Papers by Günter Purschke
7.11.1 Polygordiidae Czerniavsky, 1881
On the phylogenetic position of the Potamodrilidae Results from ultrastructural and immunohistochemical investigations
Frontiers in Zoology, Jun 23, 2020
Background: The ground pattern underlying the nervous system of the last common ancestor in annel... more Background: The ground pattern underlying the nervous system of the last common ancestor in annelids was long thought to be settled, consisting of a dorsal brain, circumoesophageal connectives and a subepithelial, ladderlike ventral nerve cord with segmental ganglia connected by paired connectives. With the advent of immunocytochemical stainings and confocal laser scanning microscopy, it becomes evident that its architecture is extremely diverse, which makes the reconstruction of a ground pattern in annelida challenging. Whereas the nervous systems of many different families has already been described, only very few studies looked at the diversity of nervous systems within such clades to give a closer estimate on how plastic the annelid nervous system really is. So far, little is known on syllid nervous system architecture, one of the largest and most diverse groups of marine annelids. The position of the brain, the circumoesophageal connectives, the stomatogastric nervous system, the longitudinal nerves that traverse each segment and the innervation of appendages are relatively uniform within the clade. Both the number of connectives within the ventral nerve cord and the number of segmental nerves, which in earlier studies were used to infer phylogenetic relationships and to reconstruct an annelid ground pattern, are highly diverse and differ between genera or even within a given genus. Differences in the distribution of somata of the brain, the nuchal innervation and its associated cell bodies were found between Syllinae and Exogoninae and may be subfamily-specific. Conclusions: The nervous system morphology of syllids very likely depends on the taxon-specific ecological requirements. Thus, it is not surprising that in a clade, which occupies such diverse niches as the Annelida, we find similar patterns in phylogenetically widely separated species in similar niches and a high degree of modularity within a family. Only standardized protocols and staining methods can lead to comparable results, but so far different approaches have been taken to describe annelid nervous systems, making homologization of certain structures difficult. This study provides the first thorough description of the nervous system in the family Syllidae, allowing more detailed comparisons between annelid families in the future.
7.7.2 Ampharetidae Malmgren, 1866
Anatomy and ultrastructure of the ventral pharyngeal organs of <i>Saccocirrus</i> (Saccocirridae) and <i>Protodriloides</i> (Protodriloidae fam. n.) with remarks on the phylogenetic relationships within the Protodrilida (Annelida: Polychaeta)
Journal of Zoology, Jul 1, 1988
General anatomy and ultrastructure of the ventral pharyngeal organs were investigated in Succocir... more General anatomy and ultrastructure of the ventral pharyngeal organs were investigated in Succocirrus krusudensis, Protodriloides chaetifer and P. symbioticus. Succocirrus papillocercus, a species without a ventral pharyngeal organ, was included for comparison. The two genera show homologous similarities in their pharynges: bulbus muscle composed of transverse muscle fibres and interstitial cells, those cells with small cell bodies and processes containing prominent tonofilaments which are orientated dorsoventrally and connect the bulbus epithelium with the investing muscle; bulbus muscle fibres circomyarian with nuclei and mitochondria located basally, investing muscle also with interstitial cells, which lack tonofilaments; oesophagus surrounded by gland cells opening into the pharynx. Most likely, a ventral pharynx with these characters was already present in the stem species of Saccocirridae, Protodriloidae fam. n. and Protodrilidae and evolutionary processes led to several changes: a tongue‐like organ with a prominent tip and supporting elements is a synapomorphic character of Protodrilus and Succocirrus; the pharyngeal organ is reduced to stomodeal pouches and salivary glands in S. papillocercus and completely lost in Asromus raenioides. These results and data from previous studies are summarized in a tentative phylogenetic dendrogram and allow the introduction of a new family, Protodriloidae.
Molecular Phylogenetics and Evolution, Feb 1, 2020
The recognition of cryptic species concealed in traditionally established species may reveal new ... more The recognition of cryptic species concealed in traditionally established species may reveal new biogeographical patterns and alter the understanding of how biodiversity is geographically distributed. This is particularly relevant for marine ecosystems where the incidence of cryptic species is high and where species distribution data are often challenging to collect and interpret. Here, we studied specimens of the 'cosmopolitan' interstitial meiofaunal annelid Stygocapitella subterranea Knöllner, 1934 (Parergodrilidae, Orbiniida), obtaining data from four coastlines in the Northern hemisphere. Using phylogenetic tools and several species-delimitation methods (haplotype networks, GMYC, bPTP, maximum likelihood, posterior probability and morphology) we describe eight new Stygocapitella species. With one exception, all species are present along a single coastline, ultimately challenging the idea that Stygocapitella subterranea has a cosmopolitan distribution. We found evidence for several oceanic transitions having occurred in the past as well as a recent translocation, potentially due to human activity. No diagnostic characters were found, and qualitative and quantitative morphological data do not allow an unequivocal differentiation of the identified cryptic species. This suggests that (i) neither traditional diagnostic features nor quantitative morphology suffice to recognise species boundaries in cryptic species complexes, such as the Stygocapitella species complex; and that (ii) the recognition and description of cryptic species is of seminal importance for biodiversity assessments, biogeography and evolutionary biology.
Anatomy and ultrastructure of ventral pharyngeal organs and their phylogenetic importance in Polychaeta (Annelida)
Zoomorphology, Aug 1, 1985
A comparative anatomical and ultrastructural study of ventral pharyngeal organs (pharyngeal bulbs... more A comparative anatomical and ultrastructural study of ventral pharyngeal organs (pharyngeal bulbs) was carried out in two species of the Dinophilidae: Dinophilus gyrociliatus and Trilobodrilus axi. Special attention was paid to the fine structure of the stomodeal epithelium, cuticle, glands, muscles, and myoepithelial junctions. The differences between the species are very slight. The pharyngeal organ of the Dinophilidae is characterized
Leptonerilla Diplocirrata, A New Genus And Species Of Interstitial Polychaetes From The Island Of Hainan, South China (Nerillidae)
Proceedings of the Biological Society of Washington., 1996
Spermatogenesis and sperm ultrastructure in the interstitial syllidPetitia amphophthalma(Annelida, Polychaeta)
Ophelia, Nov 1, 1996
Abstract The interstitial syllid Petitia amphophthalma is gonochoristic. The mature spermatozoa a... more Abstract The interstitial syllid Petitia amphophthalma is gonochoristic. The mature spermatozoa accumulate in the dorsal region of a seminal vesicle that extends over several segments. TEM studies have shown them to be filiform spermatozoa of the so-called modified type (35 µm long) typical of many interstitial polychaetes with internal fertilization: the head comprises two elongated elements, the acrosome (ca. 8 µm long) and a nucleus (only half as long, ca. 3 µm) into which the basal part of the axoneme of the flagellum projects; in the adjacent midpiece of identical diameter (0.6 µm) the axoneme is surrounded by two mitochondrial complexes over 16 µm of its length; the spermatozoon terminates in a tail (ca. 10 µm long) consisting of the axoneme alone. Spermatogenesis occurs in the ventral region of the vesicle. The gametes differentiate into morulae, which form a cytophore after the second maturation division. Striking features of both primary and secondary spermatocytes is the presence of two pairs of...
Life cycle-, ultrastructure-, total protein- and isoenzyme model experiments into methods of taxonomy of commonly identified terrestrial Enchytraeid species (Oligochaeta, Annelida)
Special Zoology. Pt. 1: Protozoa and Invertebrate Animals
(German) Dieses neue Lehrbuch der Speziellen Zoologie beschreibt die Vielfaeltigkeit der tierisch... more (German) Dieses neue Lehrbuch der Speziellen Zoologie beschreibt die Vielfaeltigkeit der tierischen Organismen anhand ihrer charakteristischen Bauplaene (einschliesslich Cytologie und Histologie) sowie ihrer Funktionsmechanismen, ...
Echinodermata (Stachelhäuter)
Springer eBooks, 2023
System des Tierreichs
Spektrum Akademischer Verlag eBooks, 2011
Die nachstehende Darstellung vermittelt einen aktuellen Grosuberblick uber das System der Tiere i... more Die nachstehende Darstellung vermittelt einen aktuellen Grosuberblick uber das System der Tiere in Anlehnung an Westheide/Rieger (Hrsg., 2007, 2009). Systematische Kategorien (z. B. Ordnung, Klasse) der Taxa werden nicht angefuhrt, da deren Verwendung obsolet ist. Da die Grossystematik zurzeit durch die Anwendung molekularer und neuerer morphologischer Methoden in der Phylogenie noch sehr im Fluss ist, ergeben sich je nach den verschiedenen im europaischen und anglo-amerikanischen Bereich verwendeten Lehrbuchern mehr oder weniger grose Abweichungen zu dem hier vorgestellten Entwurf. So wird bspw. im angelsachsischen Sprachraum der Begriff „Tiere“ im Sinne von „Vielzellige Tiere“ = „Metazoa“ benutzt; dem wird hier insoweit Rechnung getragen, dass die Einzeller als „Einzellige Eukaryota“ berucksichtigt werden, obwohl wir besser nur von Eukaryota sprechen sollten und die verschiedenen vielzelligen Lebensformen mit berucksichtigen sollten, die mit verschiedenen Gruppen einzelliger Eukaryota in einem Schwestergruppenverhaltnis stehen. Das heist, die Einzeller bilden keine monophyletische Einheit im System der Organismen.
Cnidaria (Nesseltiere)
Springer eBooks, 2023
Arthropoda (Gliederfüßer)
Springer eBooks, 2023
Annelida (Ringelwürmer)
Springer eBooks, 2023
Mollusca (Weichtiere)
Springer eBooks, 2023
Craniota (Vertebrata), Schädel- oder Wirbeltiere
Springer eBooks, 2023
Nematoda (Fadenwürmer, Rundwürmer)
Springer eBooks, 2023
Chordata, Urochordata (Tunicata, Manteltiere)
Springer eBooks, 2023
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Papers by Günter Purschke