Parasitism by Nematopsis sp. (Apicomplexa: Eugregarinida) in Mytella guyanensis at the Marine Extractive Reserve Baía do Iguape, Bahia, Brazil / Parasitismo por Nematopsis sp. (Apicomplexa: Eugregarinida) em Mytella guyanensis na Reserva Extrativista Marinha Baía do Iguape, Bahia, Brasil

Several studies show the presence of protozoa of the genus Nematopsis Schneider, 1892, in many species of bivalves. The pathogenicity of this Apicomplexa is still much debated, which is possibly related to the parasitism degree and host habitat. In this context, this study investigated parasitism by Nematopsis sp. in Mytella guyanensis (Bivalvia: Mytilidae) in a mangrove of the Marine Extractive Reserve Baía do Iguape, Bahia, Brazil. The collections were made monthly, from March 2014 to March 2015, consisting of 30 adults with shell height above 40 mm per month, totaling 360 specimens. The specimens were measured, weighed, opened, and macroscopically examined for identifying parasites and/or signs of morphological changes. After that, they were fixed in Davidson's solution and processed according to classical histological techniques, with inclusion in paraffin, obtaining 5 µm-thick sections by microtomy, and stained by Harris' Hematoxylin and Eosin (HE). The water temperature ranged from 25.5 to 33.6 ºC and the salinity from 21.1 to 34.3 Practical Salinity Units (PSU). The specimens measured between 41.1 and 68.6 mm and had an average weight of 7.24 g. Macroscopically, there was no presence of the parasite or any morphological changes related its presence. The frequency percentage of Nematopsis sp. was 99.45%. The mantle was the organ with the highest frequency of infection (46.26%), followed by the gonads (18.36%). Among the analyzed organs, all presented the parasite and, in a few severely infected cases, microscopical changes were observed in the mantle conformation. The infection intensity for most of the sessions analyzed was 1 to 3 oocysts/phagocyte; however, in one of the sessions, 9 oocysts/phagocytes were recorded. The parasite had a negative correlation with salinity. The high frequency of Nematopsis sp. should be considered for the sustainability of natural stocks, especially if such parasitism occurs simultaneously with other pathogens and stressful environmental conditions.(AU)

Diversos estudos evidenciam a presença de protozoários do gênero Nematopsis Schneider, 1892 em várias espécies de bivalves. A patogenicidade desse apicomplexo ainda é bastante debatida, a qual possivelmente relaciona-se ao grau de parasitismo e habitat do hospedeiro. Nesse contexto, este estudo investigou o parasitismo por Nematopsis sp. em Mytellaguyanensis(Bivalvia: Mytilidae) em um manguezal da Reserva Extrativista Marinha Baía do Iguape, Bahia, Brasil. As coletas foram efetuadas mensalmente, de março de 2014 a março de 2015, constando 30 adultos com altura da concha acima de 40 mm, totalizando 360 espécimens. Os espécimens foram medidos, pesados, abertos e examinados macroscopicamente para a identificação de parasitos e/ou sinais de alterações morfológicas, em seguida fixados em solução de Davidson e processados segundo técnica histológica clássica, com inclusão em parafina, obtenção de cortes de 5 µm de espessura por microtomia e coloração por hematoxilina de Harris e Eosina (HE). A temperatura da água variou de 25,5 a 33,6 ºC e a salinidade de 21,1 a 34,3 Unidades Práticas de Salinidade (UPS). Os espécimens mediram entre 41,1 e 68,6 mm e tiveram um peso médio de 7,24g. Macroscopicamente, não se observou presença do parasito ou qualquer alteração morfológica relacionada à presença do mesmo. A frequência percentual de Nematopsis sp. foi de 99,45%. O manto foi o órgão de maior frequência de infecção (46,26%), seguido das gônadas (18,36%). Entre os órgãos analisados, todos apresentaram o parasito, sendo que, para poucos casos severamente infectados, observaram-se microscopicamente modificações na conformação do manto. A intensidade de infecção para a maioria das sessões analisadas foi de 1 a 3 oocistos/fagócitos, contudo em uma das sessões foram registrados 9 oocistos/fagócitos. O parasito apresentou correlação negativa com a salinidade. A elevada frequência do Nematopsis sp. deve ser levada em consideração para a sustentabilidade dos estoques naturais, principalmente se tal parasitismo ocorrer simultaneamente a outros patógenos e condições ambientais estressantes.(AU)

Application of multiplex real-time polymerase chain reaction assay for simultaneous quantification of Escherichia coli virulence genes in oysters.

Strains of diarrheagenic Escherichia coli (DEC) are involved in foodborne disease outbreaks worldwide, especially the enterohemorrhagic E. coli O157:H7. This study describes two multiplex quantitative real time PCR (qPCR) assays for simultaneous identification and quantification of genes related to virulence of DEC; a triplex reaction for detection and quantification of stxA1, stxA2, and eaeA genes, and a duplex reaction for detection and quantification of eaeA and virA genes. The technique was applied in raw oyster samples for direct quantification of DEC, thereby evaluating the applicability of this methodology for microbiological quality assessment of food. Using custom designed primers and specific MGB probes, a triplex qPCR assay was performed to quantify stxA1, stxA2, and eaeA, and a duplex reaction was performed to quantify virA and eaeA genes. The assays showed high sensitivity, with the detection limit varying between 5 and 17 copies of the genes. The coefficient of determination (R2) of the standard curves was 0.99. The coefficient of variation was < 1% indicated high intra- and inter-assay reproducibilities. The application of this methodology in oyster samples from tropical environment provided direct quantitative data that determined the presence of the genes stxA1 (32.1%), eaeA (28.6%), stxA2 (3.6%), and virA (3.6%). This would prove critical for immediate intervention of control strategies, particularly in oysters that are often ingested as raw food.

Microbiological Quality and Prevalence of ß-Lactam Antibiotic Resistance Genes in Oysters ( Crassostrea rhizophorae ).

The microbiological quality of oysters reflects the microbiological quality of their habitats because they are filter feeders. The objective of this study was to assess the bacterial composition of the edible oyster Crassostrea rhizophorae in urban and preserved estuaries. Particularly, we assessed the presence of pathogenic bacteria, investigated antibiotic susceptibility in bacterial isolates, and quantified ß-lactam antibiotic resistance genes (blaTEM, blaSHV, and blaKPC) via quantitative PCR of oyster DNA. Our results detected total coliforms, Escherichia coli , and enterobacteria in the oysters from urban estuaries, which is indicative of poor water quality. In addition, our detection of the eaeA and stxA2 virulence genes in 16.7% of E. coli isolates from oysters from this region suggests the presence of multiantibiotic-resistant enteropathogenic and enterohemorrhagic E. coli strains. During periods of low precipitation, increased contamination by E. coli (in winter) and Vibrio parahaemolyticus (in autumn) was observed. In contrast, cultivated oysters inhabiting monitored farms in preserved areas had low levels of bacterial contamination, emphasizing that oyster culture monitoring enhances food quality and makes oysters fit for human consumption. Distinct antibiotic resistance profiles were observed in bacteria isolated from oysters collected from different areas, including resistance to ß-lactam antibiotics. The presence of the blaTEM gene in 91.3% of oyster samples indicated that microorganisms in estuarine water conferred the capability to produce ß-lactamase. To our knowledge, this is the first study to directly quantify and detect ß-lactam antibiotic resistance genes in oysters. We believe our study provides baseline data for bacterial dynamics in estuarine oysters; such knowledge contributes to developing risk assessments to determine the associated hazards and consequences of consuming oysters from aquatic environments containing pathogenic bacteria that may possess antibiotic resistance genes.

First record of Perkinsus chesapeaki infecting Crassostrea rhizophorae in South America.

This study investigated Perkinsus spp. infecting Crassostrea rhizophorae from the Jaguaribe River estuary, Ceará, Brazil. Fragments of gills and rectum of the oysters (n=150) were incubated in Ray's fluid thioglycollate medium (RFTM). Genus Perkinsus-specific PerkITS85/750 PCR assays were performed and their amplicons were sequenced by the Sanger method. The RFTM assays confirmed Perkinsus spp. The sequencing of the amplified fragments from the rDNA internal transcribed spacers (ITS) of Perkinsus spp. confirmed Perkinsus chesapeaki. Neighbor-Joining analyzes place P. chesapeaki identified in this study in a well-supported clade with other isolates of the same species. This is the first record of P. chesapeaki infecting C. rhizophorae in South America.

Detection of Perkinsus marinus in the oyster Crassostrea rhizophorae in southern Bahia by proteomic analysis / Detecção de Perkinsus marinus na ostra Crassostrea rhizophorae do sul da Bahia por análise proteômica

This study reports the presence of the pathogen Perkinsus marinus, notifiable to the World Organization for Animal Health (Office International des Èpizooties = OIE) in the oyster Crassostrea rhizophorae in southern Bahia via proteomic analysis. We analyzed Crassostrea brasiliana from a long-line cultivation system and C. rhizophorae from an adjacent mangrove in Porto do Campo, Camamu Bay, Bahia, Brazil. The collections (n = 100) were performed in October 2012. In the laboratory, the oysters were measured and opened to remove the meat, which was steeped in dry ice. For extraction of proteins, adaptation of a protocol used for mussels was used, after which separation in the first dimension was taken by isoelectric focusing (IEF). The peptides were transferred to a Mass Spectrometer. The obtained spectra were analyzed with the ProteinLynx Global Server 4.2 software tool and also by MASCOT (Matrix Science) and compared to the databases of the SWISSPROT and NCBI, respectively. The identification was evidenced by beta-tubulin, Perkinsus marinus ATCC 50983 and protein homology code in the database NCBI = gi | 294889481. This is the first record of P. marinus in Bahia and the fourth in Brazil.(AU)

Este estudo relata a presença do patógeno Perkinsus marinus, de notificação obrigatória à Organização Internacional de Epizootias (OIE) na ostra Crassostrea rhizophorae no sul da Bahia, via análise proteômica. Foram analisadas as ostras Crassostrea brasiliana de um cultivo em espinhel e C. rhizophorae de um manguezal adjacente, na localidade de Porto do Campo, Baía de Camamu, Bahia. As coletas (n = 100) foram efetuadas em outubro de 2012. Em laboratório, as ostras foram medidas e abertas para a retirada da carne, que foi macerada em gelo seco. Para a extração das proteínas, foi adotada a adaptação de um protocolo utilizado para mexilhões, após o que foi realizada a separação na primeira dimensão, por focalização isoelétrica (IEF). Os peptídeos foram transferidos para um Espectrômetro de Massas. Os espectros obtidos foram analisados no software ProteinLynx Global Server 4.2 e também pela ferramenta MASCOT (Matrix Science) e comparados com os bancos de dados do SWISSPROT e do NCBI, respectivamente. A identificação foi evidenciada por meio da beta-tubulina, homologia Perkinsus marinus ATCC 50983 e código da proteína no banco de dados NCBI = gi|294889481. Este é o primeiro registro de P. marinus na Bahia e o quarto no Brasil.(AU)

Perkinsus beihaiensis infecting the oyster Crassostrea rhizophorae under cultivation and in natural stock in Camamu Bay, Bahia, Brazil / Perkinsus beihaiensis infectando a ostra Crassostrea rhizophorae em cultivo e em estoque natural na Baía de Camamu, Bahia, Brasil

This study investigated the infection of Perkinsus beihaiensis (Perkinsozoa) in the oyster Crassostrea rhizophorae, both from a long-line cultivation system and from a nearby intertidal zone of mangrove, both in the state of Bahia, northeastern Brazil. The collections were performed in October and November 2012, and in January 2013. The oysters (n = 300) were measured, examined macroscopically for signs of infection and then submitted to the following laboratory techniques: histology, Ray"s fluid thioglycollate medium assay (RFTM), polymerase chain reaction (PCR) and sequencing, which confirmed the identification of the pathogen. Histological and RFTM analyses showed, respectively, a mean prevalence of 93.3% and of 69%. The infection was usually mild or very mild. There was no significant difference (p > 0.05) between the environments in terms of infection prevalence or severity. This is the first record of P. beihaiensis in the state of Bahia and the second in oysters from Brazil and South America...

Foi investigada a infecção de Perkinsus beihaiensis (Perkinsozoa) na ostra Crassostrea rhizophorae em um sistema de cultivo do tipo espinhel e em um estoque natural de ostras no manguezal adjacente ambos localizados no estado da Bahia, Nordeste do Brasil. As colheitas foram realizadas em outubro e novembro de 2012 e em janeiro de 2013. As ostras (n = 300) foram medidas, examinadas macroscopicamente quanto a sinais da infecção e submetidas às técnicas laboratoriais: histologia, ensaio em meio de cultivo de tioglicolato de Ray (RFTM), reação em cadeia da polimerase (PCR) e sequenciamento, que confirmou a identificação do patógeno. As análises histológicas e o RFTM mostraram, respectivamente, prevalência média de 93,3% e de 69%. A infecção foi geralmente leve ou muito leve. Não houve diferença significativa (p > 0,05) entre os ambientes em termos de prevalência ou severidade da infecção. Este é o primeiro registro de P. beihaiensis no estado da Bahia e o segundo em ostras do Brasil e América do Sul...

Parasites in the mangrove oyster Crassostrea rhizophorae cultivated in the estuary of the Graciosa River in Taperoá, Bahia.

In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs); the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.

Parasites in the mangrove oyster Crassostrea rhizophorae cultivated in the estuary of the Graciosa River in Taperoá, Bahia / Parasitos na ostra-do-mangue Crassostrea rhizophorae cultivada no estuário do rio Graciosa em Taperoá, Bahia

In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs); the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.

No presente trabalho, parasitos associados à ostra-do-mangue Crassostrea rhizophorae foram estudados em uma unidade de cultivo no estuário do rio Graciosa em Taperoá, Bahia. Mensalmente, entre abril de 2011 e março de 2012, 20 ostras foram coletadas, mensuradas e fixadas em formol a 10%. Para a identificação dos parasitos, foram utilizadas técnicas histológicas de rotina, com inclusão em parafina e obtenção de cortes com 7µm, corados com hematoxilina de Harris e eosina e examinados em microscopia de luz. Os parâmetros analisados para a qualidade da água mostraram que a temperatura variou de 23,9 °C a 29,3 °C, a salinidade de 0,4 a 24,2 PSU e a pluviometria de 80 mm a 406,4 mm/mês. Nas análises parasitológicas foram observadas infestações do poliqueta Neanthes succinea em 41% das ostras. A partir das técnicas histológicas foram identificados os seguintes parasitos: colônias de organismos assemelhados a Rickettsiae (RLOs); os protozoários Nematopsis sp. e Ancistrocoma sp.; o turbelário Urastoma sp.; o metacestóide Tylocephalum sp. e um platelminto não identificado. Os dados obtidos mostraram baixa intensidade de infecção e prevalência de parasitos, exceto para Nematopsis sp., atestando a boa condição de saúde das ostras no cultivo.

Health assessment of the oyster Crassostrea rhizophorae on the southern coast of Bahia, northeastern Brazil.

This study investigated the health of natural stocks of the oyster Crassostrea rhizophorae on the southern coast of Bahia in northeastern Brazil, during summer and winter 2010, at three localities (sampling points) in the estuaries of the Maraú (Camamu Bay) and Graciosa rivers. A total of 180 oysters (30/sampling point/season) were examined macroscopically for the presence of pathogens and anatomical changes. The specimens were subsequently fixed in Davidson solution, processed for paraffin embedding, sectioned and stained with Harris' hematoxylin and eosin. Histological analysis revealed the presence of Rickettsia-like organisms (RLOs), Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus in the sporocyst phase, a nonspecific metacercaria, and a metacestode of genus Tylocephalum. The prevalence of infection was low except for parasitism by Nematopsis sp. which also caused histopathological changes. The presence of Bucephalus sp. caused parasitic castration. These two pathogens significantly affect the health of C. rhizophorae.

Health assessment of the oyster Crassostrea rhizophorae on the southern coast of Bahia, northeastern Brazil / Avaliação da saúde da ostra Crassostrea rhizophorae no litoral sul da Bahia, nordeste do Brasil

This study investigated the health of natural stocks of the oyster Crassostrea rhizophorae on the southern coast of Bahia in northeastern Brazil, during summer and winter 2010, at three localities (sampling points) in the estuaries of the Maraú (Camamu Bay) and Graciosa rivers. A total of 180 oysters (30/sampling point/season) were examined macroscopically for the presence of pathogens and anatomical changes. The specimens were subsequently fixed in Davidson solution, processed for paraffin embedding, sectioned and stained with Harris' hematoxylin and eosin. Histological analysis revealed the presence of Rickettsia-like organisms (RLOs), Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus in the sporocyst phase, a nonspecific metacercaria, and a metacestode of genus Tylocephalum. The prevalence of infection was low except for parasitism by Nematopsis sp. which also caused histopathological changes. The presence of Bucephalus sp. caused parasitic castration. These two pathogens significantly affect the health of C. rhizophorae.

Este estudo investigou a saúde de ostras da espécie Crassostrea rhizophorae de estoques naturais do Litoral Sul do Estado da Bahia, Nordeste do Brasil, durante o verão e o inverno de 2010, em três pontos amostrais distribuídos nos estuários dos rios Maraú (Baía de Camamu) e Graciosa. Um total de 180 ostras (30/ponto amostral/período) foram examinadas macroscopicamente para a presença de patógenos e alterações anatômicas e posteriormente fixadas em solução de Davidson, processadas para inclusão em parafina, seccionadas e coradas com hematoxilina de Harris e eosina. A análise histológica evidenciou a presença de organismos com características similares a Rickettsia (RLOs), Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus em fase esporocística, metacercária inespecífica e metacestóide de Tylocephalum. As prevalências de infecção foram baixas, com exceção do parasitismo por Nematopsis sp., o qual também causou alterações histopatológicas. A presença de Bucephalus sp. causou castração parasitária. Esses dois patógenos têm interferência significativa na saúde de C. rhizophorae.

Perkinsus sp. infecting oyster Crassostrea rhizophorae (Guilding, 1828) on the coast of Bahia, Brazil.

This study investigated the occurrence of the protozoan Perkinsus in the oyster Crassostrea rhizophorae on the coast of Bahia State, Brazil. The oysters (n = 900) were collected in February-March and July-August 2010. The Ray's fluid thioglycollate medium (RFTM) analysis of gills and rectum revealed hypnospores of Perkinsus sp. with a high mean prevalence (63%). The infection intensity varied from very light to advanced. The polymerase chain reaction confirmed Perkinsus in 87.2% of the RFTM-positive oysters. Histological analysis showed trophozoites and schizonts phagocytized by hemocytes, mainly in the intestine and the stomach epithelium.

Parasites of economically important bivalves from the southern coast of Bahia State, Brazil / Parasitos de bivalves de interesse econômico no Litoral Sul do Estado da Bahia, Brasil

This study investigated the parasites of three commercially important bivalve species (Crassostrea rhizophorae, Mytella guyanensis and Lucina pectinata) from the southern coast of Bahia, Brazil. A total of 540 specimens were collected in August 2009 and February 2010, at three localities. The bivalve specimens were measured on their longest axis, opened, and macroscopically examined for the presence of parasites or signs of disease. They were then fixed in Davidson' solution and subjected to routine histological processing, with paraffin embedding and H&E staining; next, the specimens were examined under a light microscope. No parasites were observed associated with L. pectinata. Rickettsia-like organisms (RLOs), Sphenophrya sp. (Ciliophora), Nematopsis sp. (Apicomplexa), Urastoma sp. (Turbellaria) and Bucephalus sp. (Digenea) were observed in both C. rhizophorae and M. guyanensis, as well as Ancistrocoma sp. (Ciliophora) and Tylocephalum sp. (Cestoda) in the former. A high prevalence of Nematopsis sp. was seen, but caused no apparent damage to the host. Bucephalus sp. caused the destruction of tissues, with castration, but showed low prevalence. The other parasites occurred in low prevalence and intensity, without causing significant damage.(AU)

Neste estudo foram investigados os parasitos de três espécies de bivalves de interesse econômico (Crassostrea rhizophorae, Mytella guyanensis e Lucina pectinata) da Bahia. Foram analisados 540 exemplares, obtidos em duas coletas (agosto-2009 e fevereiro-2010), em três localidades. Os bivalves foram medidos quanto ao seu maior eixo, abertos e examinados macroscopicamente quanto à presença de parasitos ou sinais de enfermidades. Depois disso, foram fixados em solução de Davidson e processados por rotina de histologia, com inclusão em parafina e coloração com H&E. O material foi examinado ao microscópio de luz. Nenhum parasito esteve associado a L. pectinata. Bactérias do tipo RLOs (organismos assemelhados a Rickettsia), Sphenophrya sp. (Ciliophora), Nematopsis sp. (Apicomplexa), Urastoma sp. (Turbellaria) e Bucephalus sp. (Digenea) foram observados tanto em C. rhizophorae quanto em M. guyanensis, sendo que a primeira apresentou ainda Ancistrocoma sp. (Ciliophora) e Tylocephalum sp. (Cestoda). Nematopsis sp. ocorreu em alta prevalência, porém, aparentemente, não causou danos aos bivalves. Bucephalus sp. causou destruição de tecidos, com castração, mas foi pouco prevalente. Os demais parasitos ocorreram em baixa prevalência e intensidade de infecção e sem causar danos.(AU)

Parasites of economically important bivalves from the southern coast of Bahia State, Brazil.

This study investigated the parasites of three commercially important bivalve species (Crassostrea rhizophorae, Mytella guyanensis and Lucina pectinata) from the southern coast of Bahia, Brazil. A total of 540 specimens were collected in August 2009 and February 2010, at three localities. The bivalve specimens were measured on their longest axis, opened, and macroscopically examined for the presence of parasites or signs of disease. They were then fixed in Davidson' solution and subjected to routine histological processing, with paraffin embedding and H&E staining; next, the specimens were examined under a light microscope. No parasites were observed associated with L. pectinata. Rickettsia-like organisms (RLOs), Sphenophrya sp. (Ciliophora), Nematopsis sp. (Apicomplexa), Urastoma sp. (Turbellaria) and Bucephalus sp. (Digenea) were observed in both C. rhizophorae and M. guyanensis, as well as Ancistrocoma sp. (Ciliophora) and Tylocephalum sp. (Cestoda) in the former. A high prevalence of Nematopsis sp. was seen, but caused no apparent damage to the host. Bucephalus sp. caused the destruction of tissues, with castration, but showed low prevalence. The other parasites occurred in low prevalence and intensity, without causing significant damage.

[Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae) in Camamu Bay, Bahia, Brasil]. / Ciclo reproductivo del ostión de manglar Crassostrea rhizophorae (Bivalvia: Ostreidae) en la Bahía de Camamu, Bahia, Brasil.

The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson's solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7 microm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5 degrees C to 30 degrees C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster's height ranged from 30 to 92 mm at Point I and from 27 to 102 mm at Point II, with an average of 49.0 mm +/- 9.1 (n = 230) and 49.9 mm +/- 9.9 (n = 237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n = 237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster's percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay.

Ciclo reproductivo del ostión de manglar Crassostrea rhizophorae (Bivalvia: Ostreidae) en la Bahía de Camamu, Bahia, Brasil

Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae) in Camamu Bay, Bahia, Brasil. The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson’s solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7μm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5°C to 30°C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster’s height ranged from 30 to 92mm at Point I and from 27 to 102mm at Point II, with an average of 49.0mm±9.1 (n=230) and 49.9mm±9.9 (n=237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n=237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster’s percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay. Rev. Biol. Trop. 59 (1): 137-149. Epub 2011 March 01.

El ostión de manglar es un importante recurso pesquero que se distribuye por toda la costa brasileña y una de las especies nativas con mayor potencial para maricultura. Este estudio tuvo como objetivo conocer las características reproductivas del ostión de manglar Crassostrea rhizophorae en el estero del Río Maraú, Bahía de Camamu, Bahia, Brasil. Las muestras fueran recolectadas mensualmente, entre agosto de 2006 y septiembre de 2007, en dos sitios. Las metodologías utilizadas fueron el análisis histológico de las gónadas y el cálculo de rendimiento de carne. La temperatura del agua durante el período de estudio varió de 23.5°C a 30°C y la salinidad osciló entre 15 y 35ups. La altura de los ostiones examinados varió de 27 a 102mm (n=437). Hubo predominancia de hembras en las poblaciones de ambos sitios. Los análisis de estadios gonádicos demostraron que el proceso de reproducción de C. rhizophorae en el estero del Río Maraú es continuo durante el año, sin período de reposo sexual. El rendimiento de carne (R) fue de 8.0% a 17.7% (n=669). Los resultados de este estudio proveen informaciones para la captación de semilla e implantación de la ostricultura en la Bahía de Camamu.

Prospecção de moluscos bivalves no estudo da poluição dos rios Cachoeira e Santana em Ilhéus, Bahia, Brasil / Bivalve molluscs prospection in pollution study from Cachoeira and Santana rivers in Ilheus, Bahia, Brazil

Um levantamento sobre o nível de poluição dos Rios Cachoeira e Santana (Ilhéus, Bahia, Brasil) foi realizado durante um trimestre, por meio da avaliação da qualidade microbiológica da água e de frutos do mar (Crassostrea rhizophorae – ostra-do-mangue e Tagelus plebeius - moapem) extraídos desses rios. Tradicionais indicadores de poluição como coliformes totais (Ct) e coliformes termotolerantes (CT), além de contagem padrão de microrganismos, com isolamento e identificação das enterobactérias, foram determinados nas amostras dos rios, os quais exibiram diferentes níveis de poluição fecal. Foram isolados 68 microrganismos, distribuídos em dez espécies, dentre elas, Salmonella typhi, Escherichia coli e Shigella sp., alertando para o risco do consumo in natura desses moluscos, mesmo quando em conformidade com a legislação estabelecida para CT. A prospecção de moluscos para o acompanhamento dos índices de poluição não se mostrou efetiva considerando a pesquisa de CT em ostras e moapens. Verificou-se também o maior grau de contaminação no Rio Cachoeira, o qual serve de base para distribuição de água na região e como fonte de subsistência, por meio da atividade extrativista, para a população ribeirinha.

A survey about the pollution level of the Cachoeira and Santana Rivers (Ilheus, Bahia, Brazil) was performed for a quarter, through the assessment of the microbiological quality of water and seafood (Crassostrea rhizophorae - oyster and Tagelus plebeius – razor clam) extracted from these rivers. Traditional indicators of pollution such as total coliforms (Ct) and thermtolerant coliforms (CT), and total count of micro-organisms, with isolation and identification of Enterobacteriaceae were determined in rivers samples, which exhibited different levels of faecal pollution. An amount of 68 micro-organisms was isolated, distributed in ten species, among them, Salmonella typhi, Escherichia coli and Shigella sp., warning about the risk of consuming these shellfish in nature, even when there is accordance with the laws established for CT. The bivalve prospection to monitor pollution levels was not effective considering CT detection in oysters and moapens. There was also the highest contamination degree in the Cachoeira River, which is used for water distribution in the region and as livelihood source through extractive activities for the riverside population.

Parasites of three commercially exploited bivalve mollusc species of the estuarine region of the Cachoeira river (Ilhéus, Bahia, Brazil).

This paper reports the parasites found in three commercially exploited bivalve molluscs (Mytella guyanensis, Anomalocardia brasiliana and Iphigenia brasiliana) of an estuarine region of Ilhéus, south of Bahia, Brazil (14 degrees 48'23''S; 39 degrees 02'47''W). Samples of 20 individuals of each species were collected fortnightly from August 2005 to August 2006. A total of 1480 individuals was collected and processed by standard histologic techniques; the histologic sections were stained with Harris haematoxylin and eosin and examined with light microscope. The water temperature in the study area varied from 24 to 30.5 degrees C and the salinity from 0 to 23ppt. Remarkable differences were found in the parasitic community between the three mollusc species involved in the study, which occupied different habitats in the estuarine region of the Cachoeira river. The following parasites were found: intracellular rickettsia-like colonies in digestive epithelia; intracellular gregarine Nematopsis sp. in gills, mantle, gonad, digestive gland and foot muscle; sporocysts of a Bucephalidae trematode in gonads, mantle, gills, digestive gland and foot; unidentified digenetic metacercariae in digestive gland and gonad; metacestodes of Tylocephalum sp. in connective tissue in the digestive gland and in gonad; and an unidentified metazoan in mantle and intestinal lumen. No significant temporal variation in the prevalence of any parasite was detected, which could be due to the narrow temperature range of the region and the absence of patterns of salinity and rainfall variation through the year. The infestation by sporocyst was the only pathological threat detected for the studied populations because of its potential for host castration. The low infection intensity and/or prevalence of the other parasites and the lack of obvious lesions suggest that there is no other serious pathological risk for the studied mollusc populations.

Nematopsis sp. (Apicomplexa: Eugregarinida) em Mytella guyanensis (Lamarck, 1819) (Bivalvia:Mytilidae) da Região Estuarina do Rio Cachoeira, Ilhéus, Bahia, Brasil / Nematopsis sp. (Apicomplexa: Eugregarinida) in Mytella guyanensis (Lamarck, 1819) (Bivalvia: Mytilidae) from estuarine region of the Cachoeira river, Ilhéus, Bahia, Brazil

Exemplares do molusco Mytella guyanensis (Bivalvia: Mytilidae) da região estuarina do Rio Cachoeira (Ilhéus, Bahia) foram investigados quanto à freqüência de ocorrência e sítios de infecção por protozoários do gênero Nematopsis Schneider, 1892 (Apicomplexa: Eugregarinida: Porosporidae), no período entre agosto de 2005 e julho de 2006. Em 480 animais analisados, medindo entre 34,5 e 74,9 mm de altura (Média: 55,4 mm; DP ± 6,7), 387 apresentaram em seus tecidos o parasito e nestes, os locais com maior freqüência de ocorrência do Nematopsis foram as brânquias (298 animais) e o manto (248). O parasito foi também observado na glândula digestiva e na musculatura. Alguns indivíduos gravemente infectados apresentaram modificações na conformação das brânquias e do manto

Individuals of the clam Mytella guyanensis (Bivalvia: Mytilidae) from the estuarine region of the Cachoeira river (Ilhéus, Bahia) have been analyzed to detect the frequency of occurrence and infected sites by protozoans of the genus Nematopsis Schneider, 1892 (Apicomplexa: Eugregarinida: Porosporidae), in the period between August 2005 and May 2006. A total of 480 individuals were analyzed, measuring between 34.5 and 74.9 mm of height (Average: 55.4 mm; DP ± 6.7). Nematopsis were found in 387 of them, occurring more frequently within the gills (298 animals) and the mantle (248). The parasite was also observed in the digestive gland and the musculature. Some severely infected individuals presented modifications in the conformation of the gills and the mantle