Resumen (Objetivo). Se evaluó el manglar de Chacarita en el Pacífico Central de Costa Rica, a través de la composición florística y las poblaciones de moluscos asociados de interés comercial, con el fin de proponer actividades de aprovechamiento sustentables en el manglar. (Metodología). Mensualmente y durante un año, se realizaron visitas al área de estudio, con el propósito de establecer una base florística de árboles de mangle y medir el almacenamiento de carbono en el lugar, además, de recolectar moluscos bivalvos para analizar el estado de las poblaciones, con base en las abundancias de organismos hallados y otras características como las longitudes y la masa de estos. En los mangles, se obtuvo el diámetro de la altura de pecho (DAP en cm), la altura (m), el índice de valor de importancia (IVI) y las reservas de carbono (Mg C·ha-1). En cuanto a los moluscos, se examinaron cuatro especies de interés comercial, evaluando la longitud (cm), la masa (g) y el índice gonadosomático. Finalmente, se realizaron valoraciones económicas de los datos obtenidos en el manglar, del turismo e información histórica de pesca para el acopio de Chacarita. (Resultados). Se hallaron cinco especies de mangles, Rhizophora mangle, Rizophora racemosa, Laguncularia racemosa, Avicennia germinans y Pelliciera rhizophorae; P. rhizophorae fue la de mayor índice de valor de importancia. Se obtuvo un almacenamiento de carbono equivalente a 78.49 Mg C·ha-1. Se contabilizaron 357 organismos, de los cuales el 18 % correspondió a Anadara similis, 37.5 % a Anadara tuberculosa, 41.46 % a Leukoma spp. y 3.08 % a Mytella guyanensis. Tomando en cuenta el valor económico de las reservas de carbono y los moluscos bivalvos presentes en los muestreos, se obtuvieron valoraciones económicas de 9812.63 USD·ha-1 y 28 USD·ha-1, respectivamente. (Conclusiones). Las bajas densidades poblacionales de moluscos, especialmente del género Anadara, hacen necesario establecer medidas de gestión que permitan recuperar las poblaciones de estos. La presente investigación propone actividades de aprovechamiento sustentables, como turismo comunitario con fines educativos y culturales.

Resumo (Objetivo). O mangue de Chacarita, no Pacífico Central da Costa Rica, foi avaliado por meio da composição florística e das populações de moluscos associados de interesse comercial, com o objetivo de propor atividades de uso sustentável no mangue. (Metodologia). Foram feitas visitas mensais à área de estudo durante um ano para estabelecer uma base florística de árvores do mangue e medir o armazenamento de carbono no local, bem como para coletar moluscos bivalves para analisar o status das populações, com base na abundância de organismos encontrados e em outras características, como comprimento e massa de tais organismos. Nos manguezais, foram obtidos o diâmetro à altura do peito (DAP em cm), a altura (m), o índice de valor de importância (IVI) e as reservas de carbono (Mg C-ha-1). No que diz respeito aos moluscos, foram examinadas quatro espécies de interesse comercial., avaliando o comprimento (cm), a massa (g) e o índice gonadossomático. Por fim, foram feitas avaliações econômicas de dados de mangue, turismo e informações históricas de pesca para a coleção Chacarita. (Resultados). Foram encontradas cinco espécies de mangue, Rhizophora mangle, Rizophora racemosa, Laguncularia racemosa, Avicennia germinans e Pelliciera rhizophorae; a P. rhizophorae apresentou o índice de valor de importância mais alto. Foi obtido um armazenamento de carbono equivalente a 78.49 Mg C-ha-1. Foram calculados um total de 357 organismos, dos quais 18% correspondeu a Anadara similis, 37.5% Anadara tuberculosa, 41.46% Leukoma spp. e 3.08% Mytella guyanensis. Levando em conta o valor econômico das reservas de carbono e dos moluscos bivalves presentes nas amostras, foram obtidas avaliações econômicas de US$ 9812.63 ha-1 e US$ 28 ha-1, respectivamente. (Conclusões). As baixas densidades populacionais de moluscos, especialmente do gênero Anadara tornam necessário o estabelecimento de medidas de manejo para permitir a recuperação dessas populações. Esta pesquisa propõe atividades de uso sustentável, como o turismo comunitário para fins educacionais e culturais.

Abstract (Objective). The floristic composition and populations of associated molluscs of commercial interest of the Chacarita mangrove forest on the Central Pacific of Costa Rica were evaluated to guide proposals for sustainable exploitation activities in the mangrove forest. (Methodology). Monthly visits to the study area were conducted for one year to establish a floristic baseline of mangrove trees and measure carbon storage. Additionally, bivalve molluscs were collected to analyze the state of their populations based on the abundances of organisms found, as well as other characteristics such as length and mass. Data regarding the mangrove trees included their diameter at breast height (DBH, cm), height (m), importance value index (IVI), and carbon reserves (Mg C·ha-1). Four mollusc species of commercial interest were analyzed, using data on their length (cm), weight (g), and gonodosomatic index. Economic evaluations were also conducted using data obtained from the mangrove forest, as well as tourism and historical fishing data for the collection of Chacarita. (Results). Five species of mangroves were identified: Rhizophora mangle, Rizophora racemosa, Laguncularia racemosa, Avice germinans, and Pelliciera rhizophorae, while P. rhizophorae had the highest importance value index. The study revealed a carbon storage equivalent to 78.49 Mg C·ha-1. A total of 357 organisms were counted, with Anadara similis accounting for 18% of the total count, followed by Anadara tuberculosa (37.5%), Leukoma spp. (41.46%), and Mytella guyanensis (3.08%). When considering the economic value of carbon stocks and the bivalve molluscs obtained from the samples, economic valuations of 9,812.63 USD·ha-1 and 28 USD·ha-1 were determined, respectively. (Conclusions). The low population densities of molluscs, particularly those belonging to the Anadara genus, necessitate the establishment of management measures to facilitate the recovery of these mollusk populations. This research proposes sustainable use activities such as community tourism for educational and cultural purposes.

ABSTRACT Harmful algal blooms (HABs) can negatively affect coastal water quality, aquatic fauna, and human health from the consumption of toxin-contaminated seafood. Estuaries are especially prone to the incidence of these noxious events and sensitive to the associated damage. This study represents a comprehensive overview of previous investigations reporting the occurrence of harmful algae and/or phycotoxins in the Paranaguá Estuarine Complex (CEP), in Southern Brazil. Secondary data from 2002 to 2021 were combined with new results obtained from widely spaced sampling campaigns performed from 2018 to 2019 to assess the periods and estuarine sectors at greater risk for the incidence of HABs. In total, about 600 water/sediment samples containing harmful microalgae and 675 tissue samples of phycotoxin-contaminated fauna were analyzed. The most frequent and abundant species of potentially toxic microalgae were dinoflagellates belonging to the species complexes Dinophysis acuminata and Prorocentrum lima, producers of diarrhetic shellfish toxins (DSTs), and diatoms of the genus Pseudo-nitzschia, producers of amnesic shellfish toxins (ASTs). Okadaic acid, a DST, was by far the most common toxin in the fauna, reaching higher levels in primary consumers such as bivalve mollusks (mussels, oysters, and clams), zooplankton, and suspension-feeding crustaceans (ghost shrimps), and moderate to low levels in cephalopods, fishes, gastropods, echinoderms, sea turtles, seabirds, and cetaceans. Less rainy periods (winter-early spring) were associated with the highest incidence of DSTs and blooms of their producing algae P. lima and Dinophysis spp., mainly in the middle region of Paranaguá Bay and on the shallow continental platform adjacent to the estuarine mouth. However, certain HAB-forming species may be more successful in inner estuarine areas ( Prorocentrum cordatum) and during different periods, such as late summer—early fall ( Pseudo-nitzschia spp.). Continuous monitoring of harmful algae and toxins is therefore highly recommended to mitigate the effects of HABs in the entire estuary. (HABs quality toxincontaminated contaminated seafood damage andor or CEP, CEP , (CEP) Brazil 200 202 201 total 60 watersediment sediment 67 phycotoxincontaminated phycotoxin analyzed DSTs, (DSTs) Pseudonitzschia, Pseudonitzschia Pseudo nitzschia, nitzschia ASTs. ASTs . (ASTs) acid DST mussels, mussels (mussels oysters clams, clams clams) zooplankton suspensionfeeding suspension feeding ghost shrimps, shrimps shrimps) cephalopods fishes gastropods echinoderms turtles seabirds cetaceans winterearly winter early spring P spp spp. mouth However HABforming HAB forming cordatum summerearly summer spp.. spp.) estuary (CEP 20 6 (DSTs (ASTs 2

Abstract: Oyster Crassostrea spp. is the bivalve mollusk with the largest commercial volume in Cuba. Populations should be assessed for their management and conservation, which has been performed but with different methodologies and only in certain localities, making it difficult to evaluate and compare between periods and regions. Therefore, current state of the resource was to be determined according to maximum sustainable yield (MSY), biomass for the maximum sustainable yield (BMSY), and corresponding fishing mortality rate (FMSY). Catch Maximum Sustainable Yield (CMSY) model was applied with Monte Carlo method, resource biomass and exploitation were evaluated for northwestern (NW), northeastern (NE), southeastern (SE), and southwestern (SW) regions of the insular platform, as well as for periods (1960-1991 and 1992-2020). From 1992-2020, a 50% reduction in oyster landings was recorded when compared with 1960-1991 period, which was reflected in population indicators according to estimated fishery reference points. Based on applied model and method, current oyster fishery management is perceived as unsustainable with stock depletion and overfishing in NW, NE, and SW regions. Cuban SE region shows a more favorable status. Oyster farming should increase to obtain higher production and broodstock biomass to decrease fishing effort on wild populations.

Resumen: En Cuba, la ostra Crassostrea spp. es el molusco bivalvo de mayor volumen comercial. La evaluación de sus poblaciones es necesaria para su manejo y conservación, pero se ha realizado con diferentes metodologías y solo en localidades puntuales, lo que dificulta su evaluación y comparación entre periodos y regiones. Por lo tanto, se determinó el estado actual del recurso según el rendimiento máximo sostenible (MSY), biomasa para el rendimiento máximo sostenible (BMSY) y la tasa de mortalidad por la pesca (FMSY) correspondiente. Se aplicó el modelo CMSY con método de Monte Carlo, y se evaluó la biomasa y la explotación del recurso para las regiones noroeste (NW), noreste (NE), sureste (SE) y suroeste (SW) de la plataforma insular, así como por periodos (1960-1991 y 1992-2020). Durante 1992-2020 se registró una reducción del 50% en los desembarques de ostras respecto al periodo 1960-1991, lo que se reflejó en los indicadores poblacionales según los puntos de referencia evaluados. De acuerdo con el modelo y método aplicados, la gestión pesquera actual de la ostra se percibe no-sostenible, con agotamiento del stock y sobrepesca en las regiones NW, NE y SW. La región SE del país presenta un estado más favorable. Se sugiere incrementar la ostricultura para obtener mayor producción y biomasa de reproductores para disminuir el esfuerzo de pesca sobre las poblaciones silvestres.

Resumen El carbonato de calcio está presente en muchas estructuras biológicas, como la concha de bivalvo, que se compone principalmente de dos polimorfos de CaCO3: calcita y aragonito. Sin embargo, existen otras formas de carbonato de calcio como vaterita y carbonato de calcio amorfo (ACC) que no se reportan comúnmente. La selección de polimorfos está influenciada por la concentración de sal, los iones cofactores y la presencia de proteínas de la matriz de la cubierta (SMP) que regulan la deposición de carbonato de calcio, entre otros factores. En este estudio, se evaluó la cristalización in vitro de carbonato de calcio de cuatro soluciones salinas diferentes (1: 40 mM CaCl2, MgCl2, 100 mM NaHCO3; 2: CaCl2, 100 mM Na2CO3; 3: 40 mM CaCl2, MgSO4, 100 mM Na2CO3; 4: CaCl2/MgCl2, 100 mM NaHCO3) en dos molaridades (40 o 100 mM)con diferentes concentraciones la proteína Ps19 (0.2, 0.7 y 1.2 µg/µL) una proteína insoluble extraída de la concha de Pteria sterna, descrita anteriormente como promotora de la cristalización de plaquetas de aragonita. Las cristalizaciones in vitro mostraron que Ps19 es capaz de inducir la deposición de aragonita y calcita de forma dependiente de la dosis, pero también de vaterita en determinadas condiciones, actuando como promotor e inhibidor de la cristalización. Los resultados contribuyen a comprender cómo Ps19 controla la precipitación de polimorfos de calcio en el crecimiento de la capa prismática y de nácar de la concha de P. sterna.

Abstract Calcium carbonate is present in many biological structures such as bivalve shells, which is composed mainly of two CaCO3 polymorphs: calcite and aragonite. However, other forms of calcium carbonate exist like vaterite and amorphous calcium carbonate (ACC) that are not commonly reported. Polymorph selection is influenced by salt concentration, cofactor ions, and the presence of shell matrix proteins (SMPs) which regulates calcium carbonate deposition, among other factors. In this study, in vitro calcium carbonate crystallization of four different saline solutions (1: 40 mM CaCl2, MgCl2, 100 mM NaHCO3; 2: CaCl2, 100 mM Na2CO3; 3: 40 mM CaCl2, MgSO4, 100 mM Na2CO3; 4: CaCl2/MgCl2, 100 mM NaHCO3) at two molarities (40 o 100 mM) was evaluated with increased concentrations of the Ps19 protein (0.2, 0.7 y 1.2 µg/µL), an insoluble extracted protein from the Pteria sterna shell, previously described as a promotor of aragonite platelet crystallization. In vitro crystallizations showed that Ps19 is capable to induce aragonite and calcite deposition in a dose-dependent manner, but also vaterite under certain conditions, acting as a promoter and inhibitor of crystallization. The results contribute to understand how Ps19 control precipitation of calcium polymorphs in the growth of the prismatic and nacre layer of the shell of P. sterna.

ABSTRACT At the moment, two freshwater bivalve species were described for the continental Jurassic of Patagonia: Diplodon simplex Morton and Diplodon matildensis Morton from La Matilde Formation of the Santa Cruz province. The Cañadón Asfalto Formation located in Chubut province exhibits a high diverse invertebrate fossil fauna preserved mainly in lacustrine facies, which includes clam shrimps, bivalves, gastropods, ostracods and insects. However, few studies have been carried out on freshwater bivalve of this geological unit. In this work, a morphological description of bivalve assemblage and paleoenvironment analysis from the Cañadón Asfalto Formation was performed. Forty samples were collected from three stratigraphic levels at the Cañadón Asfalto locality. These levels are ash fall tuffs rich in glass particles accumulated in a lacustrine system with development of microbial activity. Morphological analyzes of outline and sizes were performed at each level. Our results showing the smallest-sized association of unionids recorded for the Jurassic time with size ranging from 7.6-11.7 mm long and 5.2-7.6 mm high. The environmental influence of pyroclastic falls could have played an important role in the development of the sizes of populations and shells.

RESUMEN Bivalvos de agua dulce y sus condiciones ambientales en un sistema lacustre del Jurásico (Formación Cañadón Asfalto) de la Patagonia, Argentina. Actualmente se han descrito dos especies de bivalvos de agua dulce para el Jurásico continental de la Patagonia: Diplodon simplex Morton y Diplodon matildensis Morton de la Formación La Matilde en la provincia de Santa Cruz. La Formación Cañadón Asfalto ubicada en la provincia de Chubut exhibe una fauna fósil de invertebrados muy diversa conservada principalmente en facies lacustres, que incluyen “conchostracos”, bivalvos, gasterópodos, ostrácodos e insectos. Sin embargo, se han efectuado pocos estudios sobre los bivalvos representados de esta unidad geológica. En este trabajo se realizó una descripción morfológica de restos de conchillas de bivalvos y el análisis del paleoambiente de la Formación Cañadón Asfalto. Se recolectaron cuarenta muestras de tres niveles estratigráficos en la localidad de Cañadón Asfalto. Estos niveles son tobas de caída de ceniza, ricas en partículas de vidrio acumuladas en un sistema lacustre con desarrollo de actividad microbiana. Se hicieron análisis morfológicos de contorno y tamaños en cada nivel. Nuestros resultados muestran la asociación de uniónidos de menor tamaño registrada para el Jurásico, con tamaños que oscilan entre 7,6 y 11,7 mm de largo y entre 5,2 y 7,6 mm de alto. La influencia ambiental de la caída de material piroclástico podría haber jugado un papel importante en el desarrollo de los tamaños de las poblaciones y conchillas.

Abstract Atlantic pearl oyster Pinctada imbricata is a bivalve with high potential for cultivation in tropical and subtropical environments. In this study, P. imbricata energetic metabolism was analyzed throughout a culture cycle at Gulf of Cariaco, Venezuela. Juvenile individuals (shell length 27.40 ± 2.70 mm) were cultured in a long line at 3 m depth between May-2012 and January-2013. Monthly data of biometric measurements, Fulton index (K) and protein, carbohydrate, and lipid content of the adductor muscle, digestive gland, and mantle were estimated, and were related with environmental variables: temperature, chlorophyll a (Ch a), total particulate matter (TPM), particulate inorganic matter (PIM), particulate organic matter (POM) and upwelling index (UI). Shell length increased steadily reaching 46.23 ± 3.79 mm on the 8th month of culture, while average soft tissue weight increased associated to food availability. Biometric data and biochemical substrates from the muscle, digestive gland and mantle presented significant differences among months. Principal Component Analysis (PCA) showed positive relationships between carbohydrate content and temperature; mantle and digestive gland protein content with TPM, PIM, POM, UI; lipid and protein in muscle with K. Energy allocation was associated with environmental factors, mainly through high food availability given the seasonal upwelling pulses in the area.

Resumen La ostra perlera del Atlántico Pinctada imbricata es un bivalvo con gran potencial de cultivo en ambientes tropicales y subtropicales. En este estudio el metabolismo energético de la ostra perla Pinctada imbricata fue analizado durante un ciclo de cultivo en el Golfo de Cariaco, Venezuela. El cultivo se realizó usando individuos juveniles con una longitud total de la concha de 27,40 ± 2,70 mm. Los ejemplares se cultivaron a 3 m de profundidad en un long-line, entre mayo 2012 y enero 2013. Mensualmente se obtuvieron los datos biométricos, el índice metabólico de Fulton (K), el contenido de proteína, carbohidrato y lípido del músculo aductor, la glándula digestiva y el manto los cuales se relacionaron con las variables ambientales de temperatura, clorofila a, material total en suspensión (TPM), materia inorgánica particulada (PIM), materia orgánica particulada (POM), y el índice de surgencia (UI). La longitud de la concha incrementó progresivamente hasta alcanzar 46,23 ± 3,79 mm en el octavo mes del cultivo, mientras que el incremento del peso promedio de los tejidos blandos estuvo asociado a la disponibilidad de alimento. Los promedios de las variables biométricas y bioquímicas del músculo, glándula digestiva y manto presentaron diferencias significativas entre meses. El análisis de componentes principales (PCA) indicó que hubo relaciones significativas del contenido de carbohidratos con la temperatura; las proteínas del manto y la glándula digestiva con TPM, PIM, POM y UI: del contenido de lípido y la proteína del músculo con K. Los compartimientos de energía se asociaron a factores ambientales, principalmente a la alta disponibilidad de alimento debido a los procesos de surgencia estacional de la localidad.

ABSTRACT Iphigenia brasiliensis is a bivalve mollusk exploited as a shellfish and subsistence resource on the Brazilian coast, mainly in the north and northeast regions. Genetic (allozyme electrophoresis revealed eight gene loci) and morphological variations (multivariate morphometry of valves used 13 linear measurements of traditional and 19 Fourier coefficients of geometric morphometry) were studied, considering the geographic (445 km of the southwest tropical Atlantic), environmental (mangroves and channels of communication with the sea of three estuaries in the state of Rio de Janeiro), and temporal dimensions (over two years). I. brasiliensis showed high levels of genetic variation (the average number of alleles per locus ranged from 2.8 to 3.4, and the average heterozygosity ranged from 0.441 to 0.675). Bayesian analysis of population partitioning showed that the highest LnP(D) value was achieved for K = 3. These results indicated mixed ancestry, possibly oscillations in the dispersion dynamics among the different sampling groups, and temporal oscillations in the population sizes due to the anthropogenic influence on the studied estuaries. The results of morphological variation, inferred by the PERMANOVA from the Fourier analysis, indicated that a similar influence might occur in valves (also, the discriminant analysis showed that different groups could be consistently identified). In this sense, the studied populations may be organized in a dynamic of metapopulations. Finally, these are the first data on morphological and genetic variation of the species in the latitudinal, environmental, and temporal dimensions studied simultaneously, thus providing relevant information for the exploration, management, and conservation of this commercially important species.

ABSTRACT The southwestern Gulf of California is an important source of ornamental marine species traded worldwide, wherein spider crabs Stenorhynchus debilis are popular items. However, little is known about species biology and ecology. This study involves young ovigerous females (28 in total) recollected at Bahía de La Paz, Mexico, into bivalve mariculture devices cleaned every 3-4 months. Total carapace length (TL) and carapace width (CW), weight without eggs (TW), and fecundity (F, number of eggs) were analyzed for multiple relationships. F varied into 162 and 2205 eggs ( x ¯ = 1171 ± 689 eggs), their diameter into 0.38 to 0.45 mm ( x ¯ = 0.396 ± 0.027 mm). Three persistent and interactive modes were detected: low/moderate/high F, small/medium/large size (TL and CW), and light/middle/heavy TW. Log-linearized allometric regressions were applied to determine the relative fecundity constants (RFC) by body complexion, finding high parallelism between TL and CW related to step-wise growth and size categorization upon the isosceles-shaped carapace. In contrast, TW denoted an increase in body complexion across intermolt phases. S. debilis likely completes three maturation/molt cycles within 3-4 months after the first crab instar. RFC values confirmed positive trends by body complexion where egg size and F are related to species size and shape, establishing the trade-off proportions in this study case.

Resumo Estuários recebem entradas diárias de elementos químicos, que podem impactar a qualidade de água e do sedimento, assim como a saúde da biota. Além do sedimento, moluscos bivalves têm sido utilizados no monitoramento químico desses sistemas. Neste estudo investigou-se a presença e os teores de As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb e Zn no sedimento superficial e em bivalves (Crassostrea gasar, C. rhizophorae e Mytella guyanensis) de estuários do sul / extremo sul do estado da Bahia, Nordeste do Brasil. As amostras foram avaliadas por espectrometria de emissão óptica de plasma indutivamente acoplado (ICP-OES, Varian 710). Exceto Cd, todos os demais elementos foram encontrados nas amostras, sendo que Co foi exclusivo no sedimento. Os estuários equivalentes às estações amostrais #1 - Valença, #2 - Taperoá, #3 - Ilhéus e #4 - Belmonte mostraram níveis de metais compatíveis com os estabelecidos pela legislação brasileira, porém, a #5 - Santa Cruz Cabrália, além da presença de As, apresentou alto nível de Pb e de Cu em C. gasar, o que foi atribuído aos impactos por atividades náuticas nesse local.

Abstract Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations #1 - Valença, #2 - Taperoá, #3 - Ilhéus and #4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the #5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

RESUMO: Objetivou-se com o estudo detectar Cryptosporidium sp. em ostras de cultivo e estoque natural no estado do Maranhão e determinar o(s) tecido(s) eletivo(s) para pesquisa desse protozoário. Para a realização do estudo foram adquiridas 200 ostras de cultivo do município de Raposa e 100 de Paço do Lumiar, além de 100 ostras extraídas de estoque natural do município de Primeira Cruz, totalizando 400 ostras. Estas foram agrupadas em 80 pools constituídos por cinco animais. De cada pool, as brânquias e a massa visceral foram removidas totalizando 160 pools, sendo 80 para o grupo das brânquias e 80 para o grupo de massa visceral. Na sequência, procedeu-se à extração de DNA de cada pool com a utilização de kit comercial com modificações. Posteriormente, realizou-se a detecção do DNA do protozoário por meio da técnica de Nested-PCR. Com a técnica utilizada, foi detectado o DNA do protozoário pesquisado em 2,5% (n=2/80) pools apenas de brânquias, sendo 1,25% pools (n=1/80) oriundos de cultivo e os outros 1,25% (n=1/80) de estoque natural. Com os resultados obtidos nesse estudo, conclui-se que as ostras analisadas do gênero Crassostrea sp., oriundas de cultivo e estoque natural no estado do Maranhão, estavam contaminadas por Cryptosporidium sp. e podem se reverter em fontes potenciais para seres humanos e outros animais. Para a pesquisa de Cryptosporidium sp. em ostras, as brânquias são o tecido eletivo.

ABSTRACT: This study detected Cryptosporidium spp. in cultivated oysters and the natural oyster stock of the state of Maranhão and determine the elective tissue(s) to examine this protozoan. For this purpose, 200 cultivated oysters were purchased from the municipality of Raposa and another 100 from Paço do Lumiar. Additionally, 100 oysters were extracted from the natural stock of the municipality of Primeira Cruz, thus making up a total of 400 oysters. They were grouped into 80 pools consisting of 5 oysters each. From each pool, the gills and visceral mass were removed to obtain 160 pools, 80 pools for the gill group and another 80 for the visceral mass group. Then, DNA was extracted from each pool using a commercial kit with modifications. Subsequently, the protozoan DNA was detected using nested polymerase chain reaction. With this technique, the DNA of the protozoan under investigation was detected in 2.5% (n = 2/80) of the pools containing gills, with 1.25% of the pools (n = 1/80) belonging to the cultivation group of oysters and the other 1.25% (n = 1/80) to the natural stock. With the results obtained in this study, it was concluded that the analyzed oysters of the genus Crassostrea, from cultivation and natural stock groups, found in the state of Maranhão, were contaminated by Cryptosporidium spp. and may become potential sources of infection in humans and other animals. In addition, the gills are the elective tissue for the study of Cryptosporidium spp. in oysters.

Abstract The knowledge about the effect of salinity on the physiological mechanism of bivalve reproduction is fundamental to improve production strategies in hatcheries. The present work evaluated the influence of different salinity concentrations (15, 20, 25, 30, 35 and 40 g⋅L−1) on pre- and post-fertilization development processes in the clam, Anomalocardia flexuosa, oocytes obtained by stripping. Salinity directly interfered with the germinal vesicle breakdown (GVBD) rate and in the cellular stability of unfertilized oocytes. Salinity concentrations between 30 and 35 g⋅L−1 provided better percentages of stable GVBD within 120 min, and incubation of oocytes in the salinity range of 30-35 g⋅L−1 for a time interval of 80-120 min provided > 80% GVBD. In the post-fertilization analysis, salinity affected the rate of the extrusion of the first and second polar bodies (PB1 and PB2). The release of 50% of the PBs was faster at a salinity of 35 g⋅L−1, with an estimated time of 10 min for PB1 and 30 min for PB2. Thus, chromosome manipulation methodologies aiming triploids should be applied at 35 g⋅L−1 salinity, with application of post-fertilization shock before 10 min for PB1 retention or before 30 min for PB2 retention. hatcheries 15, 15 (15 20 25 3 4 gL1 gL g L 1 pre postfertilization post fertilization clam flexuosa stripping (GVBD g⋅L− 12 3035 30-3 80120 80 80-12 analysis PB (PB . PB2) 50 Thus (1 2 g⋅L 303 30- 8012 8 80-1 5 ( 801 80-

Abstract Disarticulated shells of three bivalve mollusk species (Anomalocardia brasiliana, Codakia orbicularis, and Divaricella quadrisulcata) were experimentally tested in laboratory flumes to determine the threshold of motion and final orientation of the valves. A total of 150 current flow experiments were conducted on single shells resting on a fixed sand bed. This study demonstrated that shells in the convex-up position are more resistant to flow when the umbo is pointing downstream rather than upstream. Moreover, species with higher frontal areas were more likely to be entrained at lower flow velocities. Results of dimensionless shear stress exhibited values far below the threshold of grains movement for beds of uniform roughness (Shields curve). It was observed that circular shells in convex-up positions were mostly orientated with the umbo pointing downstream. Conversely, elliptical shells in convex-up position tended to align their longer axis parallel to the flow with the posterior side of the valve pointing downstream. These results are not only directly applicable in interpretations of incipient shell motions and in paleocurrent analyses from field and sample data, but also support construction of accurate geological models. Anomalocardia brasiliana orbicularis quadrisulcata valves 15 bed convexup convex up upstream Moreover velocities Shields curve. curve . curve) Conversely data models 1

Abstract Continental margins usually have a high degree of environmental heterogeneity, which, in turn, promotes high benthic biodiversity. The South-Southeast regions concentrate the most well-mapped areas of the Brazilian continental margin regarding seafloor geomorphology and physical oceanography. However, the structure of the soft-sediment benthic fauna of the continental slope is still unknown. Characterization and understanding of the Brazilian continental slope biota are imperative since human activities are increasing in the last decades, especially after the discovery of the pre-salt reservoir in Santos Basin. In this study, we aimed to establish a baseline of the spatial distribution of the benthic macrofaunal communities regarding their latitudinal and bathymetric patterns in the Santos Basin to support future environmental monitoring activities in the region. As part of the Santos Project – The Santos Basin Regional Environmental Characterization (PCR-BS) – coordinated by CENPES/PETROBRAS, a benthic oceanographic cruise was carried out in 2019. Sediment samples were collected using a GOMEX-type box corer in 47 stations distributed in eight transects (400– 2,400 m depth range). In total, 12 additional stations (1,300–2,200 m) were defined to cover an area where oil and gas are exploited. Our results showed that macrofaunal assemblages of the Santos Basin present strong depth zonation related to changes in organic matter input, as well as to temperature, carbonate, and grain size. At local scale, the northern sector stood out for having a higher abundance of macrofauna in the upper slope (400 m) and it probably reflects the oceanographic processes and the organic enrichment caused by the upwelling events that occur at Cabo Frio region. The zonation pattern and the dominance of some polychaete, peracarid crustacean, and bivalve families were similar to other SE Brazilian continental margins. heterogeneity which turn biodiversity SouthSoutheast South Southeast wellmapped mapped oceanography However softsediment soft sediment unknown decades presalt pre salt study region PCRBS PCR BS (PCR-BS CENPESPETROBRAS CENPES PETROBRAS CENPES/PETROBRAS 2019 GOMEXtype GOMEX type 4 400– 400 2400 2 2,40 range. range . range) total 1 1,300–2,200 13002200 300 200 (1,300–2,20 exploited input temperature carbonate size scale (40 polychaete crustacean 201 40 240 2,4 1,300–2,20 1300220 30 20 (1,300–2,2 (4 24 2, 1,300–2,2 130022 3 (1,300–2, ( 1,300–2, 13002 (1,300–2 1,300–2 1300 (1,300– 1,300– 130 (1,300 1,300 13 (1,30 1,30 (1,3 1,3 (1, 1, (1

Abstract Mytilopsis leucophaeata is an estuarine bivalve native from the Gulf of Mexico and Southeast USA, and it was introduced in Europe, Asia, Caribbean, South America and Northeast USA, showing massive colonization skills. In Brazil, the single invasion records of M. leucophaeata occur in the city of Rio de Janeiro, i.e., in the Rodrigo de Freitas Lagoon and in the Marapendi Lagoon. We conducted a new series of fieldworks in estuaries from the Rio de Janeiro state in order to evaluate the propagation of this invasive bivalve, aiming sites with proper salinities for the establishment of M. leucophaeata. A new record is given for the Maricá-Guarapina lagoon system, where M. leucophaeata mainly colonizes hard substrata (such as piers and rocks), reaching a mean density up to 43,375 specimens/m2; however, aggregates of M. leucophaeata were also observed in the soft substratum. Based on mitochondrial sequences, the taxonomic identification of the invasive bivalve was confirmed. The associated fauna to the agglomerates of M. leucophaeata in the lagoon system comprises amphipods, barnacles, tanaidaceans, isopods, crabs, polychaetes and snails. The expansion of M. leucophaeata requires a continuous investigation due to the great circulation of boats in the littoral of the Rio de Janeiro state and the increased chance of new introductions. USA Europe Asia Caribbean skills Brazil M ie i e i.e. MaricáGuarapina Maricá Guarapina such rocks, rocks , rocks) 43375 43 375 43,37 specimens/m2 specimensm2 specimensm specimens m2 m however substratum sequences confirmed amphipods barnacles tanaidaceans isopods crabs snails introductions i.e 4337 4 37 43,3 specimens/m 433 3 43,

Resumo Mytilopsis leucophaeata é um bivalve estuarino originário do Golfo do México e Sudeste dos EUA, tendo sido introduzido na Europa, Ásia, Caribe, América do Sul e Nordeste dos EUA, e apresentando massiva capacidade de colonização. No Brasil, os únicos registros de invasão de M. leucophaeata ocorrem no município do Rio de Janeiro, i.e., na Lagoa Rodrigo de Freitas e na Lagoa de Marapendi. Este estudo propõe um novo levantamento de campo em estuários fluminenses para avaliar a propagação desse bivalve invasor, visando locais com salinidade propícia para o estabelecimento de M. leucophaeata. Um novo registro é feito para o complexo lagunar Maricá-Guarapina, onde M. leucophaeata coloniza principalmente substratos duros (como píers e rochas), chegando a uma densidade média de 43.375 indíviduos/m2; porém, agregados de M. leucophaeata também foram observados em substrato inconsolidado. Com base em sequências mitocondriais, a identificação taxonômica do bivalve invasor foi confirmada. A fauna associada aos aglomerados de M. leucophaeata no complexo lagunar compreende anfípodes, cracas, tanaidáceos, isópodes, caranguejos, poliquetas e gastrópodes. A expansão de M. leucophaeata demanda uma investigação contínua devido ao alto fluxo de embarcações no litoral fluminense e elevada probabilidade de novas introduções. EUA Europa Ásia Caribe colonização Brasil M Janeiro ie i i.e. Marapendi MaricáGuarapina, MaricáGuarapina Maricá Guarapina, Guarapina Maricá-Guarapina como rochas, rochas , rochas) 43375 43 375 43.37 indíviduos/m2 indíviduosm2 indíviduosm indíviduos m2 m porém inconsolidado mitocondriais confirmada anfípodes cracas tanaidáceos isópodes caranguejos gastrópodes introduções i.e 4337 4 37 43.3 indíviduos/m 433 3 43.

Resumen Introducción: El bivalvo Semimytilus patagonicus es un bioindicador potencialmente útil por su mecanismo de alimentación, y el gusano Pseudonereis gallapagensis también es interesante como bioindicador por ser bentónico, abundante y fuente de alimento para el calamar Doryteuthis gahi. Sin embargo, su sensibilidad a los contaminantes no ha sido suficientemente estudiada. Objetivo: Probar la utilidad del mejillón S. patagonicus y el poliqueto P. gallapagensis como herramientas ecotoxicológicas para detergentes en el medio marino. Métodos: Se utilizaron 120 individuos de S. patagonicus de Miraflores y 120 de P. gallapagensis de Barranco (ambos cerca de la ciudad de Lima, Perú). Para los bioensayos se utilizaron dos detergentes aniónicos (ingrediente activo, ia, dodecilbenceno sulfonato de sodio). Para S. patagonicus, con una longitud valver promedio de 32.3 ± 6.4 mm, probamos Ariel Doble Poder® (90 %) a concentraciones de 17.5, 35, 70 y 140 mg·ia·l-1, evaluadas a las 48 y 72 h de exposición; y para P. gallapagensis, con una longitud corporal total de 20.4 ± 8.8 mm, probamos Caricia® a 62.5, 125, 250, 500 y 1 000 mg·ia·l-1 a las 24, 48 y 72 h de exposición. Resultados: Los valores de CL50 (Concentración Letal Media) fueron de 34.95 mg·ia·l-1 para S. patagonicus y 102.48 mg·ia·l-1 para P. gallapagensis a las 72 h de exposición. Los detergentes fueron tóxicos para S. patagonicus y levemente tóxicos para P. gallapagensis. La clasificación de riesgo para S. patagonicus es “nocivo” y para P. gallapagensis “no clasificable”. Conclusiones: Estos dos bioindicadores permiten evaluar la toxicidad aguda del detergente comercial a base de SDBS en el ambiente acuático marino.

Abstract Introduction: The bivalve Semimytilus patagonicus is a potentially useful bioindicator because of its feeding mechanism, and the worm Pseudonereis gallapagensis is also interesting as a bioindicator because it is benthonic, abundant, and a food source for the squid Doryteuthis gahi. However, their sensitivity to contaminants has not been sufficiently studied. Objective: To test the usefulness of the mussel Semimytilus patagonicus and the polychaete Pseudonereis gallapagensis as ecotoxicological tools for detergents in the marine environment. Methods: We used 120 individuals of S. patagonicus from Miraflores and 120 of P. gallapagensis from Barranco (both near the city of Lima, Peru). For the bioassays, we used two anionic detergents (active ingredient, ai, Sodium Dodecylbenzene Sulfonate). For S. patagonicus, with an average valve length of 32.3 ± 6.4 mm, we tested “Double power Ariel®” (90 %) at concentrations of 17.5, 35, 70 and 140 mg ai l-1, evaluated after 48 and 72 h of exposure; and for P. gallapagensis, with a total body length of 20.4 ± 8.8 mm, we tested “Caricia®” at 62.5, 125, 250, 500 and 1 000 mg of ai l-1 at 24, 48 and 72 h of exposure. Results: The LC50 values (Mean Lethal Concentration) were 34.95 mg ia l-1 for S. patagonicus and 102.48 mg ia l-1 for P. gallapagensis at 72 h of exposure. The detergents were toxic for S. patagonicus and slightly toxic for P. gallapagensis. The risk classification for S. patagonicus is “harmful” and for P. gallapagensis “not classifiable”. Conclusions: These two bioindicators allow evaluating the acute toxicity of SDBS-based commercial detergents in the marine aquatic environment.