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SOFÍA
JÁRVINEN
EDITDRS
ANIMAL
SCIENCE,
ISSUES
AND
PROFESSIONS
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ANIMAL
SCIENCK,
ISSUKS
AINU
PROKESSIONS
SNAILS
BlOLOGY,
ECOLOGY
AND
CONSERVATION
EMIL
M.
HÁMÁLÁINEN
AND
SOFÍA JÁRVINEN
EDITORS
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LIBRARY
OF
CONGRESS
CATALOGING-IN-PUBLICATION
DATA
Snails
:
biology, ecology,
and
conservation
/
editors,
Emil
M.
Hdmdldincn
and
Sofía
Jdrvincn.
p.
cm.
Includes
Índex.
ISBN
978-1-62100-788-3
(hardcover)
1.
Snails.
2.
Snails—Ecology.
3.
Snails-Conservation.
I.
Hdmdldincn,
Emil
M. II.
Jdrvinen,
Sofía.
QL430.4.S5662012
594'.3176-dc23
2011038567
d
bp
&f0pa
Obelen
ce
Publishers,
<§?MC.
CONTENTS
Preface
Chapter
1
Chaptcr
2
vü
Chapter
3
Chapter
4
Chapter
5
Neurotransmitters,
Benthic
Diatoms
and
Metamorphosis
in a
Marine
Snail
EsíherM.
Leise
andLawrence
B.
Cahoon
Parasitism
as a
Determining
Factor
of
Morphology
and
Behavior
in
Freshwater
Snails
-
With Special
Emphasis
on the
Great
Pond
Snail
Lymnaea
Stagnalis
(L.)
Ari
Voutilaincn
Melanoides
tuberculata:
The
History
of
an
Invader
Roberto
E.
Voglcr,
Verónica
Núñez,
Diego
E.
Gutiérrez Gregoric,
Ariel
A.
Bcltramino
and
Juana
G.
Peso
Cone
Snail Biology, Bioprospecting
and
Conservation
Sébastien
Dutertre
and
Richard
J.
Lewis
The
Role
of the
Transcriptional
Regulator
Snail
in
Development
and
Cáncer
Biology
Chun-Yu
Lin, Pei-Hsun Tsai,
Kevin
P-H
Lee,
Jhen-Jia Fan, Chithan
C.
Kandaswami,
Peí-
Wen
Hsiao
and
Ming-Ting
Lee
45
65
85
105
64
Ari
Voutilainen
and
population density
of its
snail
host
Lymnaea stagnalis
in
lakes
and
ponds
in
Finland.
Aquatic
Ecology,
43,
351-357.
Voutilainen,
A.,
Huuskonen,
H.
&
Taskinen,
J.
(2010). Penetration
and
migration
success
of
Diplostomum
spp. cercariae
in
Arctic
charr.
Journal
of
Parasitology,
96,
232-235.
Wilson,
R. A. &
Denison,
J.
(1980).
The
parasitic castration
and
gigantism
of
Lymnaea
tnmcatula
infected with
the
larval stages
of
Fasciola hepática.
ZeitschriftfúrParasitenkunde,
61,
109-119.
Wullschleger,
E. &
Jokela,
J.
(1999). Does
habitat-specific
variation
in
trematode
infection risks
influence
habitat distribution
of two
closely
related
freshwater snails? Oecologia, 121, 32-38.
Zbikowska,
E.
(2003).
The
effect
of
Digenea larvae
on
calcium content
in the
shells
of
Lymnaea stagnalis (L.) individuáis. Journal
of
Parasitology,
89,
76-79.
Zbikowska,
E.
(2005).
Do
larvae
of
trichobilharzia
szidati
and
echinostoma
revolutum
genérate behavioral fever
in
lymnaea
stagnalis
individuáis?
Parasitology Research,
97,
68-72.
Zbikowska,
E.
(2011).
One
snail
-
three Digenea species,
different
strategies
in
host-parasite
interaction. Animal
Biology,
61,
1-19.
Zbikowska,
E. &
Zbikowski,
J.
(2005).
Differences
in
shell
shape
of
naturally
infected
Lymnaea stagnalis (L.) individuáis
as the
effect
of the
activity
of
digenetic
trematode larvae. Journal
of
Parasitology,
91,
1046-1051.
Zbikowska,
E. &
Nowak,
A.
(2009).
One
hundred
years
of
rcsearch
on the
natural
infection
of
freshwater
snails
by
trematode larvae
in
Europe.
Parasitology Research,
105,
301-311.
Zbikowska,
E.,
Kobak,
J.,
Zbikowski,
J. &
Kajclewski,
J.
(2006).
Infestation
of
Lymnaea stagnalis
by
digenean
flukes
in the
Jeziorak Lake. Parasitology
Rcsearch,
99,
434-439.
In:
Snails: Biology, Ecology
and
Conservation
ISBN:
978-1-62100-788-3
Editors:
E.
Hámaláinen
and S.
Járvinen
©
2012 Nova Science Publishers, Inc.
Chapter
3
MELANOIDES
TUBERCULATA:
THE
HlSTORY
OF
AN
INVADER
Roberto
E.
Vogler,1'2'*
Verónica
Núñez,1'2
Diego
E.
Gutiérrez
Gregorio,1'2
Ariel
A.
Beltramino1'3
and
Juana
G.
Peso4
División Zoología
de
Invertebrados, Facultad
de
Ciencias Naturales
y
Museo,
Universidad Nacional
de la
Plata, Argentina
Consejo Nacional
de
Investigaciones
Científicas
y
Técnicas
(CONICET),
Argentina
'Agencia
Nacional
de
Promoción Científica
y
Tecnológica
(ANPCyT),
Argentina
Laboratorio
de
Plancton
y
Bentos,
Facultad
de
Ciencias
Exactas,
Químicas
y
Naturales, Universidad Nacional
de
Misiones, Argentina
ABSTRACT
The
thiarid
snail Melanoides
tuberculata
(Müller, 1774)
has
demonstrated
an
impressive
capacity
to
invade
a
range
of
tropical
and
subtropical
aquatic
ecosystems. This species
exhibits
characteristics
often
mentioned
to
increase
invasión
ability.
It
is an
ovoviviparous
species
with
parthenogenetic
reproduction
and
it
has
lile
hislory
traits
characteristic
of 'r'
strategists
(early
maturity,
66
Kobcilo
li.
Voglcr,
Vcmnira
Nuiuv,
i-|
al
relative
short
lite
span,
iteroparity
and
higli
fccimdily).
I
liis
is a
euryoic
species,
but
temperature
may
be an
imporlanl
dctemiinant
oí"
ils
distribution.
Melanoides
tuberculata
has
been
reported
in
literature
as a
nuisance
species
in
some
tropical
fish
aquaria
and in
rice paddies,
and
invading
the
heat
exchanger
of an
electric
power-plant,
causing
complete
clogging
of the
filters.
Molecular studies
suggest
an
Asian origin
for
numerous
morphs
of
this
species,
followed
by
introduction
to
both África
and
America
(from
northern
Argentina
to
southeast USA).
The New
World
was
invaded
several
times
by
several morphs
of
M.
tuberculata
from
a
large
number
of
Oíd
World
sources.
These
morphs
currently
coexist
and new
morphs
were
created
in
situ
by
hybridization
(as a
consequence
of
rare
events
of
sexual reproduction),
and
there
is
evidence
of
competitive
replacement
between
them.
In
some
places,
no
impact associated
with
this
species
on the
native
molluscan fauna
has
been observed,
but in
Brazil
and
Argentina,
preliminary
data
indícate
that
native
populations
of the
Thiaridae
were
replaced
by
populations
of M
tuberculata.
Although
M.
tuberculata
is
used
as a
control
of
schistosomiasis
(by
competitive replacement
of the
planorbid
Biomphalaria
glabrata),
it
also
plays
an
important
role,
as an
intermedíate
host,
in the
epidemiology
of
several trematode
species
which
can be
harmful
to a
number
of
vertébrate
species,
including
man.
Despite
the
importance
of
this
species
(it can
cause
ecological risks,
health
and
economic),
much
remains
yet to be
known
and
done
to
prevent
its
spreading.
The
summarized infonnation
of M.
tuberculata
in
this
chapter
is
expected
be
useful
to
shed
light
on
this
species,
propose
new
hypotheses,
and to
design
plans
to
control
the
invasión
and its
consequences.
INTRODUCTION
The
freshwater
gastropods
are a
diverse group that
comprises
in
continental
waters
ca.
4,000
valid
described species,
exhibiting
a
wide range
of
life
history
traits, reproductive modes,
and
ecological
requirements.
Among
freshwater snails, some
have
gained special attention
as
"invasive
species". This
is due to
economic, ecologic and/or sanitary consequences
where
the
pulmonates (Physidae,
Lymnaeidae,
Planorbidae)
and
parthenogenetic
species,
such
as
Melanoides tuberculata (Müller, 1774)
are
listed
among
the
most
successful
colonizers
(Strong
et
al.,
2008).
In
particular,
M.
tuberculata constitutes
a
good
example
of
how
the
combination
of
life
history traits, genetic background
and
human
facilitated
I
ulu-iciiliila
67
.li.|KT.sal
can
conlribnk-
lo
llu-
mliodui-lion
and
establishment
of new
|H>pulalions
ol'lhc
species
in
a
novel
cnvironmcnt.
Which
Characteristics
of
Melanoides
tuberculata
Make
it a
Good
lnvadcr?
Invasive
species (species that
establish
self-sustaining
populations outside
i>f
their
native range)
are
said
to
exhibit
some
Characteristics,
often
mentioned
lo
mercase
invasión ability (Lodge, 1993). These include:
r-selected
traits,
high
dispersal rate, single parent-reproduction,
high
genetic variability,
phenotypic
plasticity, large native range,
eurytopy
and
polyphagy.
Melanoides
luhcrculata
exhibits most
of
mese
Characteristics.
Morphologic
and
Genetic
Characteristics
Melanoides tuberculata
is an
operculated
snail
presenting
extensive
phenotypic
variation
in
terms
of
shell
shape, sculptures
and
pigmentation,
and
allows
for the
definition
of
discrete entities
referred
to as
morphs (Pointier,
1989;
Escobar
et
al.,
2009). This morphological variation
is
inheritable
and
more than
27
morphs
are
actually known (Pointier
et
al.,
1992; Facón
et
al.,
2003).
Currently, some
of
mese morphs co-exist,
and new
morphs were
reported
to be
created
by
hybridization
with
competitive replacement between
them
(Facón
et
al.,
2005). Each
morph
usually
corresponds
to a
single genetic
clone
or
parthenogenetic
line,
with
few
exceptions,
and
morphs
are
separated
by
considerable genetic distances (Samadi
et
al.,
1998,
1999,
2000). However,
clonal
diversity
in M.
tuberculata
seems
to not be the
product
of an
adaptation
to
a
particular ecological niche,
as the
clones
are
generalist
and the
species
is
considered
to fít the
"General
Purpose
Genotype"
(Lynch, 1984),
in
which
the
same clone
can
successfully colonize
a
variety
of
habitáis.
Such
is the
case
of
two
clones
co-occurring
in
all
the
freshwater
habitats
of the
French
Polynesian
Islands
(Myers
et
al.,
2000; Vrijenhoek
and
Parker Jr., 2009).
Additionally,
sexual
dimorphism
and
phenotypic plasticity
(often
referred
to
as
ecophenotypic
variation
when
the
precise environmental variables
involved
are
unknown)
are
proposed
as
sources
influencing
the
morphology.
The
fonner, detected
as a
marked within-morph variation between males
and
females
in
populations when males exist,
and the
latter
as an
extensive spatial
and
temporal variation within clones, representing alterations
to the
phenotypic
expression
of
particular
genotype
due to an
environmental
variation
(Samadi
et
al.,
2000).
6S
Robalo
l;.
Voglcr,
Verónica
Nmuv,
i-|
al.
Dict
Composition
The
diet
of
this
snail
consists
mainly
of
benthic,
cpiphylic
and
periphytic
algae;
bacteria, organic
partióles
deposited
on
trie
sediment;
and
decaying
plañís
(Dudgeon, 1989; Pointier
et
al,
1991;
Ben-Ami
and
Heller, 2005).
Gut
analyses
indícate
that
M.
tuberculata
indiscriminately
consume
microalgae
(e.g. diatoms)
and fine
detritus
from
solid
surfaces (Subda
Rao and
Mitra,
1982).
Furthermore,
the
species
was
observed
to be
able
to
benefít
from
feeding
on
dead animal
tissue
(Rader
et
al.,
2003). Thus,
it
appears that
M.
tuberculata
is a
generalist herbivore
and
detritivore that
will
feed
on a
variety
of
plant
and
animal tissue.
Habitat
Requirements
This snail inhabits
a
wide range
of
aquatic environments, either lentic
or
lotic,
at
depths ranging between 0.25
and 3.7 m
(Murray,
1975; Suriani, 2006;
Vasconcelos
et
al.,
2009; Peso
et
al.,
2011).
It was
found
to be
associated with
various
types
of
substrates (rock,
gravel,
mud,
clay
and
sand, Figure
1), and it
is
often
associated with macrophytes
and
substrates introduced
by man
(e.g.
plástic, wood)
(Da
Silva
et
al.,
1994).
Its
presence
has
been detected
in
rivers
and
streams
of
different
flow
rales,
lakes,
reservoirs,
dams,
and
levees.
The
ability
of M.
tuberculata
to
resist displacement
by
rapid currents
is
greater
than
South American native thiarids
(Aylacostoma
spp.)
(Quintana
et
al.,
2001-2002).
Nonetheless,
this snail
was
vastly diminished
or was
absent
in
steep rivers
with fast
current
velocities (Pointier
et
al.,
1994),
and it can
reach
high
densities
in
ponds
and
gently
ílowing
waters (Pointier
et
al.,
1993).
Although
M.
tuberculata
is
abundant
in
some
swiftly
ílowing
cañáis (42-51
cm
s"1),
it
primarily
occurs
in
macrophyte
beds where current velocities
are
reduced;
being
also
abundant
in
springheads,
marshes,
and
flowing
channels
with
current
velocities
lower
than
15 cm
s"1
(Dundee
and
Paine,
1977;
Rader
et
al.,
2003). Moreover,
it is
able
to
colonize recent water bodies
on a
permanent
basis
in a
short period
of
time (Facón
et
al,
2004).
Melanoides
tuberculata
is
able
to
exploit environments with different
degrees
of
eutrophication (from oligotrophic
to
hypereutrophic).
Moreover,
it
is
tolerant
to
low
levéis
of
dissolved
oxygen
(Neck,
1985)
and is
also
highly
resistant
against pollution, such
as
what
one
might expect
in an
urban
environment (Dudgeon,
1989).
It has a
great resistance
to
desiccation, making
it
able
to
colonize temporary aquatic environments (Dudgeon,
1986).
In
this
regard, Pointier
et al.
(1992) argüe that this snail
is
absent
or
rare
in
periodically
dry
environments.
C|CN
I
69
_
Figure
1.
Shells
of
M.
tuberculata
on
sand.
However, other studies found that
M.
tuberculata
is
resistant
to a
lack
of
water
for
prolonged periods
of
drought
(i.e.
26
months),
and
showed that
the
survival
rate
of an
individual
will decrease with
an
increase
in
drying
time
(Abílio, 2002).
Melanoides tuberculata
can
colonize environments
within
a
wide range
of
salinity
and
height..
Live
specimens
have been captured
in
waters from
freshwater
environments
at
1,500
m
altitude,
up to
estuarine waters with
salinity
levéis
as
high
as 33 ppt
-parts
per
thousand- (Russo, 1973;
Berry
and
Kadri,
1974;
Roessler
et
al.,
1977;
Starmühlner,
1979; Dudgeon, 1986,
Wingard
et
al.,
2008).
However, recent
temperature
tolerance studies which predict
the
species'
potential
distribution (Mitchell
and
Brandt,
2005),
as
well
as
previous
data
(e.g. Murray, 1971; Neck, 1985),
indícate
that temperature
may
be an
important
determinan!
of its
distribution, suggesting that waters with
temperaturas
<18°C,
or
greater than
32°C,
will probably
not
support
M.
tuberculata.
It
has
been
registered
with
greatest
abundance
between
21°C
and
30°C
(Ismail
and
Arif, 1993; Laamrani
et
al.,
1997; Duggan, 2002),
and has
been
found
hibernating
in the
wild
during
the
colder months (Livshits
and
Fishelson, 1983). Nonetheless,
after
one
year
at
constant
temperaturas
in an
aquarium
(25°C), these snails
had
lost
their hibernating habits (Livshits
and
Voglcr,
WiV>iiir;i
NIIIHV,
rl
,
Fishelson,
1983).
In
arcas
where
dayliinc
walcr
tcinpcralurcs
can
cxceed
35°C,
M.
tuberculata
is
primarily
crepuscular,
or
nocturnal
spcnding
most
of the
daylight
hours buried
in
mud
or
sand
(e.g.
Subda
Rao and
Mitra, 1982;
Pointier, 1993).
In
captivity,
M.
tuberculata showed nocturnal habits, with most
of the
individuáis
staying huddled in a
córner
of the aquarium or buried in the sand
during
the
day, increasing
its
activity
by
decreasing
light
intensity (Livshits
and
Fishelson,
1983).
Additionally,
a
study
assessing
the
effects
of
predation
risk (via
chemical
cues)
and
conspecific
density
on
temperature
selection
of M
tuberculata,
showed that this species seems
to
modify
its
thermoregulatory
behavior when exposed
to
chemical cues
(i.e.
predation risk).
The
study
also
suggests that snails favor predator avoidance over
thermal
selection when
presented
with both demands (Gerald
and
Spezzano Jr., 2005).
Life
History
and
Reproductive
Characteristics
This prosobranch
snail
is an
ovoviviparous,
gonochoric
species with
polyploidy
races
(Ben-Ami
and
Heller, 2008; Escobar
et
al,
2009).
Its
reproductive
system
is
extremely simple
in
structure
and
histology, lacking
all
the
glandular
developments
common
in
most
mesogastropods
(Berry
and
Kadri,
1974). Their
eggs,
which
are
small
(50 X 70
um),
pass
into
a
cephalic
brood-pouch
where
they develop
to
juveniles before emergence, with
up to 6
shell
whorls.
The
number
of
dcveloping
young
in the
brood-pouches
varíes
from
1 to 91
(Berry
and
Kadri,
1974;
Subda
Rao and
Mitra,
1982;
Livshits
and
Fishelson,
1983;
Pointier
et
al.,
1993),
different
from
Aylacostoma
species
that
have
an
average
of
only
3 to 5
(Quintana
et
al.,
2001-2002).
However,
other
authors
found
even
higher
numbers
of
embryos,
counting more than 450,
noting that juveniles
can
reinain
within
the
adventitious
pouch
for
long
periods
of
time
as a
result
of
inhibition
of
their
reléase during adverse scason
(Dudgeon, 1986; Bedé, 1992).
Moreover,
although
the
survivorship
of
newly
born
snails
has not
been
measured,
brooding their young
and
releasing
them
at
a
larger
size
may
be due to a
strategy
designed
to
enhance their survivorship
(Stearns, 1977).
Juveniles
commonly
emerge
from
the
brood-pouch most between
nightfall
and
midnight,
and
normal emergence
seems
to
require
a
diurna!
alternation
of
light
and
dark.
In
continuous darkness, brood-pouch counts increased
markedly,
perhaps
as a
result
of
greater activity
and
feeding during darkness
(Berry
and
Kadri,
1974).
Thus,
the
number
and
size
of
juveniles
in the
brood-
pouches varies
in
different environments,
and
generally
increases with
the
shell height
of the
parents,
implying
variation
in
fecundity (Berry
and
Kadri,
ni
ni|.
I
nlirii
ul.il.l
71
I''74;
Livshils
and
l'islirl:.c>n,
l'>Sl).
Ncvvly
born
M.
liihercitlalu
measurc
IK-IWCCII
1.5 lo 2.0
inni
ni
Irni'lli,
grow
al a
rale
of
about
2.5
mm
per
month
muí
can
bcgin
rcpioduclion
wilh
an
inilial
shell height
of 8.3 mm
after
90
days
oí
lile
(Berry
and
Kadri,
1974;
Livshits
and
Fishelson, 1983; Dudgeon, 1986;
l'ointicr
et
al.,
1993; Quintana
et
al.,
2001-2002). However, Ben-Ami
and
llodgson
(2005) found embryos
in
snails
as
small
as 7 mm in
length. Snails
¡'.reaten
than
25 mm
stop
producing
gametes,
but can
continué
to
grow
(1
jvshits
and
Fishelson,
1983).
Average adults
of M
tuberculata
may
grow
up
lo
80 mm (Murray,
1975),
but
they generally vary
in
size between
20 to 40
mm
(Berry
and
Kadri, 1974; Dudgeon, 1982; Livshits
and
Fishelson, 1983;
Ncck,
1985;
Pointier, 1989).
This
species
has an
average lifespan
of
2-3.5 years (Freitas
et
al.,
1987;
Hcdé,
1992).
It
presents with
high
birth
and
low
mortality
rales,
so it can
double
its
number
of
individuáis
in two
weeks (Abílio, 2002). Also,
it is
able
lo
maintain
high population densities
for a
long time; that
is,
intraspecific
competition
does
not
seem
especially severe (Pointier
et
al.,
1991).
In
fact,
Ihcre
are
frequent reports
of
population density between 2,000
to
15,000
individuáis
m
(Freitas
et
al.,
1987;
Lévéque, 1972; Pointier
and
McCullough,
1989;
Thomas
and
Tait,
1984),
reaching
over
50,000
individuáis
m2
in
some
cases (Murray
and
Wopschall,
1965; Roessler
et
al.,
1977).
An
importan!
issue
to
consider
is
that most populations reproduce
primarily
through
apomitic
parthenogenesis
(Jacob, 1957, 1958; Berry
and
Kadri,
1974).
Additionally,
some populations consist
of
only females, with
the
existence
of but a few
sterile males (Dudgeon, 1986). However, evidence
of
sexual reproduction
has
been found
in
populations where
male
frequencies
reached
up to 66%
(Livshits
and
Fishelson, 1983; Heller
and
Farstey, 1990;
Samadi,
1998, 1999; Ben-Ami
and
Heller, 2005). Sexual reproduction
was
suggested
by
Heller
and
Farstey (1990), based
on the
evidence
of a
higher
frequency
of
fertile
males
combined
with
the
higher
genetic
diversity
of
bisexual
populations (Ben-Ami
and
Heller,
2005,
2007).
DlSTRIBUTION
AND
INVASIÓN
Native
Distribution
There
is
still
some considerable uncertainty regarding
the
native
distribution
of M.
tuberculata.
The
species
was
described
from
the
Coromandel
Coast
of
India
in
1774
and its
distribulion,
in
publications
in the
Vof.lcr,
Vcróiiii-a
NI'IIUV,
i-l
al.
early
2ü"
ccntury,
inckides
the
intertropical
bell
oí'thc
Oíd
World
i
rom
África
to
Southeast
Asia
(Pilsbry
and
Bequaert,
1927;
l;acon
et
al.,
2003;
Escobar
et
al.,
2009).
Melanoides
tuberculata
is
characteristic
of
South Asia, Indochina,
the
Philippines
and
South
Pacific
islands, India, Arabia,
much
of
África,
Madagascar
and
northern
Australia.
Furthermore,
it is
also
found
in
European
Mediterranean
countries
and in
environments
consisting
of the hot
springs
in
Austria,
Germany,
Czech
Republic, Slovakia,
and
Hungary
(Quintana
et
al.,
2001-2002; Rader
et
al.,
2003).
Non
Native
Área:
An
Example
from the New
World
The
existence
of
populations
of M
tuberculata
on the
American Continent
has
been known since
the
mid-20th
century (Quintana
et
al.,
2001-2002),
and
involves
a
striking anthropogenic
dissemination
process. This
is
thanks
to
múltiple
introductions,
mainly
as the
result
of the
trade
of
aquarium
plants
(Madsen
and
Frandsen,
1989),
not
excluding
the
possible
introduction
through
animal
vectors such
as
birds,
fish
and
mammals (Maguire,
1963;
Correa
et
al.,
1970;
Amaya-Huerta
and
Almeyda-Artigas,
1994;
Escobar
et
al.,
2009).
The
first
record
of the
species
on the
American Continent comes from
North America, where
it
was
probably
introduced
by the
aquarium
industry
in
the
1930's
(Murray,
1971).
By the
mid-1960's
M.
tuberculata
was
reported
from
Texas, Arizona (USA), followed
by a
rapid expansión
in
nearly
all
American countries (Rader
et
al.,
2003; Wingard
et
al.,
2008).
However,
introduction
from
the
Oíd
World
to the
American Continent
was not a
unique
and
isolated event. Recent
genetic
studies
demonstrated
than
at
least
six
independen!
founding
events
occurred,
in
which
the
central
área
of the New
World
was
invaded
by
African
lineages;
and the
south
of the
American
Continent;
as
well
as
part
of
África,
by
Asian lineages (Facón
et
al.,
2003;
Vogler
et
al.,
2008).
Today,
the
species
is
established
or
reported
in
almost
all of the
regions
between
north
Argentina
and
Florida,
USA
(Peso
et
al,
2011),
including
the
West Indies,
as
well
as
Venezuela, Colombia,
Perú,
Brazil,
and
Paraguay
(Escobar
et
al.,
2009;
Peso
et
al.,
2011).
In
the
most
of the
invaded countries,
the
origin
of
their introductions
remains unknown. However,
according
to the
country
in
which
the
species
was
recorded,
different
suggestions about
its
origin
of
introduction have been
made.
For
example,
the
origin
in
Brazil
is
suggested
to
probably
be
linked
to
the
plant
and
freshwater ornamental
fish
trade, given
the first
record
of M
Mi-l.mniil.
I
nli.
i,
ul.ii.i
73
iiihi'rciilíiUi
in
llie
slale
oí
Sao
l'aulo
was in
aquarium
hobbyist
stores
in the
i
ilv
oí
Sanios
(Fernandez
el
al.,
2003).
In
contras!,
in
Argentina
and
Paraguay,
ilu-
origin
of
introduction
is
suggcsled
lo be
linked
to
passive distribution
down
the
Paraná
Rivcr
(as
il
llows
from
Brazil), perhaps
on
floating
\n
such
as
macrophytes,
which provide
a
vehicle
for
rapid
downstream
dispersa!
(Peso
et
al.,
2011).
Nevertheless,
in
Argentina,
the
introduction
via
i
IK-
commercial
trade
was
also
recently reported,
due to the
species
has
kvome
widely available
in pet
shops
and is
being
sold
on the
Internet
((iuticrrez
Gregoric
and
Vogler, 2010).
EXISTING
AND
POTENTIAL
IMPACT
ES
NON-NATIVE
ÁREAS
I
mpacts
on
Native
Fauna
The
ability
of M.
tuberculata
to
reach high
densities,
combined with
a
large
body size, suggests that competition between
this
species
and
other snails
inight
be
severe;
to the
advantage
of M.
tuberculata
(De
Freitas
and Dos
Santos,
1995).
Several studies
in the New
World, where
the
species have
become
abundant, recorded
a
significant
density decline
of
some
native
gastropods.
In Rio de
Janeiro, indigenous
Fornácea
Hneata
(Spix, 1827)
(Ampullariidae)
and
Biomphalaria
glabrata
(Say,
1818)
appear
to be
affected
by
M.
tuberculata (Fernandez
et
al.,
2001). Also
in
Brazil, abundant
populations
of
Aylacostoma
tenuilabris (Reeve, 1860) (Thiaridae)
on the
Tocantins
River, have been replaced
by
dense populations
of M.
tuberculata
(Fernandez
et
al.,
2003).
In
Argentina
and
Paraguay,
replacements
of
other
thiarids
species
was
predicted
after
M.
tuberculata
was
reported
for the first
time
(Quintana
et
al.,
2001-2002),
but no
experimental study
has
been
performed.
However,
it is
possible that native
communities
in the
invaded
aquatic
systems
may
actually be
impacted
(Peso et
al.,
2011).
Roessler et al.
(1977) found that
the
growth
and
reproduction
of a
Florida
snail,
Neritinia
virgínea
(Linnaeus,
1758), declined
in the
presence
of M.
tuberculata,
presumably because
of
resource competition (Rader
et
al.,
2003).
Also,
several
reports have documented
the
reduction,
and
even disappearance,
of
populations
of the
planorbid snails,
Biomophalaria
glabrata
and B.
straminea
(Dunker,
1848),
parallel with
the
establishment
of M.
tuberculata
in
Brazil
and
the
Caribbean (Pointier
and
McCullough, 1989; Pointier
et
al,
1994;