Parasitologists have estimated that parasites comprise over half of all animal species. That said, many regions and ecosystems remain understudied for parasites, despite free-living groups having been routinely sampled; this is especially true for the marine environment.
Current Research Focus
Over the few decades, Dr. Kirsten Jensen and colleagues have made much progress on documenting the metazoan parasite biodiversity globally, specifically of tapeworms that, as adults, parasitize the digestive tract of sharks and rays. Among the 19 orders of tapeworms currently recognized, seven orders exclusively parasitize sharks and rays. Although more than 1,050 species of tapeworms that parasitize sharks and rays as adults have been described, it is clear that this number represents only a small fraction of the vast diversity of shark and ray tapeworms that remains to be described. Within this system, major ongoing research involves the investigation of tapeworm morphology, systematics, biodiversity, coevolution, pathology, and life cycles.
In addition, patterns of host associations and geographic distributions are a central focus. Techniques employed to obtain data to address these questions include, but are not limited to, light and scanning electron microscopy, histology, and Sanger and Illumina sequencing.
Over the last several years, Kirsten Jensen and students have described more than 46 new species of tapeworms and have erected tens of new genera. An NSF-funded international collaboration resulted in a 2017 publication of a compendium on tapeworms titled Planetary Biodiversity Inventory (2008–2017): Tapeworms from Vertebrate Bowels of the Earth; this work was published through the KU Natural History Museum Special Publication series.
Recent work has focused using a phylogenomic approach to resolving the backbone of the cestode phylogenetic tree with special emphasis on elasmobranch-hosted orders, and to revise the higher-level classification of cestodes to reflect monophyletic groups