Spraguea americanus, an endemic neuroparasite of the American Anglerfish

Since its discovery in 1986, classification of the endemic anglerfish parasite Spraguea americanus (Glugea americanus) has been hotly debated, creating substantial challenges in the further study of this organism. This study establishes a new type specimen for the species Spraguea americanus, including a draft genome for this species. Genomic evidence is used to update the taxonomic classification of this species, definitively placing it in the Genus Spraguea. These results are supported by phylogenetic analysis of alpha and beta tubulin sequences from this genome, which place S. americanus in the genus Spraguea over the genus Glugea in 96/100 bootstrap replicates. A comparison of metabolic pathway completeness in S. americanus and S. lophii indicates an absence of genes involved in pentose phosphate metabolism and membrane component synthesis which are unique to each species; results which may eventually enable more accurate speciation of closely related Spraguea isolates in future works. With anglerfish populations at risk due to overfishing and climate change, more accurate identification of Spraguea isolates will enable improved monitoring of outbreaks in monkfish (genus Lophius) populations across the globe, ultimately supporting effective conservation of these species in the face of overfishing and climate change.