UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Contributions to the molecular phylogeny, phylogeography, and taxonomy of scyphozoan jellyfish Sparmann, Sarah Franziska

Abstract

Scyphozoan jellyfish are a major group of large, bloom-forming marine animals that can disrupt ecological stability and interfere with marine-oriented industries. The widespread geographical distributions and high degrees of morphological plasticity within many species make understanding the overall diversity of scyphozoans difficult. Molecular phylogenetic approaches have the potential to offer powerful insights into many aspects of scyphozoan biology, such as species identification, evolutionary history, and phylogeography that will improve our ability to monitor and manage the roles these animals play in marine ecosystems. We established datasets of 16S rDNA and cytochrome c oxidase subunit I (COI) sequences of several different species of scyphozoans in order to better understand phylogenetic, phylogeographical, and taxonomic patterns within the group. Phylogenetic analysis of 16S rDNA sequences resolved closely related taxa but was too variable to resolve deeper relationships with robust statistical support. Combining this marker with a more conserved dataset of nuclear 18S rDNA sequences resulted in a phylogenetic tree with clades that had higher statistical support than in trees inferred from each marker alone. 16S rDNA sequences also showed phylogeographical patterns in Cyanea, distinguishing clearly between a Northeastern Pacific (NEP) clade and a Northwestern Atlantic clade (NWA) (9.71 - 9.93% mean genetic difference MGD), as well as two Atlantic subclades (NWA1, NWA2) (1.79% MGD). Distances within clades ranged from 0.05 - 0.2%. Therefore, 16S rDNA sequences were able to delimit different (putative) species that reflected distinct geographical distributions. In addition, comparative analyses of morphological features and COI sequences from Northeast Pacific isolates of Cyanea demonstrated that C. ferrugenia is a valid lion’s mane species found in the Northeast Pacific Ocean.

Item Media

Item Citations and Data

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International