A first record of Amblyomma dissimile (Acari: Ixodidae) parasitizing the lizard Ameiva ameiva (Teiidae) in Brazil

A non-engorged adult female Amblyomma dissimile and two Amblyomma sp. larvae were found parasitizing the lizard Ameiva ameiva in the municipality of Chapadinha, State of Maranhão. This is the first record in the state of Maranhão and fills a gap in the distribution of A. dissimile in Brazil. The lizard A. ameiva represents a new host for A. dissimile , and also the first record of this tick species infesting lizards of the family Teiidae in Brazil.

Amblyomma dissimile Koch 1844 is an ectoparasite commonly found on amphibians and reptiles.This parasite is widely distributed across several countries in the Americas, including some states in Brazil (Acre, Amazonas, Pará, Roraima, Pernambuco, Mato Grosso do Sul, Mato Grosso, and São Paulo) (ARAGÃO, 1936;SCHUMAKER;BARROS, 1994;ONOFRIO, 2007;DANTAS-TORRES et al., 2008).Records of natural tick infestation of lizards in Brazil are rare because most published reports available in the literature on parasitism focus on either snakes or on laboratory experiments (SCHUMAKER; BARROS, 1994;FREITAS et al., 2004).At present, only two species of lizards have been reported to be infested by A. dissimile in Brazil, namely, adults from Iguana iguana (FREITAS et al., 2004) and nymphs from Tropidurus hispidus (DANTAS-TORRES et al., 2008).
The teiid lizard Ameiva ameiva is widely distributed in the Neotropics, occurring from Panama to central Brazil (SCHWARTZ; HENDERSON, 1991apud SARTORIUS et al., 1999).This species of lizard inhabits areas ranging from the Amazonian rain forest to the savanna of Cerrado and the semi-arid region of Caatinga (VITT; COLLI, 1994).Even as a medium-sized lizard, it has fast movements and is an active forager that feeds on a variety of arthropods and vertebrates (VITT; COLLI, 1994).The objective of this study is to report the occurrence of A. dissimile parasitizing the lizard A. ameiva in the state of Maranhão, Northeastern Brazil.
A specimen of A. ameiva was collected in an area of Cerrado belonging to the Universidade Federal do Maranhão (05° 44' S and 43° 10' W) in the municipality of Chapadinha, Maranhão.The lizard was visually examined for the presence of ectoparasites (Figure 1a).An engorged adult female tick and two larvae were found, collected manually and preserved in identified bottles containing 70% ethanol.The ticks were analyzed and identified with the aid of a stereomicroscope and according to the dichotomous keys of Aragão e Fonseca (1961) and Onofrio et al. (2006).The adult tick was identified as A. dissimile (Figure 1b) and the two larvae as Amblyomma sp.
Most of the studies on infestations of reptiles in Brazil concern the Amblyomma rotundatum, another parasite of "cold-blooded" animals that is well established in the country (ONOFRIO et al., 2006).This tick has been reported to be a parasite of A. ameiva (ONOFRIO, 2007), but data about the location were not reported.According to Pontes et al. (2009), data on A. dissimile The lizard A. ameiva inhabits a range of ecosystems and is abundant in natural and anthropogenic areas (VITT; COLLI, 1994).Thus, it represents a potential host for ticks of the genus Amblyomma.Information on its geographical distribution and host-parasite relationship, in addition to contributing to the current knowledge of Brazilian tick fauna, provide insights for future research on the ecological and epidemiological infestations by A. dissimile of wild reptiles.and A. rotundatum in Brazil indicate that these two species may have a geographically sympatric distribution in the country.At present, the known geographical distribution of A. rotundatum in Brazil is broader than that of A. dissimile.Thus, further studies are needed to corroborate this idea.The municipality of Chapadinha is within the known range for A. dissimile in Brazil, but the collected specimen represents the first recorded occurrence in the state of Maranhão and fills a distribution gap (Figure 2).This is a report of A. ameiva as a new host for A. dissimile and is also the first record of this tick species infesting lizards of the family Teiidae in Brazil.
Infestations by larvae and nymphs of Amblyomma spp.have been reported in some species of Brazilian reptiles (PEREIRA et al., 2000;LABRUNA et al., 2002;DANTAS-TORRES et al., 2008, 2010), but the difficulty involved in identifying the immature stages of several species of Amblyomma found in Brazil has prevented a more precise identification.