Luticola nematophagus gen. et sp. nov. (Platyhelminthes: Rhabdocoela), a Terrestrial Ascophorine Flatworm from China and Its Biological Characteristics

Rhabdocoel flatworms of the family Typhloplanidae are predominantly found in freshwater and limnoterrestrial environments, with only a few species inhabiting marine and brackish water ecosystems. In this study, a flatworm was discovered in moist soil containing nematodes in the Guizhou plateau of southwest China for the first time. A new species, Luticola nematophagus Zuo, gen. et sp. nov., belonging to a newly established genus, was described through morphological and phylogenetic analyses. The main distinguishing features of this new species include a rosette-shaped pharynx located at 1/2 of the body length, paired testes embedded in the vitellaria on either side of the pharynx, an independent copulatory bursa, and a short rod-like ascus. Additionally, a single gonopore is situated in the posterior 1/4 to 1/5 of the body length, with a distinct genito-bursal duct leading to the dorsal intestine. The new species was observed to prey on the soil nematode Meloidogyne incognita (Kofoid and White, 1919). Experiments demonstrated that the flatworms could reproduce normally over an extended period when fed on M. incognita. Isolated cultured flatworms can produce offspring, indicating their capability of self-fertilization. The findings of this study are anticipated to offer a novel solution for the biological control of agricultural soil nematodes.