diversity of these groups is yet to be realized (factually true
at the terrestrial ecosystem levels also as only a fraction of the extant diversity
of these faunal groups has so far been revealed). The constraints are many with
far-reaching implications. One
serious constraint that retards
the taxonomic activities of
identifying, naming and
documenting species is the dire
dearth of skilled taxonomists.
The replacement of new
and upcoming generation of
taxonomists in the country is
not on parity—rather it is on a downward trend—with the veteran taxonomists
leaving the eld from their active research. The support from the funding
institutions and agencies for undertaking biodiversity-related taxonomic research
in the country is not that promising as it is to the front-line research areas in
physics, chemistry and other modern streams of science. All this slackens the pace
of scientic documentation of biodiversity and estimation of species. However, in
the recent times, there is a surge of interest among new generation talents in the
biodiversity-related studies, like taxonomy and systematics of fauna pertaining to
various ecosystems, including freshwater ecosystems, in India.
A summary of the updated information on the freshwater faunal diversity of
India is presented here. The diversity of vertebrate and invertebrate groups for
which credible data are available is compared and discussed. Data are decient
for many groups of invertebrates owing to knowledge gaps, either lack of available
data of work carried out in the country/ or lack of taxonomic information from
the country, which are pressing needs to be addressed. As regards freshwater
biodiversity for sustainable management and conservation of freshwater resources,
efforts are also required to gather the environmental and ecological information
data based on monitoring observations in order to analyze the conservation issues
so that freshwater biodiversity for sustainable utilization as well as management
of the resources can be cross-linked with conservation of biodiversity.
Thirty-six chapters by 48 authors have been included in this document
dealing with updated, compiled information the faunal diversity of the freshwater
ecosystems of India. The chapters though have a general format of presentation,
some authors have however differed from the normal pattern because of the

Current Status on Freshwater Faunal Diversity of India - An Overview
9
specic features of the group of fauna they deal with. The present overview focuses
on species diversity, endemism and threat status of taxa of freshwater ecosystems
of India. The total number of species of freshwater animals, named and recorded
from India has been compared with the total number of species known from the
world, following Alfred et al. (1998); Balian et al. (2008); Chandra et al. (2016a & b).
The diversity of fauna pertaining to the freshwater ecosystems of India dealt
in this document represents the present knowledge, covering the updated, compiled
and collated data, but, doesn’t claim to be full-proof, exhaustive information that
is currently available and known from India. Almost all the authors, other than
the authors of the chapters on mammals, birds and reptiles, are of the view that
signicant share of the species diversity yet remain to be discovered and described
especially in the case of invertebrate groups. The record of 9456 species from
freshwater ecosystems of India represents approximately 9.7% of the total number
of animal species (i.e., 97,708 species) recognized from India. Given that the Indian
wetlands have altogether only 0.03% area of the total geographic extent of the
country, it becomes clear that the lotic and lentic freshwater systems of India
harbour a disproportionally large fraction (9.7%) of India’s total biodiversity.
Out of the 9456 freshwater animal species known from India, among
invertebrate groups, the phylum Arthropoda alone represents 5923 species or about
62.6% of the total. Insects (of 9 orders) have the majority with 4842 species (51.2%).
The insect order Diptera (1588 species), is the most-species rich with 16.8%, and
order Coleoptera (776 species) represents about 8.2% of all species, followed by the
orders Odonata (482 species), and Hemiptera (325 species) with 5.1% and 3.4%,
respectively. Another diverse Arthropod group class Crustacea (822 species) has
the share of 8.7% of all freshwater species. The class Arachnida (259 species) with
2.7% share is dominated by the mites (253 species), and spiders with only a few in
number (6 species). The phylum Nematoda (422 species) has the representation of
4.5% of total species. The phylum Rotifera (419 species) is represented by 4.4% of
the total. The phyla such as Mollusca (217 species) and Annelida (167 species) are
moderately diverse with 2.3%, 1.8% respectively of all the freshwater species. The
Platyhelminthes with 163 species (Turbellaria 47 species + Cestoda 116 species)
contribute 1.7% to the total. Among the remainder invertebrate groups, except for
Acanthocephala with 140 species (1.5%), all other groups have less than 40 species
(all <1% of the total): Porifera (31 species), Gastrotricha (24 species), Bryozoa (22
species), Tardigrada (10 species), Cnidaria (9 species), and Entoprocta (1 species),
which are predominantly marine. The Kingtom Protista represented by phylum
Protozoa (291 species) has a share of 3.0% of the total freshwater fauna.
The phylum Chordata comprising the vertebrates represent 1597 species
(16.9%). Among these, Pisces (Fishes) are maximum (1027 species), followed by
Amphibians (275 species) and Aves (birds) (243 species) with their shares 10.9%,
2.9% and 2.6%, respectively, of all freshwater fauna. The groups Reptiles, (46
species) and Mammals (6 species), are comparatively less in their number of
species known from the freshwater systems of India.

CHANDRA et al.
10
Table 3. Freshwater faunal diversity in the world and India
Kingdom Phylum No. of Species in
world
No. of species in
India
Total Freshwater Total Freshwater
Protista Phylum Protozoa 36400 2390 3510 291
Animalia Phylum Mesozoa 136 -- 10 --
Phylum Porifera 10876 219 502 31
Phylum Cnidaria 16383 40 1074 9
Phylum Ctenophora 187 -- 12 --
Phylum Platyhelminthes 29488 1303 1666 **116 + 47
Phylum Nemertea 1362 22 6 --
Phylum Rotifera 2049 2030 466 419
Phylum Gastrotricha 794 320 100 24
Phylum Kinorhyncha 196 -- 10 --
Phylum Nematoda 25043 1808 2914 422
Phylum Nematomorpha 360 356 20 20
Phylum Acanthocephala 1199 * 229 **140
Phylum Entoprocta 172 * 10 1
Phylum Annelida 17426 1987 1004 167
Phylum Sipuncula 147 -- 35 --
Phylum Echiura 198 -- 43 --
Phylum Arthropoda 1270711 94010 73657 5923
Subphylum Crustacea 73141 11990 3584 822
Class Insecta 1070781 75874 63880 4842
Class Arachnida 114275 6146 5907 259
Class Pycnogonida 1346 -- 17 --
Class Chilopoda 3118 -- 101 --
Class Diplopoda 7842 -- 162 --
Class Symphyla 204 -- 4 --
Class Merostomata 4 -- 2 --
Phylum Onychophora 187 -- 1 --
Phylum Tardigrada 1335 910 30 10
Phylum Mollusca 118061 5000 5188 217
Phylum Phoronida 16 -- 3 --
Phylum Bryozoa 11474 94 272 22
Phylum Brachiopoda 7390 -- 4 --
Phylum Echinodermata 6600 -- 779 --
Phylum Chaetogantha 186 -- 30 --
Phylum Hemichordata 126 -- 12 --

Current Status on Freshwater Faunal Diversity of India - An Overview
11
Kingdom Phylum No. of Species in
world
No. of species in
India
Total Freshwater Total Freshwater
Phylum Protochordata 3000 -- 119 --
Phylum Chordata 66471 17960 6002 1597
Class Pisces 33888 13000 3287 1027
Class Amphibia 7534 4117 386 275
Class Reptilia 10272 153 562 46
Class Aves 9026 566 1340 243
Class Mammalia 5751 124 427 6
1627973 128449 97708 9456
*Not estimated; **Parasitic on freshwater shes;
Source: Alfred et al. (1998); Balian et al. (2008); Zhang (2011); Chandra et al. (2016a & b)
In the biogeographic-zone perspective, the Western Ghats and Northeast
India, and the Himalayas, the three of the four biodiversity hotspots known from
India, are the most diversity-rich for most taxa, except for the groups of marine
dominant minor phyla represented from freshwater ecosystems. These three
hotspot areas also harboured the maximum number of endemic species with the
highest endemism identied from the Western Ghats, followed by northeastern
India.
Fig. 1. Freshwater faunal Diversity in India

CHANDRA et al.
12
The present assessment of freshwater diversity from India is incomplete since
the focus is on animal taxa, excluding micro-organisms such as bacteria, viruses,
etc., though such groups are as signicant to freshwater diversity and ecology, as
the taxa from protozoa to mammals considered in this documentation work. The
diversity of micro-organisms, their importance in freshwater ecology and their key
role in ecosystem functioning are understudied, which is a perceptible gap area,
among other things, in the biodiversity research and documentation works. It
needs to be taken up in the future assessments of micro-organismal diversity in
order to give the complete picture of freshwater biodiversity of India.
Kingdom Protista
Finlay and Esteban (1998) estimated about 2390 species of protozoans in
freshwater habitats out of 36400 species known from the world. In India, 3510
species in 6 phyla have been reported, of which 52% are free-living and the rest
parasitic species. According to the present estimate, about 1600 species of free
living protozoans have been recorded from India including the estuarine species. A
total of 106 species of ciliates belonging to 58 genera and 36 families are reported
from the fresh water ecosystems of India. The rhizopods are represented by 185
species belonging to 175 genera and 17 families from India. Nearly 7% of free-
living protozoans, as many as 90 species, are endemic to the country (Das, 1998).
Phylum Porifera
The poriferans, commonly known as sponges, are represented by over 219
freshwater species belong to 45 genera in six families globally. In India, 31 species
of freshwater sponges belonging to 11 genera are represented by a single family
Spongillidae (Soota, 1991), of which 11 species are endemic. Out of the 37 Oriental
species, over 81% (31 species) are known to occur in India (Jakhalekar and Ghate,
2013).
Phylum Cnidaria
Cnidarians are a composite group of animals that include medusa, anemones,
corals, polyps etc. They are remarkably successful in the marine realm and a few
are thriving in inland waters. Their global diversity in freshwater habitats is less
than 40 species. The Oriental region has 4 to 6 species in freshwater (Jankowski
et al., 2008). In India, 9 species belonging to 6 genera and 4 families are reported
to occur in freshwater.
Phylum Platyhelminthes
Among the platyhelminths, class Turbullaria includes free living forms found in
all aquatic habitats both marine and freshwater, while other classes (3 or 4) are
all parasitic. Globally about 6500 species of turbullarians are known, and 1303
species are reported from freshwaters, of which 36 species distributed in Oriental
region (Schockaert et al., 2008). However, turbullarians could not be dealt with in
this volume, and the related diversity information of 47 species follows Ghosh et
al. (1998). Current status of cestoda fauna of India parasitic on freshwater shes
accounts for 5 orders, 11 families, 3 subfamilies, 25 genera and 116 species. A total
of 46 species, 22 genera, 10 families and 5 orders of freshwater shes are found to
be infected by these 116 cestode parasites in India.

Current Status on Freshwater Faunal Diversity of India - An Overview
13
Phylum Rotifera
Rotifers play a vital role in many freshwater ecosystems and are ubiquitous,
occurring in almost all type of freshwater habitats. Globally, 2030 species were
recorded from freshwaters (Segers, 2007). Till date, 419 valid rotifer species
belonging to 67 genera and 25 families are recorded from freshwater environs of
India.
Phylum Nematomorpha
An interesting group of nematode-like animals, commonly called as horsehair
worms, whose free-living adults are found in freshwaters (with only 5 marine
forms), but the larval forms are parasitic, mainly on arthropods. As many as 356
freshwater species are known from the world (FADA 2017), with only 20 species
belonging to 5 genera being reported from India (Schmidt-Rhaesa and Yadav 2004,
2013; Schmidt-Rhaesa and Lalramliana, 2011, 2016; Schmidt-Rhaesa et al., 2015).
Phylum Gastrotricha
Gastrotrichs are among the most abundant, but poorly known group of freshwater
invertebrates. They are nearly omnipresent in the benthos and periphyton of
freshwater habitats. Globally 324 species are known from freshwater habitats
(Balsamo et al., 2013). In India, 24 species belonging to six genera are reported
(Sharma, 1990).
Phylum Nematoda
Nematodes are typically thread-like, unsegmented pseudocoelomates. They are one
of the most diverse groups of metazoa in aquatic sediments. Free living nematodes
are found possibly in all types of limnetic habitats. Of the 27,000 nominal species,
the freshwater forms are about 1808 species, about 7% of the total species known
from world (Abebe et al., 2008). So for, 412 species of freshwater nematodes
belonging to 119 genera and 57 families are reported from India.
Phylum Acanthocephala
Acanthocephala or thorny-headed worms form an important group of animal
endoparasites. Their life history involves one or more hosts, generally
invertebrates or lower vertebrates, mainly shes and also affects piscivorous birds
as intermediate host. Nabi et al. (2015) reported approximately 1150 species of
these parasites, falling in four orders: Neoechinorhynchidea, Echinorhynchidea,
Aporhynchidea and Gigantorhynchidea. Bhatacharya (1998) reported 140 species
of these parasitic worms from shes with indication of high degree of regional
endemism.
Phylum Annelida
Polychaeta: Polychaetes, commonly called as ‘brittle worms’, a non-monophyletic
group of animals among annilids, most abundantly living within sands and mud
on the seashore and marine environment. Several marine forms have penetrated
to and adapted to survive in pure freshwater systems. Globally, 168 species of
ploychaeta (Glasby and Timm, 2008) are available in freshwater. Our knowledge
on freshwater polychaete fauna of India reveals occurrence of 41 species belonging
to 25 genera in 15 families.

CHANDRA et al.
14
Oligochaeta: The oligochaetes are elongate and segmented annelids with no
appendages, and are either terrestrial soil-burrowing or aquatic in habit. About
half of the annelids are placed in subclass Oligochaeta. Globally 1700 species of
oligochaetes are reported from freshwater, and the present document recognises
72 species of oligochaetes placed under 20 genera and one family in the freshwater
environments of India.
Hirudinea: Freshwater leeches (Hirudinea) are mainly predatory and parasitic
annelids having terminal suckers that serve in attachment, locomotion and feeding.
Most of the leeches are blood-suckers on vertebrates or invertebrates, while others
are mainly predators and rarely scavengers. About 700 species of leeches are
known from the world, of which 482 species are from freshwaters. Seventy leech
species have been recorded so far from India, of which 55 species under 25 genera
and 5 families are from freshwater bodies, while 36 of them are endemics.
Phylum Arthropoda
Fig. 2. The crustacean diversity in Indian freshwater
Subphylum Crustacea
Crustaceans constitute a large group of the Arthropoda comprising crabs, lobsters,
craysh, shrimp, krill, barnacles, copepods, ostracods, etc. inhabiting a wide
range of habitats, and are free-living, parasitic or sedentary organisms. There are
over 73141 known species of crustaceans divided into a number of major groups.
Four classes namely Branchiopoda, Maxillipoda, Ostracoda and Malacostraca
are available in Indian freshwater environments. As per global estimate, 11,990
species of crustaceans are known from freshwater (Balian et al., 2008) and about
822 species have been reported from Indian freshwater habitats.
Class Branchiopoda: The branchiopods include cladocerans or Water eas, a
group of small-sized, mostly microscopic branchiopods representing one of the most
primitive groups of lower Crustacea. In all, 131 species of Cladocera are known
from inland waters of India. Other than cladocerans, the remaining are known
as large branchiopods or non-cladoceran branchiopods. Presently, 40 species of

Current Status on Freshwater Faunal Diversity of India - An Overview
15
large branchiopods under 14 genera, 11 families and 4 orders are known to occur
in India.
Class Maxillipoda: Subclass Copepoda: Of the nine orders known under the
subclass Copepoda, the free-living freshwater copepods generally belong to
three orders: Calanoida, Cyclopoida and Harpacticoida. All other orders contain
predominantly brackish water, marine and/or parasitic forms. The free-living
inland water Copepoda is so far known only by about 200 species in 60 genera from
India. The order Calanoida has 40 families. Truly freshwater Indian species are
typically planktonic, and belong to the family Diaptomidae. This family contains
about 470 species in 61 genera in the world, and with 45 species in 13 genera
in India. The order Cyclopoida comprises 12 families, but only four of them, viz.
Oithonidae, Cyclopinidae, Cyclopettide and Cyclopidae, are found in inland waters
of India. Out of 1,100 species in about 60 genera known worldwide, 86 species in 20
genera are known from India. The order Harpacticoida mostly represents benthic
organisms, inhabiting the sediment as interstitial, burrowing or epibenthic forms.
Nearly 50 families, with about 1,200 species occurr in freshwater as well as
brackish waters in the world, while 66 species in 29 genera are presently known
from Indian inland waters. The order Arguloidea comprises a group of primary
freshwater parasitic crustaceans, commonly known as ‘sh-lice’. The only family of
this order, Argulidae, comprises four genera, out of which only the genus Argulus is
represented by 17 species in India, of which 14 species are freshwater inhabitants.
Class Ostracoda: Ostracods, commonly known as seed shrimps, are microscopic
organisms existing in all aquatic (marine, brackish and freshwater) ecosystems,
including subterranean waters. Globally, 2103 species under three superfamilies,
15 families and 209 genera are known from freshwater systems (Martens et al.,
2008), of which about 154 species belonging to 05 families, 40 genera have been
documented from India.
Class Malacostraca: The class Malacostraca includes amphipods, isopods,
Bathynellacea and decapods etc. Amphipods are small crustaceans, highly diverse
in aquatic habitats and intertidal zones. Out of 161 species of amphipods known
so far from India, only 16 species are from freshwater. Most of the isopods are
marine inhabitants and have wide
distribution. Out of the 11000 species
of isopods known globally, only 301
species are reported from India,
which include marine, backwater,
terrestrial and parasitic forms, with
only 18 species occurring in freshwater
systems. The order Bathynellacea,
comprising small eumalacostracan
crustaceans, typically occurring in the
interstitial spaces of sandy shore sediments of lakes, sandy and gravelly banks of
rivers, streams etc, is represented by 24 species under 7 genera and 2 families from
India. The order Decapoda includes important crustaceans like shrimps and crabs
comprising 655 species of caridean shrimps and 1,476 species of brachyuran crabs

CHANDRA et al.
16
available in freshwater systems of the world. The caridean shrimps consisting of
118 species under 14 genera and two families, and the brachyuran crabs having
106 species under 40 genera and 5 families are known from freshwaters of India,
which include 100 species of primary freshwater crabs and 6 species of secondary
freshwater crabs.
Class Arachinida: The class Aracnida includes spiders and mites inhabiting
mostly terrestrial habitats, some in freshwater environments (Foelix, 2011). There
are 26 species under 12 genera belonging to nine families of spiders so far reported
from the World (Nyffeler and Pusey, 2014) while 6 species under 6 genera and 3
families are known so far from India. Among the mites, the Hydrachnidia (water
mites) represents the most important group of the Arachnida in fresh water. Over
6,000 species placed under 57 families, 81 subfamilies and more than 400 genera
have been described worldwide (di Sabatino, 2008), of which 253 species, 70 genera
and 25 families are reported from India, including 183 species endemic to the
country.
Class Insecta: Insects constitute the most successful among all groups of animals.
They are also the most diverse group of organisms in freshwater. It is estimated
that as many as 4842 species inhabit inland wetlands of India.
Order Hemiptera: Freshwater hemipterans, commonly known as ‘aquatic bugs’,
are secondarily adapted to aquatic ecosystems, with their nymphal and adult
stages being fully aquatic. The aquatic bugs are represented by 325 species, 84
genera and 18 families under three infraorders of suborder Heteroptera, known
from India.
Order Coleoptera: This order includes
hard bodied beetles which are
holometabolous in nature with complex
metamorphosis. The beetles are most
species-rich animal group existing on
the earth. The water-beetle fauna of
India consists of 776 species belonging
to 137 genera, and 17 families in 3
suborders.
Order Odonata: The order odonata, one of the ancient groups of insects, includes
insects with their adults having terrestrial and the larvae aquatic mode of living.
Globally, 6233 species in 685 genera of odonates are known, of which 482 species
with about 50 subspecies in 150 genera and 18 families exist in India.
Order Trichoptera: Trichoptera, commonly called Caddisies, are among the most
diverse holometabolous aquatic insects and are primary invaders of freshwaters.
Trichopterans are extensively utilized in bio-monitoring service along with other
micro-invertebrates as their larvae are an important benecial component of
the trophic dynamics and energy ow in their inhabiting lotic and lentic waters.
Over the world, 14,548 species belonging to 616 genera in 49 families have been
recognized (Morse 2017). In all, 28 families encompassing 102 genera and 1,227
species are on record from India.

Current Status on Freshwater Faunal Diversity of India - An Overview
17
Order Plecoptera: Plecoptera is a small monophyletic order of hemimetabolous
insects, commonly called stoneies with around 3625 described species globally
included under 303 genera and 16 families, of which 128 valid species under 24
genera and 8 families are reported from India, including 91 species endemic to
India.
Fig. 3. The composition of aquatic-insect groups in Indian freshwater ecosystems
Order Ephemeroptera: Ephemeropterans, commonly known as Mayies, are most
primitive and ancient group of insects. Globally, about 3000 species in 400 genera
and 42 families are known, of which
390 species, 84 genera and 20 families
occur in Oriental region (Barber-James
et al., 2008). The Indian subregion
has the representation of 204 species,
of which 146 species belonging to 58
genera and 13 families are reported
from India.
Order Lepidoptera: Lepidoptera forms a fascinating group of insects of economic
importance with high diversity of species consisting of butteries and moths.
The aquatic Lepidoptera is represented by 740 species under three subfamilies,
Acentropinae, Pyraustinae (Crambidae) at global level, and in India, 80 species are
available under 3 subfamilies and 2 families.
Order Diptera: Dipterans include the group of two-winged insects, known as true
ies, inhabiting terrestrial, semi-aquatic and aquatic habitats. Adult dipterans are
usually terrestrial in habit while their larvae and pupae are aquatic and dependent
on water. In all, 40 families of Diptera are known to be aquatic worldwide, of which
36 families, 151 genera and 1,588 species known from India are aquatic or semi-
aquatic in nature.

CHANDRA et al.
18
Order Hymenoptera: Hymenopterans are generally terrestrial insects and are
mostly benecial insects of economic importance as agents of biological control.
Most of them have a parasitic mode of life (parasites or parasitoids) on other group
of insects. Globally, 150 species 51 genera from 11 families of Hymenoptera are
recognized as aquatic, of which 10 species in 7 genera under 3 families from or near
water bodies are known from India.
The insect orders Megaloptera and Neuroptera (not dealt with among chapters
of insect groups of this document) are closely related members of the superorder
Neuropterida (Cover and Resh, 2008). A total of 328 species of Megaloptera and
73 species of Neuroptera are known globally. In India 26 species of Megaloptera
belonging to 7 genera under a single family are known from the freshwater
ecosystem. The Indian freshwater neuropterans are represented by 4 species
placed under 2 genera and a single family.
Phylum Mollusca
Freshwater molluscs play an important role, as the prominent links in the trophic
structure of freshwater ecosystem. The freshwater molluscs have an estimated
global diversity of 5000 species, of which 217 species comprising 150 species of
gastropods and 67 species of bivalves are reported from freshwater ecosystems of
India. About 15 species of gastropods and 18 species of bivalves have discontinuous
distribution. As many as 77 freshwater molluscs are endemic to the Western Ghats
biodiversity hotspot.
Phylum Bryozoa
The Bryozoa, also known as polyzoa, ectoprocta or moss animals, are colonial
organisms primarily inhabiting marine environment. Bryozoa is divided into two
distinctive classes, Phylactolaemata and Gymnolaemata, of which the former is
strictly restricted to fresh waters. Besides 5,000 marine species, 94 species under
24 genera, 10 families are known from the freshwaters from the world. The Indian
fauna comprise 22 species under 13 genera and 6 families.
Fig. 4. Freshwater vertebrates in India

Current Status on Freshwater Faunal Diversity of India - An Overview
19
Phylum Chordata
Class Pisces: Indian freshwater sh diversity is very rich with as many as 1027
species, comprising of primary, secondary and alien freshwater shes. Among
them primary freshwater shes include 858 species belonging to 167 genera under
40 families and 12 orders. Further, 137 species of secondary freshwater shes
that frequently enter and thrive in freshwater reaches of rivers are also known
from India. Alien shes that have become naturalized in Indian freshwater bodies
account for 32 species, of which 16 are considered to be potentially invasive. More
than 60.3% of the primary freshwater shes of India are endemic to the country,
with maximum endemism of species found in Western Ghats.
Class Amphibia: Amphibians include three living orders, Anura (frogs and toads
with 6706 species worldwide), Caudata
(salamanders and newts with 693
species worldwide) and Gymnophiona
(caecilans or limbless amphibians
with 205 species worldwide), thus,
accounting 7604 species known from
the world. Of these, 386 species
belonging to 59 genera and 15 families
are known from India, sharing about
5% of the total species from the
world. Of the 386 species of Indian
amphibians, about 275 species, out of 386, dwell in freshwater bodies.
Class Reptilia: Reptiles are the rst terrestrial, poikilothermic and omniote
vertebrates occurring in all kind of environment except severe cold region. About
250 species of turtles of the total 320 recognized in the world are freshwater
dwellers (Bour, 2008); though none of the lizards are strictly aquatic, at least 73
species regularly utilize freshwater habitats (Bauer and Jackman, 2008); and, 24
species of crocodilians live in tropic and warm temperate freshwater ecosystems of
the world (Martin 2008). More than 570 species of reptiles have so for been reported
from India (3 crocodiles, 33 testudines, 234 lizards and 296 snakes), which include
46 species of freshwater species, comprising one species each of Crocodylia and
Gavialidea, 21 species of testudines, two species of monitor lizards, one species
of skink, and 21 species of snakes, which are primarily or partially occurring in
freshwater habitats.
Class Aves: Birds (Aves) have colonized all continents (from the Arctic to the
Antarctic) and all habitats on earth (from the desert to the open sea). Approximately
10,000 species have been described, of which nearly 5% (560 species) need
imperative freshwater habitat in order to satisfy at least one of their life-history
traits (Dehorter and Guillemain, 2008). A total of 243 species of birds, including
wetland dependants were recorded from the wetlands of India. However, 67 forest
birds also frequent freshwater bodies.
Class Mammalia: Mammals include about 5500 species belonging 29 Orders, 154
families, of which, a total of 124 species of mammals belonging to 11 orders are
freshwater forms occurring in all continents except Antarctica. Out of 124 species

CHANDRA et al.
20
of global freshwater mammals, only 6 species namely, South-Asian river dolphin,
Oriental small-clawed otter, European otter, Smooth-coated otter, Himalayan
water-shrew and Elegant water-shrew, are found in India.
Knowledge gaps
There are several groups for which the information on the diversity richness and
distribution of species are vague or inaccurate. Other than the vertebrate groups,
which are reasonably better-documented in the biodiversity-related studies, all
other groups, especially minor phyla and many groups even within the major taxa
such as many minor insect orders, and families of the large orders of insects, like
Coleoptera, Diptera, Hemiptera, Hymenoptera, etc. are still understudied for their
diversity known from the freshwater ecosystems. Similarly, knowledge-gaps on
species-habitat interaction (autecology), systematic surveys and monitoring of
species diversity, status dynamics vis-à-vis habitat degradation through scientic
species sampling and analyses methodologies, need to be addressed appropriately.
Diversity and distribution of vertebrates, like shes, are though better
documented than other groups, new species of freshwater shes, or amphibians,
are still being described regularly from the previously unexplored or underexplored
areas, which itself is the evidence for the gap areas in the spatial coverage of
exploration of important ecosystems for biodiversity related assessment and status
studies. Almost all invertebrate groups of the freshwater ecosystems, including
molluscs, crustaceans, insects and arachnids that are generally better covered in
the biodiversity documentation studies, are still remaining unrevealed for their
realistic species diversity known from the pristine and riparian habitat environs
of major ecosystems like tropical rainforests, which are geographical gaps in the
exploration programmes. Because of these reasons, our current assessments of
estimating the faunal-diversity potential of freshwater ecosystems, or of terrestrial
ecosystems for that matter, should be interpreted with care and caution. Some
primitive invertebrate phyla such as Platyhelminthes, Nemertea, Nematomorpha,
Gastrotricha, Tardigrada, etc. are also amongst the less or least known groups for
which taxonomic knowledge and available data are to be substantially generated.
In most of these groups, their freshwater diversity is relatively poor studied,
compared to their marine or terrestrial counterparts.
Threats to the freshwater faunal diversity
Around the world, freshwater habitats are under increasing threats and pressures
due to both local and global changes (Dudgeon et al., 2005; Pattnaik, 2007).
Besides, freshwater bodies like rivers, lakes, tanks and ponds are overstrained
by poisoning in various ways like industrial wastes, sewage, and agricultural
runoff with chemical wastes and excess nutrients. Discharges of pollutants can
degrade the quality of water, as well as affect the health of its aquatic ecosystem.
Wetzel (1992) reported that freshwater bodies of the world are collectively
experiencing accelerating rates of qualitative and quantitative degradation.
Dudgeon et al. (2005) documented threats to global freshwater biodiversity under
ve categories like overexploitation, water pollution, ow modication, distraction
and degradation of habitat and invasion of exotic species. These combined and

Current Status on Freshwater Faunal Diversity of India - An Overview
21
interacting inuences have resulted in the population decline and range reduction
of freshwater biodiversity worldwide.
Freshwater ecosystems are known to be the most endangered ecosystems in
the world. Declines in biodiversity are far greater in fresh waters than in the most
affected terrestrial ecosystems (Sala et al., 2000). The threats to global freshwater
biodiversity due to overexploitation, water pollution, ow modication, destruction
or degradation of habitat, and invasion of exotic species result in population
declines and range reduction of freshwater biodiversity worldwide (Dudgeon et
al., 2005). In addition, climate change, increasing levels of water scarcity and
development goals such as increasing access to clean drinking water and sanitation
are all going to have major impacts upon freshwater systems in the future (IUCN,
2008). Conservation efforts for freshwater biodiversity are constrained by the fact
that most of the species in diverse communities are rare (Sheldon, 1988) and thus
their natural histories tend to be poorly known. Globally, awareness of the need to
conserve freshwater biodiversity seems limited. Between 1997 and 2001, only 7%
of papers in the leading journal in the eld of Conservation Biology were concerned
with freshwater species or habitats (Abell, 2002).
Essential ecosystem services, such as shes for consumption, water for
drinking and food production as well as transportation and cultural purposes, are
mostly contributed by freshwater ecosystems (Balian et al., 2008). Biodiversity
of freshwater is declining at a faster rate than that of terrestrial ecosystem, and
therefore the freshwater systems are also the most challenged ecosystem in the
world (Sala et al., 2000; Covich et al., 2004; Dudgeon et al., 2005). Protection of one
or a few water bodies cannot serve the purpose of conservation of all freshwater
biodiversity within a region.
Freshwater biodiversity provides a broad variety of valuable goods and
services for human societies. Some are irreplaceable. Conservation strategies
protecting all elements of freshwater biodiversity would guarantee that water
use for humans is sustainable while, in contrast, the magnitude of the threat
to and loss of biodiversity would be an indicator of the extent to which current
practices are unsustainable. A mixture of strategies will be essential to preserve
freshwater biodiversity in the long term. It must include reserves that protect key,
biodiversity-rich water-bodies (especially those with important species radiations)
and their catchments. In parallel, scientists must more effectively communicate
the importance and value of freshwater biodiversity to stakeholders and policy
makers, so as to make certain that all available information on freshwater
biodiversity is applied effectively to ensure its conservation.
Way forward for freshwater taxonomy in India
Inventories of freshwater biodiversity are incomplete in many parts of the
world, especially in the tropics, and rates of species loss may be higher than the
currently estimated. An immediate, coordinated effort to assess global freshwater
biodiversity, including major hotspots is an imperative necessaity . This exercise
should take place in parallel with the ongoing development of strategies for the
conservation and management of freshwater biodiversity.

CHANDRA et al.
22
An inference emerged out of this documentation work by ZSI is that taxonomic
research and identication of species based on increased systematic sampling
efforts are needed to address the existing geographical and taxonomical knowledge
gaps in the current understanding of knowledge on the faunal biodiversity of
freshwater ecosystems in India. In terms of diversity-richness and endemism of
species, considerable chunk of ecosystem areas including freshwater systems in
the country still remains little or under-explored, and the situation is especially
critical for the least-known groups of invertebrates. More systematic exploration
surveys are imperative, which will require additional, young-generation taxonomic
experts and increased nancial means.
ACKNOWLEDGEMENTS
We wish to express our sincere thanks and deep sense of gratitude to eminent
taxonomists: Dr. Y. Ranga Reddy, Dr. K.G. Sivaramakrishnan, Dr. B.K. Sharma,
Dr. Sumita Sharma, Dr. M.M. Saksena, Dr. Q. Tahseen and many other taxonomic
experts who have contributed to this document chapters on various groups of fauna
of freshwater ecosystems. We are deeply indebted to Dr. J.R.B. Alfred, former
Director, Zoological Survey of India, for his constant encouragement, advice and
suggestions and also for critically going through the manuscripts of the chapters.
We were fortunate to have the help and cooperation of our several scientists and
colleagues as Dr. Anjum Rizvi, Dr. L. Kosygin Singh, Dr. N. Marimuthu, Dr.
S.S. Mishra, and others, assisting us in several ways, especially in correcting
and setting the chapters. We are also thankful to Shri Ratiram, Publication and
Production Ofcer of Zoological Survey of India for his untiring efforts in bringing
out this document in time.
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