Ecological consequences of hidden pathology by larval digeneans in South American mollusks.

The study of digeneans and their association with mollusks commenced in Europe and South America during the mid-19th to early 20th centuries. Digenean infestation can severely degrade host tissue, leading to diminished energy resources and eventual host mortality. However, these parasites can also induce various non-lethal effects, including changes in growth rates, survival rates, and reproductive capabilities, alongside physiological and behavioral alterations. While numerous studies have explored the ecological effects of digeneans on hosts in Europe and North America, our understanding of these dynamics in South America, particularly in first intermediate hosts, remains limited. Therefore, this paper aims to provide an overview of ecological investigations into digenean-mollusk systems in South America, emphasizing the importance of robust sampling designs and statistical analyses to address key ecological inquiries. Although fascinating examples exist of parasitism influencing different hierarchical levels of digenean-mollusk systems, particularly at the individual, population, and community levels, documentation of their ecosystem-level impacts is comparatively sparse. As South American studies of digenean-mollusk systems from an ecological perspective are still in their early stages, there is immense potential for uncovering unique ecological patterns in this largely unexplored region, propelling us toward further developmental strides in the parasite ecology.

Semperula wallacei (Mollusca, Veronicellidae) um hospedeiro natural recém-descoberto de Angiostrongylus cantonensis (Nematoda, Angiostrongylidae) na Bacia do Pacífico.

Semperula wallacei (Issel, 1874) is a species of terrestrial slug that occurs in southeast China and the Pacific Basin and is the only species of its genus that occurs beyond the Oriental region and to the east of Wallace's line in the Australian region, where it has probably been introduced. In this study, we report for the first time S. wallacei as an intermediate host for Angiostrongylus cantonensis (Chen, 1935) based on histological and molecular analyses of slugs from Tuamasaga, Samoa, deposited at the Medical Malacological Collection (Fiocruz-CMM). DNA was obtained from the deparafinized tissues scraped from specimen slides. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) targeted to the internal transcribed spacer 2 (ITS2) region were carried out using the restriction enzyme Cla I. The RFLP profile observed for our larval specimen of S. wallacei was identical to the profile previously established for A. cantonensis, demonstrating that S. wallacei can be naturally infected with A. cantonensis and is likely to be an intermediate host for this parasitic nematode species in the field. The potential for geographical range expansion of S. wallacei in the Pacific Basin, its small size, and the general role of veronicellids as crop pests and hosts of nematodes, indicate the significance of S. wallacei as an invasive species in the Pacific Basin. Our work also highlights the importance of biological collections for investigating the environmental impact of invasive species on agriculture, public health, and biodiversity conservation.

Diversity and abundance of terrestrial molluscs and their associated nematode fauna in urban kitchen gardens in the city of Rio de Janeiro, Brazil.

Terrestrial molluscs can become agricultural pests and transmit parasites, playing an important role in different biological communities. In the present study, we evaluated the diversity and abundance of this group in two horticultural areas in Rio de Janeiro (Manguinhos and Jacarepaguá neighborhoods), as well the presence of parasitic nematodes associated with these molluscs. We collected specimens in the austral spring and summer, with four sites being sampled within each study area, including malabar spinach, sweet potato, chicory greens, and cassava plantations, and one site in an adjacent, non-cultivated area. We collected a total of 522 live mollusc specimens and identified 16 species from 10 different families. The greatest abundance of molluscs was recorded in summer (363) and at Jacarepaguá (309). Overall, 174 (57%) of the 303 specimens analyzed parasitologically were positive for nematodes. Larvae of superfamily Metastrongyloidea, which includes nematodes that are a concern for public health and veterinary medicine, were found parasitizing the slug Sarasinula linguaeformis, in Manguinhos. Our results contribute to understanding of the diversity of terrestrial molluscs occurring in kitchen gardens in the city of Rio de Janeiro, and provide important insights for generating subsidies for health education actions and control of parasitic diseases transmitted by them.

A checklist of larval Digenea (Platyhelminthes: Trematoda) in molluscs from inland waters of Argentina: one hundred years of research.

A checklist of larval digeneans parasitising molluscs from inland waters of Argentina is presented here. Based on the bibliographical survey of 113 scientific articles and nine theses published between 1930 and 2021, 213 digeneans were found, which were distributed within 13 superfamilies and 35 families. The parasites were identified in 102 locations, encompassing eight of the sixteen biogeographical provinces in Argentina. Digeneans were found in 34 mollusc species (31 gastropods and three bivalves) belonging to 17 genera. The available data are presented for each digenean species, and included host information, localities, prevalence values, type of habitat, life cycle information (natural or experimental host), and information on material and genetic sequences deposited in repositories. Only 21.1% of individuals were identified to species level, and 8.5% to genus level. In addition, the genetic sequences of only 10 species (4.7%) were available at GenBank. This survey constitutes the first checklist of parasitic helminths in molluscs from inland waters of Argentina.

Evaluation of the reproductive profile of Subulina octona (Gastropoda, Subulinidae) experimentally infected by Paratanaisia bragai (Digenea, Eucotylidae) / Avaliação do perfil reprodutivo de Subulina octona (Gastropoda, Subulinidae) infectada experimentalmente por Paratanaisia bragai (Digenea, Eucotylidae)

Snails infected by trematodes may increase or decrease their reproductive activity in response to the presence of infection. Our aim was to verify the reproductive alterations in Subulina octona after infection by Paratanaisia bragai. The infected snails were individually exposed for 24 hours to 20 parasite eggs and four groups were formed (10, 20, 30 and 40 d.p.i.- days after infection), along with control groups. Every 10 days, the number of eggs in the reproductive tract, number of eggs hatched, galactogen content and histopathological changes were evaluated. The reproductive in the control and infected snails presented an alternating pattern, where periods of high production of eggs and newly hatched were followed by periods of low production. However, in relation to the amount of galactogen, both control and infected groups followed the same pattern of variation. In the histology, we observed the presence of male and female gametes with marked reduction in the number of oocytes. The results indicate that the intra-snail development of the parasite affects the reproductive biology of the host.(AU)

Moluscos infectados por trematódeos podem aumentar ou diminuir sua atividade reprodutiva em resposta à presença da infecção. Nosso objetivo foi verificar as alterações reprodutivas de Subulina octona após a infecção por Paratanaisia bragai. Os moluscos infectados foram individualmente expostos durante 24 horas a 20 ovos do parasito e quatro grupos foram formados (10, 20, 30 e 40 d.p.i. dias pós infecção), com respectivos grupos controle. A cada 10 dias, o número de ovos no trato reprodutivo, o número de ovos eclodidos, o conteúdo de galactogênio e alterações histopatológicas eram avaliadas. O padrão reprodutivo nos moluscos controle e infectados evidenciou um comportamento alternante, nos quais períodos de alta produção de ovos e filhotes foram seguidos por períodos de baixa produção. No entanto, em relação ao conteúdo de galactogênio, moluscos controle e infectados seguiram o mesmo padrão de variação. Na histologia, observamos a presença de gametas masculinos e femininos com acentuada redução no número de óocitos. Os resultados indicam que o desenvolvimento intramolusco do parasito afeta a biologia reprodutiva do hospedeiro.(AU)

Abdominal angiostrongyliasis in the Americas: fifty years since the discovery of a new metastrongylid species, Angiostrongylus costaricensis.

Angiostrongylus costaricensis is a zoonotic parasitic nematode described for the first time in 1971 by Pedro Morera and Rodolfo Céspedes in Costa Rica. This parasite causes an infection known as abdominal angiostrongyliasis, affecting mainly school-aged children and young adults. Infection with A. costaricensis has been associated with a myriad of rodent and mollusk species in the Americas and the Caribbean, as its natural hosts and reservoirs. In this commemorative review, we highlight the extensive research collected through a 50-year journey, which includes ecological, pathological, and molecular studies on A. costaricensis and its implicated disease. We also identify major knowledge gaps in its evolutionary history, the ecological role of imported and invasive mollusk species, and immune response. We propose that the advent of -omics analyses will allow us to gather novel information regarding A. costaricensis biology and infection dynamics, as well as to promote the design of much-needed sensitive and specific diagnostic tools.

Identification of the avian tracheal trematode Typhlocoelum cucumerinum (Trematoda: Cyclocoelidae) in a host-parasite-environment system: diagnosis, life cycle and molecular phylogeny.

Typhlocoelum cucumerinum is a tracheal parasite of birds widely distributed across the globe. Nevertheless, aspects of the biology of this cyclocoelid are still poorly understood. Herein, we report the finding of T. cucumerinum in definitive and intermediate hosts from an urban waterbody of Brazil. The parasite was initially detected during the necropsy of domestic Muscovy ducks (Cairina moschata) found dead in the locality. Coproparasitological tests in live animals revealed that 12/47 (25.53%) Muscovy ducks and 2/8 (25%) mallards (Anas platyrhynchos platyrhynchos) were infected with T. cucumerinum. Moreover, rediae and metacercariae morphologically similar to T. cucumerinum were found in 3/248 (1.33%) Biomphalaria straminea collected in the same waterbody frequented by the birds. The conspecificity between the adult and the larval stages was confirmed molecularly (100% similarity in Cox-1). Moreover, the phylogenetic position of T. cucumerinum was determined for the first time based on partial fragments of the 28S, Cox-1 and Nad-1 genes. The species grouped with other members of the subfamily Typhlocoelinae with sequences available, but the data obtained do not support the distinctiveness of the genera Typhlocoelum and Tracheophilus. Further studies involving a broader range of species can result in taxonomic rearrangements in Typhlocoelinae.

Angiostrongylus cantonensis in urban populations of terrestrial gastropods and rats in an impoverished region of Brazil.

The nematode Angiostrongylus cantonensis is the most common cause of neuroangiostrongyliasis (manifested as eosinophilic meningitis) in humans. Gastropod molluscs are used as intermediate hosts and rats of various species are definitive hosts of this parasite. In this study, we identified several environmental factors associated with the presence and abundance of terrestrial gastropods in an impoverished urban region in Brazil. We also found that body condition, age and presence of co-infection with other parasite species in urban Rattus norvegicus, as well as environmental factors were associated with the probability and intensity of A. cantonensis infection. The study area was also found to have a moderate prevalence of the nematode in rodents (33% of 168 individuals). Eight species of molluscs (577 individuals) were identified, four of which were positive for A. cantonensis. Our study indicates that the environmental conditions of poor urban areas (presence of running and standing water, sewage, humidity and accumulated rain and accumulation of construction materials) influenced both the distribution and abundance of terrestrial gastropods, as well as infected rats, contributing to the maintenance of the A. cantonensis transmission cycle in the area. Besides neuroangiostrongyliasis, the presence of these hosts may also contribute to susceptibility to other zoonoses.

Risk factors and prevalence of enteroparasitic diseases in shellfish pickers from a lake area in the Northeast of Brazil / Fatores de risco e prevalência de enteroparasitoses em marisqueiras de uma região lagunar no Nordeste do Brasil

INTRODUCTION: Intestinal parasitosis are a public health problem worldwide. There are several risk factors and a high association with some specific labor activities. OBJECTIVE: The present study assessed the risk factors and prevalence of enteroparasitic diseases in shellfish pickers from one district of Maceió, Alagoas state, Brazil. METHODS: Crosssectional study of 41 female shellfish pickers including parasitological tests in fecal samples and a questionnaire with objective and subjective questions. Sand samples from their working environment were also analyzed. RESULTS: At least one species of parasite was found in 19.51% of the fecal samples. Pathogenic species of Giardia lamblia, Trichuris trichiura, Schistosoma mansoni, Ascaris lumbricoides, Enterobius vermicularis, from the Ancylostomatidae family, and non-pathogenic species of Entamoeba coli were found. Polyparasitism was diagnosed in 37.5% of the positive samples. A total of 57.14% of sand samples contained hookworm larvae. Regarding the risk factor, low educational level was statistically associated to the presence of parasites (p<0.05). CONCLUSION: Greater investment in basic education is needed to increase the knowledge about preventive measures against parasitic diseases and the promotion food-handling courses in order to change existing inadequate habits in the community. Basic sanitation is also essential in preventing environmental contamination.

INTRODUÇÃO: As parasitoses intestinais representam um problema de saúde pública mundial. Estão associados inúmeros fatores de risco, bem como atividades laborais específicas. OBJETIVO: O presente estudo avaliou os fatores de risco e a prevalência de enteroparasitoses em marisqueiras de um bairro da cidade de Maceió, Alagoas, Brasil. MÉTODOS: Procedeu-se um estudo de corte transversal, sendo 41 marisqueiras avaliadas mediante exame parasitológico de fezes e questionário contendo questões discursivas e de múltipla escolha. Foram analisadas também amostras de areia do ambiente de trabalho das mesmas. RESULTADOS: A positividade para pelo menos uma espécie de parasito nas fezes foi de 19,51%. Foram encontradas as espécies patogênicas Giardia lamblia, Trichuris trichiura, Schistosoma mansoni, Ascaris lumbricoides, Enterobius vermicularis e da família Ancylostomatidae, e a espécie não patogênica, Entamoeba coli. Poliparasitismo foi diagnosticado em 37,5% dos exames positivos. Um total de 57,14% das amostras de areia continha larvas de ancilostomatídeos. Em relação aos fatores de risco, a baixa escolaridade foi estatisticamente associada à presença de parasitas (p<0,05). CONCLUSÃO: É necessário maior investimento na educação básica para aprimorar o conhecimento das formas de prevenção das parasitoses e a promoção de cursos de boas práticas de manipulação de alimentos, a fim de modificar hábitos errôneos já incorporados na comunidade. O saneamento básico também é fundamental para evitar contaminação ambiental.

El caracol gigante africano (Achatinafulica) y sus efectos en la salud humana / The giant African snail (Achatinafulica) and its effects on human healt

Introducción: el caracol gigante africano (CGA) o Achatinafulica se considera una de las cien especies exóticas invasoras más dañinas del mundo. Su principal riesgo para la salud humana resulta de la posibilidad de actuar como huésped de nematodos. Desarrollo: el CGA es el hospedero intermediario de varios parásitos incluidos Aelurostrongylusabstrusus, Angiostrongyluscantonensis, Angiostrongyluscostaricensis, Schistosomamansoni, Hymenolepisspp y Fasciola hepática. El A. cantonesis es el principal microorganismo causal de la meningitis eosinofílica (ME) y es agente trasmisor de la bacteria gramnegativa Aeromonashydrophila. Entre las manifestaciones clínicas más comunes de la ME se incluyen cefalea intensa, rigidez nucal, náuseas vómitos y parestesias. La detección de eosinófilos en el líquido cefalorraquídeo (LCR) y la sangre periférica contribuyen a su diagnóstico. El tratamiento en formas graves de la ME se basa en el uso de corticosteroides y punciones lumbares seriadas para extracción del LCR. El empleo de antihelmínticos es controversial. Conclusiones: la presencia del caracol gigante africano en Cuba eleva el riesgo de enfermedades. La aparición de manifestaciones clínicas del sistema nervioso central impone la necesidad de indagar sobre la exposición a este molusco y demanda de la búsqueda de signos y síntomas de meningitis eosinofílica. Se requiere desarrollar en el futuro estudios controlados y aleatorizados sobre la eficacia de los fármacos para el tratamiento de la enfermedad, entre ellos los antihelmínticos(AU)

Introduction: the giant African snail (CGA) or Achatinafulica is considered one of the one hundred most harmful invasive alien species in the world. Its main risk to human health results from the possibility of acting as a host of nematodes. Development: the CGA is the intermediate host of several parasites including Aelurostrongylusabstrusus, Angiostrongyluscantonensis, Angiostrongyluscostaricensis, Schistosomamansoni, Hymenolepisspp and Fasciola hepatica. A. cantonesises is the main causative organism of eosinophilic meningitis (ME) and is a transmitting agent of the gram-negative bacterium Aeromonashydrophila. The most common clinical manifestations of ME include intense headache, nuchal rigidity, nausea, vomiting and paresthesias. The detection of eosinophils in the cerebrospinal fluid (CSF) and peripheral blood contribute to its diagnosis. Treatment in severe forms of EM is based on the use of corticosteroids and serial lumbar punctures for CSF removal. The use of anthelmintics is controversial. Conclusions: the presence of the giant African snail in Cuba increases the risk of diseases. The appearance of clinical manifestations of the central nervous system imposes the need to inquire about the exposure to this mollusk and demand the search for signs and symptoms of eosinophilic meningitis. In the future, controlled and randomized studies on the efficacy of drugs for the treatment of the disease, including anthelmintics, need to be developed(EU)

Temporal variations of larval digenean assemblages parasitizing Heleobia parchappii (Mollusca: Cochliopidae) in two shallow lakes from the Buenos Aires province, Argentina

The larval digenean assemblages in snail hosts are influenced by biotic and abiotic factors and by environmental disturbances due to human activities. Given their susceptibility to different types of impact, they can be useful tools for the study of temporal variations in parasite communities. The study of temporal dynamics in prevalence and species richness of larval digenean assemblages of Heleobia parchappii (DOrbigny, 1835), in two Pampean lakes, provides a good opportunity to test the supposition that seasonal variations in digenean assemblages are determined by a series of biotic and abiotic factors that operate interdependently. To analyze the temporal variations, and to evaluate how local factors influence these digenean assemblages in Los Padres and La Brava lakes (Buenos Aires province, Argentina), 2,400 specimens of H. parchappii were collected seasonally, during one year. The digenean assemblages in Los Padres and La Brava lakes were composed of 13 and 12 species respectively. These larval digenean assemblages showed similarities in the number and in the seasonal frequency of occurrence of species (eight of which were present in both lakes). However, despite these similarities, the assemblages showed different temporal dynamics in La Brava and Los Padres lakes and, also, different correlations with the abiotic and biotic factors analyzed during this study (temperature, high of the water column and snail relative abundance). Temporal dynamics in prevalence and species richness of larval digenean assemblages of H. parchappii in both lakes seems to be influenced by a series of factors (diversity and abundance of definitive hosts, intermediate and definitive host location, snail relative abundance and anthropogenic disturbances). Our results highlight the importance of analyzing the role and interaction of local factors, especially in studies dealing with spatiotemporal fluctuations or with distance decay of similarities in species richness of parasite assemblages.(AU)

Temporal variations of larval digenean assemblages parasitizing Heleobia parchappii (Mollusca: Cochliopidae) in two shallow lakes from the Buenos Aires province, Argentina

The larval digenean assemblages in snail hosts are influenced by biotic and abiotic factors and by environmental disturbances due to human activities. Given their susceptibility to different types of impact, they can be useful tools for the study of temporal variations in parasite communities. The study of temporal dynamics in prevalence and species richness of larval digenean assemblages of Heleobia parchappii (DOrbigny, 1835), in two Pampean lakes, provides a good opportunity to test the supposition that seasonal variations in digenean assemblages are determined by a series of biotic and abiotic factors that operate interdependently. To analyze the temporal variations, and to evaluate how local factors influence these digenean assemblages in Los Padres and La Brava lakes (Buenos Aires province, Argentina), 2,400 specimens of H. parchappii were collected seasonally, during one year. The digenean assemblages in Los Padres and La Brava lakes were composed of 13 and 12 species respectively. These larval digenean assemblages showed similarities in the number and in the seasonal frequency of occurrence of species (eight of which were present in both lakes). However, despite these similarities, the assemblages showed different temporal dynamics in La Brava and Los Padres lakes and, also, different correlations with the abiotic and biotic factors analyzed during this study (temperature, high of the water column and snail relative abundance). Temporal dynamics in prevalence and species richness of larval digenean assemblages of H. parchappii in both lakes seems to be influenced by a series of factors (diversity and abundance of definitive hosts, intermediate and definitive host location, snail relative abundance and anthropogenic disturbances). Our results highlight the importance of analyzing the role and interaction of local factors, especially in studies dealing with spatiotemporal fluctuations or with distance decay of similarities in species richness of parasite assemblages.

First records of molluscs naturally infected with Angiostrongylus cantonensis (Nematoda: Metastrongyloidea) in Northeastern Brazil, including new global records of natural intermediate hosts.

Human neural angiostrongyliasis is an emerging infectious disease caused by nematode Angiostrongylus cantonensis. The present study investigated the presence of Angiostrongylus spp. in terrestrial molluscs collected from the following areas in the Metropolitan Region of Aracaju, Sergipe State, Brazil: Barra dos Coqueiros, Nossa Senhora do Socorro, Sao Cristovao and Aracaju. In total, 703 specimens representing 13 mollusc species were screened for Angiostrongylus spp. Larvae of Angiostrongylus spp. were found in three species. Larvae recovered from Achatina fulica were used for experimental infection in Wistar rats (Rattus norvegicus). For specific identification of nematodes, the mitochondrial cytochrome c oxidase subunit I (COI) was sequenced from both larvae and adults recovered from molluscs and rats, respectively. Infection with A. cantonensis was detected in all municipalities and in the following three host species: Bulimulus tenuissimus, Cyclodontina fasciata (Barra dos Coqueiros), and A. fulica (Aracaju, Nossa Senhora do Socorro and Sao Cristovao). Co-infections were also found with Caenorhabditis sp. and Strongyluris sp. larvae. This is the first study of the helminth fauna associated with the terrestrial malacofauna in Sergipe State, and confirms that these three snail species are involved in the transmission of A. cantonensis in the state. In addition, B. tenuissimus and C. fasciata are newly reported natural hosts of the parasite.

Bulimulus tenuissimus (mollusca) as a new potential host of Angiostrogylus cantonensis (nematoda), a histological and metabolic study.

The terrestrial gastropod Bulimulus tenuissimus is widespread in South America. It is an intermediate host of many parasites, but there are no records of infection of this snail by Angiostrongylus cantonensis, despite the occurrence of this parasite and angiostrongyliasis cases in the same areas in which B. tenuissimus occurs. For this reason, it is important investigate the susceptibility of B. tenuissimus to A. cantonensis-infection, since it can be used as intermediate host of A. cantonensis, increasing the list of terrestrial gastropods that infect wild and domestic animals and humans with this parasite. The purpose of this study was to evaluate the susceptibility of B. tenuissimus to experimental infection with L1 larvae of A. cantonensis. The snails were exposed to 1200 L1 larvae and it was possible observe many developing larvae in the cephalopedal mass and mantle tissues, with intense hemocyte infiltration and collagen deposition, but no typical granuloma structures were formed. The glucose content and lactate dehydrogenase activity in the hemolymph varied, indicating an increase of anaerobic energy metabolism in the middle of infection, but with a tendency to return to normal values at the end of pre-patent period. This was corroborated by the marked reduction in the glycogen content in the cephalopedal mass and digestive gland in the first and second week after exposure, followed by a slight increase in the third week. The content of pyruvic acid in the hemolymph was 14.84% lower at the end of pre-patent period, and oxalic acid content was 41.14% higher. These results indicate an aerobic to anaerobic transition process. The PAS reaction showed a large amount of glycogen inside the developing larvae and muscular tissues of the cephalopedal mass, indicating that despite the high consumption of this polysaccharide by the parasite, the snail is able to maintain its energy metabolism based on carbohydrates. The results reveal that B. tenuissimus is a robust host, which can live with the developing larvae of A. cantonensis and overcome the metabolic damages resulting from parasitism.

Influência de Furcraea foetida (L.) Haw. sobre a sobrevivência, crescimento e reprodução de Subulina octona (Brugüiére, 1789) (Mollusca, Subulinidae) / Influence of Furcraea foetida (L.) Haw. on the survival, growth and reproduction of Subulina octona (Brugüiére, 1789) (Mollusca, Subulinidae)

Subulina octona is a terrestrial mollusc found in gardens andplantations which may act as intermediate host for helminths and as vector for various pathogens. Furcraeafoetida is a naturalized plant, commonly used as ornament or as hedge. It has steroidal saponins on its secondarymetabolism, which are promising substances for mollusc control. The use of vegetal molluscicides has beenstudied for pest control since they are not as aggressive for both men and the environment and they may bea less toxic alternative for controlling these animals. This study aimed to analyze the influence of F. foetida onthe survival, growth and reproduction of S. octona. In order to assess the effect of the aqueous extract of thesap of F. foetida, the direct contact and indirect contact bioassays were used on S octona eggs, immatures andadults in laboratory conditions. Phytochemical analysis of F. foetida sap indicated presence of saponin in theleaves. The aqueous extract of F. foetida sap influenced on the survival and hatching of eggs in direct contact(without subtract) and indirect contact (with subtract); on the other hand, it had no influence on the growthor reproduction of S. octona. Immature and adult mortality rates were 100% in direct contact assays, and therewas significant difference for indirect contact assays regarding blank and negative control groups, which makesF. foetida sap a promising option for S. octona control.

Subulina octona é um molusco terrestre encontrado em jardins e culturas agrícolas, pode atuar comohospedeiro intermediário de helmintos e como vetor de vários patógenos. Furcraea foetida é uma planta naturalizada,muito usada para a ornamentação e cerca viva. Possui em seu metabolismo secundário saponinasesteroidais que são substâncias promissoras no controle de moluscos. O uso de moluscicidas de origem vegetaltem sido estudado para o controle de pragas, pois agridem menos o ambiente e ao homem, podendo ser uma alternativa menos tóxicas para o controle desses animais. O presente trabalho como objetivo avaliar a influênciade F. foetida sobre a sobrevivência, crescimento e reprodução de S. octona. Para avaliar o efeito do extratoaquoso da seiva de F. foetida, foram utilizados o teste de contato direto e contato indireto sobre ovos, jovense adultos de S. octona em condições de laboratório. A análise fitoquímica da seiva de F. foetida acusou a presençade saponina nas folhas. O extrato aquoso da seiva de F. foetida influenciou na sobrevivência e eclosão deovos no contato direto (sem substrato) e contato indireto (com substrato), por outro lado, não influenciou nocrescimento e na reprodução de S. octona. A mortalidade de jovens e adultos foi de 100% para os tratamentosdo experimento com contato direto e houve diferença significativa para os tratamentos do experimento comcontato indireto em relação ao controle branco e o negativo. Tornando a seiva de F. foetida, promissora para.

Influência de Furcraea foetida (L.) Haw. sobre a sobrevivência, crescimento e reprodução de Subulina octona (Brugüiére, 1789) (Mollusca, Subulinidae) / Influence of Furcraea foetida (L.) Haw. on the survival, growth and reproduction of Subulina octona (Brugüiére, 1789) (Mollusca, Subulinidae).

Subulina octona is a terrestrial mollusc found in gardens andplantations which may act as intermediate host for helminths and as vector for various pathogens. Furcraeafoetida is a naturalized plant, commonly used as ornament or as hedge. It has steroidal saponins on its secondarymetabolism, which are promising substances for mollusc control. The use of vegetal molluscicides has beenstudied for pest control since they are not as aggressive for both men and the environment and they may bea less toxic alternative for controlling these animals. This study aimed to analyze the influence of F. foetida onthe survival, growth and reproduction of S. octona. In order to assess the effect of the aqueous extract of thesap of F. foetida, the direct contact and indirect contact bioassays were used on S octona eggs, immatures andadults in laboratory conditions. Phytochemical analysis of F. foetida sap indicated presence of saponin in theleaves. The aqueous extract of F. foetida sap influenced on the survival and hatching of eggs in direct contact(without subtract) and indirect contact (with subtract); on the other hand, it had no influence on the growthor reproduction of S. octona. Immature and adult mortality rates were 100% in direct contact assays, and therewas significant difference for indirect contact assays regarding blank and negative control groups, which makesF. foetida sap a promising option for S. octona control.(AU)

Subulina octona é um molusco terrestre encontrado em jardins e culturas agrícolas, pode atuar comohospedeiro intermediário de helmintos e como vetor de vários patógenos. Furcraea foetida é uma planta naturalizada,muito usada para a ornamentação e cerca viva. Possui em seu metabolismo secundário saponinasesteroidais que são substâncias promissoras no controle de moluscos. O uso de moluscicidas de origem vegetaltem sido estudado para o controle de pragas, pois agridem menos o ambiente e ao homem, podendo ser uma alternativa menos tóxicas para o controle desses animais. O presente trabalho como objetivo avaliar a influênciade F. foetida sobre a sobrevivência, crescimento e reprodução de S. octona. Para avaliar o efeito do extratoaquoso da seiva de F. foetida, foram utilizados o teste de contato direto e contato indireto sobre ovos, jovense adultos de S. octona em condições de laboratório. A análise fitoquímica da seiva de F. foetida acusou a presençade saponina nas folhas. O extrato aquoso da seiva de F. foetida influenciou na sobrevivência e eclosão deovos no contato direto (sem substrato) e contato indireto (com substrato), por outro lado, não influenciou nocrescimento e na reprodução de S. octona. A mortalidade de jovens e adultos foi de 100% para os tratamentosdo experimento com contato direto e houve diferença significativa para os tratamentos do experimento comcontato indireto em relação ao controle branco e o negativo. Tornando a seiva de F. foetida, promissora para. (AU)

Phylogeography and connectivity of molluscan parasites: Perkinsus spp. in Panama and beyond.

Panama is a major hub for commercial shipping between two oceans, making it an ideal location to examine parasite biogeography, potential invasions, and the spread of infectious agents. Our goals were to (i) characterise the diversity and genetic connectivity of Perkinsus spp. haplotypes across the Panamanian Isthmus and (ii) combine these data with sequences from around the world to evaluate the current phylogeography and genetic connectivity of these widespread molluscan parasites. We collected 752 bivalves from 12 locations along the coast of Panama including locations around the Bocas del Toro archipelago and the Caribbean and Pacific entrances to the Panama Canal, from December 2012 to February 2013. We used molecular genetic methods to screen for Perkinsus spp. and obtained internal transcribed spacer region (ITS) ribosomal DNA (rDNA) sequences for all positive samples. Our sequence data were used to evaluate regional haplotype diversity and distribution across both coasts of Panama, and were then combined with publicly available sequences to create global haplotype networks. We found 26 ITS haplotypes from four Perkinsus spp. (1-12 haplotypes per species) in Panama. Perkinsus beihaiensis haplotypes had the highest genetic diversity, were the most regionally widespread, and were associated with the greatest number of hosts. On a global scale, network analyses demonstrated that some haplotypes found in Panama were cosmopolitan (Perkinsus chesapeaki, Perkinsus marinus), while others were more geographically restricted (Perkinsus olseni, P. beihaiensis), indicating different levels of genetic connectivity and dispersal. We found some Perkinsus haplotypes were shared across the Isthmus of Panama and several regions around the world, including across ocean basins. We also found that haplotype diversity is currently underestimated and directly related to the number of sequences. Nevertheless, our results demonstrate long-range dispersal and global connectivity for many haplotypes, suggesting that dispersal through shipping probably contributes to these biogeographical patterns.

What determines sclerobiont colonization on marine mollusk shells?

Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts.

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A epibiose é um tipo de interação entre duas espécies. O epibionte é o organismo que coloniza um substrato vivo durante a fase séssil do seu ciclo biológico, e o basibionte é o organismo que serve de base para a colonização. A epibiose pode se apresentar como um epizoísmo, fenômeno no qual o epibionte coloniza um animal; e epifitismo, fenômeno no qual uma planta serve como base para a colonização.

Vai uma carona aí?

A epibiose é um tipo de interação entre duas espécies. O epibionte é o organismo que coloniza um substrato vivo durante a fase séssil do seu ciclo biológico, e o basibionte é o organismo que serve de base para a colonização. A epibiose pode se apresentar como um epizoísmo, fenômeno no qual o epibionte coloniza um animal; e epifitismo, fenômeno no qual uma planta serve como base para a colonização.(AU)