Leerbooek Der Vergelijkende Ontleedkunde Van De Vertebraten

v,415 hal,;ill,;22 c

Ueber Ancylostoma perniciosum v. Linstow und die Strongyliden des Elefanten

Als Herr Prof. MAX WEBER mich aufforderte einen Beitrag zu liefern zur Festschrift zum 70. Geburtstag des Herrn Dr. C. KERBERT, des verdienstvollen Direktors der Königlichen Zoologischen Gesellschaft „Natura Artis Magistra”, leistete ich mit Freude dieser Einladung Folge, da ich in den Jahren, in welchen ich als Assistent am zoologischen Institut der Universität Amsterdam beschäftigt war, öfters mit Herrn Dr. KERBERT in angenehmster Weise in Berührung kam und mehrfach Gelegenheit hatte ihn hochschätzen zu lernen als Mensch, Direktor des zoologischen Gartens und Forscher. Das Material für diesen kleinen Beitrag zur näheren Kenntnis einiger Nematoden stammt aus dem so vorzüglich von Dr. KERBERT geleiteten, Amsterdamer Zoologischen Garten. Herr Prof. WEBER überliess mir nämlich die Untersuchung einer ziemlich umfangreichen Sammlung von Nematoden und Acanthocephalen, welche im Lauf mehrerer Jahre bei der Sektion von im Tiergarten gestorbenen Tieren erbeutet waren. Bis jetzt habe ich von dieser Sammlung näher untersucht Ancylostoma perniciosum v. Linstow aus Felis pardus und Murshidia falcifera (Cobbold) aus Elephas indicus, welche Würmer den Gegenstand dieses kurzen Aufsatzes bilden

Phylogenetic analysis of phenotypic characters of Tunicata supports basal Appendicularia and monophyletic Ascidiacea

With approximately 3000 marine species, Tunicata represents the most disparate subtaxon of Chordata. Molecular phylogenetic studies support Tunicata as sister taxon to Craniota, rendering it pivotal to understanding craniate evolution. Although successively more molecular data have become available to resolve internal tunicate phylogenetic relationships, phenotypic data have not been utilized consistently. Herein these shortcomings are addressed by cladistically analyzing 117 phenotypic characters for 49 tunicate species comprising all higher tunicate taxa, and five craniate and cephalochordate outgroup species. In addition, a combined analysis of the phenotypic characters with 18S rDNA ‐sequence data is performed in 32 OTU s. The analysis of the combined data is congruent with published molecular analyses. Successively up‐weighting phenotypic characters indicates that phenotypic data contribute disproportionally more to the resulting phylogenetic hypothesis. The strict consensus tree from the analysis of the phenotypic characters as well as the single most parsimonious tree found in the analysis of the combined dataset recover monophyletic Appendicularia as sister taxon to the remaining tunicate taxa. Thus, both datasets support the hypothesis that the last common ancestor of Tunicata was free‐living and that ascidian sessility is a derived trait within Tunicata. “Thaliacea” is found to be paraphyletic with Pyrosomatida as sister taxon to monophyletic Ascidiacea and the relationship between Doliolida and Salpida is unresolved in the analysis of morphological characters; however, the analysis of the combined data reconstructs Thaliacea as monophyletic nested within paraphyletic “Ascidiacea”. Therefore, both datasets differ in the interpretation of the evolution of the complex holoplanktonic life history of thaliacean taxa. According to the phenotypic data, this evolution occurred in the plankton, whereas from the combined dataset a secondary transition into the plankton from a sessile ascidian is inferred. Besides these major differences, both analyses are in accord on many phylogenetic groupings, although both phylogenetic reconstructions invoke a high degree of homoplasy. In conclusion, this study represents the first serious attempt to utilize the potential phylogenetic information present in phenotypic characters to elucidate the inter‐relationships of this diverse marine taxon in a consistent cladistic framework.Peer Reviewe