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Morphological characters in 33 Balkan rissooid genera (Adriohydrobia, Adrioinsulana, Alzoniella, Anagastina, Belgrandiella, Bithynia, Boleana, Bythinella, Bythiospeum, Daphniola, Dianella, Emmericia, Graecorientalia, Graziana, Grossuana, Hauffenia, Heleobia, Horatia, Hydrobia, Islamia, Lithoglyphus, Litthabitella, Marstoniopsis, Orientalina, Paladilhiopsis, Parabythinella, Pontobelgrandiella, Pseudamnicola, Pseudobithynia, Pyrgula, Sadleriana, Trichonia, Ventrosia) are discussed and illustrated based on the literature and, where necessary, on the presented additional data. These include shell macrocharacters, protoconch sculpture, soft part morphology and pigmentation, radulae, stomach, female reproductive organs, male reproductive organs. Based on partial sequences of the ribosomal 18S RNA gene, a molecular phylogeny is presented for all the genera, and based on fragments of CO1 gene in mitochondrial DNA, for all except six genera. Based on the Adams consensus tree the two gene phylogenies are summarised and systematics of the group is proposed. Adrioinsulana is considered a junior synonym of Pseudamnicola; Parabythinella a junior synonym of Marstoniopsis; a new name: Radomaniola n. gen. is proposed as a replacement name for the preoccupied Orientalina. Litthabitella, morphologically and molecularly distinct from the hydrobioids, probably belongs to the Assimineidae. Marstoniopsis belongs to the Amnicolidae, Bythinella to Bythinellidae, Lithoglyphus to Lithoglyphidae, Heleobia to Cochliopidae, Bithynia and Parabithynia to Bithyniidae, Emmericia to Emmericiidae. Paladilhiopsis and Bythiospeum belong to the Moitessieriidae, there being no reason for homologising the two genera. All the other genera belong to the monophyletic family Hydrobiidae, within which two subfamilies can be distinguished: Hydrobiinae and Sadlerianinae. The latter includes mostly very closely related genera, which makes splitting of this subfamily into more groups of this rank unjustified. The phylogeny of the molecular characters is mapped on two molecular trees. The caecal appendix on the stomach, reduction of the basal cusps on the rhachis and the so called “spermathecal duct” evolved parallelly, and are thus homoplastic. The network of pores on the protoconch and the flagellum seem to be uniquely derived. The seminal receptacles and lobes on the penis seem to be phylogenetically old, not prone to changes and rather useful in phylogeny reconstruction. The morphologically inferred relationships of Emmericiidae and the systematic position of the two species of Parabythinella are discussed in Appendix 2 and Appendix 3, respectively. Destroyed type localities of Balkan rissooids are listed in Appendix 4.
Phylogenetic position of Boleana umbilicata (Kuščer, 1932) from Močilnik spring in Slovenia, the type locality of the species, was inferred with ML technique using nucleotide sequences of mitochondrial cytochrome oxidase subunit I (COI) and nuclear 18S rRNA genes. Boleana belongs to the Hydrobiidae, Sadlerianinae, and Graziana is its sister taxon.
The morphology of shell, penis, and female reproductive organs was studied in five populations of Pseudamnicola exilis (Frauenfeld) from southern Peloponnese and Kithira Island (Greece). No interpopulation differences were found in any of the characters. Thirty eight sequences of mitochondrial cytochrome oxidase subunit I (COI) and nuclear ribosomal 18S RNA genes were analysed. In COI 19 haplotypes, high haplotypy diversity, low nucleotide diversity in each population, and restricted gene flow between populations were found. NCA indicated allopatric fragmentation for all populations, and long-distance colonisation and/or past fragmentation for populations 4 and 5. Mismatch distribution in the most polymorphic population 4 reflected a bottleneck followed by population growth. The values of K2P interpopulation distances, though relatively low, pointed to congeneric distinct species within the Rissooidea. The monophyly of Pseudamnicola/Adrioinsulana clade was confirmed. Most probably the studied populations of Pseudamnicola were part of a flock of vicariant species little differentiated in morphology and ecology, many of which must have disappeared due to human impact.
A valvatiform hydrobiid gastropod, found in a spring at Dhiaselo, W of Sparta, N. Taigetos Mts., Peloponnese, Greece, was identified as Horatia hadei Gittenberger, 1982. Its protoconch sculpture, female reproductive organs and penis morphology are characteristic of Daphniola Radoman, 1973. Maximum likelihood phylogenetic analysis based on COI (cytochrome oxidase subunit I) fragments of mtDNA proved that the species is congeneric with D. exigua (A. Schmidt, 1856) and D. louisi Falniowski et Szarowska, 2000, and thus belongs to the genus Daphniola, and that D. hadei, D. exigua and D. louisi are species-level distinct taxa.
Horatia Bourguignat, 1887 was the first genus established for hydrobiid snails with valvatoid shell, and numerous valvatoid-shelled hydrobioids were classified as Horatia. The genus was the type one for some tribe/family-rank taxa. Thus it is one of the “crucial” hydrobiid genera. Horatia seems to inhabit only Croatia and Macedonia, and its type species: H. klecakiana Bourguignat, 1887, inhabits the springs in the Cetina River Valley. In the present paper the shell, operculum, soft part pigmentation, protoconch SEM microsculpture, female reproductive organs, and penis of H. klecakiana from the spring Studenci, N of Kučiće, in the valley of the Cetina River, Croatia, are described, to confirm the identity of the studied specimens with this species. Mitochondrial cytochrome oxidase subunit I (COI) and nuclear 18S ribosomal RNA gene sequences are used to infer phylogenetic relationships of Horatia, especially with Radomaniola and the sequence of Horatia from GenBank. The results suggest close relationships of the genus with Sadleriana, not with Radomaniola.
Morphology of Dalmatinella fluviatilis Radoman, 1973, a putative endemite of the Zrmanja River (Croatia), was checked. Shell, radula, and soft part anatomy were considered. In both male and female genitalia D. fluviatilis resembled Anagastina and Radomaniola. Molecular phylogeny, inferred from the mitochondrial cytochrome oxidase subunit I (COI) and nuclear 18S rRNA gene partial sequences, confirmed morphological observations: the sister taxa of Dalmatinella being Graecoarganiella, Radomaniola and Anagastina, and Dalmatinella belonging to the Sadlerianinae.
A new species: Daphniola louisi n. sp. from the spring at Kessariani, Athens, Greece, is described. This minute valvatoid-shelled snail is the second representative of the genus known so far. The shell, protoconch macro- and microsculpture, and radula are described and illustrated with SEM photographs. The other characters dealt with are: external morphology and soft part pigmentation, ctenidium and osphradium, penis, female reproductive organs. Differences between the newly described species and Daphniola exigua (A. Schmidt, 1856) are listed; phenetic relationships between the valvatoid-shelled Balkan hydrobiids are presented.
In September 2003 we visited localities of rissooid snails in continental Greece, known from the literature. Nine springs (type localities included), situated in urbanized or cultivated areas, were destroyed, changed or under stress. Localities of Rissooidea in Greece need urgent protection, otherwise the snails may disappear altogether.
Using molecular data (DNA sequences of mitochondrial COI and nuclear ribosomal 18SrRNA genes), we describe the occurrence of two species of Ventrosia Radoman, 1977: V. ventrosa (Montagu, 1803) and V. maritima (Milaschewitsch, 1916) in Greece. These species are found at two disjunct localities: V. ventrosa at the west coast of Peloponnese (Ionian Sea) and V. maritima on Milos Island in the Cyclades (Aegean Sea). Our findings expand the known ranges of both species: we provide the first molecularly confirmed record of V. ventrosa in Greece, and extend the range of the presumably Pontic V. maritima nearly 500 km SSW into the Aegean Sea. Our data confirm the species distinctness of V. maritima.
The phylogenetic relationships of the monogeneric rissooid family Emmericiidae Brusina, 1870 are unclear. The single genus Emmericia Brusina, 1870 occurs along the Adriatic coast from NE Italy to south- ern Croatia. It is characterised by the peculiar anatomy of the male genitalia (tri-lobed penis, bifurcate flagellum and penial gland). Mitochondrial cytochrome oxidase subunit I (COI) gene sequences, analysed to- gether with nuclear 18S ribosomal RNA gene sequences, showed Bithyniidae and Bythinellidae as the sister taxa of the Emmericiidae, and confirmed the homology of the flagellum and penial gland in the Emmericiidae, Bythinellidae, Amnicolidae and Bithyniidae.
Lithoglyphus prasinus (Küster, 1852) is the only representative of the genus Lithoglyphus which, instead of rivers, inhabits oligostenothermal waters of karst springs. The taxon is probably endemic to central and southeastern Slovenia and the adjacent territories of Croatia. Apart from the ecology and shell morphology, there are no differences between L. prasinus and the other Lithoglyphus species. The species distinctness of the taxon is doubtful; it has been postulated to be an oligostenothermal ecotype or race of L. naticoides. In the present paper partial sequences of cytochrome oxidase subunit I (COI) of mtDNA were used to check the species distinctness of L. prasinus from the Močilnik spring of Ljubljanica river in Slovenia. For the COI sequences K2P distances between the two taxa were 0.03170-0.03347. This, coupled with small intraspecific differences in both taxa, suggests that L. prasinus is a distinct species.
The paper describes morphometric and allozymic differences between 20 Central European populations of Bythinella. Morphometric differences were studied using principal component analysis, based on 40 biometrical characters in males and 42 in females, for each sex separately. The results showed a slight interand a wide intrapopulation morphometric variation, the variability ranges of the populations and postulated morphospecies overlapping. To visualize the pattern of interpopulation allozymic differences, studied at 9 loci, correspondence analysis of allele frequencies and multidimensional scaling based on genetic distances (Prevosti, unbiased Nei and Cavalli-Sforza and Edwards arc distance) were used. The values of Nei distances between populations (0.000–0.362) ranged from ones typical of conspecific populations (in the majority of populations) to ones characteristic rather of congeneric species. The patterns of interpopulation distinctness for molecular and morphological data were different and did not unequivocally confirm either the morphological or molecular distinctness of the distinguished morphospecies. All the genetic distances and Euclidean (morphology-based) distances were correlated with geographic distances, whereas no significant correlations were observed between the genetic and Euclidean distances.
Three sets of sequences of cytochrome oxidase subunit I (COI) from a spring snail Bythinella representing all the Balkans (63 sequences), Greece (78 sequences), and Romania (136 sequences), were used to infer maximum likelihood ultrametric trees. The trees were used to run General Mixed Yule Coalescent (GMYC) analyses assuming single threshold and multiple threshold models. For the single threshold model the threshold value was identical (0.00248 substitution per site) for each data set; for the multiple one the threshold value varied widely for the Balkan tree. Despite the same threshold value, the distinctness of the same lineages varied among trees, mostly due to differences in the models of substitution inferred for each set of sequences, but also due to different proportions of singletons in the data sets. The inferred numbers of ML entities, theoretically equalling the numbers of species, compared with all the biological evidence available so far, were overestimated in Romanian and Greek trees, but realistic in the tree for all the Balkans.
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