An investigation on the helminth parasites of Caspian turtle (Mauremys caspica) with a taxonomic note on recovered Falcaustra Lane, 1915 (Nematoda: Kathlaniidae) and Spiroxys Schneider, 1866 species (Nematoda: Gnathostomatidae)

Ehsan Rakhshandehroo, Amin Gholamhosseini, Amin Ahmadi, Mostafa Rakhshaninejad, Amir Ali Heidari


In this study, the digestive tracts of the Caspian turtles (Mauremys caspica) were investigated for the presence of helminth infections. Specimens of roundworms were recovered from the large intestine and stomach of the Caspian turtles. The morphologic measures revealed the infection with nematodes of the genus Falcaustra and Spiroxys. However, some differences were found in the collected Falcaustra specimens compared to the previous descriptions. In parallel, samples were analyzed by sequencing of the ribosomal gene targets. The phylogenetic analysis showed that the Falcaustra species as members of superfamily Cosmocercoidea were grouped with some members of Ascaridoidea and Spiruroidea. Despite the significant morphologic differences, Spiroxys species formed a sister group with ascaroid and cosmocercoid roundworms. Therefore, our molecular findings revealed that the taxonomic position of both nematodes need be revised.


Caspian turtle; Falcaustra; Spiroxys; Phylogeny

Full Text:



Baker M.R. (1986). Falcaustra species (Nematoda: Kathlaniidae) parasitic in turtles and frogs in Ontario. Canadian Journal of Zoology, 64: 228-237.

Baker M.R. (1987). Synopsis of the Nematoda parasitic in amphibians and reptiles. Memorial University of Newfoundland Occasional Papers in Biology, 11: 1-325.

Berry G.N. (1985). A new species of the genus Spiroxys (Nematoda; Spiruroidea) from Australian chelonians of the genus Chelodina (Chelidae). Systematic Parasitology, 7: 59-68.

Bursey C.R., Platt S.G., Rainwater T.R. (2000). Falcaustra kutcheri n. sp. (Nematoda: Kathlaniidae) from Geoemyda yuwonoi (Testudines: Emydidae) from Sulawesi, Indonesia. Journal of Parasitology, 86: 344-349.

Bursey C.R., Kinsella J.M. (2003). Falcaustra greineri n. sp. (Nematoda: Kathlaniidae) from Orlitia borneensis (Testudines: Emydidae). Journal of Parasitology, 89: 961-964.

Bursey C.R., Goldberg S., Kraus F. (2007) A new species of Falcaustra (Nematoda, Kathlaniidae) and other nematodes from Sphenomorphus simus (Squamata, Scincidae) from Papua New Guinea. Acta Parasitologica, 52: 142-145.

Bursey C.R., Goldberg S.R., Kraus F. (2009). New species of Falcaustra (Nematoda: Kathlaniidae) in Nyctimystes cheesmani (Anura: Hylidae) from Papua New Guinea. Journal of Parasitology, 95: 146-151.

Bursey C.R., Rivera S. (2009). New species of Falcaustra (Nematoda; Ascaridida: Kathlaniidae) in the impressed tortoise, Manouria impressa (Testudines: Testudinidaae). Comparative Parasitology, 76: 141-148.

Bursey C.R., Brooks D.R. (2011). Nematode parasites of five species of turtles from the Area de Conservación Guanacaste, Costa Rica, with description of a new species of Falcaustra. Comparative Parasitology, 78: 107-120.

Hasegawa H., Hayashida S., Ikeda Y., Sato H. (2009). Hyper-variable regions in 18S rDNA of Strongyloides spp. as markers for species specific diagnosis. Parasitology Research, 104: 869-874.

Hidalgo-Vila J., Ribas A., Florencio M., Pérez-Santigosa N., Casanova J.C. (2006). Falcaustra donanaensis sp. nov. (Nematoda: Kathlaniidae) a parasite of Mauremys leprosa (Testudines, Bataguridae) in Spain. Parasitology Research, 99: 410-413.

Li L., Hasegawa H., Roca V., Xu Z., Guo Y.N., Sato A., Zhang L.P. (2014). Morphology, ultrastructure and molecular characterisation of Spiroxys japonica Morishita, 1926 (Spirurida: Gnathostomatidae) from Pelophylax nigromaculatus (Hallowell) (Amphibia: Ranidae). Parasitology Research, 113: 893-901.

Mader D.R., Garner M.M. (2006). Euthanasia and Overview of biopsy and necropsy techniques. In: D.R. Mader (Ed.). Reptile Medicine and Surgery. Elsevier, St. Louis, Missouri. pp: 564-578.

Rajabloo M., Sharifiyazdi H., Namazi F., Shayegh H., Rakhshandehroo E., Farjanikish G. (2017). Morphological and molecular analyses of the spiruroid nematode, Falcaustra araxiana Massino, 1924 (= Spironoura araxiana) from the European pond turtle (Emys orbicularis). Journal of Helminthology, 91: 356-359.

Roca V., García G., Montesinos A. (2007). Gastrointestinal helminths found in the three freshwater turtles (Erymnochelys madagascariensis, Pelomedusa subrufa and Pelusios castanoides) from Ankarafantsika National Park, Madagascar. Helminthologia, 44: 1-6.

Roca V., García G. (2008). A new species of the genus Spiroxys (Nematoda: Gnathostomatidae) from Madagascan pleurodiran turtles (Pelomedusidae). Journal of Helminthology, 82: 301-303.

Tamura K., Dudley J., Nei M., Kumar S. (2007). MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. Molecular Biology and Evolution, 24: 1596-1599.

Underwood W., Raymond A. (2020). AVMA Guidelines for the Euthanasia of Animals. Version 2020.0.1. pp: 92-94.

Youssefi M.R., Mousapour A., Nikzad R., Gonzalez-Solis D., Halajian A., Rahimi M.T. (2016). Gastrointestinal helminths of the Caspian turtle, Mauremys caspica (Testudines), from Northern Iran. Journal of Parasitic Diseases, 40: 65-68.


  • There are currently no refbacks.