119 research outputs found
Occurrence of the scalloped ribbonfish Zu cristatus(Lampridiformes) in coastal waters of the central Tyrrhenian Sea, Italy
The occurrence of two individuals of Zu cristatus at 2 m depth in coastal waters of the Gulf of Castellamare (Tyrrhenian Sea, Italy) together with records of this rare pan-Oceanic mesopelagic species is reported. Analyses of two mitochondrial genes (12 s and 16 s; 936 bp) revealed a 2.6% sequence divergence between Mediterranean and Pacific (Japanese) samples of the species
Molecular systematics, phylogeny and biogeography of roaches (Rutilus, Teleostei, Cyprinidae)
The aims of the present study are: (1) to produce a phylogenetic
hypothesis for the genus Rutilus by using sequence variation of the
entire mitochondrial (mt) cytochrome b (cyt-b) gene. To accomplish
this we had sampled a total of 22 populations from the Eastern
peri-Mediterranean area and Central Europe. These include 12
species (five of which with multiple populations; Fig. 1 and Table
1) out of the 14 reported in FishBase; (2) to test whether molecular
data support the current systematics of the genus; and (3) to
produce a biogeographic hypothesis for its diversification based
on estimates of divergence times. Results will be discussed in light of the two contrasting biogeographic scenarios available for Southern
European primary freshwater fishes
Foreword to the special issue "new frontiers for monitoring European biodiversity: The role and importance of amphipod crustaceans"
[No abstract available
Adaptive radiation in African weakly electric fish (Teleostei : Mormyridae : Campylomormyrus): a combined molecular and morphological approach
We combined multiple molecular markers and geometric morphometrics to revise the current taxonomy and to build a phylogenetic hypothesis for the African weakly electric fish genus Campylomormyrus. Genetic data (2039 bp DNA sequence of mitochondrial cytochrome b and nuclear S7 genes) on 106 specimens support the existence of at least six species occurring in sympatry. We were able to further confirm these species by microsatellite analysis at 16 unlinked nuclear loci and landmark-based morphometrics. We assigned them to nominal taxa by comparisons to type specimens of all Campylomormyrus species recognized so far. Additionally, we showed that the shape of the elongated trunk-like snout is the major source of morphological differentiation among them. This finding suggests that the radiation of this speciose genus might have been driven by adaptation to different food sources
Molecular phylogeny of two lineages of Leuciscinae cyprinids (Telestes and Scardinius) from the peri-Mediterranean area based on cytochrome b data.
We examined phylogenetic relationships in two lineages of Leuciscinae cyprinid fishes based on the sequence data of the complete
mitochondrial DNA region coding for the cytochrome b gene (1140 bp). Telestes includes obligate riverine, moderately cold wateradapted
species whereas Scardinius comprises warm-adapted species living in lowland lakes and still waters of rivers and streams.
We also analysed selected representatives of Leuciscus and Phoxinellus because the taxonomic status of some species belonging to
these genera is dubious and they could be placed in the genus Telestes. The study includes 18 species, 43 populations, and 111
individuals from 9 of the 14 peri-Mediterranean ichthyogeographic districts. Clades recovered from the phylogenetic analyses do not
support previous taxonomic assumptions based on morphology. Telestes, Leuciscus, and Phoxinellus do not form monophyletic
assemblages; phylogenetic analyses suggest that L. polylepis, L. turskyi, P. croaticus, and P. metohiensis should be included in
Telestes. Similarly, populations of Scardinius erythrophthalmus do not cluster together and the endangered S. scardafa, endemic to
central Italy and surviving in a single locality, is nested within them. The radiations of Telestes and Scardinius occurred in different
time periods. A major diversification of Telestes is consistent with a sea dispersal during the freshwater Messinian ‘‘Lago Mare’’
phase of the Mediterranean Sea. Cladogenetic events within Scardinius are likely related to the extension and confluence of river
drainages in lowlands following multiple lowering of the sea level during the Quaternary glaciations
The genetic structure and connectivity in two sympatric rodent species with different life histories are similarly affected by land use disturbances
The negative impact of habitat fragmentation due to human activities may be different in different species that co-exist in the same area, with consequences on the development of environmental protection plans. Here we aim at understanding the effects produced by different natural and anthropic landscape features on gene flow patterns in two sympatric species with different specializations, one generalist and one specialist, sampled in the same locations. We collected and genotyped 194 wood mice (generalist species) and 199 bank voles (specialist species) from 15 woodlands in a fragmented landscape characterized by different potential barriers to dispersal. Genetic variation and structure were analyzed in the two species, respectively. Effective migration surfaces, isolation-by-resistance (IBR) analysis, and regression with randomization were used to investigate isolation-by-distance (IBD) and the relative importance of land cover elements on gene flow. We observed similar patterns of heterozygosity and IBD for both species, but the bank vole showed higher genetic differences among geographic areas. The IBR analysis suggests that (i) connectivity is reduced in both species by urban areas but more strongly in the specialist bank vole; (ii) cultivated areas act as dispersal corridors in both species; (iii) woodlands appear to be an important factor in increasing connectivity in the bank vole, and less so in the wood mouse. The difference in dispersal abilities between a generalist and specialist species was reflected in the difference in genetic structure, despite extensive habitat changes due to human activities. The negative effects of fragmentation due to the process of urbanization were, at least partially, mitigated by another human product, i.e., cultivated terrains subdivided by hedgerows, and this was true for both species
Mitochondrial DNA Regionalism and Historical Demography in the Extant Populations of Chirocephalus kerkyrensis (Branchiopoda: Anostraca)
Background: Mediterranean temporary water bodies are important reservoirs of biodiversity and host a unique assemblage of diapausing aquatic invertebrates. These environments are currently vanishing because of increasing human pressure.
Chirocephalus kerkyrensis is a fairy shrimp typical of temporary water bodies in Mediterranean plain forests and has
undergone a substantial decline in number of populations in recent years due to habitat loss. We assessed patterns of genetic connectivity and phylogeographic history in the seven extant populations of the species from Albania, Corfu Is. (Greece), Southern and Central Italy.
Methodology/Principal Findings: We analyzed sequence variation at two mitochondrial DNA genes (Cytochrome Oxidase I and 16s rRNA) in all the known populations of C. kerkyrensis. We used multiple phylogenetic, phylogeographic and coalescence-based approaches to assess connectivity and historical demography across the whole distribution range of the species. C. kerkyrensis is genetically subdivided into three main mitochondrial lineages; two of them are geographically localized (Corfu Is. and Central Italy) and one encompasses a wide geographic area (Albania and Southern Italy). Most of the detected genetic variation (<81%) is apportioned among the aforementioned lineages.
Conclusions/Significance: Multiple analyses of mismatch distributions consistently supported both past demographic and spatial expansions with the former predating the latter; demographic expansions were consistently placed during interglacial warm phases of the Pleistocene while spatial expansions were restricted to cold periods. Coalescence methods revealed a scenario of past isolation with low levels of gene flow in line with what is already known for other co-distributed fairy shrimps and suggest drift as the prevailing force in promoting local divergence. We recommend that these evolutionary trajectories should be taken in proper consideration in any effort aimed at protecting Mediterranean temporary water bodies
Permanent Genetic Resources added to Molecular Ecology Resources Database 1 April 2011-31 May 2011
This article documents the addition of 92 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anopheles minimus, An. sinensis, An. dirus, Calephelis mutica, Lutjanus kasmira, Murella muralis and Orchestia montagui. These loci were cross-tested on the following species: Calephelis arizonensi, Calephelis borealis, Calephelis nemesis, Calephelis virginiensis and Lutjanus bengalensis
Evolutionary Origin and Phylogeography of the Diploid Obligate Parthenogen Artemia parthenogenetica (Branchiopoda: Anostraca)
Background: Understanding the evolutionary origin and the phylogeographic patterns of asexual taxa can shed light on the origin and maintenance of sexual reproduction. We assessed the geographic origin, genetic diversity, and phylogeographic history of obligate parthenogen diploid Artemia parthenogenetica populations, a widespread halophilic crustaceanPeer reviewe
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