Pearl mussels of the genus Dahurinaia (Bivalvia, Margaritiferidae): Differently sized groups of Margaritifera dahurica Middendorff, 1850

Abstract

Molecular and genetic studies have revealed that all five species of pearl mussels of the genus Dahurinaia (Bivalvia, Margaritiferidae) inhabiting the upper basin of the Amur River on the territory of Transbaikalia belong to Margaritifera dahurica Middendorff, 1850. Based on the statistical analysis, it has been shown that morphometric shell ratios form continuous variation series without differentiation on dis crete groups. It has been found that changes in these ratios are caused by the shell growth of pearl mussels and their morphological variations reflects the high level of polymorphism. The so called "comparator" species of the genus Dahurinaia are differently sized groups of one polymorphic biological species M. dahurica.

Synonymy in the family Margaritifera (Bivalvia: Unionidae)

“…(Ziuganov et al, 1994;Bolotov et al, 2015Bolotov et al, , 2016. Эта точка зрения подтверждается данными генетического и морфологического анализа (Klishko, 2014;Bolotov et al, 2016). В связи с этим валидные виды рода Margaritifera приведены в соответствии с классификацией Болотова и соавторов (Bolotov et al, 2017).…”

“…Однако в последнее время получены результаты, свидетельствующие о том, что соотношение размеров, также как и компараторный метод не дают возможности четкого определения видовой принадлежности (Сергеева и др., 2008 [Sergeeva et al, 2008]; Bolotov et al, 2013). Более того, генетический анализ показывает, что некоторые из видов, описанные по конхиологическим признакам, на самом деле являются одним и тем же видом (Klishko, 2014).…”

The species question in freshwater malacology: from Linnaeus to the present day

“…There was a lengthy discussion about the geometric foundations of the 'comparatory' method (kafanoV 1975, 1998, bogatoV 2014), however, whether or not the method was mathematically correct, the validity of the 'comparatory' species had to be checked by independent methods. The first attempts to test it were based on cytotaxonomy (pershko 2011) and multivariate statistical analyses (SergeeVa et al 2008, klishko 2014, Vinarski 2014b. However, the DNA taxonomy is the most powerful and convincing tool to do it.…”

Specific features of linear growth influencing morphometric parameters of the shell in Margaritifera margaritifera (Bivalvia: Margaritiferidae)

“…Molecular genetic data show that several species of the family Margaritiferidae that have been identified on the basis of shell dimensions actually belong to the same polymorphic species (Geist et al, 2010;Klishko, 2014). In particular, this concerns pearl mussels from the upper Amur River basin (Transbaikalia) that are referred to as Dahurinaia transbaicalica, D. prozoro vae, D. ussuriensis, D. tiunovae, and D. dahurica (Klishko, 2014).…”

“…In particular, this concerns pearl mussels from the upper Amur River basin (Transbaikalia) that are referred to as Dahurinaia transbaicalica, D. prozoro vae, D. ussuriensis, D. tiunovae, and D. dahurica (Klishko, 2014). Their segregation into an individual genus is also questionable, and the author of the above study proposed to return to the previous name, Mar garitifera dahurica, applying it to all these forms.…”