Infection rates of pentastomids on lizards in urban habitats in the Brazilian

The rates of pentastomid infections in the syntopic lizards Hemidactylus mabouia and Tropidurus hispidus inhabiting buildings at the Federal University of Paraiba, in João Pessoa, NE Brazil were examined. A total of 30 specimens of Hemidactylus mabouia and 55 specimens of Tropidurus hispidus were examined. The animals were sacrificed by freezing and then fixed and conserved in 70% alcohol. Analyses of the respiratory tract of Hemidactylus mabouia demonstrated that these lizards were infected by Raillietiella frenatus at a rate of 20% (6/30) with an average infection intensity of 1.33 ± 0.21, 1-2. None of the specimens of T. hispidus analyzed were infected. Hemidactylus mabouia and R. frenatus are of African origin and it is possible that there are specific relationships, or preferences, between these two species.


Introduction
Parasites can be important regulatory agents in reptile populations, affecting fertility, dietary habits, death rates, or even causing local extinctions.The examination of parasite/host relationships is of known importance in studies of the dynamics, conservation and management of reptile populations (Marcogliese, 2004).
The Pentastomida constitute an important group of respiratory tract parasites in vertebrates, especially reptiles, although they have been little studied in the neotropics (Almeida and Christoffersen, 2002).Works undertaken in Brazil on pentastomid parasitism have focused on numerous topics, including studies of the systematics of this group and rates of reptilian infection (Rego, 1984;Almeida and Christoffersen, 1999;2002;Vrcibradic et al., 2002;Dias et al., 2005;Almeida et al., 2006a;2006b;Almeida et al., 2007;2008a;b;c;Anjos et al., 2008).However, lung infection rates by pentastomids have so far only been determined in eight reptile species.Vrcibradic et al. (2002) examined the infection of Mabuya agilis by larvae of Raillietiella sp.(collected in coastal dunes areas in the states of Rio de Janeiro and Sergipe); Dias et al. (2005) found infections of Raillietiella aff.furcocerca in the lungs of Cnemidophorus abaetensis and C. ocellifer (in coastal dune areas of Bahia State); Only a single species of Pentastomida (Raillietiella frenatus) was found parasitizing adults of H. mabouia.The general prevalence of infection was 20% (6/30) and the average infection intensity was 1.33 ± 0.21 (range 1-2).No significant differences were detected in infection rates (3 males and 3 females) or in the average infection intensities according to sex (1.33 ± 0.33, 1-2).Parasite infection was not observed in juvenile specimens.

Discussion
Parasitism on H. mabouia by R. frentatus in Brazil was reported by Anjos et al. (2008).An analysis of 37 specimens of H. mabouia performed by these authors revealed an infection rate of 43.2%, with an average intensity of 1.8 ± 1.4.That prevalence was higher than the analysis presented here, although the infection intensities were very similar.
The present study evaluated the rates of pentastomid infection in two syntopic species of lizards in an urban habitat in order to examine the composition of the pentastomid fauna and to determine infection rates (prevalence and intensity).

Materials and Methods
Eighty-five specimens of lizards (30 H. mabouia and 55 T. hispidus) were collected in December 2006 in houses on the campus of the Federal University of Paraíba, in the municipality of João Pessoa, Paraíba State (7° 09' S and 34° 47' W), northeastern Brazil.The local climate is hot and humid, with the heaviest rainfall occurring between the months of March through August.The average annual temperature is approximately 25 °C, the total rainfall varies between 1,500 and 1,700 mm, and the relative humidity stays near 80%.The dry season usually varies from between one to three months (October through December) (Lima and Heckendorff, 1985).
Lizards were collected by hand and were quickly euthanized by freezing and then fixed and preserved in 70% ethanol.Lizard snout-vent length (SVL) was measured with a ruler (to the nearest 0.1 mm).Voucher specimens were deposited in the Herpetology Collection of the Department of Systematics and Ecology of the Federal University of Paraíba, in João Pessoa, Paraíba State, Brazil.
The lungs were removed from the lizards and examined for pentastomids using an optical stereomicroscope.The pentastomids found were either preserved in 70% alcohol or mounted on slides and treated with Hoyer's mounting medium.Pentastomid identification was based on the dimensions of the hooks and copulatory spiculae of the males (measured with the aid of a microscope fitted with a micrometer eyepiece) (Ali et al., 1981).Drawings were made with the aid of a drawing tube connected to a brightfield microscope.
Ecological terms related to parasitology used in the present study follow Bush et al. (1997).
The absence of infection by R. frenatus on T. hispidus may be the result of behavioral differences between these diurnal tropidurids and the nocturnal gecko H. mabouia.However, Almeida et al. (2008c) reported parasitic infections in diurnal syntopic lizards (T.hispidus and T. semitaeniatus) as well as in nocturnal species (P.periosus and P. pollicaris) caused by the same pentastomid species (R. mottae).Almeida et al. (2008c) suggested that tropidurids and gekkonids feed on ants and termites that are abundant in Caatinga rock outcrops and that these are likely intermediate hosts of R. mottae.There is also the possibility that the exotic pentastomid R. frenatus is specific for H. mabouia.Other investigations suggest that exotic geckos retained their natural pentastomid fauna (Self and Diaz, 1961;Ali et al., 1981;Ali and Riley, 1983;Pence and Selcer, 1988;Riley et al., 1988;1991).These exotic pentastomids appear to have been able to colonize intermediate hosts having wide geographic distributions, such as the cockroach, Periplaneta americana (Ali and Riley, 1983;Jeffery et al., 1985;Bosch, 1986;Criscione and Font, 2001).More studies will be required to address these questions.