The population density of Lymnaea columella (Say, 1817) (Mollusca, Lymnaeidae) an intermediate host of Fasciola hepatica (Linnaeus, 1758), in the Caparao microregion, ES, Brazil/Densidade populacional de Lymnaea columella (Say, 1817) (Mollusca, Lymnaeidae) hospedeiro intermediario de Fasciola hepatica (Linnaeus, 1758) na microrregiao do Caparao, ES, Brasil.
Molluscs of the Lymnaeidae family have a cosmopolitan distribution, and in Brazil the Lymnaea genus is represented by three species: L. viatrix (d'Orbigny, 1835), L. cubensis (Pfeiffer, 1839) and L. columella (Say, 1817), all recognized as intermediate hosts of the trematode Fasciola hepatica (Linnaeus, 1758), etiologic agent of bovine fasciolosis (Maure et al., 1998).
Lymnaea columella has a wide geographical distribution, being found in state of Espirito Santo (Medeiros et al., 2014). The structure and abundance of its populations are directly related to the intrinsic interactions of the species and extrinsic properties imposed by the local habitat. In addition, factors as temperature, rainfall and human actions are regarded as especially important in the structural process of establishment and population survival (Ollerenshaw, 1971; Torgerson and Claxton, 1999).
Populations of this mollusc are subject to many ecological constraints imposed by temporal fluctuations in their environment (Gerard, 2001). Explosive growth because of high reproductive rates under favorable conditions alternate with drastic declines under unfavorable periods in for its development (Malone et al., 1984). Accordingly, small populations can quickly recover in number, since individuals are also able to self-fertilization (Dillon, 2004).
Similarly, the epidemiology of fasciolosis is linked to environmental and climatic factors, and its occurrence is usually associated with areas of high slope and precipitation, which contributes fairly to the establishment of wetlands, important niches for the maintenance of L. columella (Dutra et al., 2010). In this context, the state of Espirito Santo becomes a potential breeding site, due to the warm and humid climate and local topography to the development of the parasite and its host (Bernardo et al., 2011). Martins et al. (2012) observed the existence of risk areas for fasciolosis in the southern region of this state and Freitas et al. (2014) reported prevalence rates of up to 28.41% for the disease. These data reflect the importance of the state of Espirito Santo as being a reservoir area for the disease and investigations on factors that determine mollusc species richness and distribution in wetland systems are scarce in the Neotropical region (Maltchik et al., 2010).
Considering that knowledge of the time of occurrence of mollusc is most important for the establishment of control programs for fasciolosis, and the population studies of the intermediate hosts contribute to the knowledge of the ecology of these, the aim of this study was to monitor the population density of L. columella in various aquatic habitats and in drinking waters from production systems at the Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo on Caparao Microregion, state of Espirito Santo, during the years 2010 to 2013.
2. Material and Methods
2.1. Location of the experiment
The experiment was conducted from November 2010 to June 2013. Monthly samplings were performed at five selected points representing drainage areas and drinking water in cattle and goat production systems at the Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo (IFES), located in the city of Alegre, state of Espirito Santo, in the Caparao microregion. The collect points were delimited in an area of 1 [m.sup.2], perpendicular at your source. Point 1 was a drinking water reservoir for calves in a cattle production system (S 20[degrees]45'880", W 41[degrees]27'319"). Point 2 was a wetland close to the reservoir for a drinking water for calves in a cattle production system (S 20[degrees]45'879", W 41[degrees]27'270"). Point 3 was a drinking water reservoir for a goat production system (S 20[degrees]45'692", W 41[degrees]27'556"). Point 4 and 5 were a drinking water reservoir for goats (S 20[degrees]45'691", W 41[degrees]27'544" and S 20[degrees]45'682", W 41[degrees]27'529").
2.2. Collection and analysis of molluscs
Molluscs in the margins of drinking water reservoir were collected, submersed or not, and in around vegetation. Also collected within the flooded regions, adhering to aquatic and terrestrial plants that were present. Vegetation samples were collected from the area to determine the presence of mollusc eggs. All procedures were performed manually with specific equipment such as sieves, nettings and filters. After collection, the molluscs were sent to the parasitology laboratory of the Hospital Veterinario da Universidade Federal do Espirito Santo (HOVET-UFES), where they were separated according to points, counted and identified according to Paraense (1975, 1983, 1986). Samples ofL. columella were directly exposed to artificial light for four hours and then analysed to determine the presence of larval form of F. hepatica. This procedure was performed according to the Manual of Surveillance and Control of Molluscs of Epidemiological Importance (Brasil, 2008).
2.3. Meteorological data collection
Meteorological data were provided by the Instituto Capixaba de Pesquisa, Assistencia Tecnica e Extensao Rural (INCAPER). The data were analysed and correlated with the presence of molluscs over the study period.
2.4. Statistical analysis
Descriptive tabular statistics were calculated to report the frequency of molluscs collected. Monthly variations in temperature and precipitation relative to the frequency of Lymnaea columella were graphically analysed. Monthly averages were calculated over the study period. The seasons were classified according to precipitation levels: dry season (April to September) and rainy season (October to March). The monthly number of mollusc according to season (dry or rainy) was tested for normality and analyzed nonparametrically with a Mann-Whitney test. A significance level of p<0.05 was used for all tests.
A total of2038 molluscs were collected. Of these 1558 (76.45%) belonged to the genus Lymnaea (d'Orbigny, 1835), 240 (11.78%) to the genus Physa (Draparnaud, 1801) and 240 (11.78%) to the genus Biomphalaria (Preston, 1910). Points 1 and 5 presented higher average number of molluscs collected per year, with predominance of Lymnaea columella (Say, 1817) (Figure 1). Points 3 and 4 showed higher occurrence of Biomphalaria sp. and point 2 presented higher occurrence of Physa sp. as shown in Table 1. No L. columella specimens showed evidence of the larval stages of Fasciola hepatica.
[FIGURE 1 OMITTED]
The average number ofL. columella collected decreased in 2011. Although only two months of evaluation were performed in 2010, the average number of this species was higher in this year, as in 2013. During the 32 months of study, the average temperature was 23.7[degrees]C, and the average precipitation was 141 mm. The greatest average numbers of L. columella were found in the months with the greatest precipitation. The monthly distribution of these molluscs and the precipitation and temperature data for 2011, 2012 and 2013 are shown in Figure 2.
In 2011, the average precipitation was 130 mm, and the average temperature was 23[degrees]C. Note the extended period of rainfall during the rainy season and the marked decrease during the dry season. The numbers of L. columella only began to increase in September, with a slight decrease in January, February and March. The highest temperatures of the year were observed during these three months, averaging 27.1[degrees]C, 27.6[degrees]C and 25[degrees]C, respectively.
The rainfall in 2012 was less than that in 2011. In 2012, the average precipitation was 84 mm, and the average temperature was 24[degrees]C. Lymnaea columella population showed two peaks in 2012. A total of 120 specimens were collected in January, and a total of 134 were collected in December. These data are consistent with the major peaks of precipitation. In 2013, the averages, computed through June, were 171 mm precipitation and 24[degrees]C temperature. Therefore, the seasons were similar in 2013 and 2011, except after March, when the precipitation level corresponded to lower numbers of L. columella. The correlation between the monthly number of molluscs and the season was not significant (p=0.30).
[FIGURE 2 OMITTED]
The southern region of the state of Espirito Santo is characterized by the presence of mountainous areas cut by the work of many river valleys that harboured it, thus creating zones of constant floods during the rainy season (Toledo et al., 2009). By to present habits amphibians, molluscs of the genus Lymnaea become extremely dependents on environmental constants, since the populations of aquatic molluscs are submitted to severe ecological restraints imposed by temporal fluctuations of their environmental conditions. Their success depends on their physiological capacity to tolerate these fluctuations (Russel-Hunter, 1961). Factors as temperature, precipitation, and anthropogenic influences can also directly affects structure and abundance of these populations (Prepelitchi et al., 2011). Maltchik et al. (2010) observed in southern Brazil that richness and the composition of molluscs were associated with area, altitude, water conductivity and dominant vegetation.
A population decrease was observed at certain sampling points during the study. This decrease resulted from human activity at points 2 and 3. A drainage procedure was performed on the wet land at point 2. This procedure interfered with the collection of molluscs. These molluscs commonly occur in water tanks, small water reservoirs, irrigation ditches (Coelho and Lima, 2003; Carvalho et al., 2005) and back waters (Serra-Freire, 1995). If these areas are drained, the increased exposure to solar radiation at high temperatures may cause mortality in the mollusc populations. Beginning in January 2011, the reservoir at point 3 was used for other farm activities, resulting in a decrease in the amount of available substrate. As a result, the mollusc populations at points 2 and 3 decreased and eventually disappeared. Similarly, Coelho and Lima (2003) observed 5.2% to 3.9% decreases in mollusc populations in an area after removal of aquatic plants and the application of drainage procedures.
Increases in precipitation and temperature levels favour increases in mollusc populations. Muller et al. (1999) have shown that temperatures ranging between 10[degrees] and 25[degrees]C favour mollusc development. Claxton et al. (1999) have reported similar findings, showing that growth in molluscs is slow at temperatures less than 10[degrees]C, increases rapidly up to 25[degrees]C, and becomes slower if exposure to 25[degrees]C is prolonged. Consistent with these reports, Martins et al. (2012) have found that one factor that supports the development of intermediate hosts in the southern region of the state of Espirito Santo is an average temperature greater than 20[degrees]C.
However, a slight decrease in growth may result from an increase in temperature that occurs in the dry season, independent of precipitation level. Mas-Coma et al. (2009) have reported that climate changes resulting in higher temperature may negatively affect the development of trematode larvae and the intermediate host of the studied trematodes. In the current study, temperatures of 25[degrees]C or greater were associated with decreases in the number of molluscs in the study area. In addition, none of the months analysed had average temperatures less than 20[degrees]C. As a result, decrease in the growth rate due to low temperatures was not observed.
Maure et al. (1998) at studying the population dynamic of L. columella grazing in farms positive for bovine fasciolosis, in the municipalities of Piquete and Redencao da Serra of the state of Sao Paulo, observed that increase in the range of population density fluctuated inversely to temperature and precipitation ranges, concluded that these factors are responsible for establishment or not of these species in the locality studied.
Although the relationship between the number of molluscs and the seasons do not differ significantly, it shows that independent of the season, even presenting the highest average during the rainy season, L. columella occurred during all year. According Maltchik et al. (2010) many bivalve populations are restricted to shallow waters and susceptible to droughts or dry periods, but their study showed that the mollusc richness and composition were similar both in permanent and intermittent wetlands. Thus, the population of this mollusc was stable during the period of study in the sampled points: however, it should be emphasize that for the maintenance of the fasciolosis cycle, the presence of the parasite Fasciola hepatica (Linnaeus, 1758) has to be detected, which was not registered in this study.
Specimens ofL. columella can spread to other locality due to the influence of precipitation. According Busetti (1982) in certain regions, during the rainy season, population dispersal to surroundings areas can occur. Furthermore, with increase climatic factor to this spread can occur by floods, going to areas closer or more distant areas (Acha and Szyfres, 1986). This dispersion was not registered in this study.
The understanding of population density in L. columella is important to create programmes for the control and treatment of fasciolosis. According to Serra-Freire (1995), large numbers ofF hepatica eggs are excreted by the host during the dry season. The eggs hatch at the beginning of the rainy season. Subsequently, large numbers of cercariae are released by molluscs at the primary focus of the disease. Thus, having higher water availability, populations of molluscs may increase and expand foci of dissemination and vulnerability to disease, because the points are studied in the region of high prevalence for fasciolosis, as verified by Freitas et al. (2012). This situation is considered serious, since the beginning of the rainy season cattle leaving a little feeding and face a high infection by intake metacercariae on abundant grassland. Serra-Freire (1990) has stated that even if control is difficult, fascioliasis is a tightly regulated parasitosis with a stable sensitivity to changes in the environment.
Therefore, situations that affect the soil moisture, as precipitation and temperature will change the population density of the host and, as consequence favor their presence or not in environments they are where found. In this context, effective control programs for bovine fasciolosis can be performed in any region, from the moment that the intermediate host population studies are conducted.
The mollusc L. columella predominated in all sampled points studied and the population remained stable and can be found throughout the year. No L. columella specimens showed evidence of the larval stages of Fasciola hepatica.
CAPES for the financial support of this project PROCAD 093/2007.
ACHA, P.N. and SZYFRES, B., 1986. Zoonosis y enfermedades transmissibles comunes al hombre y a los animales. Washington, D. C.: Organizacion Panamericana de La Salud.
BERNARDO, C.C., CARNEIRO, M.B., AVELAR, B.R., DONATELE, D.M., MARTINS, I.V. and PEREIRA, M.J., 2011. Prevalence of liver condemnation due to bovine fasciolosis in Southern Espirito Santo: temporal distribution and economic losses. Revista Brasileira de Parasitologia Veterinaria, vol. 20, no. 1, pp. 49-53. http://dx.doi.org/10.1590/S1984-29612011000100010. PMid:21439232.
BRASIL. Ministerio da Saude - MS, 2008. Surveillance and control of molluscs of epidemiological importance: technical guidelines: surveillance Program, and Schistosomiasis Control (PCE). 2nd ed. Brasilia: Editora do Ministerio da Saude. 178 p.
BUSETTI, E.T., 1982. Additional information on liver fluke in Curitiba (Parana, Brazil). Revista do Instituto de Medicina Tropical de Sao Paulo, vol. 24, no. 2, pp. 102-106. PMid:7134738.
CARVALHO, S.O., STEPS, L.K.J., MENDONCA, C.L.F.G., CARDOSO, P.C.M. and BOILER, R.L., 2005. Molluscs of Medical Importance in Brazil. Belo Horizonte: FioCruz/ Centro de Pesquisas Rene Rachou. 51 p.
CLAXTON, J.R., SUTHERST, J., ORTIZ, P and CLARKSON, M.J., 1999. The effect of cyclic temperatures on the growth of
Fasciola hepatica and Lymnaea viatrix. Veterinary Journal (London, England), vol. 157, no. 2, pp. 166-171. http://dx.doi. org/10.1053/tvjl.1998.0293. PMid:10204412.
COELHO, L.H. and LIMA, W.S., 2003. Population dynamics of Lymnaea columella and its natural infection by Fasciola hepatica in the State of Minas Gerais, Brazil. Journal of Helminthology, vol. 77, no. 1, pp. 7-10. http://dx.doi.org/10.1079/JOH2002138. PMid:12590657.
DILLON, R.T., 2004. The ecology of freshwater molluscs. Cambridge: Cambridge University Press. 499 p.
DUTRA, L.H., MOLENTO, M.B., NAUMANN, C.R.C., BIONDO, A.W., FORTES, F.S., SAVIO, D. and MALONE, J.B., 2010. Mapping risk of bovine fasciolosis in the south of Brazil using Geographic Information Systems. Veterinary Parasitology, vol. 169, no. 1-2, pp. 76-81. http://dx.doi.org/10.1016Zj.vetpar.2009.12.015. PMid:20071083.
FREITAS, D.F., MARTINS, I.V., SANTOS, G.M., SANTOS, A.R. and GOMES, D.S., 2014. Bioclimatic distribution and prevalence maps for Fasciola hepatica in Espirito Santo State, Brazil. The Journal of Venomous Animals and Toxins Including Tropical Diseases, vol. 29, no. 32, pp. 1-11. PMid:25101121.
FREITAS, D.F., MARTINS, I.V.F., TULER, V.O., SANTOS, G.M. and SANTOS, A.R., 2012. Vulnerability to the occurrence of Fasciolosis in the Experimental Area of the Federal Institute of Education, Science and Technology of Espirito Santo, IFES, Alegre, ES, Brazil. Arquivos do InstitutoBiologico, vol. 79, no. 4, pp. 533-540. http://dx.doi.org/10.1590/S1808-16572012000400010.
GERARD, C., 2001. Consequences of a drought on freshwater gastropod and trematode communities. Hydrobiologia, vol. 459, no. 1/3, pp. 9-18. http://dx.doi.org/10.1023/AT012567102396.
MALONE, J.B., LOYACANO, A.F., HUGH-JONES, M.E. and CORKUM, K.C., 1984. A three-year study on seasonal transmission and control of Fasciola hepatica of cattle in Louisiana. Preventive Veterinary Medicine, vol. 3, no. 2, pp. 131-141. http://dx.doi. org/10.1016/0167-5877(84)90003-5.
MALTCHIK, L.A., STENERT, C.A., KOTZIAN, C.B.B. and PEREIRA, D.C., 2010. Responses of freshwater molluscs to environmental factors in Southern Brazil wetlands. Brazilian Journal of Biology = Revista Brasileira de Biologia, vol. 70, no. 3, pp. 473-482. http://dx.doi.org/10.1590/S1519-69842010005000003. PMid:20737115.
MARTINS, I.V.F., AVELAR, B.R., PEREIRA, M.J.S. and FONSECA, A.H., 2012. Application of a geographical information system approach for risk analysis of fascioliasis in southern Espirito Santo state, Brazil. Geospatial Health, vol. 6, no. 3, pp. 87-93. http://dx.doi.org/10.4081/gh.2012.126. PMid:23032288.
MAS-COMA, S., VALERO, M.A. and BARGUES, M.D., 2009. Climate change effects on trematodiases, with emphasis on zoonotic fascioliasis and schistosomiasis. Veterinary Parasitology, vol. 163, no. 4, pp. 264-280. http://dx.doi.org/10.1016/j.vetpar.2009.03.024. PMid:19375233.
MAURE, E.A.P., BUSTAMANTE, M., SERRA-FREIRE, N.M. and GOMES, D.C., 1998. Population dynamic of Lymnaea columella (Say, 1817), intermediate host of Fasciola hepatica (Linnaeus, 1758) in municipalities of the Sao Paulo State, Brazil. Brazilian Journal of Veterinary Research and Animal Science, vol. 35, no. 4, pp. 151-155. http://dx.doi.org/10.1590/S141395961998000400001.
MEDEIROS, C., SCHOLTE, R.G.C., D'AVILA, S., CALDEIRA, R.L. and CARVALHO, O.S., 2014. Spatial Distribution of Lymnaeidae (Mollusca, Basommatophora), Intermediate Host of Fasciola hepatica (Linnaeus, 1758) (Trematoda, Digenea) in Brazil. Revista do Instituto de Medicina Tropical de Sao Paulo, vol. 56, no. 3, pp. 235-252. http://dx.doi.org/10.1590/S003646652014000300010. PMid:24879003.
MULLER, G., BERNE, M.E.A., RAFFI, L.L., JESUS, L.P., PAULSEN, R.M.M. and SINKOC, A.L., 1999. Influence of temperature on longevity of metacercariae of Fasciola hepatica. Revista Brasileira de Agrociencia, vol. 5, no. 2, pp. 164-165.
OLLERENSHAW, C.B., 1971. Some observations on the epidemiology of Fascioliasis in relation to the timing of molluscicide applications in the control of the disease. The Veterinary Record, vol. 88, no. 6, pp. 152-164. http://dx.doi.org/10.1136/vr.88.6.152. PMid:5102169.
PARAENSE, W.L., 1975. Current status of the systematics of Brazilian snails. Arquivos do Museu Nacional do Rio de Janeiro, vol. 55, pp. 105-128.
PARAENSE, W.L., 1983. Lymnaea columella in Northern Brazil. Memorias do Instituto Oswaldo Cruz, vol. 78, no. 4, pp. 477-482. http://dx.doi.org/10.1590/S0074-02761983000400011.
PARAENSE, W.L., 1986. Physa marmorata Guilding, 1828 (Pulmonata: Physidae). Memorias do Instituto Oswaldo Cruz, vol. 91, no. 4, pp. 459-469. http://dx.doi.org/10.1590/S007402761986000400014.
PREPELITCHI, L., PIETROKOVSKY, S., KLEIMAN, F., RUBEL, D., ISSIA, L., MORIENA, R., RACIOPPI, O., ALVAREZ, J. and WISNIVESKY-COLLI, C., 2011. Population structure and dynamics of Lymnaea columella (Say, 1817) (Gastropoda: Lymnaeidae) in wetlands of northeastern Argentina. Zoological Studies (Taipei, Taiwan), vol. 50, no. 2, pp. 164-176.
RUSSEL-HUNTER, W., 1961. Annual variations in growth and density in natural populations of freshwater snails in the West of Scotland. Proceedings of the Zoological Society of London, vol. 136, no. 2, pp. 219-253. http://dx.doi.org/10.1111/j.1469-7998.1961. tb06175.x.
SERRA-FREIRE, N.M., 1990. Fasciolosis in the Paraiba Valley. Agrotecnica Ciba-Geigy, vol. 14, no. 1, pp. 14-19.
SERRA-FREIRE, N.M., 1995. Fasciolosis hepatica. A Hora Veterinaria, vol. 1, no. 1, pp. 13-18.
TOLEDO, J.V., MARTINS, L.D., KLIPPEL, V.H., PEZZOPANE, J.E.M., TOMAZ, M.A. and AMARAL, J.F.T., 2009. Agro-Climatic Zoning for The Cultivation Jatropha (Jatropha curcas L.) and Castor (Ricinus communis L.) in the State of the Espirito Santo. Agropecuaria Cientifica no Semi-Arido, vol. 5, pp. 41-51.
TORGERSON, P. and CLAXTON, J., 1999. Epidemiology and control. In: J.P DALTON, ed. Fasciolosis. London: CABI International, pp. 113-149.
S. C. G. D'Almeida (a) *, D. F Freitas (b), M. B. Carneiro (c), P. F Camargo (d), J. C. Azevedo (d) and I. V F Martins (d)
(a) Unidade de Investigacao em Parasitologia Medica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 100, 1300114, Lisboa, Portugal
(b) Centro de Biociencias e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, CEP 28013-600, Campos dos Goytacazes, RJ, Brazil
(c) Departamento de Medicina Veterinaria, Escola Superior Sao Francisco de Assis, Rua Bernardino Monteiro, 700, CEP 29650-000, Santa Teresa, ES, Brazil
(d) Departamento de Medicina Veterinaria, Laboratorio de Parasitologia, Universidade Federal do Espirito Santo, Alto Universitario, s/n, CEP 29500-000, Alegre, ES, Brazil
* e-mail: firstname.lastname@example.org
Received: August 4, 2014--Accepted: June 23, 2015--Distributed: May 31, 2016
(With 2 figures)
Table 1. Average number of Lymnaea columella (Say, 1817), Physa sp. and Biomphalaria sp. by sampled points in the years 2010, 2011, 2012 and 2013, collected from Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo (IFES), in the Caparao microregion, state of Espirito Santo, Brazil. Points Years Molluscs Lymnaea columella Physa sp. Biomphalaria sp. 2010 32.5 - - Point 1 2011 19.8 0.17 0.14 2012 26.8 - - 2013 6.17 0.15 - 2010 - 2.83 - Point 2 2011 2.58 - - 2012 0.08 - 0.17 2013 - - - 2010 17.5 8.5 6.5 Point 3 2011 0.08 0.07 0.17 2012 - - 0.14 2013 - - - 2010 3.5 - 6.0 Point 4 2011 - - 7.0 2012 0.33 - 0.17 2013 - - - 2010 51.0 2.5 - Point 5 2011 8.75 7.67 7.0 2012 26.3 6.25 0.17 2013 51.0 - - Total 246 29.4 29.4
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|Title Annotation:||Original Article|
|Author:||D'Almeida, S.C.G.; Freitas, D.F.; Carneiro, M.B.; Camargo, P.F.; Azevedo, J.C.; Martins, I.V.F.|
|Publication:||Brazilian Journal of Biology|
|Date:||Apr 1, 2016|
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