Records of three mammal tick species parasitizing an atypical host, the multi-ocellated racerunner lizard, in arid regions of Xinjiang, China.

BACKGROUND

Ticks are ectoparasites that feed on blood of a broad taxonomical range of terrestrial and flying vertebrates and are distributed across a wide range of environmental settings. To date, the species identity, diversity, and relationships among the ticks on lizards in China have been poorly understood.

METHODS

In this study, 30 ticks, collected from the multi-ocellated racerunner (Eremias multiocellata) lizard in the Tarim Basin and adjacent Yanqi Basin of the Xinjiang Uygur Autonomous Region in China, were identified by morphological observation and confirmed by DNA-based techniques. The mitochondrially encoded 12S rRNA, 16S rRNA, and COI gene fragments of ticks were amplified and sequenced. To understand the genetic polymorphisms, 47 ticks collected from hedgehogs and 1 from brushwood in the Tarim Basin were also included. Species identification was based on both morphological and molecular characters. The median-joining network approach was used to evaluate the intraspecific genealogies of the ticks and their relatedness with the geographical origin or hosts.

RESULTS

The sequence similarity analysis confirmed that the 30 ticks belong to three genera and three species including 11 individuals of Hyalomma asiaticum, 3 of Rhipicephalus turanicus, and 16 of Haemaphysalis sulcata. A network approach revealed paraphyletic populations of R. turanicus and Hy. asiaticum at the intraspecies level regarding geographical origin and low host specificity. For R. turanicus and Hy. asiaticum, common ancestry was observed between COI sequences from lizards and other sequence types from different hosts and countries.

CONCLUSIONS

To our knowledge, our study is the first to conduct a molecular survey of ticks from lizards in the arid regions of Xinjiang, China. Eremias multiocellata is an atypical host of the three tick species. Notably, two species of ticks, Hy. asiaticum and R. turanicus, have been collected and identified from lizards in China for the first time. Star-like networks suggest both of them might have experienced recent population expansion. The discoveries are closely related to the geographical environments in Xinjiang and will provide information for the control of ticks and tick-borne pathogens in Northwest China.