Phylogenetic systematics of the sea slug genus, Cyerce Bergh 1871 (Mollusca: Gastropoda: Sacoglossa)

• Main Author: Moreno, Karina
• Other Authors: Valdes, Angel
• Format: Other/Unknown Material
• Language: English
• Published: California State Polytechnic University, Pomona 2020
• Subjects: Cyerce specimens; Cyerce Bergh 1871; Biological and Agricultural Sciences; Pacific; North Atlantic
• Online Access: https://hdl.handle.net/20.500.12680/pz50h080n

The genus Cyerce Bergh 1871 is a group of sea slugs including eleven accepted species distributed throughout tropical and subtropical areas of the lndo-West Pacific, Eastern Pacific, and North Atlantic. Species of Cyerce are stenotropic herbivores that possess remarkable adaptations such as aposematic coloration, synthesis of polypropionates, and acquisition of plastids from their algal hosts. The evolution of these traits in Cyerce has not been studied. Cladistic analyses have been performed on Sacoglossa, but a species level phylogenetic analysis for the genus Cyerce are lacking. The objective of this study is to produce a monographic review of Cyerce using both molecular and morphological data. In order to resolve the evolutionary relationships among Cyerce species, two mitochondrial genes (CO1, 16S) and nuclear gene (H3) were sequenced from 140 specimens borrowed from museums, collaborators, or collected in the field. Bayesian analyses were used to generate phylogenetic trees. A species delimitation analysis with ABGD was performed using CO1 aligned sequences to support phylogenetic analyses. The internal anatomy of the Cyerce specimens was studied to supplement molecular data. This included dissections of the radula and male reproductive anatomy. Twenty-three genetically distinct species of Cyerce were recovered from the analyses with observed differences in size of the buccal mass and radula across species. This study also resulted in novel findings, such as the evidence of fifteen new species of Cyerce. These results are significant in modeling how phylogenetics can be used to study biodiversity and evolutionary factors that drive speciation.