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The commercially significant Foveaux Strait Ostrea chilensis fishery has been typified by consistently low brooding rates and recruitment failures since recurrent mass mortalities from Bonamia exit...

Bonamia eustachioi is here described as a new species of Convolvulaceae from the states of Bahia and Minas Gerais, Brazil, where it grows in Caatinga and Cerrado vegetation. It is described, illustrated, and compared to similar species.

There is a growing effort throughout Europe to restore populations of native oysters (Ostrea edulis), with the ecological objective of enhancing ecosystem biodiversity and resilience.The introduced parasite, Bonamia ostreae, caused catastrophic mortalities during the 1980s, furthering the decline of this species, and is now present throughout much of the natural range of O. edulis. It is therefore important that restoration attempts avoid further introduction and spread of this parasite, which can cause lethal infections of O. edulis.This article presents a comprehensive overview of the scale and distribution of current infection, transmission pathways, and preventive measure guidelines, focusing on the seas, inlets, and estuaries of north‐west Europe, where most ecological restoration attempts for the native European oyster have occurred so far.This is critical information for restoration project planning in which the risk of Bonamia infection must be taken into account.

The host:parasite interactions of the 3 serious haplosporidian pathogens of oysters, on which most information exists, are reviewed. They are Bonamia ostreae in Ostrea spp. and Crassostrea gigas; Bonamia exitiosa in Ostrea spp.; and Haplosporidium nelsoni in Crassostrea spp. Understanding the haemocytic response to pathogens is constrained by lack of information on haematopoiesis, haemocyte identity and development. Basal haplospridians in spot prawns are probably facultative parasites. H. nelsoni and a species infecting Haliotis iris in New Zealand (NZAP), which have large extracellular plasmodia that eject haplosporosomes or their contents, lyse surrounding cells and are essentially extracellular parasites. Bonamia spp. have small plasmodia that are phagocytosed, haplosporosomes are not ejected and they are intracellular obligate parasites. Phagocytosis by haemocytes is followed by formation of a parasitophorous vacuole, blocking of haemocyte lysosomal enzymes and the endolysosomal pathway. Reactive oxygen species (ROS) are blocked by antioxidants, and host cell apoptosis may occur. Unlike susceptible O. edulis, the destruction of B. ostreae by C. gigas may be due to higher haemolymph proteins, higher rates of granulocyte binding and phagocytosis, production of ROS, the presence of plasma β-glucosidase, antimicrobial peptides and higher levels of haemolymph and haemocyte enzymes. In B.exitiosa infection of Ostrea chilensis, cytoplasmic lipid bodies (LBs) containing lysosomal enzymes accumulate in host granulocytes and in B. exitiosa following phagocytosis. Their genesis and role in innate immunity and inflammation appears to be the same as in vertebrate granulocytes and macrophages, and other invertebrates. If so, they are probably the site of eicosanoid synthesis from arachidonic acid, and elevated numbers of LBs are probably indicative of haemocyte activation. It is probable that the molecular interaction, and role of LBs in the synthesis and storage of eicosanoids from arachidonic acid, is conserved in innate immunity in vertebrates and invertebrates. However, it seems likely that haplosporidians are more diverse than realized, and that there are many variations in host parasite interactions and life cycles.

Bonamia spp. cause epizootics in oysters worldwide. In southern Australia, Bonamia exitiosa Hine, Cochennac and Berthe, 2001 threatens aquaculture of Ostrea angasi Sowerby, 1871. Bonamia spp. infections can display strong seasonality, but seasonal dynamics of B. exitiosa-O. angasi are unknown. Ostrea angasi naive to B. exitiosa infection were stocked onto farms in three growing regions, and B. exitiosa was monitored seasonally for one year. Environmental parameters we measured did not correlate with B. exitiosa prevalence or infection intensities. Extreme temperatures suggest O. angasi culture systems need development. Bonamia exitiosa prevalence increased over time. After three months, O. angasi had B. exitiosa prevalence of 0.08-0.4, and after one year, the prevalence was 0.57-0.88. At some sites, O. angasi had >0.5 B. exitiosa prevalence in >6 months, but at other sites, >9 months passed before prevalence was >0.5. Bonamia exitiosa infection intensities were low with no seasonal pattern but were affected by the interaction of site, season and oyster meat:shell ratio. Understanding infection and initiating a breeding programme for resistance would provide benefits for O. angasi industry expansion.

The annual production of European flat oysters (Ostrea edulis) in Croatia is about 50 to 65 tons, and it has a long tradition. All Croatian oyster farms are subjected to the national surveillance program aiming to detect the presence of Bonamia ostreae and Marteilia refringens according to the Council Directive 2006/88/EC. Within the surveillance program, the first findings of the parasite Bonamia spp. occurred in 2016 in two production areas in the north and south of the Eastern Adriatic coast. The repeated findings of the parasite were noted up to 2020 but also on two additional sites in the north. The parasite was detected by cytological analysis of stained heart smears, histological examination, and PCR. PCR positive samples were sequenced for SSU rDNA gene, and BLAST analysis confirmed infection with Bonamia exitiosa. Attempts to prove the Pacific oyster as a putative vector of the parasite failed. The infection prevalence from 2016 until 2020 ranged from 3.3 to 20% in different sites. No mortalities were reported from the infected sites, and it seemed that infection of flat oysters with B. exitiosa did not affect their health. The study has not shown the source and way of infection spread, which imposes the need for more comprehensive molecular and epidemiological studies.

The fan mussel, Pinna nobilis (Linnaeus 1758), is an endemic bivalve of the Mediterranean basin, protected by international legislation as an endangered species. In the early summer of 2018, a mass mortality event (MME) of P. nobilis was recorded in the Gulf of Taranto (Southern Italy, Ionian Sea). Moribund specimens of P. nobilis were collected by scuba divers and processed by bacteriological, parasitological, histopathological and molecular analyses to investigate the causes of this MME. Different developmental stages (i.e., plasmodia, spores and sporocysts) of a presumptive haplosporidian parasite were observed during the histological analysis in the epithelium and in the lumen of the digestive tubules, where mature spores occurred either free or in sporocysts. The spores presented an operculum and an ovoid shape measuring 4.4 µm (±0.232) in length and 3.6 µm (±0.233) in width. BLAST analysis of an 18SrRNA sequence revealed a high nucleotide similarity (99%) with the reference sequence of Haplosporidium pinnae available in GenBank database. Phylogenetic analysis clustered the sequence of the pathogen in a paraphyletic clade with the reference sequence of H. pinnae, excluding other haplosporidians (i.e., Bonamia and Minchinia genera). Based on data reported, H. pinnae was the causative agent of MME in the populations of P. nobilis sampled in the Ionian Sea, where the conservation of this endangered species is heavily threatened by such a protozoan infection. Further investigations should contribute to knowledge about the life cycle of H. pinnae in order to reduce spread of the pathogen and to mitigate the burden of the disease where P. nobilis is facing the risk of extinction.

Bonamia Thouars (Convolvulaceae) comprises about 60 species, widely distributed through North and South America, Africa, Madagascar, South and Southeast Asia, and Australia. Bonamia is variable, possessing at least two different pollen types, and its current circumscription is controversial. From recent phylogenetic studies in the family, it is established that Bonamia is paraphyletic. Ongoing taxonomic, morphological and molecular phylogenetic studies for the clarification of the real circumscription of Bonamia and its infrageneric relationships, have involved also the pollen analyses of 36 species of Bonamia. The pollen grains were acetolyzed and microphotographed under light microscopy and analyses under Scanning Electron Microscopy. The results increase with descriptions of pollen for taxa never described, as well as species recently described for science and have demonstrated that the pollen grains of all species analyzed are monads, with isopolar, 3-colpate (32 spp.) and 12–32-pantocolpate (4 spp.) since only two pollen types and some variations were cited for the genus we present here five pollen types divided by sections. The exine presented variable ornamentation, with microspines, granules or verrucae and formation of perforations, microreticula and reticula. The palynological features allowed the classification into two major groups: (1) with polar pollen grains and 3-colpate apertures and; (2) with apolar pollen grains with 12–32-pantocolpate. We conclude that Bonamia, in its current circumscription, is euripalynous mainly in what concerns polarity and aperture type.

Since 2017, the European flat oyster (Ostrea edulis) reappeared in the Wadden Sea after decades of absence. In several countries, restoration and reinforcement projects have been initiated. Better insight in Ostrea behaviour is needed to ensure sustainable conservation in the future. In order to acquire substantial numbers of oysters for eco-physiological and transplant experiments without threatening the small local population, indoor rearing facilities were set-up at Royal NIOZ. Here, a broodstock of 38 adults originating from the western Wadden Sea, produced over 21 million larvae in 10 batches within 3 months (Sept-Nov 2018). Release of larvae and rearing took place at a water temperature of 19.7 ± 0.6 °C and a salinity of 30.5 ± 0.5 PSU. Outbreaks of Vibrio bacteria did not occur. The growth rate before settlement was 1.5–1.7 μm per day, which was at the low end of growth rates reported in previous studies. The first competent larvae were observed 17–22 days after release. Size at settlement varied between 255−325 μm. Survival until settlement was 0.96−0.98 per day. After settlement, growth rates increased to 30−47 μm per day, with batches that were released in September having a significantly higher growth rate and initial size compared to larvae that were released later. Mortality from release to the end of the experiment (Feb 2019) was 0.04−0.05 per day. A cryopreservation trial did not result in living larvae after thawing, most likely due to their advanced development when preserved. The larvae and juveniles were negatively tested for the parasite Bonamia ostrea and can thus be used in oyster conservation and restoration projects. Recommendations for future breeding attempts include the use of a higher water temperature and slightly higher food concentrations.

Aquaculture including shellfish production is an important food resource worldwide which is particularly vulnerable to infectious diseases. Marteilia refringens, Bonamia ostreae and Bonamia exitiosa are regulated protozoan parasites infecting flat oysters Ostrea edulis that are endemic in Europe. Although some PCR assays have been already developed for their detection, a formal validation to assess the performances of those tools is often lacking. In order to facilitate the diagnosis of flat oyster regulated diseases, we have developed and evaluated a new multiplex Taqman (R) PCR allowing the detection of both M. refringens and Bonamia sp. parasites in one step. First part of this work consisted in assessing analytical sensitivity and specificity of the new PCR assay. Then, diagnostic performances were assessed by testing a panel of field samples with the new real-time PCR and currently recommended conventional PCR methods for the detection of M. refringens and Bonamia sp. Samples were collected from the main flat oyster production sites in France (N = 386 for M. refringens and N = 349 for B. ostreae). In the absence of gold standard, diagnostic sensitivity and specificity of the new PCR were estimated through Bayesian latent class analysis (DSe 87,2% and DSp 98,4% for the detection M. refringens, DSe 77,5% and DSp 98,4% for the detection of Bonamia sp.). Those results suggest equivalent performances for the detection of Bonamia sp. and an improved sensitivity for the detection of M. refringens compared to commonly used conventional protocols. Finally, the new PCR was evaluated in the context of an inter-laboratory comparison study including 17 European laboratories. Results revealed a very good reproducibility with a global accordance (intralaboratory precision) >96% and a global concordance (inter-laboratory precision) >93% for both targets, demonstrating that this new tool is easily transferable to different laboratory settings. This is the first assay designed to detect both Marteilia refringens and Bonamia sp. in a single step and it should allow reducing the number of analysis to monitor both diseases, and where relevant to demonstrate freedom from infection.

This paper reviews current knowledge of the structure, genesis, cytochemistry and putative functions of the haplosporosomes of haplosporidians (Urosporidium, Haplosporidium, Bonamia, Minchinia) and paramyxids (Paramyxa, Paramyxoides, Marteilia, Marteilioides, Paramarteilia), and the sporoplasmosomes of myxozoans (Myxozoa – Malacosporea, Myxosporea). In all 3 groups, these bodies occur in plasmodial trophic stages, disappear at the onset of sporogony, and reappear in the spore. Some haplosporidian haplosporosomes lack the internal membrane regarded as characteristic of these bodies and that phylum. Haplosporidian haplosporogenesis is through the Golgi (spherulosome in the spore), either to form haplosporosomes at the trans-Golgi network, or for the Golgi to produce formative bodies from which membranous vesicles bud, thus acquiring the external membrane. The former method also forms sporoplasmosomes in malacosporeans, while the latter is the common method of haplosporogenesis in paramyxids. Sporoplasmogenesis in myxosporeans is largely unknown. The haplosporosomes of Haplosporidium nelsoni and sporoplasmosomes of malacosporeans are similar in arraying themselves beneath the plasmodial plasma membrane with their internal membranes pointing to the exterior, possibly to secrete their contents to lyse host cells or repel haemocytes. It is concluded that these bodies are probably multifunctional within and between groups, their internal membranes separating different functional compartments, and their origin may be from common ancestors in the Neoproterozoic.

Bonamiosis has developed as a problem in Australian native oysters Ostrea angasi since the parasite Bonamia spp. was first detected in Port Phillip Bay, Victoria, in the early 1990s. At that time, large-scale mortalities in both farmed and wild oysters saw the demise of the pilot native oyster culture industry. More recent attempts to farm the species resulted in subclinical infections that progressed over time to clinical disease. The aim of this work was to establish what environmental factors result in the clinical manifestation of disease; determine the diagnostic sensitivity and diagnostic specificity of histopathological examination and a quantitative polymerase chain reaction (qPCR) test for the diagnosis of B. exitiosa infection in clinically diseased farmed native oysters; and calculate the optimal qPCR threshold cycle (CT) epidemiological cut-point for classification of positive and negative cases. After applying a range of stressors to tank-held oysters, results indicated a 58% increased risk (95% CI: 16%, 99%) of a Bonamia-infected oyster dying if the oyster was held at a higher temperature (p = 0.048). Starving and tumbling oysters, in isolation, was not significantly associated with clinical bonamiosis, but a Bonamia-infected oyster was at the greatest risk of death when increased water temperature was combined with both starvation and increased motion (p = 0.02; odds ratio = 3.47). The diagnostic sensitivity and specificity of the World Organisation for Animal Health qPCR protocol were calculated for increasing CT value cut-points from ≤25 to ≤40, with an optimal cut-point identified at ≤34.5 (specificity: 92.2; 95% posterior credible intervals [PCI]: 76.2, 99.8; Sensitivity: 93.5; 95% PCI: 84.7, 99.1).

The decline of the European flat oyster Ostrea edulis represents a loss to European coastal economies both in terms of food security and by affecting the Good Environmental Status of the marine environment as set out by the European Council’s Marine Strategy Framework Directive (2008/56/EC). Restoration of O. edulis habitat is being widely discussed across Europe, addressing key challenges such as the devastating impact of the haplosporidian parasite Bonamia ostreae. The use of resistant, tolerant, or resilient oysters as restoration broodstock has been proposed by restoration practitioners, but the definitions and implications of these superficially familiar terms have yet to be defined and agreed by all stakeholders. This opinion piece considers the challenges of differentiating Bonamia resistance, tolerance, and resilience; challenges which impede the adoption of robust definitions. We argue that, disease-resistance is reduced susceptibility to infection by the parasite, or active suppression of the parasites ability to multiply and proliferate. Disease-tolerance is the retention of fitness and an ability to neutralise the virulence of the parasite. Disease-resilience is the ability to recover from illness and, at population level, tolerance could be interpreted as resilience. We concede that further work is required to resolve practical uncertainty in applying these definitions, and argue for a collaboration of experts to achieve consensus. Failure to act now might result in the future dispersal of this disease into new locations and populations, because robust definitions are important components of regulatory mechanisms that underpin marine management.

Background and aims: Bonamia Thoaurs (Convolvulaceae) comprises about 70 species with a tropical and subtropical distribution. Morphological and molecular studies in Bonamia were carried out to clarify relationships in and out of the genus and throughout this work it was detected the need for re-limit the circumscription of some taxa. This paper contributes to the circumscription and lectotypification of Bonamia sericea (Griseb.) Hallier f., an endemic species from northern Argentina. M&M: Morphological analysis of Bonamia sericea, were made based on a study of specimens of herbaria, including the type-material, digital type images and other herbaria website. Results: A new synonym for B. sericea is proposed. The lectotype of B. sericea is here designated and a complete description and illustrations are presented.

Shellfish aquaculture (in particular oyster cultivation) has the potential to play a significant role in refreshing the coastal economy in the state of Maine (USA). Although ocean warming and acidification are often listed as the primary manifestations of climate change in the marine environment, the issue of expanding geographic ranges of parasites and pathogens is an equally serious threat to shellfish populations. Protozoan parasites of the genera Bonamia, Haplosporidium, and Perkinsus, the bacterial pathogen responsible for Roseovarius oyster disease, and the disease condition is known as disseminated neoplasia are currently recognized as some of the significant threats to natural and farmed bivalve populations. We have analyzed the peer-reviewed literature for reports of these pathogens/conditions in Maine. Most reports focus on oysters from the Damariscotta River Estuary and are the result of directed studies into the biology of a particular pathogen rather than the result of intensive monitoring programs. The sampling effort could be interpreted in several ways including; the pathogens/conditions not impacting the annual harvest to any great extent due to limited distribution of the causative agent, the oysters developing a tolerance to the diseases, or just a lack of resources directed at studying this topic. With the shellfish aquaculture industry expected to grow in the next several decades, we recommend that a rigorous and sustained survey of parasitic diseases and believe that such an effort is fundamental to the success, resilience, and well-being of Maine's shellfish aquaculture industry.

Raw-bivalves consumption is a wide trend in Mediterranean countries. Despite the unambiguous nutritional value of seafood, raw consumption of bivalves may involve risks that could pose a significant threat to consumers’ health. Their filter-feeding behavior is responsible for the potential hosting of a wide variety of microorganisms, either pathogenic for the bivalves or public health threats. Under this prism, the current study was conducted in an effort to evaluate the risk of eating raw bivalves originating from the two biggest seafood markets in Thessaloniki, the largest production area of bivalves in Greece. Both microbiological and molecular methodologies were applied in order to assess the presence of various harmful microbes, including noroviruses, Bonamia, Marteilia, Esherichia coli, Salmonella, and Vibrio. Results indicated the presence of several Vibrio strains in the analyzed samples, of which the halophilic Vibrio harveyi was verified by 16S rRNA sequencing, other than this, no enteropathogenic Vibrio spp. was detected. Furthermore, although Esherichia coli was detected in several samples, it was mostly below the European Union (EU) legislation thresholds. Interestingly, the non-target Photobacterium damselae was also detected, which is associated with both wound infections in human and aquatic animals. Regarding host pathogenic microorganisms, apart from Vibrio harveyi, the protozoan parasite Marteilia refrigens was identified in oysters, highlighting the continuous infection of this bivalve in Greece. In conclusion, bivalves can be generally characterized as a safe-to-eat raw food, hosting more bivalve pathogenic microbes than those of public health concern.

A 2007 study of Suminoe (Crassostrea ariakensis) and eastern (Crassostrea virginica) oysters exposed to Indian River Lagoon (IRL), Florida waters revealed the presence of Bonamia spp. in exposed oysters. In 2010, a survey of oysters and other bivalves (n = 721, 18 species) was conducted in the southern IRL (10 sites) and in the more southerly Lake Worth Lagoon (LWL, 3 sites). Polymerase chain reaction (PCR) was used to assess the prevalence of three oyster parasites, Bonamia spp., Perkinsus marinus, and Haplosporidium nelsoni, in collected samples. Histology, fluorescent in situ hybridization (FISH) and standard H&E staining, was used to confirm PCR-positive Bonamia results. Bonamia spp. was detected in eight species (Brachidontes exustus, Crassostrea virginica, Geukensia demissa, Ischadium recurvum, Isognomon alatus, Isognomon bicolor, Mercenaria campechiensis, and Ostrea stentina). The prevalence was 17.3% in the IRL and 9.9% in LWL with 66% of PCR-positive samples subsequently identified as either Bonamia exitiosa or Bonamia perspora. The presence of Bonamia spp. was confirmed by FISH in C. virginica, O. stentina, I. alatus, I. bicolor, and G. demissa, although only C. virginica and O. stentina showed evidence of infection. The presence of P. marinus was detected in eight species (Atrina rigida, B. exustus, C. virginica, G. demissa, I. recurvum, I. alatus, I. bicolor, and O. stentina). The prevalence was 12.4% in the IRL and 7.7% in LWL. The presence of MSX was not detected in any of the collected bivalves. This study confirms the presence of Bonamia spp. and P. marinus in Florida east coast waters and widens the described geographic range for Bonamia spp., and provides further evidence that MSX is unlikely to be found in Florida waters

The flat oyster, Ostrea chilensis, native to New Zealand (NZ) and Chile is considered an important ecological, cultural and fisheries resource. Currently, commercial landings of this species in NZ are restricted due to low population numbers caused by ongoing mortalities resulting from the presence of the haplosporidian parasite, Bonamia exitiosa. More recently, the arrival of B. ostreae in NZ led to major mortalities in farmed stocks. To understand how diseases caused by Bonamia spp. affect this oyster species, a more complete understanding of its biology, physiology and immune system is needed. The present study characterized, for the first time, hemocytes of adult O. chilensis, from the Foveaux Strait, NZ, using flow cytometry (FCM) and histology. Based on the internal complexity of the hemocytes, two main circulating hemocyte populations were identified: granulocytes and hyalinocytes (accounting for ~30% and ~70% of the total circulating hemocyte population, respectively). These were further divided into two sub-populations of each cell type using FCM. A third sub-population of granulocytes was identified using histology. Using FCM, functional and metabolic characteristics were investigated for the two main hemocyte types. Granulocytes showed higher phagocytic capabilities, lysosomal content, neutral lipid content and reactive oxygen species production compared to hyalinocytes, indicating their important role in cellular immune defence in this species. Methods of hemocyte sampling and storage were also investigated and flow cytometric protocols were detailed and verified to allow effective future investigations into the health status of this important species.

Este artículo contiene 11 páginas, 4 figuras, 1 tabla., A mass mortality event is devastating the populations of the endemic bivalve Pinna nobilis in the Mediterranean Sea from early autumn 2016. A newly described Haplosporidian endoparasite (Haplosporidium pinnae) is the most probable cause of this ecological catastrophe placing one of the largest bivalves of the world on the brink of extinction. As a pivotal step towards Pinna nobilis conservation, this contribution combines scientists and citizens’ data to address the fast- and vastdispersion and prevalence outbreaks of the pathogen. Therefore, the potential role of currents on parasite expansion was addressed by means of drift simulations of virtual particles in a high-resolution regional currents model. A generalized additive model was implemented to test if environmental factors could modulate the infection of Pinna nobilis populations. The results strongly suggest that the parasite has probably dispersed regionally by surface currents, and that the disease expression seems to be closely related to temperatures above 13.5 °C and to a salinity range between 36.5–39.7 psu. The most likely spread of the disease along the Mediterranean basin associated with scattered survival spots and very few survivors (potentially resistant individuals), point to a challenging scenario for conservation of the emblematic Pinna nobilis, which will require fast and strategic management measures and should make use of the essential role citizen science projects can play., This study was financed by the special action project “NACRAS – Evaluación de la magnitud de un evento de mortalidad combinando censos científicos ampliados con observaciones de ciencia ciudadana” cofunded by the Regional Government and Direcció General d’Innovació i Recerca of the Balearic Islands and the European Social Fund 2014–2020. Salinity and temperature data at Alfacs Bay was provided from the “Programa de Seguimiento de la calidad de las aguas, moluscos y fitoplancton tóxico en las zonas de producción de marisco del litoral catalán (PSQAM) de la DGPAM.” The authors acknowledge the MEDCLIC project, funded by “La Caixa” Foundation, contributing to the development of the WMOP hydrodynamic model. Maite Vázquez- Luis and Miguel Cabanellas-Reboredo were supported by a postdoctoral contract co-funded by the Regional Government of the Balearic Islands and the European Social Fund 2014–2020. Also, Vázquez-Luis was also supported by a postdoctoral contract Juan de la Cierva-Incorporación (IJCI-2016-29329) of Ministerio de Ciencia, Innovación y Universidades. Elvira Álvarez was supported by a Personal Técnico de Apoyo contract (PTA2015-10829-I) funded by the Spanish Ministry of Economy and Competiveness. Iris E. Hendriks was supported by Ramon y Cajal Fellowship RYC-2014-14970, cofunded by the Conselleria d’Innovació, Recerca i Turisme of the Balearic Government (Pla de ciència, tecnologia, innovació i emprenedoria 2013-2017) and the Spanish Ministry of Economy, Industry and Competitiveness. Jose Rafael Garcia-March and Jose Tena were supported by the project BF/HEM 15-1662

The haplosporidian Bonamia was first detected in Australian shellfish in 1991. Australian isolates in Ostrea angasi Sowerby, 1871 were identified as Bonamia exitiosa Hine, Cochennac and Berthe, 2001, which threatens development of an O. angasi aquaculture industry. European field data suggest that Bonamia ostreae Pichot, Comps, Tige, Grizel and Rabouin, 1980 infections in Ostrea edulis Linnaeus, 1758 build slowly, but infection dynamics of B. exitiosa in O. angasi are unknown. We investigated B. exitiosa infection in O. angasi by cohabiting uninfected juvenile O. angasi with adults infected with B. exitiosa. Oysters were sampled at 10, 21 and 40 days after cohabitation, and B. exitiosa prevalence and intensity were assessed. Bonamia exitiosa rapidly infected and caused disease in O. angasi. Mortalities began at 12 days, with ˜50% mortality by day 21 and >85% mortality by day 40. Mortalities displayed pathology consistent with clinical B. exitiosa infection. Time to first infection is likely influenced by a combination of parasite infectivity, host exposure and host immune capacity. Host death is not required for transmission, but probably facilitates release of parasites from decaying tissue. Understanding B. exitiosa transmission informs design and interpretation of field studies and aids development of management strategies for oyster aquaculture.

The pustulose ark, Anadara tuberculosa , is considered as an emblematic species of the east Pacific mangrove ecosystem. The decline of its populations is of increasing preoccupation, in particular in Peru. The use of hatchery-produced larvae for stock enhancement or aquaculture is attractive but raises strong criticisms from an ecological point of view, as it could conduce to loss of genetic diversity in wild populations and favor the disease spreading from hatcheries to the environment. In this works, spat production through traditional aquaculture/biotechnology technologies was associated with pathogen molecular diagnostics and with genetic diversity estimation to produce specific pathogen-free (SPF) larvae from genetically characterized populations. All PCR and nested-PCR diagnostics of common bivalve pathogens, such as Bonamia , Martelia , Perkinsus and OsHV1, led to negative results for healthy or moribund adults and spat samples. Microbiological and molecular analyses realized during mortalities led to identifying a pathogenic Pseudomonas strain present on culture tank walls, in moribund spats and adults´ blood. Population genetic variation was assessed by mitochondrial COI gene sequences which showed 36.7% haplotype diversity. This study with hatchery production, pathology and genetic components for an overexploited native bivalve represents an original model for successful mollusk stock enhancement or/and innovative aquaculture programs. Normal 0 21 false false false ES-EC X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-ansi-language:ES-MX; mso-fareast-language:ES-MX;}

Bonamia linearifolia A.L.C.Moreira & Sim.-Bianch., a new species from the Cerrado of Central Brazil, is described and illustrated; its distinctive morphological characters are discussed and compared with other related species.

Bonamia chontalensis Carranza sp. nov. is described and illustrated as a new species from the south of Oaxaca, Mexico. It is a rare plant, known only from a few collections in coastal areas. The species differs from other bonamias by evident unequal, suborbicular external and ovate to long-ovate internal sepals. Possible relations with other species and an identification key for the Mexican species are discussed and provided.

14 páginas, 1 figura, 3 tablas.-- Simone Sühnel ... et al., The protozoans Perkinsus marinus, Perkinsus olseni, Bonamia ostreae, Bonamia exitiosa, and Marteilia refringens are responsible for some of the most detrimental diseases in the production of cultivated shellfish worldwide and are classified as notifiable diseases by the World Organization for Animal Health (OIE). This study examined the general health status of wild and cultured bivalves from southern Brazil and included diagnostic tests for the presence of Perkinsus sp., Bonamia sp., andMarteilia sp. Cultured bivalves included the mangrove oyster Crassostrea gasar (syn. Crassostrea brasiliana), the brown mussel Perna perna, the lion's paw scallop Nodipecten nodosus, andwing pearl oyster Pteria hirundo. Themangrove oyster Crassostrea rhizophorae and the carib pointed venus clam Anomalocardia brasiliana (syn. Anomalocardia flexuosa) were collected from wild populations. A variety of parasitic or commensal organisms were detected by histology including Ancistrocoma-like and Spenophrya-like organisms; Bucephalus genus, Nematopsis sp., Steinhausia sp., and Tylocephalum sp.; unidentified trematode; unknown protozoan and metazoans; and an amoeba parasite. Hemocytic infiltration was most commonly associated with parasitized animals. Histological, culture and molecular diagnostic tests did not find any evidence of the presence of OIE-listed pathogens or related species in this study. Although the current survey did not identify any pathogens or diseases of concern, it provides baseline health assessment data for these species against which any future disease developments or significant changes in population health can be compared. These data are also valuable with respect to the development and implementation of public policies related to aquatic animal health, We would like to thank to the Ministry of Fisheries and Aquaculture, Brazil, for the research support provided to the Fundaçao de Amparo à Pesquisa do Estado de Santa Catarina (FAPESC), Brazil; the National Council of Technological and ScientificDevelopment, Brazil (CNPq-558222/2008-0), for supporting themacro- andmicroscopical analysis and for providing a grant (CNPq-301072/2007-8); the Coordenaçao de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Brazil, for post-doctoral scholarship support for SS; the Pacific Biologic Station and Vancouver Island University (VIU) in Canada for supporting the molecular studies

The Phylum Haplosporidia consists of four genera (Minchinia, Haplosporidium, Urosporidium and Bonamia) that are endoparasitic protists of a wide range of marine invertebrates including commercial bivalve species. Characterization of haplosporidian species remains a challenge due to their patchy spatial and temporal distributions, host-restricted occurrence, and poorly known life cycles. However, they are commonly associated with significant mortality events in bivalves. Due to the recent sporadic mortality events that have occurred in cockles in Europe, the objectives of this study were to determine the diversity, distribution and seasonality of haplosporidian species in Cerastoderma edule populations at several Irish sites. The role of abiotic (temperature, salinity and dissolved oxygen in water) and biotic (cockle size and age) factors as drivers or inhibitors of haplosporidian infection were also assessed. Cockles (n = 998) from the intertidal were sampled from April/July 2018 to April 2019 at three sites with no commercial fishing activity on the south coast (Celtic Sea) and one site on the northeast coast (Irish Sea) with an active commercial fishery. Screening of the cockles by molecular techniques (PCR, Sanger sequencing) and by histopathology was carried out. Two species were identified and confirmed in Irish C. edule for the first time, Minchinia mercenariae -like (14.8%) and Minchinia tapetis (29.6%). Similar to other haplosporidian parasites, the Minchinia spp. detected in our study were present year-round at all sites, except for M. tapetis in Youghal Bay (Celtic Sea). Coinfection of both Minchinia species was only observed in Cork Harbour (Celtic Sea) and Dundalk Bay (Irish Sea), where Minchinia spp. showed a higher presence compared to Youghal Bay and Dungarvan Harbour (Celtic Sea). Moreover, haplosporidians detected with generic primers, were present at all of the sample sites throughout the year but had a higher occurrence during the winter months and were positively correlated with dissolved oxygen. Likewise, smaller and older C.edule seemed to be more vulnerable to the haplosporidian infection. Furthermore, haplosporidian distribution displayed spatial variability between and within sample sites, with the highest presence being observed in cockles at one of the commercially fished Dundalk beds, while the lowest presence was observed in cockles at the second Dundalk bed that was more influenced by freshwater runoff when the tide was out. Findings from this study provide additional information on the distribution and seasonal presence of novel haplosporidian species and their potential abiotic and biotic drivers/inhibitors of infection.

Bonamia spp. parasites threaten flat oyster (Ostrea spp.) farming worldwide. Understanding test performance is important for designing surveillance and interpreting diagnostic results. Following a pilot survey which found low Bonamia sp. intensity in farmed Ostrea angasi, we tested further oysters (n = 100-150) from each of three farms for Bonamia sp. using heart smear, histology and qPCR. We used a Bayesian Latent Class Model to assess diagnostic sensitivity (DSe) and specificity (DSp) of these tests individually or in combination, and to assess prevalence. Histology was the best individual test (DSe 0.76, DSp 0.93) compared to quantitative polymerase chain reaction (qPCR) (DSe 0.69, DSp 0.93) and heart smear (DSe 0.61, DSp 0.60). Histology combined with qPCR and defining a positive from either test as an infected case maximized test performance (DSe 0.91, DSp 0.88). Prevalence was higher at two farms in a high-density oyster growing region than at a farm cultivating oysters at lower density. Parasite intensities were lower than in New Zealand and European studies, and this is probably contributed to differences in the performance of test when compared to other studies. Understanding diagnostic test performance in different populations can support the development of improved Bonamia surveillance programs.

European flat oyster Ostrea edulis populations have suffered extensive mortalities caused by bonamiosis. The protozoan parasite Bonamia ostreae is largely responsible for this disease in Europe, while its congener B. exitiosa has been detected more recently in various European countries. Both of these intracellular parasites are able to survive and proliferate within haemocytes, the main cellular effectors of the immune system in molluscs. Two-dimensional electrophoresis was used to compare the haemolymph protein profile between Bonamia spp.-infected and non-infected oysters within 3 different stocks, a Galician stock of oysters selected for resistance against bonamiosis, a non-selected Galician stock and a selected Irish stock. Thirty-four proteins with a presumably relevant role in the oyster-Bonamia spp. interaction were identified; they were involved in major metabolic pathways, such as energy production, respiratory chain, oxidative stress, signal transduction, transcription, translation, protein degradation and cell defence. Furthermore, the haemolymph proteomic profiles of the non-infected oysters of the 2 Galician stocks were compared. As a result, 7 proteins representative of the non-infected Galician oysters selected for resistance against bonamiosis were identified; these 7 proteins could be considered as candidate markers of resistance to bonamiosis, which should be further assessed.

This study provides morphological and molecular characterization of a new species, Haplosporidium pinnae), very likely responsible for mass mortality of fan mussels, Pinna nobilis, in the Western Mediterranean Sea. The parasite was found in dead or moribund P. nobilis but did not occur in healthy fan mussels from locations that were not affected by abnormal mortality. Histological examination of infected fan mussels showed uninucleate cells of a haplosporidan parasite throughout the connective tissue and hemolymph sinuses of the visceral mass and binucleate cells and, rarely, multinucleate plasmodia were also detected in the connective tissue. Additionally, stages of sporulation occurred in the epithelium of the host digestive gland tubules. Spores were slightly ellipsoidal with a hinged operculum in one pole. Typical haplosporosomes were not found with TEM but vesicles with two concentric membranes resembling haplosporosomes were abundant in the cytoplasm of the multinucleate plasmodia occurring in host digestive gland tubules. SEM analysis showed multiple structures on the spore surface; some spores had two or four long tape-like filaments attached to the spore wall. Phylogenetic analysis based on the SSU rDNA sequence placed this parasite within a large clade including species of the order Haplosporida, not in the Bonamia/Minchinia subclade or the subclade containing most Haplosporidium species, but within a subclade of Haplosporidium sp. from Penaeus vannamei. Our results suggested that H. pinnae and the parasite of P. vannamei may represent a distinct new genus within the order Haplosporida.

10 pages, 3 tables, 7 figures, The purpose of this study was to compare the parasites of two coexisting bivalves, the edible Puelche oyster (Ostrea puelchana) and the false oyster (Pododesmus rudis) that lives attached to O. puelchana shells, and to investigate their host specificity. Samples from wild populations, 465 O. puelchana and 131 P. rudis, were collected seasonally during two years in the San José Gulf (northern Patagonia, Argentina) and were processed using standard histological techniques. To increase the natural low prevalences of Bonamia spp. and Perkinsus spp. that are present in wild populations, an in situ experiment was performed by maintaining captive sentinel bivalves at high densities inside a plastic mesh bag to enhance parasite transmission. Polymerase chain reaction (PCR) assays were used to test for apparent Bonamia sp. infections among captive sentinel O. puelchana specimens (n = 80), and Ray’s fluid thioglycollate medium (RFTM) assays and histological immunoassays tested for apparent Perkinsus sp. infections among captive sentinel P. rudis specimens (n = 100). Despite histological observations that revealed the presence of microcells resembling Bonamia sp. infecting hemocytes of some Puelche oysters, PCR assays did not confirm that parasite identification. Among captive sentinel P. rudis that showed histological evidence of Perkinsus sp. infections, neither RFTM nor immunoassays confirmed such parasites. Ostrea puelchana from wild populations were occasional hosts for both Rickettsia-like organism (RLOs) and Urastoma-like turbellarians. In contrast, six parasite taxa infected P. rudis from coexisting populations, including RLOs, Urastoma-like turbellarians, an intracellular gregarine species, Nematopsis-like oocysts, an unidentified coccidian and a Perkinsus qugwadi-like protozoan. These results demonstrated specific infection patterns of the identified parasites in relation to their hosts, Financial support was provided by the Agencia Nacional de Promoción Científica y Tecnológica (Préstamo BID PICT 2013- 1702 and 2582) and by Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (PIP 0670/14)

The production of native oysters Crassostrea rhizophorae and Crassostrea gasar is expanding in northeastern Brazil, where reports of bivalve pathology are scarce. Recently, Perkinsus marinus was detected for the first time infecting C. rhizophorae in the state of Paraiba, in northeastern Brazil. Thus, more information on factors affecting the health of oysters is needed, especially concerning the pathogens listed by the World Organisation for Animal Health (OIE). The current study evaluated the health status of wild and cultured C. gasar mangrove oysters from the estuary of the Rio Sao Francisco, Sergipe state, northeastern Brazil. Results show that C. gasar oysters cultivated in the Rio Sao Francisco estuary had a greater prevalence of diseases and pathogens than oysters from a natural population in the same estuary, including maladie du pied (shell disease), Rickettsia—like organisms in gills, Steinhausia sp. oocyte infections, and Polydora sp. valve infestations. Of the two OIE notifiable diseases investigated, perkinsosis occurred at variable levels of prevalence that were always greater among cultured oysters (50.8%) than wild oysters (25.8%), and the intensity was predominantly low, suggesting low mortality impact. Bonamiosis was not detected.