Phylogenetic position of Tefennia Schütt et Yildirim, 2003 (Caenogastropoda : Rissooidea)

The phylogenetic position of Tefennia tefennica Schutt et Yildirim, 2003, an endemic snail species from southwestern Turkey, was inferred with maximum likelihood analyses of DNA sequences of mitochondrial cytochrome oxidase subunit I and nuclear 18S rRNA. Tefennia belongs to the Hydrobiidae, Sadlerianinae; its sister clade comprises Grossuana Radoman, 1973, Trichonia Radoman, 1973 and Daphniola Radoman, 1973. Shell, radula and soft parts of T. tefennica are presented

Oriented clonal cell dynamics enables accurate growth and shaping of vertebrate cartilage.

Cartilaginous structures are at the core of embryo growth and shaping before the bone forms. Here we report a novel principle of vertebrate cartilage growth that is based on introducing transversally-oriented clones into pre-existing cartilage. This mechanism of growth uncouples the lateral expansion of curved cartilaginous sheets from the control of cartilage thickness, a process which might be the evolutionary mechanism underlying adaptations of facial shape. In rod-shaped cartilage structures (Meckel, ribs and skeletal elements in developing limbs), the transverse integration of clonal columns determines the well-defined diameter and resulting rod-like morphology. We were able to alter cartilage shape by experimentally manipulating clonal geometries. Using in silico modeling, we discovered that anisotropic proliferation might explain cartilage bending and groove formation at the macro-scale

Oriented clonal cell dynamics enables accurate growth and shaping of vertebrate cartilage

Cartilaginous structures are at the core of embryo growth and shaping before the bone forms. Here we report a novel principle of vertebrate cartilage growth that is based on introducing transversally-oriented clones into pre-existing cartilage. This mechanism of growth uncouples the lateral expansion of curved cartilaginous sheets from the control of cartilage thickness, a process which might be the evolutionary mechanism underlying adaptations of facial shape. In rod-shaped cartilage structures (Meckel, ribs and skeletal elements in developing limbs), the transverse integration of clonal columns determines the well-defined diameter and resulting rod-like morphology. We were able to alter cartilage shape by experimentally manipulating clonal geometries. Using in silico modeling, we discovered that anisotropic proliferation might explain cartilage bending and groove formation at the macro-scale

Molecular phylogeny, systematics and morphological character evolution in the Balkan rissooidea (Caenogastropoda)

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

Destroyed and threatened localities of rissooid snails (Gastropoda: Rissooidea) in Greece

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

Horatia Bourguignat, 1887: is this genus really phylogenetically very close to Radomaniola Szarowska, 2006 (Caenogastropoda: Truncatelloidea)?

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

Phylogenetic relationships of Dalmatinella fluviatilis Radoman, 1973 (Caenogastropoda: Rissooidea)

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