Litobothriidae is a family of marine tapeworms that parasitize the spiral valve of lamniform sharks. This family contains one genus, Litobothrium,which includes 9 species. Litobothriidean tapeworms typically bear a triangle shaped scolex with an apical sucker and multiple cruciform pseudosegments. This morphology is seen in 8 of the 9 species, the most recently described speceis on the other hand bears no resemblance to its congeners. Instead L. aenigmaticumbears a dome shaped scolex and an elongate cephalic peduncle. Despite its odd morphology molecular data robustly places this new worm within the genusLitobothrium (Caira et al. 2014). Most species in this group are euapolytic, which means they shed their proglottids as they reach maturity. L. aenigmaticumis the only one that appears to be hyperapolytic, proglottids are released while they are immature. Members of this family have been found in Mexico, the United States, Australia, and Taiwan. Their hosts includeAlopias pelagicus,A. superciliosus, Odontaspis ferox, andMitsukurina owstoni.
