Description of a new tick species, closely related to Amblyomma javanense (Supino, 1897), associated with Varanus bengalensis (Squamata: Varanidae) in Pakistan

Abstract

The genus Amblyomma contains the highest percentage of reptile-associated ticks, and comprises approximately nine subgenera. One of these subgenera is Adenopleura, which also encompasses Amblyomma javanense, and its type species Amblyomma compressum. This study describes a new Amblyomma species associated with Bengal monitor lizards (Varanus bengalensis) based on morphology and its mitogenome in Khyber Pakhtunkhwa, Pakistan. Reptiles belonging to different genera were examined for Amblyomma ticks and only the monitor lizard was infested with ticks in the District Bajaur. Collected Amblyomma cf. javanense ticks were analyzed and formally described as a new species. Overall, 57 A. cf. javanense ticks were collected on monitor lizards (4/27) with a 15% prevalence of infestation, 2.1 mean abundance, and 14.3 mean intensity. Ticks comprised males (n = 23, 40%), females (n = 14, 25%) and nymphs (n = 20, 35%), while no larvae were found. BLAST analysis of A. cf. javanense sequences showed the following maximum identities; 98.25% with undetermined Amblyomma species based on 12S rRNA, 96.07% with A. javanense based on 16S rRNA, 99.56% and 90.95% with an Amblyomma sp. and A. javanense, respectively, based on ITS2. Moreover, the mitochondrial genome of A. cf. javanense showed maximum identities of 80.75%, 80.48% and 79.42% with Amblyomma testudinarium, A. javanense, and Amblyomma sp., respectively. The phylogenetic analysis of A. cf. javanense revealed that its 12S rRNA and 16S rRNA are closely related to an Amblyomma sp. and A. javanense, respectively, from Sri Lanka, its ITS2 is closely related to A. javanense from China and an Amblyomma sp. from Sri Lanka, and its mitogenome is closely related to A. javanense and Amblyomma sp. from China. The pairwise distance analysis resulted in divergence of 0–1.71% (12S rRNA), 0–17.5% (16S rRNA), 0–9.1% (ITS2) and 0–20.5% (mitochondrial genome). We also contributed the full-length mitochondrial genome sequence of A. compressum and showed that this species does not share a most recent common ancestor with A. javanense. As the subgenus Adenopleura is paraphyletic, this study could help to understand the systematics and phylogeny of this taxon.