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Ramon Moreno-amich - One of the best experts on this subject based on the ideXlab platform.
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Studies on Large Branchiopod Biology 4. © 2002 Kluwer Academic Publishers. Printed in the Netherlands.
2015Co-Authors: Dani Boix, Jordi Sala, Ramon Moreno-amichAbstract:Population dynamics of Triops cancriformis (Crustacea: Branchiopoda: Notostraca) of the Espolla temporary pond in the northeastern Iberian peninsul
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Population dynamics of Triops cancriformis (Crustacea: Branchiopoda: Notostraca) of the Espolla temporary pond in the northeastern Iberian peninsula
Hydrobiologia, 2002Co-Authors: Dani Boix, Jordi Sala, Ramon Moreno-amichAbstract:The population dynamics of Triops cancriformis in Espolla temporary pond (NE Iberian peninsula) were studied during 1996 and 1997, which encompassed six flooded periods. Data were collected on each individual's size, sex, and, if female, on number of eggs in the oostegopodes. Male-biased sex ratios were found only in the drying-out phase and variations in fecundity were strongly related to hydroperiod duration. Sex ratio variation during the drying-out phase can be attributed to female mortality because the very low recruitment observed does not support the hypothesis of an increase of males. Two hypotheses are advanced to account for female mortality: (1) differential reproductive effort, and (2) size selective predation by herons. This population is characterised by low values of maximum densities compared with other Notostracan populations, and by higher densities in the spring–summer hydroperiods than in the winter ones.
Barbara Mantovani - One of the best experts on this subject based on the ideXlab platform.
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Mitochondrial genome diversity and evolution in Branchiopoda (Crustacea)
Zoological Letters, 2019Co-Authors: Andrea Luchetti, Giobbe Forni, Alyza M. Skaist, Sarah J. Wheelan, Barbara MantovaniAbstract:Background The crustacean class Branchiopoda includes fairy shrimps, clam shrimps, tadpole shrimps, and water fleas. Branchiopods, which are well known for their great variety of reproductive strategies, date back to the Cambrian and extant taxa can be mainly found in freshwater habitats, also including ephemeral ponds. Mitochondrial genomes of the Notostracan taxa Lepidurus apus lubbocki (Italy), L. arcticus (Iceland) and Triops cancriformis (an Italian and a Spanish population) are here characterized for the first time and analyzed together with available branchiopod mitogenomes. Results Overall, branchiopod mitogenomes share the basic structure congruent with the ancestral Pancrustacea model. On the other hand, rearrangements involving tRNAs and the control region are observed among analyzed taxa. Remarkably, an unassigned region in the L. apus lubbocki mitogenome showed a chimeric structure, likely resulting from a non-homologous recombination event between the two flanking trnC and trnY genes. Notably, Anostraca and Onychocaudata mitogenomes showed increased GC content compared to both Notostraca and the common ancestor, and a significantly higher substitution rate, which does not correlate with selective pressures, as suggested by dN/dS values. Conclusions Branchiopod mitogenomes appear rather well-conserved, although gene rearrangements have occurred. For the first time, it is reported a putative non-homologous recombination event involving a mitogenome, which produced a pseudogenic tRNA sequence. In addition, in line with data in the literature, we explain the higher substitution rate of Anostraca and Onychocaudata with the inferred GC substitution bias that occurred during their evolution.
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mitochondrial genome diversity and evolution in branchiopoda crustacea
Zoological Letters, 2019Co-Authors: Andrea Luchetti, Giobbe Forni, Alyza M. Skaist, Sarah J. Wheelan, Barbara MantovaniAbstract:The crustacean class Branchiopoda includes fairy shrimps, clam shrimps, tadpole shrimps, and water fleas. Branchiopods, which are well known for their great variety of reproductive strategies, date back to the Cambrian and extant taxa can be mainly found in freshwater habitats, also including ephemeral ponds. Mitochondrial genomes of the Notostracan taxa Lepidurus apus lubbocki (Italy), L. arcticus (Iceland) and Triops cancriformis (an Italian and a Spanish population) are here characterized for the first time and analyzed together with available branchiopod mitogenomes. Overall, branchiopod mitogenomes share the basic structure congruent with the ancestral Pancrustacea model. On the other hand, rearrangements involving tRNAs and the control region are observed among analyzed taxa. Remarkably, an unassigned region in the L. apus lubbocki mitogenome showed a chimeric structure, likely resulting from a non-homologous recombination event between the two flanking trnC and trnY genes. Notably, Anostraca and Onychocaudata mitogenomes showed increased GC content compared to both Notostraca and the common ancestor, and a significantly higher substitution rate, which does not correlate with selective pressures, as suggested by dN/dS values. Branchiopod mitogenomes appear rather well-conserved, although gene rearrangements have occurred. For the first time, it is reported a putative non-homologous recombination event involving a mitogenome, which produced a pseudogenic tRNA sequence. In addition, in line with data in the literature, we explain the higher substitution rate of Anostraca and Onychocaudata with the inferred GC substitution bias that occurred during their evolution.
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draft genomes and genomic divergence of two lepidurus tadpole shrimp species crustacea branchiopoda Notostraca
Molecular Ecology Resources, 2019Co-Authors: Castrense Savojardo, Andrea Luchetti, Pier Luigi Martelli, Rita Casadio, Barbara MantovaniAbstract:Crustaceans of the order Notostraca (Branchiopoda) are distributed worldwide and are known for the remarkable morphological stasis between their extant and Permian fossil species. Moreover, these crustaceans show relevant ecological traits and a wide range of reproductive strategies. However, genomic studies on Notostracans are fairly limited. Here, we present the genome sequences of two Notostracan taxa, Lepidurus arcticus and Lepidurus apus lubbocki. Taking advantage of the small genome sizes (~0.11 pg) of these taxa, genomes were sequenced for one individual per species with one run on the Illumina HiSeq X platform. We finally assembled 73.2 Mbp (L. arcticus) and 90.3 Mbp (L. apus lubbocki) long genomes. Assemblies cover up to 84% of the estimated genome size, with a gene completeness >97% for both genomes. In total, 13%-16% of the assembled genomes consist of repeats, and based on read mapping, L. apus lubbocki shows a significantly lower transposable element content than L. arcticus. The analysis of 2,376 orthologous genes indicates an ~7% divergence between the two Lepidurus taxa, with a nucleotide substitution rate significantly lower than that of Daphnia taxa. Ka /Ks analysis suggests purifying selection in both branchiopod lineages, raising the question of whether the low substitution rate of Lepidurus is correlated with morphological conservation or is linked to specific biological traits. Our analysis demonstrates that, in these organisms, it is possible to obtain high-quality draft genomes from single individuals with a relatively low sequencing effort. This result makes Lepidurus and Notostraca interesting models for genomic studies at taxonomic, ecological and evolutionary levels.
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Draft genomes and genomic divergence of two Lepidurus tadpole shrimp species (Crustacea, Branchiopoda, Notostraca)
2018Co-Authors: Castrense Savojardo, Andrea Luchetti, Pier Luigi Martelli, Rita Casadio, Barbara MantovaniAbstract:Crustaceans of the order Notostraca (Branchiopoda) are worldwide-distributed and known for their remarkable morphological stasis between extant and Permian fossil species. Moreover, they show relevant ecological traits and a wide panel of reproductive strategies. However, genomic studies on Notostracans are fairly limited. We here present the genome sequences of two Notostracan taxa, Lepidurus arcticus and L. apus lubbocki. Taking advantage of the small genome size (~0.11 pg), we set the sequencing on Illumina HiSeq X platform for a single run on a single individual per species. We finally assembled 73.2 Mbp - L. arcticus - and 90.3 Mbp - L. apus lubbocki long genomes. Assembly cover up to 80% of estimated genome size, with a gene completeness >97% for both genomes. 10-15% of assembled genomes consist of repeats and, although L. apus lubbocki experienced a marked increase of LTR and DNA transposons, there is no significant difference in copy number. The analysis of 2,376 ortholog genes indicates a ~7% of divergence between the two Lepidurus species, with a nucleotide substitution rate significantly lower than the Daphnia one. Ka/Ks analyses suggests purifying selection in both branchiopod lineages, raising the question whether the lower substitution rate is correlated with the Lepidurus morphological conservation or it is attributable to specific biological traits. Our analysis demonstrates that in these organisms it is possible to obtain draft genomes with high completeness from single individuals with a relatively small sequencing effort. This makes Lepidurus, and Notostraca, an interesting model for studies in population, ecological and evolutionary genomics.
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molecular characterization of ribosomal intergenic spacer in the tadpole shrimp triops cancriformis crustacea branchiopoda Notostraca
Genome, 2006Co-Authors: Andrea Luchetti, Franca Scanabissi, Barbara MantovaniAbstract:Nuclear ribosomal DNA constitutes a multigene family, with tandemly arranged units linked by an intergenic spacer (IGS), which contains initiation/termination transcription signals and usually tandemly arranged subrepeats. The structure and variability of the IGS region are analyzed here in hermaphroditic and parthenogenetic populations of the "living fossil" Triops cancriformis (Branchiopoda, Notostraca). The results indicate the presence of concerted evolution at the population level for this G+C-rich IGS region as a whole, with the major amount of genetic variability found outside the subrepeat region. The subrepeats region is composed of 3 complete repeats (a, c, d) intermingled with 3 repeat fragments (b, e, f) and unrelated sequences. The most striking datum is the absolute identity of subrepeats (except type d) occupying the same position in different individuals/populations. A putative promoter sequence is present upstream of the 18S rRNA gene, but not in subrepeats, which is at variance with othe...
Dani Boix - One of the best experts on this subject based on the ideXlab platform.
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Studies on Large Branchiopod Biology 4. © 2002 Kluwer Academic Publishers. Printed in the Netherlands.
2015Co-Authors: Dani Boix, Jordi Sala, Ramon Moreno-amichAbstract:Population dynamics of Triops cancriformis (Crustacea: Branchiopoda: Notostraca) of the Espolla temporary pond in the northeastern Iberian peninsul
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Population dynamics of Triops cancriformis (Crustacea: Branchiopoda: Notostraca) of the Espolla temporary pond in the northeastern Iberian peninsula
Hydrobiologia, 2002Co-Authors: Dani Boix, Jordi Sala, Ramon Moreno-amichAbstract:The population dynamics of Triops cancriformis in Espolla temporary pond (NE Iberian peninsula) were studied during 1996 and 1997, which encompassed six flooded periods. Data were collected on each individual's size, sex, and, if female, on number of eggs in the oostegopodes. Male-biased sex ratios were found only in the drying-out phase and variations in fecundity were strongly related to hydroperiod duration. Sex ratio variation during the drying-out phase can be attributed to female mortality because the very low recruitment observed does not support the hypothesis of an increase of males. Two hypotheses are advanced to account for female mortality: (1) differential reproductive effort, and (2) size selective predation by herons. This population is characterised by low values of maximum densities compared with other Notostracan populations, and by higher densities in the spring–summer hydroperiods than in the winter ones.
Franca Scanabissi - One of the best experts on this subject based on the ideXlab platform.
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molecular characterization of ribosomal intergenic spacer in the tadpole shrimp triops cancriformis crustacea branchiopoda Notostraca
Genome, 2006Co-Authors: Andrea Luchetti, Franca Scanabissi, Barbara MantovaniAbstract:Nuclear ribosomal DNA constitutes a multigene family, with tandemly arranged units linked by an intergenic spacer (IGS), which contains initiation/termination transcription signals and usually tandemly arranged subrepeats. The structure and variability of the IGS region are analyzed here in hermaphroditic and parthenogenetic populations of the "living fossil" Triops cancriformis (Branchiopoda, Notostraca). The results indicate the presence of concerted evolution at the population level for this G+C-rich IGS region as a whole, with the major amount of genetic variability found outside the subrepeat region. The subrepeats region is composed of 3 complete repeats (a, c, d) intermingled with 3 repeat fragments (b, e, f) and unrelated sequences. The most striking datum is the absolute identity of subrepeats (except type d) occupying the same position in different individuals/populations. A putative promoter sequence is present upstream of the 18S rRNA gene, but not in subrepeats, which is at variance with othe...
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MOLECULAR TAXONOMY AND PHYLOGENY OF THE 'LIVING FOSSIL' LINEAGES TRIOPS AND LEPIDURUS (BRANCHIOPODA: Notostraca)
Zoologica Scripta, 2004Co-Authors: Barbara Mantovani, Michele Cesari, Franca ScanabissiAbstract:Mantovani B. Cesari M. & Scanabissi F. (2004). Molecular taxonomy and phylogeny of the ‘living fossil’ lineages Triops and Lepidurus (Branchiopoda: Notostraca). —Zoologica Scripta, 33, 367–374. European Triops cancriformis and Lepidurus apus were analysed for 12S and 16S mitochondrial genes and compared to North American and Japanese taxa. There are no cryptic species among European T. cancriformis populations, which are highly homogeneous in comparison to conspecific Japanese samples. T. cancriformis differs from congeneric taxa all over its range, which can be explained by its antiquity. In contrast, the parapatric subspecies L. apus apus and L. apus lubbocki are morphologically conserved and differ substantially at the mtDNA level. The genetic distance values between them are of the same order of magnitude as those observed between American Lepidurus species. Their subspecific status therefore requires further analysis. L. apus apus is more closely related to a L. arcticus sample from Iceland than to L. apus lubbocki. It is also related to a Canadian L. couesii population. Further analyses of populations from the whole range of L. arcticus and the European range of L. couesii are needed to understand the relationships among these Notostracan taxa. When considering the two genera, it is clear that Lepidurus is a well supported monophyletic unit, while Triops is polyphyletic, embodying very divergent taxa.
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a survey of the reproductive biology in italian branchiopods part a the female gonad of limnadia lenticularis linnaeus 1761 spinicaudata and lepidurus apus lubbocki brauer 1873 Notostraca
Hydrobiologia, 2002Co-Authors: Franca Scanabissi, Corrado MondiniAbstract:Main reproductive features of Limnadia lenticularis (Linnaeus, 1761) (Spinicaudata) and Lepidurus apus lubbocki Brauer, 1873 (Notostraca) are given and compared to those of other Italian species. Gametogenesis, germ cell distribution, gonadal architecture, eggshell origin and development, and somatic tract of the gonad structure are studied by means of TEM and SEM. At variance of previous reports suggesting a parthenogenetic reproduction of Limandia lenticularis, we show an hermaphroditic condition for this taxon and that fertilization occurs. On the other hand, the female apparatus of the Notostracan Lepidurus opus lubbocki appears perfectly functional in all analyzed aspects of the gametogenesis. A comparison with Triops cancriformis (Bosc, 1801) - the other Italian Notostracan - indicates a high degree of morphological affinity, also for the absence of male germinal areas.
Erich Eder - One of the best experts on this subject based on the ideXlab platform.
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Freshwater branchiopods in Austria LARGE FRESHWATER BRANCHIOPODS IN AUSTRIA: DIVERSITY, THREATS AND CONSERVATIONAL STATUS
2015Co-Authors: Erich Eder, Walter Hödl, Kluwer Academic/plenum Publishers, E. Escobar-briones, F. AlvarezAbstract:For the first time, Anostraca, Notostraca and Conchostraca (Laevicaudata, Spinicaudata) will be listed in the Austrian Red Data Book of Endangered Species. According to the 1999 IUCN draft criteria, eight out of 15 large branchiopod species recorded be
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1997 Kluwer Academic Publishers. Printed in Belgium. Distribution and phenology of large branchiopods in Austria
2014Co-Authors: Erich Eder, Renate GottwaldAbstract:In Austria, the distribution of Anostraca, Notostraca, and Conchostraca is mainly confined to the flood plains of the rivers Morava and Danube, and the shallow alkaline pans of the Seewinkel region in Burgenland province. Occasionally, large branchiopods can also be found in rain pools of the eastern and central Austrian lowlands, where topography and climate favour the existence of astatic water bodies. Differences in hydrology, temperature and water chemistry requirements may be reflected in local species compositions and species seasonal appearance. A survey conducted from 1994 through 1996 found that Chirocephalus shadini, Eubranchipus grubii, and Lepidurus apus occurred in late winter and spring, while Branchinecta ferox, Branchinecta orientalis, Cyzicus tetracerus and Chirocephalus carnuntanus were found exclusively in spring. Streptocephalus torvicornis, Tanymastix stagnalis, and Eoleptestheria ticinensis were present in spring and summer. Branchipus schaefferi was found in summer and fall, whereas Imnadia yeyetta, Leptestheria dahalacensis, Limnadia lenticularis, and Triops cancriformis occurred throughout spring, summer and fall. Streptocephalus torvicornis was documented for Austria for the first time sinc
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pH-related Hatching Success of Triops cancriformis (Crustacea: Branchiopoda: Notostraca)
Hydrobiologia, 2006Co-Authors: Iris Maria Schönbrunner, Erich EderAbstract:Six different pH ranges were tested for the hatching rate of Triops cancriformis cysts. Cumulative hatching numbers approach to approximately 50% of cysts. The highest hatching rates, co-occurring with the shortest hatching times, were recorded in the neutral range. No hatching took place at pH values 9 and above. This corresponds with the most frequent habitats of this species, snowmelt pools of river flood plains as well as aestival pools caused by heavy rainfalls. Occurrences in sodic alkaline pans can be explained by relatively low pH values at the time of inundation.
