© Biospeologica Bibliographia - Publications 2010-2

© Biospeologica Bibliographia
Publications 2010-1
Page 33 sur 116
traits in both subspecific taxa and raised them to a species level.
Moreover, G. Karaman also reported on coexisting populations of N.
krameri and N. spinulifemur inhabiting northern Istra Peninsula and
Italian Venezia Giulia lacking crossbreeds. More recently, we
distinguished three distinct, geographically well-delimited morphs of N.
krameri s. str. that can be identified on a basis of setal patterns on
gnathopods in adult specimens. Despite the congruence between
morphological and geographic data, no taxonomic conclusions were
made in that study. Here we approached the problem using molecular
data. Newly obtained 28S rDNA (nuclear) and COI (mitochondrial)
sequences for 19 specimens from 11 localities were aligned with
published sequences and subjected to a phylogeny test. Results show a
clear separation of specimens into two strongly supported clades that
match with geographical division and agree, to some extent, with the
distribution of setal patterns. It is evident that gene flow between some
populations is restricted, probably due to poor dispersal abilities in a
geologically diverse environment, which supports the idea of N. krameri
being in the course of speciation and perhaps also morphological
differentiation. All datasets justify hypothesizing a new species
distributed across W and N Istria. http://www.icsb2010.net/
FLOT (J.-F.), BAUERMEISTER (J.) & DATTAGUPTA
(S.), 2010. Niphargus amphipods and their Thiothrix
ectosymbionts in Frasassi (Central Italy): a tale of multiple
invasions and host specificity:166-167. In: 20 th
International Conference on Subterranean Biology,
Postojna, Slovenia, 29 August-3 September 2010, ICSB
2010 Abstract Book, edited by: Ajda MOŠKRIČ and Peter
TRONTELJ, ISBN 978-961-269-286-5. ABS: The sulfide-rich
Frasassi caves in central Italy contain a rare example of a freshwater
ecosystem supported entirely by chemoautotrophy. Niphargus ictus, the
only amphipod species previously reported from this locality, was
recently shown to host Thiothrix ectosymbionts on its cuticle. Whereas
chemoautotrophic symbioses are widespread in the marine environment,
this is the first instance of such a symbiosis to be reported from a
freshwater ecosystem. Since the habitat of N. ictus is highly fragmented
and is comprised of streams and lakes with various sulfide
concentrations, we conducted a detailed study to examine the potential
genetic diversity of this species within Frasassi. By sequencing one
nuclear (ITS) and two mitochondrial (COI and 12S) regions, we found
that four partially sympatric Niphargus clades are present in Frasassi.
One of these clades corresponds to the published description of N. ictus,
two others have since then been described as N. frasassianus and N.
montanarius, and the fourth clade remains undescribed due to the scarcity
of available specimens. Phylogenetic analyses of 28S ribosomal DNA
(rDNA) sequences reveal that, among these four putative species, only N.
montanarius and the fourth clade are closely related to each other. These
results suggest that the Frasassi cave ecosystem was invaded
independently by three different Niphargus lineages, one of which
eventually split into two clades. Our unexpected finding of distinct
Niphargus species in Frasassi prompted us to look for Thiothrix
symbionts on each of them. Scanning electron microscopy showed
filamentous ectosymbionts on all three Niphargus species examined to
date (N. ictus, N. frasassianus and N. montanarius), and their assignment
to the genus Thiothrix was confirmed by sequencing 16S rDNA libraries.
Phylogenetic analyses of 16S rDNA sequences reveal that Thiothrix
ectosymbionts are not monophyletic. Moreover, some symbiotic
Thiothrix lineages are found on more than one Niphargus species, which
may indicate past lateral transfers. In spite of this, ARISA (Automated
Ribosomal Intergenic Spacer Analysis) shows that the symbiotic
communities associated with the three Niphargus hosts are distinct and
highly host-specific, suggesting that ongoing symbiont transmission
occurs chiefly from parent to offspring. http://www.icsb2010.net/
FLOT (J.-F.), WÖRHEIDE (G.) & DATTAGUPTA (S.),
2010. Unsuspected diversity of Niphargus amphipods in
the chemoautotrophic cave ecosystem of Frasassi, central
Italy. BMC Evolutionary Biology 10:171. DOI:
http://dx.doi.org/10.1186/1471-2148-10-171. ABS:
Background: The sulfide-rich Frasassi caves in central Italy contain a rare
example of a freshwater ecosystem supported entirely by
chemoautotrophy. Niphargus ictus, the sole amphipod species previously
reported from this locality, was recently shown to host the first known
case of a freshwater chemoautotrophic symbiosis. Since the habitat of N.
ictus is highly fragmented and is comprised of streams and lakes with
various sulfide concentrations, we conducted a detailed study to examine
Bernard LEBRETON & Jean-Pierre BESSON
Créé le : 01.01.2010
Modifié le : 30.06.2010
the potential genetic diversity of this species within Frasassi. Results: By
sequencing one nuclear (ITS) and two mitochondrial (COI and 12S)
regions, we show that four partially sympatric Niphargus clades are
present in Frasassi. Morphological and behavioral data obtained for three
of these clades are perfectly congruent with this molecular delineation
and make it possible to distinguish them in the field. Phylogenetic
analyses of 28S ribosomal DNA sequences reveal that, among the four
clades, only two are closely related to each other. Moreover, these four
clades occupy distinct niches that seem to be related to the chemical
properties and flow regimes of the various water bodies within Frasassi.
Conclusions: Our results suggest that four distinct Niphargus species are
present in Frasassi and that they originated from three or four
independent invasions of the cave system. At least two among the four
species harbor Thiothrix epibionts, which paves the way for further
studies of the specificity and evolutionary history of this symbiosis.
FONG (D. W.) & KAVANAUGH (K. E.), 2010. Population
dynamics of the stygobiotic amphipod crustacean
Stygobromus tenuis potomacus and isopod crustacean
Caecidotea kenki at a single hypotelminorheic habitat over
a two-year span:22-23. In: 20 th International Conference
on Subterranean Biology, Postojna, Slovenia, 29 August-3
September 2010, ICSB 2010 Abstract Book, edited by:
Ajda MOŠKRIČ and Peter TRONTELJ, ISBN 978-961-
269-286-5. ABS: We monitored the population size of the stygobiotic
amphipod, Stygobromus tenuis potomacus, and of the stygobiotic isopod,
Caecidotea kenki, at the resurgence of a hypotelminorheic habitat for two
years at an average sampling interval of 10 days. Surface abundance of S.
tenuis ranged from zero to 35 around a mean of 12.02, while C. kenki
ranged from 10 to 101 around a mean of 44.86. Water temperature varied
from 9.4 to 17.8ºC about a mean of 14.15ºC, while depth varied from 2 to
14 mm about a mean of 6.10 mm. Temperature was uncorrelated with
depth. Abundances of the two species were also uncorrelated. Abundance
of S. tenuis showed a significant decrease with increasing temperature
(R2 = 0.51), and a weak increase with increasing depth but a decrease
beyond a depth of 8 mm (R2 = 0.23). Abundance of C. kenki showed a
weak increase with increasing temperature with a decrease beyond 15ºC
(R2 = 0.28), and no dependence on depth (R2 = 0.03). We conclude that
C. kenki is a specialist of the surface habitat immediately adjacent to the
resurgence of hypotelminorheic water, and that S. tenuis is adapted to the
colder subterranean water of the hypotelminorheic. When surface
temperature is low, S. tenuis may actively move to the surface to forage.
We suggest that this movement may be associated with lower
temperatures because at higher temperatures the quality and quantity of
resources may be insufficient to offset metabolic losses.
http://www.icsb2010.net/
FOSTER-TURLEY (P.), GRIMES (A.) & SEDEJ (M.),
2010. Biodiversity analysis update for Montenegro, May
2010, 53 p.
FOWLER (R.), 2010. Quantitative Real-Time PCR as a tool
for the quantification and characterization of
microorganisms in caves and karst aquifers:
phytoplankton, lampenflora, bacterial communities, and
fecal source tracking:167-168. In: 20 th International
Conference on Subterranean Biology, Postojna, Slovenia,
29 August-3 September 2010, ICSB 2010 Abstract Book,
edited by: Ajda MOŠKRIČ and Peter TRONTELJ, ISBN
978-961-269-286-5. ABS: PCR is a molecular tool to generate many
copies of a specific DNA in a process called amplification, and
quantitative Real-Time PCR (qRT-PCR) includes monitoring
fluorescence during the PCR reaction and amplification process. In qRT-
PCR, increase in fluorescence accompanies the accumulation of multiple
copies of a target DNA fragment after successive cycles of PCR with
specific primers. We use fluorescence measurements along with
calibrated standards as a means to quantify specific sequences of DNA in
complex mixtures of DNA extracted from the environment. Three
examples are presented in detail: 1) DNA was extracted from cultures of
Chlorella algae and from field samples along karstic surface streams.
qRT-PCR with primers specific for Chlorella 18S rDNA was to measure
concentrations of Chlorella, an indicator of phytoplankton abundance at
cave springs or in surface channels. Chlorella is also a constituent of
lampenflora, and qRT-PCR will soon be applied in lampenflora growth
experiments; 2) Environmental DNA was extracted from cave sediments