Morphological and allozymic variation within and between populations of Bythinella Moquin-Tandon, 1855 (Gastropoda: Prosobranchia). I. Morphological characters

Abstract

Morphology and anatomy of 20 Central European populations of the spring snail Bythinella Moquin-Tandon are described and illustrated. Detailed descriptions, drawings and SEM photographs, as well as measurements of shells, opercula, radulae and soft parts are presented, special attention being paid to the reproductive organs. Intrapopulation and interpopulation differences in 40 biometrical characters in males and 42 in females are analysed, for each sex separately, by means of descriptive statistics and ANOVA. Relations between variables are tested with Kendall's correlation coefficient. Biometrical characters vary widely within and slightly between the studied populations, whose variability ranges overlap. The length ratios: shell/radula, bursa/bursa duct and bursa/receptacle, as well as the length of bursa copulatrix and ctenidium display a statistically significant S-N clinal variation. The wide intrapopulation variation combined with the slight differences between the distinguished morphospecies in almost all the morphological characters examined indicates a limited diagnostic value of these characters in Bythinella.

Does the genetic structure of spring snail Bythinella (Caenogastropoda, Truncatelloidea) in Bulgaria reflect geological history?

“…Only Bythinella gloeeri (Clade III) and Bythinella stoychevae (Clade II) have been found to be molecularly distinct from Bythinella hansboetersi (Clade I). However, all morphological character states given in the descriptions of the Bulgarian species are variable even within a population in Bythinella (Falniowski 1987, Mazan 2000, Mazan and Szarowska 2000a, b). …”

Morphological and allozymic variation within and between populations of Bythinella Moquin-Tandon, 1855 (Gastropoda: Prosobranchia). III. Phylogenetic analysis

“…In 1994-95, Bythinella was sampled at 20 localities in Hungary (population 1), Slovakia (populations 2-5) and . A detailed description of the localities, a distribution map, collection and fixation techniques applied, methods of morphometric and allozymic studies, as well as multidimensional phenetic analysis of morphological and allozymic variation, have been described in MAZAN (2000) and MAZAN & SZAROWSKA (2000). About 300 specimens were collected from each population.…”

“…Results of the molecular study on the evolutionary processes in the studied populations of Bythinella have been published elsewhere (FALNIOWSKI et al 1998, 1999. Analysis of biometrical variation revealed considerable intrapopulation and slight interpopulation differences (MAZAN 2000, MAZAN & SZAROWSKA 2000. In this paper, the analysis of morphological and allozymic differentiation within Bythinella was aimed at a comparison of the evolution of morphological and allozymic characters, and an attempt was made at a phylogeny reconstruction within the genus.…”

“…In this paper, the analysis of morphological and allozymic differentiation within Bythinella was aimed at a comparison of the evolution of morphological and allozymic characters, and an attempt was made at a phylogeny reconstruction within the genus. The phylogenetic analysis has enabled us to make an attempt to determine not only their overall similarity reflected by the phenetic approach applied in MAZAN & SZAROWSKA (2000) but also the genealogical relationships between the studied populations.…”

<i>Bythinella hansboetersi</i> Glöer et Pešić, 2006 (Gastropoda: Rissooidea) in Bulgaria: Its Morphology, Molecular Distinctness, and Phylogeography

“…Among others, this concerns the genus Bythinella (WOHLBEREDT 1911, WAGNER 1927, JAECKEL et al 1957, RADOMAN 1976, 1983, ANGELOV 2000, BANK 2004, GLÖER & PEŠIAE 2006, HUBENOV 2007, GEORGIEV & STOYCHEVA 2008. Much more is known on Bythinella in Central, South and West Europe (RADOMAN 1976, 1983, JUNGBLUTH & BOETERS 1977, GIUSTI & PEZZOLI 1977, 1980, FALNIOWSKI 1987, 1992, SZAROWSKA 1996, BOETERS 1998, FALNIOWSKI et al 1998, 1999, BER-NASCONI 2000, MAZAN 2000, MAZAN & SZAROWSKA 2000a, b, GLÖER 2002, SZAROWSKA & WILKE 2004. However, the systematic position of the genus and species discrimination within it have been somewhat less enigmatic since only recently (WILKE et al 2001, SZAROWSKA & WILKE 2004, SZAROWSKA 2006, BICHAIN et al 2007, the pattern of Bythinella speciation still remaining unclear ).…”