Ours was the first study to employ a targeted gene capture approach for tapeworms. We have developed ~400 orthogroups (~1,000+ exons) with varying degrees of phylogenetic signal and thus of potential application for phylogenetic work in other groups of flatworms beyond tapeworms (e.g., digeneans, monogeneans). The project resulted in the publication of 1 new family, 7 new genera, and descriptions of 73 new species. Our phylogeny represents the most comprehensive and robust phylogeny of tapeworms available. It reveals that the tapeworms of elasmobranchs are key to the evolution of all groups of acetabulate tapeworms. One of the most interesting outcomes of our work is that it has provided strong evidence that the Cyclophyllidea—the order that includes not only the majority of species that parasitize birds, mammals, amphibians, and herptiles, but almost all of the species of tapeworms that parasitize terrestrial vertebrates—had its origins in the tapeworms that parasitize elasmobranchs. While the evidence is not definitive, it suggests that origin involved a group of batoids. The phylogeny revealed hundreds of the species across the topology that are new to science. The fact that the molecular work required to confirm that novelty has already been conducted paves the way for the descriptive work required to formally describe these species. The phylogeny also serves as a framework for future work on the evolution of tapeworms. A species level tree for tapeworms serves as a resource for future work investigating the evolution of morphological traits, adaptations to attachment to host mucosa, diversification across lineages, and, given we have also generated a species-level tree for the hosts, cophylogenetic signal between the tapeworms and their elasmobranch hosts. The revised classification changes the landscape of our understanding of higher-level diversity in the tapeworms of elasmobranchs. We have resolved the rampant polyphyly of the suite of taxa known as the “tetraphyllidean relicts”. As a result of the new classification all orders of tapeworms are now monophyletic and can be investigated as unified evolutionary units. It also provides a definitive answer to the question of whether hooks that have been shown to be composed of different proteins are homologous—the answer is a resounding NO! The tapeworms that possess hooks represents 6 distinct mutually monophyletic orders, none of which are each other’s closest relatives. We are the first to assemble genomes for any of the orders that parasitize elasmobranchs and bonyfish. Prior to our work, genome data were limited to a handful of species of medical importance in the cestode orders Cyclophyllidea and Diphyllobothriidea. By assembling genomes for taxa across the phylogenetic tree of eucestodes we have provided important context. We engaged 2 postdoctoral fellows, 2 technicians, 7 graduate students, 13 undergraduate students and 1 post-bac student. We collectively presented a total of 36 talks at regional, national, and international meetings. The project resulted in a total of 23 publications. We completed the development of the web application for the visual, multi-entry, interactive online key to the identification of elasmobranch tapeworm genera (https://tapeworms-unlocked.info). Finally, we produced an interactive online version of our children’s book “Meet the Suckers” which can also be accessed via the tapeworm key site (https://book.tapeworms-unlocked.info/).

Last Modified: 02/28/2025
Modified by: Janine N Caira