The aims of the study were (i) to reveal the pattern of phylogeny of Pseudamnicola inhabiting the Aegean Islands, (ii) to describe and analyse the variation of the morphology in 17 populations of Pseudamnicola from the springs on the Aegean Islands not studied so far and considering also another seven populations studied earlier and (iii) to find out which model is more applicable to the island Pseudamnicola populations: either a model in which a relict fauna rich in endemics is differentiated in a way that mainly reflects the geological history of the area or a model in which a relatively young fauna is composed of more or less widely distributed taxa, with relatively high levels of gene flow among the springs they inhabit. To address the above issues, the morphology and the mitochondrial genes-cytochrome oxidase subunit I (COI) and ribosomal 16S-and nuclear genes-ribosomal 18S, 28S and histone 3 (H3)-were analysed. COI and COI+16S rRNA+18S datasets gave trees with identical topology in both ML and Bayesian inference. The 24 studied populations of Pseudamnicola form 16 clades, each of them generally having low levels of intrapopulation genetic differentiation. The generalised mixed Yule coalescent (GMYC) procedure and the Automatic Barcode Gap Discovery (ABGD) analysis for COI identified 16 Pseudamnicola entities coinciding with clades of the ML tree based on 44 haplotypes and 189 sequences. The present pattern of diversity, together with dating of divergence time, reflects a short story of colonisation/recolonisation, supported by the Late Pleistocene land bridges, rather than the consequences of earlier geological events. The principal component analysis (PCA) on the shells of the molecularly distinct clades showed differences, although variability ranges often overlap. Female reproductive organs showed no differences between the clades, and penile characters differed only in some cases.

Lumbricid earthworms Eisenia andrei (Ea) and E. fetida (Ef) are simultaneous hermaphrodites with reciprocal insemination capable of self-fertilization while the existence of hybridization of these two species was still debatable. During the present investigation fertile hybrids of Ea and Ef were detected. Virgin specimens of Ea and Ef were laboratory crossed (Ea+Ef) and their progeny was doubly identified. 1 –identified by species-specific maternally derived haploid mitochondrial DNA sequences of the COI gene being either ‘a’ for worms hatched from Ea ova or ‘f’ for worms hatched from Ef ova. 2 –identified by the diploid maternal/paternal nuclear DNA sequences of 28s rRNA gene being either ‘AA’ for Ea, ‘FF’ for Ef, or AF/FA for their hybrids derived either from the ‘aA’ or ‘fF’ ova, respectively. Among offspring of Ea+Ef pairs in F1 generation there were mainly aAA and fFF earthworms resulted from the facilitated self-fertilization and some aAF hybrids from aA ova but none fFA hybrids from fF ova. In F2 generation resulting from aAF hybrids mated with aAA a new generations of aAA and aAF hybrids were noticed, while aAF hybrids mated with fFF gave fFF and both aAF and fFA hybrids. Hybrids intercrossed together produced plenty of cocoons but no hatchlings independently whether aAF+aAF or aAF+fFA were mated. These results indicated that Ea and Ef species, easy to maintain in laboratory and commonly used as convenient models in biomedicine and ecotoxicology, may also serve in studies on molecular basis of interspecific barriers and mechanisms of introgression and speciation. Hypothetically, their asymmetrical hybridization can be modified by some external factors.

No abstract

To explain the origin of the differentiation of the spring-inhabiting fauna on an island system, this study focused on the Aegean Islands and the Bythinella snails as a model organism. We inferred the phylogeographic pattern of the Aegean Bythinella with two molecular markers, and compared the inferred pattern with the geological history of the region and the estimated levels of biodiversity of Bythinella in Greece. 95 sequences of COI and 60 of ITS-1 were obtained from samples collected from Andros, Crete, Naxos, Chios, Kithira, and western Turkey, and pooled with previously published sequences from continental Greece. Phylogenetic analysis based on the COI revealed seven new clades. On Crete, three distinct clades were identified. The estimated divergence time indicated that the geological history of the island, which was divided into smaller islands until 2-3 Mya, was most probably responsible for such high diversity. Bythinella populations inhabiting Turkey were distinct from the Aegean populations, and the divergence began after the Zanclean flood (5.3 Mya). Shell morphology and anatomy of reproductive organs confirmed that molecularly distinct clades were real entities. Biodiversity analysis revealed that, in addition to five previously known Bythinella hotspots, there is a sixth in central Greece.Keywords Origin and history of spring fauna Á Springs as ephemeral habitats Á mtDNA Á COI Á ITS-1 Á Morphology Á Phylogeography Á Biodiversity

Eisenia andrei/fetida complex of lumbricid earthworms contains E. andrei (Ea) and two mitochondrial lineages of E. fetida (Ef), referred to as Ef1 and Ef2. These earthworms are hermaphrodites capable of self-fertilization and hybridization as evidenced in laboratory mated earthworms from Ea and Ef1 lineage of Ef. The aim of the present investigations was to compare reproductive performance of Ea and Ef2 lineage from French laboratory stocks reared for a decade in Polish laboratories. These were cultured either in isolation and/or in intra-specific or inter-specific pairs for up to 57 weeks from hatching. Parental specimens and offspring were identified by species/lineage-specific sequences of the haploid mitochondrial COI gene, either 'a' or 'f2', and species-specific sequences of the nuclear 28s rRNA gene, either 'AA' or 'FF', thus delimitated as aAA or f2FF for Ea or Ef2, respectively, or aAF for hybrids. Isolated virgin earthworms produced a few sterile cocoons only, more frequently in Ef2 than in Ea, but no hatchlings. Analysis of cocoon production and reproduction of laboratory-mated intra-specific Ea+Ea and Ef2+Ef2 pairs revealed higher fecundity of Ea than Ef2 measured by numbers of cocoons and hatchlings, while inter-specific Ea+Ef2 pairs gave plenty cocoons but low numbers of aAF hybrids developed from Ea ova fertilized by Ef2 spermatozoa.