Land snails (Mollusca: Gastropoda) of
India: status, threats and conservation strategies
Sandeep
Sen 1, G. Ravikanth 2 & N.A. Aravind 3
1,2,3 Suri
Sehgal Centre for Biodiversity and Conservation, Ashoka Trust for Research in
Ecology and the Environment (ATREE),
Royal Enclave, Srirampura, Jakkur PO,
Bengaluru, Karnataka 560064, India
Email: 1sandeep.sen@atree.org, 2 gravikanth@atree.org, 3 aravind@atree.org
(corresponding author)
Date of publication (online): 26
September 2012
Date of publication (print): 26 September 2012
ISSN 0974-7907 (online) | 0974-7893 (print)
Editor: Fred Naggs
Manuscript details:
Ms # o2722
Received 03 March 2011
Final received 18 July 2012
Finally accepted 24 August 2012
Citation: Sen,
S., G. Ravikanth & N.A. Aravind (2012). Land snails (Mollusca: Gastropoda) of India: status,
threats and conservation strategies. Journal
of Threatened Taxa 4(11): 3029–3037.
Copyright: © Sandeep Sen, G. Ravikanth & N.A. Aravind 2012. Creative Commons Attribution 3.0 Unported License. JoTT
allows unrestricted use of this article in any medium for non-profit purposes,
reproduction and distribution by providing adequate credit to the authors and
the source of publication.
Author Details: Mr.
Sandeep Sen is a research intern at the Conservation Genetics
Department at ATREE. Basically a
geneticist by training, He is studying phylogenetics and population genetics of
land snails of the Western Ghats. He is also developing species pages for
Indian mollusk fauna.
Dr. Ravikanth leads the conservation Genetics Lab at ATREE. He has been actively
involved in working out genetic structure of threatened species in the Western
Ghats. He has undertaken a number of research projects related to the
conservation and species recovery of economically important and/or endangered
species.
Dr. Aravind is a Fellow at ATREE. He has been working on
ecology and taxonomy of non-marine mollusk of the Western Ghats for a decade.
He is collaborating with Natural History Museum, London on non-marine mollusc
taxonomy.
Author Contribution: All authors have contributed
equally to this manuscript
Acknowledgements: The authors greatly acknowledge the Darwin Initiative
via DEFRA, Government of UK for funding. We are also grateful to Drs. T.
Ganesh, Soubadra Devy and K.V. Gururaja for critical comments on the earlier
version of the manuscript. We also thank two anonymous reviewers for their
critical comments that greatly helped in improving the manuscript.
Abstract:Land snails form an important
component in the forest ecosystem. In terms of number of species, the phylum
Mollusca, to which land snails belong, is the largest phylum after
Arthropoda. Mollusca provide unique
ecosystem services including recycling of nutrients and they provide a prey
base for small mammals, birds, snakes and other reptiles. However, land
snails have the largest number of documented extinctions, compared to any other
taxa. Till date 1,129 species of
land snails are recorded from Indian territory. But only basic information is known
about their taxonomy and little is known of their population biology, ecology
and their conservation status. In
this paper, we briefly review status, threats and conservation strategies of
land snails of India.
Keywords:Biodiversity, conservation, land
snails, taxonomic bias, reintroduction, Western Ghats
For
figures, images, tables -- click here
Introduction
The
tropics have faced massive biodiversity loss due to intensive anthropogenic
activities such as changes in land use and degradation of environment. Recent
reports suggest that the tropics are losing biodiversity at an alarming rate
(Sodhi 2008). Much of this
biodiversity loss has been reported for vertebrates and plants. However, there is very little knowledge
on the extent of loss in lesser known groups,
especially the invertebrates. In
this paper, we highlight the importance of land snails and the need for their
conservation.
Land
snails include several distinct lineages of terrestrial gastropods and belong
to the second largest phylum after arthropods in terms of number of species
with more than one lakh described species (Lydeard et al. 2004). Land snails constitute about six per
cent of the total species on Earth (Clark & May 2002). A large part of molluscan fauna in many
tropical regions of the world is still poorly known. They form an important component of the
forest ecosystem by recycling nutrients (Graveland et al. 1994; Dunk et al.
2004) and are the prey base for a number of small mammals, birds, reptiles,
amphibians and other invertebrates, including carnivorous snails (Deepak et al.
2010). In calcium poor habitats
land snails can form an important source of calcium for other animals. Land snails also serve as an indicator of
ecological conditions, and are very sensitive to climatic and ecological change
(Shimek 1930; Simone 1999; Čejka
& Hamerlík 2009). Thus,
they are useful for reconstructing past environments (Bar-Yosef Mayer 2002;
Gümüş 2009). As early as 1839 Charles Darwin showed the value of land
snails in studying environmental change (Naggs et al. 2006). Terrestrial
snails prove to be valuable research subjects for studies in evolutionary
biology, biogeography, phylogeography, biodiversity, ecology
and conservation biology (Schilthuizen et al. 2007; Davison et al. 2008;
Richards & Davison 2010). With
their generally low dispersal powers, land snails tend to exhibit conservative
distribution patterns, making them valuable subjects in studying historical
biogeography (Solem 1984; Naggs & Raheem 2005; Wade et al. 2006). Highly diverse and narrowly distributed,land snails are good
indicators of areas of conservation importance and endemicity when compared to
widely distributed groups such as vertebrates (Moritz et al. 2001).
The
distribution and activity of land snails depends on several factors including
precipitation, soil pH, soil Ca content, canopy density, etc. Calcium availability in the soil is a
major limiting factor for their survival as it is required for their shell
formation. Several studies have
shown that Ca is positively correlated with species richness and density (Burch
1955; Hotopp 2002; Aravind 2005). However, in the regions such as the Western Ghats, where the soil is
usually acidic the snail richness is usually high but abundance is low.
The
past two decades have seen a large number of studies highlighting the need for
mollusc conservation globally (Bouchet 1992; Ponder 1997; Herbert 1998; Killeen
& Seddon 2004; Budha
2005; Solymos & Feher 2005; Régnier et al. 2009). Killeen & Seddon (2004)
notably edited a volume with global coverage on molluscan biodiversity and
conservation, highlighting the importance of molluscan ecology and
conservation. However, very little
information is available on the status and threats of land snails in
India. Here, we review current
status of ecology, conservation and threats to land snails with particular
reference to India and discuss the strategies required for conserving this important
group.
Early studies on
land snails in India
Indian malacology was pioneered by William Henry Benson (1803–1870),
who contributed significantly to our knowledge on Indian land snails in the mid
19th century (Naggs 1997). The Blanford bothers-William and Henry, H. Theobald, L. Pfeiffer, G.K.
Gude, H.H. Godwin-Austen and R. Beddome, led Indian land snail research until
the early 20th century, but Gude and Pfeiffer’s research was based
entirely on museum material as neither visited India. These malacological pioneers laid the
foundation of our knowledge on the taxonomy and distribution of Indian land
snails. Following this period of
intensive study, there was a drastic decline in studies on Indian land snails.
More recent studies in India, have mainly concentrated on inventorying regional
snail faunas (like state or protected areas) and less on species description,
ecology and conservation (Aravind et al. 2010). While globally, there has been a renewed
interest in land snail research, in India the research has truly been at a
snail’s pace (Aravind et al. 2005, 2008, 2010; Aravind & Naggs 2012). Little information is available on
species limits, distribution ranges and patterns of diversity. Recent analysis of Indian land and
freshwater molluscan literature has confirmed that that there are hardly any
studies on the ecology and conservation of Indian land snails compared to the
wide range of historical literature available on taxonomy (Aravind et al.
2010). There are no studies on the
population status, phylogeny
and taxonomic revision of different families or genera of Indian land snails.
Species diversity
and rarity in land snails
Globally,
nearly 35,000 species of land snails have been described and there may be
30,000 to 60,000 additional species yet to be described (Lydeard et al. 2004). Within modern India’s boundaries 1129
species belonging to 140 genera and 26 families of land snails have been
recorded (Ramakrishna et al. 2010). The Western Ghats hotspot has 270 species of land snails of which 76%
are endemic to this region (Aravind 2005) and 40% are
micro-gastropods (i.e. <5mm on greatest dimension) (Aravind et al.
2008). Unlike most other systematic
groups many land snail species have restricted range distributions with some
endangered species having a range of less than 5km2 and many endemic
species having ranges less than 10km2 (Cameron 1998; Dunk et al.
2004). According to Solem (1984) nearly half of all
terrestrial molluscs have a species range of less than 100km2. Within the
Western Ghats, species distributed in the southern region are absent in the
northern region. Further, there is
very little overlap between the southern and central, and central and northern
regions (Table 1; Aravind 2005). Nearly 75% of land snails from the Western Ghats have been reported from
less than three sites (Fig. 1). This data clearly indicates how vulnerable this group is to any small scale change in the ecosystem. The situation in other regions of India
is also cause for concern. Northeastern
India harbours a rich mixture of Indian and Burmese/Malayan snail groups
resulting in the highest species diversity in this region, but there are hardly
any studies on their distribution and threats. Our information on the land
snails of northeastern India, is basically from the Fauna
of British India and a few Zoological Survey of India reports. Conversely, though less rich, the land
snail fauna of the Western Ghats is better known when compared to other regions
of India (Rao 1924; Sathyamaurthi 1960; Subbarao
& Mitra 1979; Ramakrishna & Mitra 2002; Madhyastha et
al. 2004; Mavinkurve et al. 2004a,b; 2005; Aravind 2005; Aravind et al. 2005,
2008; Rajashekhar & Aravind 2012).
Threats
The
major threats to the native land snail fauna include habitat loss and
fragmentation as a result of anthropogenic activities such as intense land use,
construction of roads, dams, plantations, pollution and the spread of invasive
species (Aravind 2005; Aravind et al. 2005) which reduce diversity and change
the community structure of land snails (Aravind 2005; Rajashekhar & Aravind
2012). Between 1973 and 1995 the
southern Western Ghats lost nearly 25 percent of forest cover (Jha et al. 2000). This region of the Ghats harbours high
species diversity and endemism in land snails (Aravind 2005). Poor dispersal and small distribution ranges of many land snails have
undoubtedly contributed to high levels of extinction. Because of strict habitat preference, any
fragmentation of populations could affect their gene flow. Even, cutting of roads within a
protected area could fragment populations of snails. However, for a subset of forest snail
species, man-made habitats such as home gardens and plantations can act as
either refugia or corridors between forest patches (Aravind 2005; Raheem et al.
2008). Climate change is considered to be a
threat to many species (Thomas et al. 2004), and land snails are particularly
vulnerable (Pounds & Crump 1994; Pounds et al. 1999; Sternberg 2000;
Bezemer & Knight 2001; Gerlach 2007). Changes in rainfall patterns and fluctuation in soil temperature could
lead to the death of juvenile snails and impair mobility across a fragmented
mosaic of natural and transformed habitats in response to climate change. Extinction of
land snail species due to change in climatic conditions such as a decrease in
rainfall and global warming has also been reported (Baur &
Baur 1993; Gerlach 2007). In India,
we do not have any information on potential impact of climate change on land
snails.
A vast extent of the Western Ghats is
covered in plantations such as tea, coffee, areca, rubber etc. A wide variety
of pesticides/herbicides are used to control several species of arthropods,
fungi and plants that infest these plantation crops (Dipti & Velho 2007). The impact of these chemicals on the
local flora and fauna including endemic land snails as well as other
invertebrates is unknown. Forest
fires (even surface fires) and reduction in vegetation cover are also major
threats to land snails.
Neglected taxa in
conservation
The
scarcity of malacologists in India has had a serious impact on studies related
to taxonomy, diversity, distribution, endemism, threats and conservation of
land snails. Lack of interest in
land snail research is also due to poor funding opportunities for taxonomy and
basic biology, unavailability of good taxonomic keys and field guides. The science of taxonomy is practised on
an international level. Indian Biodiversity Act of 2002 does not
permit exchange of specimens with international scientific communities, which
further hinders the taxonomic studies on land snails (Prathapan et al. 2006). Further, most researchers and
conservation biologists show considerable interest in “charismatic
conservation” (Burner et al. 2001). Molluscs have the largest number of documented extinctions since 1500AD
(www.redlist.org). Non-marine
species (terrestrial and freshwater) constitute 99 percent of all molluscan
extinctions. Among the 566 extinct
molluscs, the largest proportion is of the land snails (422 species) followed
by freshwater molluscs (140 species). Till date there are only four recorded extinctions of marine molluscs
(Lydeard et al. 2004; Regnier
et al. 2009). In the
last 300 years, the Indian Ocean Islands of Mauritius, Rodrigues and Reunion
have lost 30 species of land snails (Burner et al. 2001) and St. Helena and
Madeira in the Atlantic Ocean have lost 36 species of land snails (WCMC 1992). Although terrestrial vertebrate extinctions
are well documented, invertebrate extinctions often go unnoticed. Only a small fraction, i.e., <2% of
known molluscan species have had their conservation status properly assessed
(Lydeard et al. 2004; Naggs et al. 2006). Despite having the largest extinction
rates and highest number of threatened species (Fig. 2), land snails are still
not considered worthy for conservation efforts despite having deep independent
phylogenetic lineages in many groups.
Conservation of Land snails in India
The role of
communities and organisations
Land
snails have a very poor image among the public, forest managers and policy
makers (Seddon 1998) and a lack of public support. Recently, an attempt was made to
popularise land snails to a wider audience in India in the form of an
illustrated guide, produced by the Natural History Museum, London in
association with ATREE, Bengaluru on land snails of the Western Ghats (Appendix
1). This guide not only assists
conservation biologists but also amateur naturalists, students and the lay
public alike to identify land snails of the Western Ghats (Raheem et al. 2009).
Effective
conservation also requires awareness regarding importance of thistaxa in the ecosystem and the services they provide. Communicating the importance of snails
and their role in ecosystem health, could also attract interest of wider
ranging audience. An organization
called Buglife in Europe was set up to conserve rare invertebrates in Britain
(www.buglife.org.uk). Such efforts
are needed in this country for effective conservation of invertebrates in
general and land snails in particular.
Species-specific
conservation plans
A
notable exception to the general apathy towards snail conservation is the
International Partula Conservation Programme, a unique ex-situ breeding
programme initiated by Prof.
Bryan Clarke at the University of Nottingham and coordinated by the Zoological
Society of London. About 25 Partulasnail species were exterminated in the wild by the predatory snail, Euglandina
rosea that was introduced from Florida in a misguided attempt to
control the introduced Giant African Snail Lissachatina fulica. This program involved a managed breeding programme for 25
species of Partula in 15 collaborating zoos globally along with local
conservationists, local communities and the French Polynesian Government. To date more than 30 species of Partulahave been rescued and captive breeding populations have been established in
18 zoos and laboratories throughout the world (Pearce-Kelly et al. 1997). In another collaborative
effort of the Natural History Museum, Bermuda and London Zoo, 56 species of
highly endangered land snails from Bermuda were captive bred and reintroduced
as a part of their species conservation action plan
(www.zsl.org/zsl-london-zoo//news/snail-mail-from-bermuda,123,NS.html). In the USA plans for reintroductions to
conserve the Stock Island Tree Snail Orthalicus reses have been taken up
(Boresma et al. 2001; Froys et al. 2001). In India the lack of information base, studies on the distribution,
ecology, genetics and threats, has hindered the development of an informed
conservation plan. However, a
captive breeding program for selected species would help in increasing public awareness. Hence, setting
up of “snailariums” for breeding of endemic snails could usefully be taken up
by national parks and zoos. This might raise public interest in
snail conservation across the country.
Habitat
conservation
In
India, many forested areas, which are devoid of large and charismatic mammal
species, have high land snail diversity. However, these reserve forests generally receive little protection
status as they fall outside the protected area network. These reserve forests are open access
and hence they are prone to a variety of anthropogenic disturbances such as
collection of minor forest products, grazing, fire, etc. Significant proportions of endemic
species are distributed in these non-protected areas and hence are vulnerable
to extinction. Current habitat
conservation practice is focussed on encompassing iconic but generally widely
distributed/low risk species. Conversely habitats with the highest total of biological diversity are
not targeted. Land snails are of
potential value as indicators of high diversity habitats for a wide range of
plant and animal groups. Thus,
snails can be utilised for identifying biodiversity rich habitats that should
be given high conservation priorities. In addition, the high geographical turnover of many land snail species
exemplifies the value of local scale conservation in capturing biological
diversity in general (Ponder 1997; Raheem et al. 2009). For example, the low elevation evergreen
reserve forests of Agumbe, Hulikal, etc., in the central Western Ghats have
lower levels of protection but harbour high species diversity of land snails
(Aravind 2005). The top down
approach of conserving large mammals will exclude the majority of land snails,
other invertebrates and plants from protection (Aravind et al.
2005). Hence, for effective
conservation of land snails, some of the species rich areas surrounding the
protected areas such as Agumbe, Hulikal and similar areas rich in land snail
diversity need to be given additional protection. In India and other developing countries,
where information is seriously lacking, an alternative approach to maximise the
conservation of rare and endemic species is by identifying sites with high
diversity and endemism and protecting the habitat itself (Gaston 1996).
Need for future
research
Research
on land snails in India should focus on their distribution patterns, taxonomy
and ecology. Taxonomic expertise is
a basic foundation for estimation of global biodiversity and formulation of
policy on conservation of biological diversity (Golding & Timberlake 2002;
Budha 2005). One of the greatest
impediments for malacological research in India has been a severe lack of
trained malacologists. The
initiative such as All India Coordinated Project on Taxonomy (AICOPTAX) by
Ministry of Environment and Forests (MoEF) produced little work on molluscan
taxonomy. The recent collaborative
project “Developing land snail expertise in South and Southeast Asia” funded
under Darwin Initiative Project by DEFRA, UK, helped build capacity on land
snail taxonomy not only in India but also in Sri Lanka, Nepal, Laos, Thailand,
Malaysia and Vietnam (Naggs et al. 2006). However, more funds need to be allocated for capacity building in the
areas of taxonomy, natural history, ecology and biology of the species in
India. Developing databases on
ecology, breeding behaviour, distribution and other details of land snails
should be encouraged and made accessible in the public domain, which could
change the esoteric status of malacology. In recent years, there have been accidental introductions of alien and
invasive species into the Indian subcontinent. The impact of these invasive snails and
slugs such as Lissachatina fulica, Derocerus leave, Semiperulasp. on native land snail populations needs to be monitored. The introduced species generally occupy transformed habitats and their
agricultural/horticultural pest status is more of an issue than being a threat
to the native snails. However,
impact of invasive and pest species on native land
snails and on the economic damage they incur to agriculture and horticultural
crops needs to be assessed. For the
exotic invasive malacofauna of the Indian sub-continent to be controlled in a
timely way its status urgently needs to be assessed. Land snails such as the African Giant
Snail and others are hosts for the rat-lung
worm, which can transmit meningitis to humans. In India, we hardly have
any information on what percent of human population is affected by this
parasite; what are the health implications and how many species are carriers
for the same. Hence, research is
needed in this direction as well. Indian
land snails include lineages (Pulmonata and Caenogastropda) that diverged as
far back as the Devonian (416 to 359.2 million years ago) and there are a
number of deep independent lineages of ancient groups some of which are unique
to South Asia (Wade et al. 2006). Thus, research should also focus on the biogeographical patterns,
phylogeny and evolution of Indian land snail fauna. Further, studies to resolve the taxonomically problematic
groups such as Glessula through molecular phylogenetic applications or
through DNA barcoding should be initiated.
Conclusion
For
informed conservation measures to be implemented, detailed studies on land
snail systematics, on threats to survival and on identifying “hot-spots” for
narrow range endemics are urgently needed. Serious attention needs to be paid towards protecting remaining forested
areas, maintaining and possibly restoring connectivity, especially in the
tropical rain forests which support rich snail diversity (Emberton 1996). More funds need to be allocated to
capacity building in malacology. Land snail expertise is urgently needed
for economic reasons; awareness of native species will certainly help in
recognizing newly introduced exotic species allowing effective control or
management before they become invasive. Efforts should be made to establish snailariums in zoos in order to
create awareness about snails among people. Priority should be given to conserve
critical habitat for conservation of land snails. India should also start an
initiative such as the Frozen Arc Project(www.frozenark.org), where the viable cells of a number of near extinct species
could be stored for possible use in the future.
References
Aravind, N.A. (2005). Ecology of Land Snails of Western Ghats. PhD Thesis, Department of Applied Zoology, Mangalore University,
Mangalore, 182pp.
Aravind,
N.A. & F. Naggs (2012). Snailing up the
Canopies of Western Ghats, pp. 43–46. In: Devy,
M.S., T. Ganesh & A. Tripaty (eds.), Canopies of South Asia - A Glimpse.ATREE, Bangalore.
Aravind, N.A., K.P. Rajashekhar & N.A Madhyastha
(2005). Species diversity, endemism and
distribution of land snails of Western Ghats, India; Records of Western
Museum Supplement 68: 31–38.
Aravind, N.A., K.P. Rajashekhar & N.A. Madhyastha
(2008). Micromolluscs of Western Ghats, India: Diversity, distribution and
threats. Zoosymposia 1: 281–294.
Aravind, N.A., K.P. Rajashekhar & N.A Madhyastha
(2010). A review of ecological studies on patterns and processes of
distribution of land snails of the Western Ghats, India. Proceeding of
World Congress of Malacology, 222pp.
Bar-Yosef Mayer, D.E. (2002). Archaeomalacology:
Molluscs in former environments of human behaviour (1. An
Introduction to Archaeomalacology). 9th ICAZ Conference,
Durham.
Baur, B. & A. Baur (1993). Climatic warming due to thermal radiation from an urban area as
possible cause for the local extinction of a land snail. Journal of Applied Ecology 30: 333–340.
Bezemer,
T.M & K.J. Knight (2001). Unpredictable
responses of garden snail (Helix aspersa) populations to climate
change. Acta Oecologica 22: 201–208.
Boresma, D.P., P. Kareiva, F.W. Fagan, A.J. Clarak
& M.J. Hoekstra (2001). How good are endangered species recovery plans? Bioscience 51: 643–649.
Bouchet, P. (1992). Extinction and
preservation of species in the tropical world: What future for Molluscs? American
Conchologist: 20: 20–24.
Budha,
P.B. (2005). Nepalese
malacology trails behind “catch up”. Himalayan Journal of
Sciences 3: 9–10.
Burch, J.B. (1955). 1962 How To Know the Eastern Land Snails. Wm. C. Brown, Dubuque, 214pp.
Burner, A.G., E.G. Raymond, R.E.
Rice & da G.A.B. Fonseca (2001). Effectiveness of parks in protecting tropical biodiversity. Science 291: 125–128.
Cameron, R.A.D. (1998). Dilemmas of
rarity: biogeographical insights and conservation priorities for land mollusca. Journal of Conchology. Special
Pubication 2: 51–60.
Čejka,
T. & L. Hamerlík (2009).Land snails as indicators of soil humidity in Danubian woodland (SW Slovakia). Polish
Journal of Ecology 57: 741–747
Clark, J.A. & R.M. May (2002). Taxonomic bias in Conservation Research. Science297: 191–192.
Davison,
A. & S. Chiba (2008).Contrasting response to Pleistocene climate change by ground-living and
arboreal Mandarina snails from the oceanic Hahajima archipelago. Philosophical Transactions of the Royal Society of London.Series B: Biological Sciences 363: 3391–3400.
Deepak, V., K. Vasudevan & B.
Pandav (2010). Preliminary observation on the diet
of the cane turtle (Vijayachelys silvatica). Hamdaryad34: 166–168.
Dipti,
H. & N. Velho (2007). The need for studies on amphibians in India. Current
Science 92: 1032.
Dunk, J.R., W.J. Zielinski & H.K. Preisler (2004).Predicting the occurrence of rare mollusks in northern California forests. Ecological Applications 14: 713–729.
Emberton, K.C. (1996). Conservation
priorities for the forest flower invertebrates of the south
eastern half of the Madagascar evidence from two land-snail clades. Biodiversity and Conservation 5: 729–741.
Forys, E.A., C.R. Allen & D.P. Wojcikthe (2001). Likely cause of extinction of the tree snail Orhtalicus reses
reses (Say). Journal of Molluscan Studies67: 369–376.
Gaston, K.J. (1996). Biodiversity
congruence. Progress in Physical Geography 20:
105–112.
Gerlach, J. (2007). Short-term climate change and the extinction of the snail Rhachistia
aldabrae (Gastropoda: Pulmonata). Biology
Letters 3: 581–585.
Golding,
J.S. & J. Timberlake (2002).How taxonomists can bridge the gap between taxonomy and conservation science. Conservation Biology 17: 1177–1178.
Graveland,
J.R, van der WAL, J.H. van Balen & A.J. van Noordwijk (1994). Poor
reproduction in forest passerines from decline of snail abundance on acidified
soils. Nature 368: 446–448.
Gümüş, B.A. (2009). Anadolu’da
Gerçekleştirilen Arkeomalakolojik Çalışmalar. Paleontoloji-Stratigrafi Çalıştayı, 01–04 Ekim 2009,
Kemaliye, Erzincan (Sözlü Sunum, kitapçık, s. 22).
Herbert,
D.G. (1998). Molluscan
conservation in South Africa: Diversity, issues and priorities, pp.
61–76. In: Killeen, I.J., M.B. Seddon & A.M. Holmes(eds.). Molluscan Conservation: A Strategy for the 21st Century. Journal of Conchology Special Publication 2.Dorchester (UnitedKingdom): Conchological Society of Great Britain and Ireland,
Dorset Press.
Hotopp, K.P. (2002).Land snails and soil calcium in central Appalachian Mountain forest. South
Eastern Naturalist 1: 27–44.
Jha,
C.S., C.B.S. Dutt & K.S. Bawa (2000). Deforestation and land use changes in Western Ghats, India.Current Science 79: 231–238.
Killeen, I.J. & M.B. Seddon (2004). Molluscan
Biodiversity and Conservation. Journal of Conchology Special
Publication 3: 172.
Lydeard, C., R.H. Cowie, W.F. Ponder, A.E. Bogan, P.
Bouchet, S.A. Clark, K.S. Cummings, T.J. Frest, O. Gargominy, D.G. Herbert, R.
Hershler, K.E. Perez, B. Roth, M. Seddon, E.E. Strong & F.G. Thompson (2004).The Global Decline of Non-marine Molluscs. BioScience54: 321–330
Madhyastha,
N.A., R.G. Mavinkuruve & S.P. Shanbhag (2004). Land snails of Western Ghats. In: Gupta, A.K., A. Kumar
& V. Ramakantha (eds). ENVIS Bulletin: Wildlife and Protected Areas,
Conservation of Rainforest in India 4: 143–151.
Mavinkurve, R.G., S.P. Shanbhag & N.A. Madhyastha (2004a). Checklist of land
snails of Karnataka. Zoos’ Print Journal 19(11):
1684-1686.
Mavinkurve, R.G., S.P. Shanbhag & N.A. Madhayasta
(2004b). Non-Marine mollusks of Western Ghats. Zoos’
Print Journal 19(12): 1708–1711.
Mavinkurve , R.G., S.P. Shanbhag & N.A.
Madhayasta (2005). The land snails of Sharavati Wildlife Sanctuary. Records
of Zoological Survey of India 104: 123–131
Moritz,
C., K.S Richardson, S. Ferrier, G.B Monteith & J. Stanisic (2001). Biogeographical
concordance and efficiency of taxon indicators for establishing conservation
priority in a tropical rainforest biota. Proceedings
of the Royal Society of London B. 268: 1875–1881.
Naggs, F. (1997). William
Benson and the study of land snails of British India and Ceylon. Archives of Natural History 24: 37–88.
Naggs,
F. & D. Raheem (2005).Sri Lankan snail diversity: faunal origins and future prospects. Records of the Western Australia Museum, Supplement No. 68:
11–29.
Naggs, F., S. Panha & D. Raheem
(2006). Developing
Land Snail Expertise in South and Southeast Asia, a New Darwin Initiative
Project. The Natural History Journal of Chulalongkorn
University 6: 43–46
Pearce-Kelly,
P., D. Clarke, C. Walker & P. Atkin (1997). A conservation programme for the partulid
tree snails of the Pacific region. Memoirs of
Museum of Victoria 56: 431–433.
Ponder, W.F. (1997). Conservation Status, Threats and Habitat requirements of Australian
Terrestrial and Freshwater Mollusca. Memoirs of
Museum of Victoria 56: 421–430.
Pounds,
J.A. & M.I. Crump (1994).Amphibian declines and climate disturbance: the case of the golden toad and the
harlequin frog. Conservation Biology 8: 72–85.
Pounds,
J.A., M.P.L. Fogden & J.H. Campbell (1999). Biological response to climate change on a tropical mountain. Nature 398: 611–615.
Prathapan,
K.D., D.R. Priyadarsanan, T.C. Narendran, C.A. Viraktamath, K.A.
Subramanian, N.A. Aravind & J. Poorani (2006). Biological Diversity Act,
2002: Shadow of permit-raj over research. Current Science 91:
1006–1007
Raheem,
C.D., F. Naggs, R.C. Preece, Y. Mapatuna, L. Kariyawasam & P. Eggleton
(2008). Strucutre and conservation of Sri Lankan land- snail assemblages in
frgamented lowland rainforest and village home gardens. Journal of Applied Ecology 45: 1019–1028.
Raheem, C.D., F. Naggs, N.A. Aravind & R.C. Preece
(2009). An Illustrated Guide to The Land
Snails of Western Ghats of India. The Natural History
Museum London.
Raheem, C.D., F. Naggs, P.D.J. Chimonides, R.C. Preece
& P. Eggleton (2009). Fragmentation and pre-existing species turnover
determine land-snail assemblages of tropical rain forest. Journal
of Biogeography 36: 1923–1938.
Rajashekhar, K.P. & N.A. Aravind (in press). Perturbation in the pattern of land snail diversity due to
anthropogenic disturbance to wet evergreen forests of the Western Ghats, India.In: Priyadarsanan, D.R.,
M.S. Devy, K.A. Subramanian, N.A. Aravind & N. Seena (eds.).Invertebrate Diversity and Conservation in the Western Ghats. ATREE,
Bangalore.
Ramakrishna
& S.C. Mitra (2002). Endemic land molluscs of India. Records of
Zoological Survey of India, Occasional Paper 196: 1–65
Ramakrishna, S.C. Mitra & A. Dey
(2010). Annotated Checklist of Indian Land
Mollusc. Zoological Survey of India,
Kolkata, 359pp.
Rao, H.S.
(1924). Asiatic Succineidae in the Indian Museum. Records of Indian Museum 26: 367–408.
Régnier, C.,
B. Fontaine & P. Bouchet (2009). Not Knowing, Not Recording, Not Listing: Numerous Unnoticed Mollusk Extinctions. Conservation Biology 23:
1214–1221.
Richards,
P.M & A. Davison (2010).Adaptive Radiations: Competition Rules for Galápagos Gastropods. Current
Biology 20: R28–R29.
Satyamurti,
S.T. (1960). The land and freshwater mollusca in the collection of the Madras
Government Museum. Bulletin of the Madras
Government Museum, Madras.
Schilthuizen, M., T-S.Liew, B.B.
Elhahan & I. Lackman-Ancrenaz (2007). Effects of Karst Forest Degradation on Pulmonate and Prosobranch
Land Snail Communities in Sabah, Malaysian Borneo. Conservation
Biology 19: 949–954.
Seddon, M. (1998). Red listing of
Molluscs: a tool for conservation? Journal of Conchology (Special
Publication) 2: 27–44.
Shimek, B. (1930). Land Snails as
Indicators of Ecological Conditions. Ecology 11:
673–686.
Simone, L.R.L. (1999). Mollusca
Terrestres, p. 5: 3–8. In: Brandão, C.R. & E.M.
Cancello, (Org.). Biodiversidade do Estado de São Paulo, Brasil: síntese do
conhecimento ao final do século XX: Invertebrados Terrestres. FAPESP Editora,
São Paulo, São Paulo, Brasil.
Sodhi, N.S. (2008).Tropical biodiversity
loss and people- a brief review. Basic and Applied Ecology9: 93–99.
Solem, A.
(1984). A world model for land snail diversity and abundance. In:
Solem A. & A.C. van Bruggen (eds). Worldwide snails: Biogeographical
Studies on Non-Marine Mollusca. E.J. Brill/Dr W.
Backhuys, Leiden, 289pp.
Sólymos,
P. & Z. Fehér
(2005).Conservation prioritization using land snail distribution data in Hungary. Conservation Biology 19: 1084–1094.
Sternberg,
M. (2000).Terrestrial gastropods and experimental climate
change: A field study in a calcareous grassland. Ecological
Research 15: 73–81.
Subbarao,
N.V. & S.C. Mitra (1979).On the land and freshwater molluscs of Pune district, Maharastra. Records of Zoological Survey of India 75: 1–37.
Thomas,
C.D., A. Cameron, R.E. Green, M. Bakkenes, L.J. Beaumont, Y.C. Collingham,
B.F.N. Erasmus, M.F. de Siqueira, A. Grainger, L. Hannah, L. Hughes, B.
Huntley, A.S. van Jaarsveld, G.F. Midgley, L. Miles, M.A. Ortega-Huerta, A.T.
Peterson, O.L. Phillips & S.E. Williams (2004). Extinction risk from
climate change. Nature 427:
145–148
Wade, C.P.,
P.B. Mordan & F. Naggs (2006).Evolutionary relationships among the Pulmonate land snails and slugs. Biological Journal of the Linnaean Society 87: 593–610.