Diversity of freshwater mollusc in the Western Ghats
Suri Sehgal Centre for Conservation Science, Ashoka Tr st for Research in Ecolog and the En ironment
N.A. Aravind* and N.A. Madhyastha**Ashoka Trust for Research in Ecology and the Environment
(ATREE), Bangalore- 560024.
**Malacology Centre, Poorna Prajna College, Udupi- 576101.
DIVERSITY OF FRESHWATER MACROINVERTEBRATES
HABITAT DIVERSITY OF FRESHWATER ECOSYSTEMS
PONDS LAKES
STREAMS AND RIVERS BACKWATERS AND ESTUARIES
FRESHWATER BIODIVERSITY HOTSPOTS OF THE WORLD
The Western Ghats is a hotspot for freshwater fishes, crabs and Mollusks
Estimated numbers of described and undescribed terrestrial and freshwater mollusc
70000
ity
50000
60000
Max Undescribed
Described
mol
lusc
div
ersi
pec
ies)
50000
40000
Min
Non
mar
ine
m(N
um
ber
of
sp
30000
20000 Max
N (
10000Min
Source: Lydeard et al. 2004
Freshwater0
Terrestrial
Taxonomic break up of Indian freshwater mollusc fauna
Gastropods Bivalves Total Western Ghats
Families 12 09 21 13Genus 36 21 57 20Species 170 113 214 60
Source: Subba Rao 1989 and Shivaramakrishnan et al. 1999
Cremnochonchus sahydarensisLithtotis rupicola
Arsidopsis sp
Arsidopsis footi
Arsidopsis sp, Pseudomulleria dalyii
Cremnochonchus sp
Paracrostoma tigrina, Paracrostoma martini
Habitat preference of freshwater molluscs of the Western Ghatsof the Western Ghats
Rivers and stream are species rich habitats
70
Arsidopsis footi Pseudomulleria dalyiHabitat distribution of Freshwater molluscs
40
50
60
ices
10
20
30
40
Perc
ent s
pe
0
10
Lentic Lotic Both
Habitat
Zoo-geographically interesting species in the Western Ghats
Marine elements in the freshwater mollusc fauna of the Western Ghats
Neritinea perottetiana (Neritidae)
Cremnoconchus syhadrensis (Litterorinidae)
Zoo-geographical significance of Western Ghats molluscan fauna
Cremnochonchus
Pseudomulleria
Paracrostoma
Cremnochonchus sp.• Member of marine family• Shows that Part of the Western• Shows that Part of the Western
Ghats was under the sea• Highly specialsed habitat-Highly specialsed habitat
waterfalls• Only on the western slopes
Zoo-geographically interesting species in the Western Ghats
Family: Etheriidae
Genus: 3
Species: 3
South America, Madagascar, Tropical Africa and IndiaAfrica and India
A Gondwana relict cemented bivalve of the Western GhatsA Gondwana relict, cemented bivalve of the Western Ghats
Pseudomulleria dalyiiy
Only Five populations of <2000 individuals
Family Etheridae-A G d l d li tAn Gondwanaland relict
PseudomulleriaPseudomulleria
Western Ghats
EtheriaAcostea
Africa and Madagascar Colombia
Adamietta
… Into IndiaAdamietta
Brotia
BrotiaAdamietta
Paracrostoma
Adamietta
“…origins of the Indian biota (freshwater g (mollusc) are more complex and diverse
than assumed under the standard Mesozoic vicariance model…”
Kohler and Glaubrecht 2007
Importance
• Food: – For humans: Clams, Pila, Thiara etc– AnimalsAnimals
• Nutrient cycling: In Terrestrial and FreshwaterIndicator of ecosystem health Bioindicators• Indicator of ecosystem health-Bioindicators
• Agricultural pests• Invasive
Threats
THREAT STATUS OF RIVER CATCHMENTS OF THE WORLDWORLD
River catchments of peninsular India is most threatened
Pollution GastropodsBivalves
Dams Bivalves Gastropods
Mines Bivalves Gastropods
Agriculture Bivalves Gastropods
Urbanization Bivalves Gastropods
Percentage of extinct animals in different faunal groupsfaunal groups
C t
Others0%
Crustaceans1%
Amphibians1% Reptiles
3%
Insects10%
MammalsMollusca
43%
Mammals11%
Fishes12%12%
Birds
Source: www.redlist.org.
Total number of threatened species of molluscmollusc
12221200
1400
708800
1000
pec
ies
429400
600
# s
p
41
0
200
T rr tri l Fr h t r M rin L t C n rnTerrestrial Freshwater Marine Least ConcernGroup
Source: www.redlist.org.
India and Western Ghats???India and Western Ghats???
O l ONE h b li t d d IUCN dOnly ONE has been listed under IUCN red list category
Pseudomulleria dalyii
The big challenge of freshwater biodiversityConservation-
Environmental water demand and social requirement
Significant wetlands of the western ghats and their western ghats and their conservation status
GODAVARI CATCHMENT
WetlandHabitats
Nos./Region/Locality
PROTECTION
Rivers 3 large, 13 3 RiverKRISHNA Rivers 3 large, 13medium and 17
minor
3 River Sanctuaries
(Fish)
Backwaters Ashamudi, 2 Ramsar sites
CATCHMENT
Kuttanad, Vembanad, Kole
wetlands (Kerala)CAUVERY
Estuaries/Mangroves
Bharatapuzha,Netravathi, Gurupura, Gangolli
NilCAUVERYCATCHMENT
Gangolli, Sharavathi,
Aghanasini, Kali, Mandovi
A Gap AnalysisNo comprehensive assessment of freshwater biodiversity of the regiony g
F t i t di f h t llFew taxonomic studies on freshwater molluscs
Little information available on the distribution and ecology of the most of the speciesgy p
Few studies on the river ecology and its interaction with other species
AcknowledgementsAcknowledgements
Dept. of Science and Technology
EndemicsEndemics
Current Threats (Contd..)
DAMS MINES
MINES AGRICULTURE EXPANSION
Current Threats
RIPARIAN DEFORESTATION WASTE DISPOSAL
INFRASTRUCTURE DEVELOPMENT INDUSTRIAL POLLUTION
Endemism and habitat preference of freshwater molluscs of The Western Ghats
Rivers and stream are species rich habitatsRivers and stream are species rich habitats.
70
Arsidopsis footi Pseudomulleria dalyiHabitat distribution of Freshwater molluscs
40
50
60
ices
10
20
30
40
Perc
ent s
pe
0
10
Lentic Lotic Both
Habitat