A ten-month diseases survey on wild Litopenaeus setiferus (Decapoda: Penaeidae) from Southern Gulf of Mexico Diez meses de análisis de las enfermedades en especímenes silvestres de Litopenaeus setiferus en el sur del Golfo de México
Rodolfo Enrique del Río-Rodríguez1*, Daniel Pech1,3*, Sonia Araceli Soto-Rodriguez2*, Monica Isela Gomez-Solano1 & Atahualpa Sosa-Lopez1
The development of shrimp aquaculture in Mexican coasts of the Gulf of Mexico began to be explored using the Pacific white shrimp Litopenaeusvannamei in the mid 90´s. Many concerns over the risk of disease transmission to the economically important native penaeids, have been the main deterrent ]]>
L. vannamei in the region. Concurrently, more than 10 years of research experience on the aquaculture suitability of the native Litopenaeus setiferus from the Terminos Lagoon, in the Yucatán Peninsula, have been accumulated. The aim of this study was then to determine the seasonal variations of the naturally acquired diseases and the possible detection of exotic pathogens. For this, random subsamples (n~60) of juveniles L. setiferus were collected from monthly captures. In order to detect the widest range of pathogens, ]]>
L. ]]>
carry a wide variety of pathogens and symbionts that seem to be endemic to penaeids of the Gulf of Mexico, and those juveniles were more conspicuous to acquire pathogens and symbionts than adults.
Durante la década de los 90´s se introdujo el camarón blanco del Pacífico Litopenaeus ]]>
a los Estados costeros mexicanos del Golfo de México con fines acuícolas, por lo que desde entonces existe preocupación por la posible introducción de enfermedades que puedan afectar a las poblaciones de camarones nativos. La investigación sobre la domesticación de especies nativas para una acuacultura sustentable se ha realizado por más de 10 años, sin embargo, aún existe escasa información sobre las enfermedades que se presentan de manera natural en estas ]]>
Litopenaeus setiferus del Área natural protegida Laguna de Términos, estado de Campeche, México. Técnicas de histología y biología molecular fueron utilizadas como herramientas de diagnóstico. Se encontró que L. setiferus es portador ]]>
Palabras clave:Litopenaeus setiferus, peneidos silvestres, enfermedades, Sur del Golfo de México
The decline of shrimp fisheries in the Gulf of Mexico in the last 10 years, have prompted the state governments of the region to promote the aquaculture ]]>
Litopenaeus vannamei. However, due to outbreaks of Taura syndrome and White Spot viruses in shrimp farms of the Pacific coast (Jiménez et al. 1999, Lyle-Fritch et al. 2006), the Federal Government expressed concerns over the risk of disease ]]>
L. vannamei culture expansion in Southeast Mexico.
Between 1997 and 2002, three independent studies were carried out to determine the frequency and ]]>
et al. (2002) informed the presence of one flagellate, five ciliates, one Microsporideans, one gregarine and six metazoan parasites on four native shrimp species along the coast of Yucatan state; the ectosymbionts shown the highest prevalence in all hosts. In May and September 1999, a team lead by Chavez-Sanchez et al. (2002) sampled wild and cultured penaeid species in 10 stations along three coastal ]]>
et al. (2009) determined the seasonal variation of ectosymbiotic ciliates on farmed and wild shrimps during a 12-month period (December 2001-November 2002) from the Yucatan state coasts. They found that patterns of ciliate invasions differed between cultured (L. vannamei) and wild stocks (Farfantepenaeus duorarum and F. brasiliensis); heavier intensities of colonization by Zoothamniun sp. ]]>
Epistylis sp. (in order of importance) occurred in cultured shrimp during the rainy season, (September-November) while in wild shrimp, higher intensities of infection occurred later in the year (winter frontal storms, December to the following February). For the cultured L. vannamei, temperature, turbidity-as indirect measure of pond fertilization-and survival variations, were accounted as significant explanatory variables of ciliates seasonality patterns. Explanatory variables for the ciliate mean intensity of infestations of the wild ]]>
Litopenaeus setiferus, the white shrimp of the Gulf of Mexico has one of its major breeding grounds within the influence area of the Terminos Lagoon. In the last 10 years there has been an important effort to evaluate the suitability of L. ]]>
domestication for its use in aquaculture. This Atlantic species has been considered as alternative species for shrimp culture in the American Atlantic area, due to some promising aquaculture traits and that represents a low ecological or disease risk as a consequence of unintended release associated with floods or hurricanes (Arena et al. 2003). However a detailed knowledge on the natural disease fluctuation affecting this species is still needed. It is yet to be discovered if there are significant pathogens affecting these natural ]]>
Since 2002 a ]]>
L. setiferus has been carried out in order to establish the baseline knowledge of its aqua- culture traits and the diseases affecting these particular stocks, also testing the probable presence of exotic pathogens. Here by using histology as the main presumptive diagnostic technique, the microbial diseases and parasites affecting juveniles and adults of L. setiferus are presented. Molecular methods were also used to ]]>
L. vannamei.
Materials and Methods
]]>
Sample collection: Monthly captures of shrimp (L. setiferus) from July 2002 to June 2003 were carried out at two selected sites from the Terminos lagoon (Fig. 1), Southeast Gulf of Mexico for aquaculture experiments. The sample schedule was intended to cover a 12-month period, but samplings of ]]>
Adult (ADU) shrimp (avg wt 36.26g, SD±3.47; avg tot length 17.35g SD±1.08; 139 males and 163 females) were collected at “Punta de las Disciplinas” (site 1, 91°55´14´´ N - 18°43´34´´ W) sea bound North-West mouth of the lagoon. Juvenile (JUv) shrimp (avg wt 10.68g, SD±4.16; avg total length 11.58g SD±1.82) were captured using gill nets at “Desembocadura de Boca Chica” (site 2, 92°15´46´´ N - 18°43´21´´ W). Shrimp were fixed, processed for histology and stained with Mayer-Bennett’s Hematoxylin and Eosin-Phloxine (H&E) according to Bell & Lightner (1988) and Lightner (1996).
Molecular methods for viral detection: A small portion of muscle, hepatopancreas and pleopods from each shrimp were excised and fixed in ethanol 96° (prior to histological fixation). A subsample (n=90) was selected subsequently to histopathological observations that could indicate possible virus involvement (i. e. spheroids in lymphoid organ, apparent inclusion bodies, cuticular epithelium and antennal gland necrosis) and was analyzed for white spot syndrome virus (WSSv) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) by PCR methods following the protocols of Centro de Investigación en Alimentación y Desarrollo (CIAD Mazatlan Unit). DNA extraction kit (IQ2000) was used for extraction of viral DNA according to the manufacturer’s instructions. Briefly, approximately 20mg of tissue was homogenized in 500mL lysis buffer, incubated for 10min at 95ºC followed by centrifugation for 10min at 1 200g and the supernatant was transferred to a new tube. DNA was precipitated by the addition of 400mL of 95% cold ethanol. Pel- leted DNA was washed with 95% ethanol by centrifugation and airdried. The dried DNA pellets were suspended in 100mL of double dis- tilled water (ddH2O) or Diethylpyrocarbonate treated Water (DEPC - H2O).
The DNA samples were submitted to one-step for IHHNv and nested PCR tests for WSSv using the IQ2000TM detection system. PCR reactions were carried out in a 10.0 and 17.0μL (WSSV) reaction mixture for the first and nested step, and 13μL for IHHNV. Amplification was performed in a programmable thermal cycler (Eppendorf Mastercycler). The amplified products were fragments of 550 and 296bp for WSSv and fragments of 438 or 644bp for IHHNv. Products were separated in 2.0% agarose gels, stained with ethidium bromide and visualized using a Gel Documenta- tion System (UvP BioImaging Systems).
Prevalence was taken in this study as the number of instances of disease expressed in percentage in a known population, at a desig- nated time, without distinction between old and new cases (Thrusfield 2007). The percentage of infected host (PIH) is defined as the number of hosts of one species infected with one or more infectious agent in a sample divided by the total number of hosts of that species within a discrete time (Pech et al. 2010). A Kruskal-Wallis non-parametric ANOVA was used to test differences in histological anomalies between juvenile and adult shrimps and among months. The significance of statistical analysis was established at α=0.05, unless otherwise stated.
Results
Prevalence of diseases between juvenile and adult shrimp: A total of 16 distinctly histological anomalies were detected, and in most of them the aetiological agent was generically identified. The anomalies found and their prevalence is depicted in Table 1. Significant differences in the prevalence as a function of the life stage of L. setiferus and the type of infection were observed. No effect of sampling month was observed (Table 2). Juvenile (JUV) organisms showed the highest prevalence (Fig. 2A) of metazoan parasites and undetermined anomalies seem to be the most conspicuous in L. setiferus (Fig. 2B). Using PIH as a variable summarizing all the anomalies detected in L. setiferus, significant differences were observed showing that JUv life stage showed the most propensity at acquiring infections (Table 2) independently of the sampling month (Fig. 3). ]]>
Microbial diseases and simbionts: In adult (ADU) and JUv specimens, a low prevalence of spheroid formations was detected in the lymphoid organ (LO) (Fig. 4A). During fresh examination the specimens with this pathology did not displayed any of the known gross signs of disease caused by major known viruses in the Americas (WSSV, TSV, IHHNV) and ]]>
Nodular lesions were observed in mid and distal hepatopancreas intratubular epithelium in both age groups (Fig. 4B). The presence of these nodules peaked in March and prevailed in JUv in April (Table 2), which suggest that this ]]>
Gill tissue contained the most diverse range of microorganisms from all the histopathological findings. Colonial peritrichous protozooans treated here as ]]>
Epistylis-Zoothamnium complex were observed in JUV, with the highest prevalence in November (34%). It was not always possible to discern the presence of the myonem in Zoothamnium sp. from the histological sections, that would allow us differentiating between the common characteristics shared with Epistylis sp. (i. e. ]]>
Ascophrys spp. (Fig. 4C) that infected half of the JUv ]]>
Fig. 4D) and we believe that represents an sporulated oocyst of the Apicomplexa.
Parasites: ]]>
Thelohania (Agmasoma) penai was observed infecting ADU all over the sampling period except in April, May and June, indicating that this infection prevails in this segment of the population during the main rainy period of the year. Infection prevalence, however, seems to remain low (Table 1). This microsporidean was observed in JUVonly in November, April and May, which suggests that pluvial runoff into the ]]>
Intracellular haplosporideans were readily identified in tissue sections of HP (Fig. 4F). It was possible to observe several plasmodia stages occurring in one single organism, from uninucleated immature to ruptured mature- releasing trophonts. The presence of this parasite was almost confined ]]>
We found a trematode embedded in the hepatopancreatic intratubular lumina, forming a very thin capsule ]]>
O. fimbriatus (Fig. 5A). The affected tissue showed a mild inflammatory response. Its prevalence suggests that this par- asite infests preferently JUV shrimp rather than ADU.
Prochristrianella penaei was invariably observed immersed in the hepatopancreas or related tissues (Fig. 5B). There was a peak in July (2002) and March (2003) in JUv and ADU, respectively. Also cestode larvae bearing a prominent apical sucker were observed in the intestine of L. setiferus, where apparently causes sloughing of epithelial cells of the mucosal ]]>
Fig. 5C). Enterocytes going through necrotic stages could be observed detached into the lumen (hypertrophy, karyor- rhexys, pyknosis).
An unidentified nematode was commonly found coiled and circumscribed to the sub-mucosa of the anterior ceca of L. setiferus where it prompts a relatively mild ]]>
Fig. 5D). This response does not appear to have an effect on the parasite, which remains practi- cally intact in the host’s tissues, and it does not seem to burrow in the posterior ceca. This nematode was present in JUv all over the year except in June. Coincidentally, with respect to the cestode, the peak of JUV ]]>
Gregarines were observed in only one JUV specimen during November (Fig. 5E). It is likely ]]>
Histological anomalies of uncertain aetiology: A number of anomalies, for which it was not possible ]]>
Fig. 4E). These damages were observed ]]>
Discussion
]]>
The etiology of spheroid formation in LO could not be determined in this study, since PCR results were negative. LO spheroids have been observed in positive IHHN and TSv in wild (Morales-Covarrubias & Chavez-Sanchez 1999) and experimentally induced infections in L. vannamei (Hasson et al. 1999); they have also been related to other systemic viral infections (Pantoja & Ligthner 2003). However, shrimp of this study ]]>
The nodular lesions observed in this study could be caused by bacteria from the natural environment, and may be associated to animals whose health was compromised and for which this environment is more challenging during the dry season. ]]>
et al. (1998) bacteria can be isolated from several tissues including hepatopancreas of normal shrimp reared under experimental conditions; they isolated a wide range of species of the genus Vibrio spp. in those conditions. It has also been proven that wild and cultured penaeids harbor similar gut bacterial floral composition where members of the genus Vibrio were quantitatively dominant (Oxley
et al. 2002). A high density of vibrios has been recently informed from the hepatopancreas of farmed L. vannamei jóvenes from Northwestern Mexico (Soto-Rodriguez et al. 2010). It is possible that a diverse range of vibrios are likely to be present in hepatopancreas since this organ runs through the digestive tract of shrimp and it is contaminated with bacterial flora. This differs from diseased animals where one or two species of bacteria predominate. ]]>
Vibrio spp. (100%) has been informed for natural populations of L. vannamei broodstock from the Pacific coast of Mexico (Morales-Covarrubias et al. 1999); authors suggested that sampled population might have been severely stressed, although no high mortality of this species has been recorded or was observed in the area during that study. ]]>
Since early 70´s, microsporideans are known to infect L. setiferus in the coast of United States where their occurrence is common (Couch 1978). Furthermore, T. penaei was first informed in wild juveniles of the pink shrimp – Farfantepenaeus duoraum- and the red shrimp –F. brasiliensis- ]]>
et al. 2002), as well as in farmed L. vannamei in a nearby location; this may suggest a possible disease transference between wild and cultured shrimp. Microsporidians are common in wild shrimp inhabiting waters near to aquaculture devel- opments (Toubiana et al. 2004). It is likely that this parasite has a wider ]]>
Dyková et al. (1988) first described patho- genic haplosporideans infesting shrimp in 1998 from introduced L. vannamei into Cuba from Nicaragua, and recently, they seem to have reemerged –in the same host- in Belize (Nunan
et al. 2007). To our knowledge, haplosporideans have been scarcely studied in wild penaeids. For the Mexican coasts, haplosporidiosis has been informed in the Pacific blue shrimp L. stylirostris (Lightner 1996) and from the Gulf of Mexico, only one specimen of F. duorarum from a locality known as Champoton, was informed infected with haplosporideans for the first time (Chavez-Sanchez et ]]>
. 2002); therefore, L. setiferus must also be registered as a new host. The prevalence of this parasite observed in the present study, suggest that this haplosporidean might be endemic to juvenile L. setiferus from the Terminos lagoon and since pathogenic, it may influence the recruiting rate of juveniles into the adult population during the rainy season.
]]>
With respect to the gregarines, two unspecified genera (Nematopsis spp. and Cephalolo- bus spp.) were informed by Chavez-Sanchez and co-workers (2002) with a prevalence that reached up to 53% in fresh samples of several species of native penaeids, distributed from Tamaulipas to Campeche, Mexico. A high prevalence of this parasite has been observed in the Bob shrimp Xiphophorus kroyeri, captured by our team in the same area (unpublished data). It is likely that the gregarines observed in L. setiferus belong ]]>
L. vannamei for aquaculture in the Gulf of Mexico so far.
During the rainy months, epibionts ]]>
et al. (2009) informed that epibionts –especially Epistylis sp. and Zoothamnium sp.– are very common as mixed infections in wild shrimps from the coast of Yucatán during a year cycle, peaking during the Northern winter storm season. Interestingly, those researchers did also notice that the prevalence of Epistylis sp. was higher than ]]>
Zoothamnium sp. in wild specimens, contrary to what they found for farmed L. vannamei in the study area. Zoothamnium sp. seems to have a higher infesting capacity in pond environments, a fact noticed by Overstreet in 1973. In this work, our results suggests that rainy conditions (from June to December) seem to favor the colonization of juveniles over adults, tending to drop below detection levels –established for this survey– during the dry ]]>
Zoothamnium sp. and Epistylis sp. colonization on free living crustaceans, has revealed that their infestation prevalence, higher during the spring and summer months, is not significantly associated to environmental variables but to the host abundance (Pinto-Utz 2003), emphasizing the opportunistic nature of these obligate epibionts.
To the best of our ]]>
Cephalolobus spp. or any other Apicomplexa that produces oocysts with at least four infective sporozoites. Nematopsis spp. can be discarded as they produce oocysts with a ]]>
Cephalolobus spp., although the family Cephalolobidae contains five species divided into two genera and all are intestinal parasites of crustacea. Oocysts are also shed along the faeces of infected vertebrate animals (Modry et al. 2001), and L. setiferus may be playing a role in keeping the infection in the lagoon system, as this protozoan was present during the rainy months ]]>
Metazoan parasites, such as trematodes, cestodes and nematodes affecting the HP and the anterior ceca appear to have an important involvement in the health status of both age groups of L. setiferus. Metazoan parasites have been identified in fresh samples of penaeid shrimps from the Mexican part of ]]>
Helicometrina nimia, Opecoeloides fimbriatus (Trematoda), Prochristianella penaei (Cestoda) and Hysterothylacyum sp. (Nematoda) by Chavez-Sánchez et al. (2002) and Vidal-Martinez et al. (2002). Opecoeloides fimbriatus has been long informed in wild penaeid shrimp, being ]]>
L. setiferus captured from Ossabaw Sound, Georgia (USA) harbors this parasite that matures in teleost fish mainly in the Sciaenidae family (Overstreet 1973). It has been also informed by vidal et al. (2002) in F. aztecus from one locality in the Yucatán Peninsula. The presence ]]>
L. setiferus as intermediate hosts and we found the infection to be persistent in all sampling months. ]]>
Dasyatis sabina and D. say. The former species is informed as a common inhabitant of the Terminos lagoon, where it penetrates to feed on juveniles or migrating sea-bound adult shrimps (Ramos-Miranda et al. 2005).
Hutton in 1959 ]]>
L. schmitti from Maracaibo Lake in venezuela (Boada et al. 1999), and is probably the same unidentified larvae found in low prevalence in L. setiferus (3%) and F. aztecus (17%) from two locations in the Gulf ]]>
et al. (2002). We observed that the prevalence and frequency of these larvae was also low.
At least four genera of nematodes occur in shrimp species of the Gulf of Mexico (Hutton 1962, Overstreet 1973, Feigenbaum 1975). It is not possible to suggest an identification of the nematode found here from histological sections. ]]>
Leptolaimus has been informed to inhabit the anterior caecum of F. aztecus and L. setiferus as a comensal (Hutton 1962, Overstreet 1973), and Thynnascaris sp. as larvae in F. brasiliensis (Feigenbaum 1975). Hysterothylacium sp. was ]]>
F. brasiliensis captured in a coastal environment from Yucatán by Vidal-Martínez et al. (2002), although the organ in which this nematode was collected from was not specified. The study by Chavez-Sánchez et al. (2002), did not report nematodes in juvenile shrimps from the Gulf of Mexico, therefore examination of fresh material would be necessary to confirm the identification of our ]]>
Gills are exposed organs susceptible to many aquatic diseases; therefore they are considered aquatic environmental indicators. Severe black-pigmented lesions have been informed to occur in gills of shrimp after 15 days exposure to cadmium and nickel under experimental conditions (Denton & Camp- bell 1990). Couch (1977) described extensive lesions in gills after exposure to certain concentrations ]]>
et al. 2006); pollution, in combination with the salinity fluctuation, may be contributing to the aetiology and prevalence of gill necrosis found here, although the contributing factors or their synergism as the origin of this specific pathology, might be worthy of further research.
The role of disease in species with ]]>
Litopenaeus setiferus specimens have been collected for aquaculture research purposes from the Terminos lagoon for a number of years. Terminos is the largest coastal lagoon ecosystem of México and its complex environmental evolution has been continuously studied. Similarly to the results of other surveys in open environments, L. setiferus carry a wide variety of pathogens and opportunists, which mostly seem to be endemic to penaeids of the Gulf of Mexico. Their varying prevalence may be the consequence of the ]]>
]]>
At the end of the 90´s, some reports on viruses in wild penaeid populations from the Mexican Pacific coast were issued (Morales- Covarrubias et al. 1999, Pantoja et al. 1999); no definitive evidence indicating the presence of major viral pathogens was found in shrimp from this survey sites. Unfortunately, occurrence of IHHNv and TSV has been informed for wild L. setiferus ]]>
F. aztecus from Laguna Madre in Tamaulipas, the bordering state of the Gulf of México. Guzmán-Sáenz et al. (2009) found low prevalence of infected individuals of both species, suggesting that the origin of these infections in 2005 are due to local shrimp farming with L. vannamei or its closeness to Texas where TSV impacted shrimp aquaculture in 2004. Moreover, between 2008 and 2010, farmed
L. vannamei infected with IHHNV was informed for the first time in Tamaulipas and Tabasco (Lopez-Tellez et al.2010), the latter a neighboring state close to the Terminos Lagoon.
The Terminos lagoon ]]>
L. vannamei for aquaculture purposes that did not progress, and federal law currently prohibits it. Native shrimp species are still under study aiming to rural aquaculture development. The establishment of disease status of a native species previous to being developed in enclosed environments may help to solve future controversies with respect to the assessment of disease outbreaks ]]>
Acknowledgments
This study was partially financed by the National Council for Science and Technology (CONACYT Mexico, Project – 36780B): “Risk factors and ]]>
Farfantepenaeus duorarum, Litopenaeus setiferus and L. vannamei) from the coast of Campeche and Yucatán” (in Spanish). The authors are indebted to the researchers and personnel of the Unidad Multidisciplinaria de Investigación UNAM currently located at Sisal Yucatán, formerly known as Laboratorio de Ecofisiología, Facultad de Ciencias UNAM, and also to Edgar ]]>
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*Correspondencia: Rodolfo Enrique del Río-Rodríguez: Instituto EPOMEX and Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Campeche, Av. Agustín Melgar s/n, entre Juan de la Barrera y calle 20, Colonia Buenavista, CP 24039, Campeche, Campeche México; redelrio@uacam.mx Daniel Pech: Instituto EPOMEX and Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Campeche, Av. Agustín Melgar s/n, entre Juan de la Barrera y calle 20, Colonia Buenavista, CP 24039, Campeche, Campeche México. Departamento de Ciencias de la Sustentabilidad, ECOSUR, Unidad Campeche, Av. Rancho Polígono 2-A, Col. Ciudad Industrial, 24500 Lerma, Campeche, México; danielpech@uacam.mx Sonia Araceli Soto-Rodriguez: Unidad Mazatlán en Acuicultura y Manejo Ambiental del CIAD, Av. Sabalo Cerritos s/n, Estero del Yugo, A. P. 711, CP 82010, Mazatlán Sinaloa, México; ssoto@ciad.mx Monica Isela Gomez-Solano: Instituto EPOMEX and Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Campeche, Av. Agustín Melgar s/n, entre Juan de la Barrera y calle 20, Colonia Buenavista, CP 24039, Campeche, Campeche México; moigomez@uacam.mx Atahualpa Sosa-Lopez: Instituto EPOMEX and Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Campeche, Av. Agustín Melgar s/n, entre Juan de la Barrera y calle 20, Colonia Buenavista, CP 24039, Campeche, Campeche México; moigomez@uacam.mx, atahsosa@uacam.mx 1. Instituto EPOMEX and Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Campeche, Av. Agustín Melgar s/n, entre Juan de la Barrera y calle 20, Colonia Buenavista, CP 24039, Campeche, Campeche México; redelrio@uacam.mx, danielpech@uacam.mx, moigomez@uacam.mx, atahsosa@uacam.mx 2. Unidad Mazatlán en Acuicultura y Manejo Ambiental del CIAD, Av. Sabalo Cerritos s/n, Estero del Yugo, A. P. 711, CP 82010, Mazatlán Sinaloa, México; ssoto@ciad.mx 3. Departamento de Ciencias de la Sustentabilidad, ECOSUR, Unidad Campeche, Av. Rancho Polígono 2-A, Col. Ciudad Industrial, 24500 Lerma, Campeche, México. ]]>
Received 20-vIII-2012. Corrected 10-XII-2012. Accepted 22-I-2013. ]]>20004085-92200334981-99019921469-731988Special publication No. 41999593-15200233316-3292002p. 205-288197729267-2881978761-442008p. 137-157200319903287-29719881115-22197525491-51419981631-9200944663-67219993893-1051962199921-3198919962009287271-2772010200635135-146200148117-123199930192-200199911296-30120077467-75OIE200919732105-140200293214-22319991123-34200321847-54201040937-9442003200566513-53020104176-832007p. 46-74.20045879-8220021457-64200680159-1741988p. 1-26