Phylogenetic Relationships Among Dorid Nudibranchs


Sarah Madero


  • Jermaine Mahguib, Graduate Student, California Polytechnic University, Pomona
  • Angel Valdes, Professor, Pricipal Investigator, California Polytechnic University, Pomona

Dorids are a clade of nudibranch sea slugs whose evolutionary relationships are still uncertain. Nudibranchs are invertebrate, marine gastropods and the clade itself is vastly diverse. Morphologically, Dorids can typically be distinguished by the presence of a dorsal gill, and species within the clade Doridoidea exhibit similar body shapes. Elucidating relationships among these organisms will allow for further understanding of the phylogeny of nudibranchs in general, as well as provide insight into the mechanisms of development of chemical defenses employed by the group. Investigating the manner by which certain Dorids can assimilate toxins from prey and use these toxins in their own defense has future potential to aid in pharmacological research. I conducted a molecular analysis of various species of Dorids in order to generate a phylogenetic tree showing the evolutionary relationships within the clade. DNA was extracted from acquired samples and polymerase chain reactions [PCR] were run on extractions in order to amplify 16S, H3, and CO1 genes respectively. I then confirmed the presence of the gene under investigation using gel electrophoresis. Positive PCR results were purified and sent offsite for sequencing. Obtained sequences were then edited and phylogenetic trees assembled according to best fit models. Original results added little insight and branches on the phylogenetic trees first generated were poorly supported. Additional sequences were acquired in an effort to further clarify the phylogeny of the Doridoidea clade and a more tree with greater statistical support was generated. Well supported taxa agree with previously proposed relationships among Dorids. However, explicating overall branching within the group will require further investigation and I am currently working to obtain a greater number of gene sequences with which to run analysis.

Presented by:

Sarah Madero


Saturday, November 23, 2013




Poster Session 3 - Villalobos Hall

Presentation Type:

Poster Presentation