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Are specialized troglobiont ciliates exist

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We hypothesized that the population structure of
planktonic grazers in a high productivity site differs
from that known for typical oligotrophic sites. We
expected the high productivity site to harbor more
species. We compared a high productivity site with
dense populations of N-fixing Trichodesmuim,
and a distant oligotrophic site. We examined
patterns of species abundance distribution and the
abundance distribution of ecological types, that
is species of similar shell or lorica oral diameter,
analogous to gape size. We also examined species
packing within ecological types, defined as lorica
oral diameter size-classes. Population abundance
differed between the sites by a factor of 3, and the
productive site population was highly dominated by
a single species (not found at the oligotrophic site)
but species richness and turnover were very similar.
Species abundance distributions for both sites on
all dates most closely fit a log-series or lognormal
distribution. Abundance distributions of ecological
types, forms of distinct lorica oral diameter, were
the typical geometric for the oligotrophic site. In
contrast, at the high productivity site, lognormal
or log-series distributions provided equally good
fits. In the oligotrophic site there was a positive
relationship between the number of individuals in a
lorica size-class and the number of species but not
in the productive site. Despite large differences in
population size and dominance, the two populations
were surprisingly similar by most measures. Our
results suggest that overall food web structure is
likely similar as well.
Dovgal I.V.
Kovalevsky Institute of Marine Biological Research
The organisms inhabiting in subterranean waters
can be separated into two groups. One of them
is represented by species, which for any reasons
being situated in the underground habitats and
have adapted to them. As a rule, these are the same
species as in epigean waters or soils and possible
has originated from mentioned habitats. Thus, the
group might denoted as epigean. Another group of
organisms is represented by specialized troglobiont
species. The list of ciliated protozoans living in
subterranean waters comprises about 150 species,
but most of them can be defined as representatives
of epigean group. Only a few ciliate species,
which are host-specific commensals or parasites
of subterranean animals (especially crustaceans)
possibly, should be considered as troglobionts. In
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such a way, the list of specialized troglobiont ciliates
must include suctorians Spelaeophrya troglocaridis
from shrimps, Tokophrya bathynellae from syncarids,
Echinophrya stenaselli and T. microcerberi from
subterranean isopods. The analysis of literary and
own data on distribution and host prevalence of
suctorian ciliate T. niphargi from amphipods and
peritrich ciliate Ballodora marceli from wood louses
permit to define these ciliates to epigean group of
species. As for apostomes Gymnodinioides sp. from
cavernicolous amphipods and shrimps, status of
these ciliates remains to be seen.
Dubrovsky Yu.V.1, Mylnikov A.P.2
- Institute for Evolutionary Ecology of the Nacional
Academy of Sciences of Ukraine (IEE NAS of Ukraine), Laboratory of Wildlife Protection and Restoration
- Papanin Institute for Biology of Inland Waters,
Russian Academy of Sciences, Borok, Russia
Twenty-seven species and forms of heterotrophic
flagellates have been found in the result of analysis of
8 water and 4 soil samples (downstream of river Ros’,
Ukraine, 49º37´N; 31º30´E) during summer 2014.
Observed species belongs to Opisthokonta (2 species), SAR (17), Excavata (8) and incertae sedis
group (2). The most flagellates were bacterivorous.
Allantion tachyploon, Kathablepharis sp., Alphamonas edax, Colponema vietnamica, Diphyleia rotans,
Rhynchobodo armata belonged to predators and
Goniomonas truncata and Paraphysomonas spp. were
omnivorous. The relationship between locality of
the sample and species composition has not been
revealed. This fact indicates the random character
of species distribution. The most abundant (9-13
species) were overgrown river floodplain creeks
and ponds, as well as wet soil deciduous forest.
The silted ponds and creeks without flow, as well
as coastal soils, are characterized by the average
species richness (6-7 species). River watercourse,
dried puddle, bedrock at a depth of 12 m and the soil
under field crops possess the lowest species richness
(2-4 species). The vast majority of species is common for all investigated biotopes and occurs both in
water and in the soil. Among the 11 species occurring
in more than three samples, 7 species are inhabited
both water and soil, and 4 species were found only
in water samples. The average number of species for
water and soil samples (7 and 6 correspondingly) was
not significantly differed. The specificity of species
composition within habitats is not observed. This
study was supported by the Russian Foundation for
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exist, specialized, troglobiont, ciliates
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