Kantharellidae is a family of worms belonging to the class Rhombozoa, order unassigned. The family consists of only one genus: Kantharella Czaker, 1994.[1] The only species in the genus is Kantharella antarctica.[2] This species is most closely related to other species of the order Dicyemida, which only has one other family, Dicyemidae.[3]
Kantharella is characterized by species that are parasitic endosymbiotes[4] and live within renal sacs of species of cephalopods.[5] They consist of only about 30 cells and they feed off of nutrients in the urine of cephalopods.[5]
The genus contains only one species Kantharella antarctica and is the only member of the family Katharellidae.[6] Katharellidae is one of three members of the order Dicyemids which also includes Dicyemidae and Conocyemidae.[6]
Kantharella are bilaterally symmetrical with a vermiform body shape.[7] They are carnivores that utilize their cephalopod hosts for nutrition.[7] They exclusively live in the ocean and reproduce asexually.[7]
The parasitic nature of Kantharella is a trait that evolved significantly long ago as all species within the class Rhomobozoa, also known as Dicyemida, are parasites.[8] There is debate to which species are closest living relatives to Kantharella as there is molecular phylogenies supporting differing species.[8] They have been found to share genetic similarities with roundworms as well as species in the phylum Orthonectida.[8]