Freire and Lopes , 2008 , infecting lizards in an area of caatinga , northeast , Brazil

Pentastomids can infect the respiratory tract of lizards, causing their death and as a result influencing the population size of hosts. Despite this, studies on rates of pulmonary infection of Brazilian lizards, including those living in Caatinga ecosystems of northeastern Brazil are scarce. Active collections of lizards were performed from October to December 2004 in an area of Caatinga of the Estação Experimental de São João do Cariri − EESJC (07° 25’ S and 36° 30’ W), located in the state of Paraíba, Northeast of Brazil. Forty-five lizards inhabiting granite outcrops in an area of Caatinga were captured, belonging to the following species: Tropidurus hispidus (Spix, 1825) (18 individuals), T. semitaeniatus (Spix, 1825) (15 individuals), Phyllopezus periosus Rodrigues, 1986 (6 individuals), and P. pollicaris (Spix, 1825) (6 individuals). Laboratory examination revealed that all species had some degree of pulmonary infection caused by Raillietiella mottae. The highest rates of prevalence (66.7%) and mean intensity of infection (5.25 ± 2.01, range of 2-11) were observed in P. periosus. The results obtained in this study show that lizards of the Brazilian semiarid region are infected by a generalist species of pentastomid. The most likely cause for such pattern is the similarity in lizards’ diets (ants and termites). It is particularly noteworthy that T. semitaeniatus, P. periosus, and P. pollicaris represent new host records for R. mottae.


Introduction
Brazil still holds one of the most significant biological diversities in the world, with a herpetofauna represented by a great number of species described (Rodrigues, 2005).A rich fauna of endoparasites is associated to reptiles, but much of the published work on these animals is mostly descriptive (Vicente et al., 1993;Rocha et al., 2000).Studies on community variables, like abundance, prevalence, and mean intensity of infection have only recently been published (Ribas et al., 1995;1998;Rocha, 1995;Vrcibradic et al., 1999;Vrcibradic et al., 2000;Vrcibradic et al., 2002a;2002b;Rocha et al., 2003;Rocha and Vrcibradic, 2003;Dias et al., 2005;Anjos et al., 2005).
Recent publications have included evaluations on infection rates, prevalence, and mean intensity of infection in studies of snakes, amphisbaenians and lizards of the northeastern region of Brazil (Dias et al., 2005;Almeida et al., 2006a;Almeida et al. 2006b;Almeida et al. 2007;Almeida et al. 2008a;Almeida et al. 2008b;Anjos et al., 2008), nevertheless, only four lizard species were investigated.Dias et al. (2005) reported a likely new species of Raillietiella aff.furcocerca (Diesing, 1863) infecting the lungs of two whiptail lizard species, Cnemidophorus abaetensis Dias, Rocha andVrcibradic, 2002 andC. ocellifer (Spix, 1825) in a restinga habitat in the state of Bahia.Almeida et al. (2008b) investigated infection caused by R. mottae in the lungs of Tropidurus hispidus (Spix, 1825) living in the semi-arid region of Cariri, state of Ceará, northeastern Brazil. Anjos et al. (2008) reported Hemidactylus mabouia (Moreau de Jonnès, 1818), a dwelling's invader gecko in the Cariri region (municipality of Barbalha, Ceará state), as a new host of R. mottae.The authors reported in their work, the first occurrence in Brazil of R. frenatus Ali, Riley and Self, 1981 parasitizing H. mabouia.In the present study we evaluate infections caused by pentastomids in an assemblage of lizards living in an area of Caatinga.It is specifically addressed here i) the composition of pentastomid fauna and ii) rates of infection (prevalence and intensity).

Material and Methods
Diurnal and nocturnal active lizards living on granite outcrops in the Caatinga were captured using sling-shots and through manual collection, from October to December 2004.The outcrops, locally known as 'lajeiros', are situated in the Estação Experimental de São João do Cariri − EESJC (07° 25' S and 36° 30' W), in the state of Paraíba, Northeast Brazil.The area where the animals were captured is characterized by xerophytic vegetation, with thorny shrubs, stunted trees with entwined branches, having high density of cacti and bromeliads (Mélo and Bandeira, 2004;Andrade et al., 2005).It is situated in the semi-arid region of Paraíba, characterized temperatures ranging between 28 and 35 °C on average and annual mean rainfall of 387 mm.The rainfall concentrates from February to April.During drier years the dry period lasts over eight months (Núcleo de Meteorologia Aplicada, 1987).
Upon collection, the lizards were frozen-euthanized and their snout-vent length (SVL) measured with a ruler (to the nearest 1 mm).They were then fixed in formalin 10% and preserved in ethanol 70%.
The respiratory tracts of the lizards were removed and the search for pentastomids was carried out under a stereomicroscope.The pentastomids collected were cleared in Hoyer's medium, temporarily slide-mounted and preserved in ethanol 70%.Identification was performed based on dimensions of the hooks and copulatory spiculae of males, with the aid of a microscope with a micrometric eyepiece (see Ali et al., 1984;1985;Almeida et al., 2008b).

Results
Forty-five lizards were captured, being 18 individuals of the species T. hispidus, 15 of T. semitaeniatus (Spix, 1825), 6 of P. periosus Rodrigues, 1986 , and 6 of P. pollicaris.All species had their lungs infected by only one species of pentastomid, R. mottae (Table 1; Figure 1).The highest rates of prevalence and mean intensity of infection were found in P. periosus.Almeida et al. (2008b), using data from literature reports, emphasized the possibility of specificity of R. mottae parasitizing T. hispidus, which had not yet been recorded as a host of any species of pentastomid.Almeida et al. (2008b) stated that together with morphological evidence, such evaluation would reinforce the proposition for the existence of a new species.However, data obtained by Almeida et al. (2006a;2008a;2008b) indicates that two species of pentastomids, Cephalobaena tetrapoda Heymons, 1922 and Raillietiella furcocerca, should be generalists because of their recorded variety of hosts.Anjos et al. (2008) reported only one female of gecko, H. mabouia, parasitized by R. mottae.This isolated case reported by these above-mentioned authors could have resulted from the low sampling they performed.

Discussion
The results obtained in the present study suggest that R. mottae is a generalist parasite and does not have any reptile specificity, at least with respect to the lizard species investigated.All lizards studied are insectivores and foragers, and therefore, could be deemed as predators with short handling times when compared to their search times.Searching is always moderately time consum-ing, so searchers should be generalists, a similar condition to the one of birds reported by Begon et al. (2006).Lizards would have an overall profitability maximized by a broader diet, constituted by minute insects thriving on outcrops of the Caatinga.Tropidurus hispidus and T. semitaeniatus are diurnal predators while P. periosus and P. pollicaris are nocturnal predators.Both groups (tropidurid and geckonid) feed on ants and termites that are abundant on Caatinga outcrops, as we could observe in situ, and they are likely intermediate hosts of R. mottae.
Rates of infection intensity obtained here for T. semitaeniatus (4.0 ± 3.0, range 1-7) and P. pollicaris (5.0) and also the value of 4.5 obtained for C. abaetensis by Dias et al. (2005) are similar to values obtained by Almeida et al. (2008b).
The higher values of mean rates of infection recorded for R. mottae refer to P. periosus, which had mean rate of infection of 5.25 (± 2.01, range 2-11).According to Riley et al. (1991), burdens of 9-20 worms per host frequently killed geckos.
Despite all these discrepancies, it is important to emphasize that similarity and difference in rates of in- fection intensity may result from stochastic events and vary according to sample size and specific environmental characteristics from the studied areas.Therefore, it must be emphasized the need for further studies on patterns of pulmonary infection by pentastomids in lizards, in the neotropical region.
Acknowledgements -Our thanks to D. Noronha, curator of the Helminthological Collection of the Instituto Oswaldo Cruz, for the loan of pentastomid specimens; to FUNCAP -the Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico (Ref.943/03 -Edital 003/03) for the research grant to W. O. Almeida; to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the research grant received through the Programa Ecológico de Longa Duração (PELD); to the Fundação Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the scholarship to G. G. Santana.We also thank the Brazilian Institute for the Environment and Natural Resources (IBAMA) for permission to collect samples from protected areas (Documents nr 02021.000075/2006-7and 080/04 -RAN/ IBAMA 02007.001009/04-73); to B. Grisi for the suggestions and the English version of the manuscript; to E. Medeiros (UEPB) for revising the English version of the text; and to two anonymous reviewers for their valuable suggestions and comments on the manuscript.