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Berbigões, Anomalocardia brasiliana (Gmelin, 1791), de bancos naturais da Ilha de Santa Catarina e região continental adjacente (SC, Brasil), foram examinados quanto a presença de simbiontes. Holothuriophilus tomentosus (Ortmann, 1894) (Brachyura), Sphenia antillensis Dall & Simpson, 1901 (Bivalvia) e poliquetos espionídeos (Polychaeta) foram observados macroscopicamente. A análise das secções histológicas evidenciou esporocistos de trematódeos (Digenea), um metacestóide (Cestoda) e dois ciliados (Ciliophora).

Mangrove oysters Crassostrea rhizophorae were sampled monthly in the estuary of Jaguaribe River, on the east coast of Ceará State, Brazil, between August, 2000 and December, 2001, making up 170 individuals. The water temperature varied from 26 to 30 °C and salinity from 21 to 42‰. The animals' size ranged from 3.4 to 7.2 cm height. Macroscopical and histopathological analyses were carried out in the oysters' tissues. The histological exams showed protozoans and metazoans of genera Nematopsis and Tylocephalum, respectively. Nematopsis prevalence varied from 60 to 100% and it was higher in the gills and mantle. The oocysts presented a mean size of 11.5 µm (±1.32) length and 9.1 µm (±1.06) width (n = 30), up to 3 oocysts/phagocyte having been observed. Several animals presented focal hemocitical reaction.

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.

SUMMARY: Mollusc species composition, abundance and spatial distribution were analysed from April 1996 to October 1997 on two tidal flats in Paranaguá Bay (SE Brazil) at the entrance (St. I) (Lat. 25º32'S) and in the intermediate sector (St. II) (Lat. 25º30'S) of the estuary. At St. I, with the highest and least variable salinity, species richness (R = 40) and diversity (H´ = 1; D S = 0.85) were higher than at St. II (R = 22 and H´ = 0.54; D S = 0.57). The tropical clam Anomalocardia brasiliana was the most conspicuous mollusc of the two assemblages, followed by Cerithium atratum, Neritina virginea and Crassostrea sp. at St. I and by Macoma constricta and N. virginea at St. II. On the two flats, the decrease in species richness and abundance towards the upper tidal levels suggests a strong relationship between relative tolerance to physiological stress in the organisms and the degree of immersion/submersion.Key words: Benthic molluscs, species composition, spatial distribution, tidal flats, Anomalocardia brasiliana, Paranaguá Bay, southeastern Brazil. RESUMEN: COMPOSICIÓN Y DISTRIBUCIÓN DE MOLUSCOS BENTÓNICOS EN LLANOS INTERMAREALES DELA BAHÍA DE PARAGUA-NÁ (PARANÁ, BRASIL). -Se ha analizado la composición específica de moluscos, abundancia y distribución espacial en dos llanos intermareales de la bahía de Paraguaná (SE de Brasil), entre abril de 1996 y octubre de 1997, en la boca (estación I) (Lat. 25º32'S) y en el sector intermedio (estación II) (Lat. 25º30' S) del estuario. En la estación I, con la salinidad más elevada y menos variable, la riqueza específica (R = 40) y diversidad (H' = 1; D s = 0.85) fueron superiores a los valores detectados en la estación II (R = 22 y H' = 0.54; D s = 0.57). El bivalvo tropical Anomalocardia brasiliana fue el molusco más conspícuo de las dos zonas, seguido por Cerithium atratum, Neritina virginea y Crassostrea sp. en la estación I y por Macoma constricta y N. virginea en la estación II. En los dos llanos, el descenso en riqueza específica y en abundancia hacia los niveles mareales superiores sugiere una fuerte relación entre la tolerancia relativa al estrés fisiológico en los organismos y en el grado de inmersión/emersión.Palabras clave: moluscos bentónicos, composición específica, distribución espacial, llanos intermareales, Anomalocardia brasiliana, Bahía de Paraguaná, Brasil.

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.

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.