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Differentiation in the Trochulus hispidus complex and related taxa (Pulmonata: Hygromiidae): morphology, ecology and their relation to phylogeography.

Duda M, Kruckenhauser L, Sattmann H, Harl J, Jaksch K, Haring E - J. Molluscan Stud. (2014)

Bottom Line: Finally, we compared the ecological requirements of the taxa.Thus, our morphological data do not provide evidence that any of the mitochondrial T. hispidus clades represent separate species.We suggest that its subspecies spent at least the last glaciation in or close to the presently inhabited areas.

View Article: PubMed Central - PubMed

Affiliation: 3rd Zoological Department , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria.

ABSTRACT
In this study we investigated the morphology and ecology of representatives of the taxonomically ambiguous genus Trochulus. The main focus was on the T. hispidus complex, which comprises several genetically highly divergent mitochondrial clades, as determined in a parallel molecular genetic study. We analysed shell morphology and anatomical traits and asked whether the clades are differentiated in these characters. In addition, the related species T. oreinos and T. striolatus were investigated and compared with the T. hispidus complex. Finally, we compared the ecological requirements of the taxa. Among the genetic clades of the T. hispidus complex there was no clear morphological differentiation and geographic populations could not be distinguished based on their morphology. The investigated characters of the genital anatomy did not allow discrimination of any of the T. hispidus clades and were not even diagnostic for the group as a whole. The morphotype of T. sericeus is present in all clades and thus cannot be assigned to a genetic group or any specific population. Thus, our morphological data do not provide evidence that any of the mitochondrial T. hispidus clades represent separate species. Concerning interspecific delimitation, the T. hispidus complex was clearly differentiated from T. striolatus and T. oreinos by shell morphological and anatomical characters, e.g. sculpture of shell surface and details of the penis. Finally, the habitat of T. oreinos is different from those of the other two species. In contrast to the lack of correspondence between genetic and morphological differentiation within the T. hispidus complex, related species display intraspecific morphological differentiation corresponding with mitochondrial clades: within T. striolatus there was a slight morphological differentiation between the subspecies T. s. striolatus, T. s. juvavensis and T. s. danubialis. The two subspecies of T. oreinos could be discriminated by a small but consistent difference in the cross-section of the penis. The unequal levels of intraspecific differentiation are caused by different evolutionary histories as a consequence of disparities in ecological demands, dispersal ability and use of glacial refugia: both the T. hispidus complex and T. striolatus are fast-spreading, euryoecious organisms which are able to (re-)colonize habitats and survive under different climate conditions. While the T. hispidus complex probably survived the Pleistocene in several glacial refugia, for T. striolatus one glacial refugium is suggested. Trochulus oreinos differs from the other taxa, as it is a slow disperser with a narrow ecological niche. We suggest that its subspecies spent at least the last glaciation in or close to the presently inhabited areas.

No MeSH data available.


Related in: MedlinePlus

Genital duct of Trochulus oreinos (top) and T. striolatus (bottom). Abbreviations: A, albumen gland; E, epiphallus; F, flagellum; HD, hermaphroditic duct; HG, hermaphroditic gland; ID, inner dart sacs; M, mucous glands; OD, outer dart sacs; P, penis; R, retractor muscle; SD, spermathecal duct; ST, spermatheca; VA, vagina; VD, vas deferens.
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EYU023F8: Genital duct of Trochulus oreinos (top) and T. striolatus (bottom). Abbreviations: A, albumen gland; E, epiphallus; F, flagellum; HD, hermaphroditic duct; HG, hermaphroditic gland; ID, inner dart sacs; M, mucous glands; OD, outer dart sacs; P, penis; R, retractor muscle; SD, spermathecal duct; ST, spermatheca; VA, vagina; VD, vas deferens.

Mentions: Besides these specific traits, the general genital anatomy of T. oreinos, T. striolatus and T. hispidus showed no constant differences. Examples of the genital duct and cross sections of the penis of the various taxa are shown in Figures 7, 8 and in the Supplementary Material (Figs S5–S8).Figure 8.


Differentiation in the Trochulus hispidus complex and related taxa (Pulmonata: Hygromiidae): morphology, ecology and their relation to phylogeography.

Duda M, Kruckenhauser L, Sattmann H, Harl J, Jaksch K, Haring E - J. Molluscan Stud. (2014)

Genital duct of Trochulus oreinos (top) and T. striolatus (bottom). Abbreviations: A, albumen gland; E, epiphallus; F, flagellum; HD, hermaphroditic duct; HG, hermaphroditic gland; ID, inner dart sacs; M, mucous glands; OD, outer dart sacs; P, penis; R, retractor muscle; SD, spermathecal duct; ST, spermatheca; VA, vagina; VD, vas deferens.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4214462&req=5

EYU023F8: Genital duct of Trochulus oreinos (top) and T. striolatus (bottom). Abbreviations: A, albumen gland; E, epiphallus; F, flagellum; HD, hermaphroditic duct; HG, hermaphroditic gland; ID, inner dart sacs; M, mucous glands; OD, outer dart sacs; P, penis; R, retractor muscle; SD, spermathecal duct; ST, spermatheca; VA, vagina; VD, vas deferens.
Mentions: Besides these specific traits, the general genital anatomy of T. oreinos, T. striolatus and T. hispidus showed no constant differences. Examples of the genital duct and cross sections of the penis of the various taxa are shown in Figures 7, 8 and in the Supplementary Material (Figs S5–S8).Figure 8.

Bottom Line: Finally, we compared the ecological requirements of the taxa.Thus, our morphological data do not provide evidence that any of the mitochondrial T. hispidus clades represent separate species.We suggest that its subspecies spent at least the last glaciation in or close to the presently inhabited areas.

View Article: PubMed Central - PubMed

Affiliation: 3rd Zoological Department , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria.

ABSTRACT
In this study we investigated the morphology and ecology of representatives of the taxonomically ambiguous genus Trochulus. The main focus was on the T. hispidus complex, which comprises several genetically highly divergent mitochondrial clades, as determined in a parallel molecular genetic study. We analysed shell morphology and anatomical traits and asked whether the clades are differentiated in these characters. In addition, the related species T. oreinos and T. striolatus were investigated and compared with the T. hispidus complex. Finally, we compared the ecological requirements of the taxa. Among the genetic clades of the T. hispidus complex there was no clear morphological differentiation and geographic populations could not be distinguished based on their morphology. The investigated characters of the genital anatomy did not allow discrimination of any of the T. hispidus clades and were not even diagnostic for the group as a whole. The morphotype of T. sericeus is present in all clades and thus cannot be assigned to a genetic group or any specific population. Thus, our morphological data do not provide evidence that any of the mitochondrial T. hispidus clades represent separate species. Concerning interspecific delimitation, the T. hispidus complex was clearly differentiated from T. striolatus and T. oreinos by shell morphological and anatomical characters, e.g. sculpture of shell surface and details of the penis. Finally, the habitat of T. oreinos is different from those of the other two species. In contrast to the lack of correspondence between genetic and morphological differentiation within the T. hispidus complex, related species display intraspecific morphological differentiation corresponding with mitochondrial clades: within T. striolatus there was a slight morphological differentiation between the subspecies T. s. striolatus, T. s. juvavensis and T. s. danubialis. The two subspecies of T. oreinos could be discriminated by a small but consistent difference in the cross-section of the penis. The unequal levels of intraspecific differentiation are caused by different evolutionary histories as a consequence of disparities in ecological demands, dispersal ability and use of glacial refugia: both the T. hispidus complex and T. striolatus are fast-spreading, euryoecious organisms which are able to (re-)colonize habitats and survive under different climate conditions. While the T. hispidus complex probably survived the Pleistocene in several glacial refugia, for T. striolatus one glacial refugium is suggested. Trochulus oreinos differs from the other taxa, as it is a slow disperser with a narrow ecological niche. We suggest that its subspecies spent at least the last glaciation in or close to the presently inhabited areas.

No MeSH data available.


Related in: MedlinePlus