Rearing and Maintenance of Biomphalaria Glabrata (Say, 1818): Adults and Embryos Under Laboratory Conditions
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Central Annals of Aquaculture and Research Short Communication *Corresponding author Lenita de Freitas Tallarico, Laboratório de Parasitologia/ Malacologia, Instituto Butantan, Avenida Vital Brasil, Rearing and Maintenance of 1500, CEP 05503-900, São Paulo, SP, Brazil, Tel: 55-11- 2627-9770; Fax: 55-11-2627-9581; Email: Biomphalaria glabrata (Say, Submitted: 20 May 2016 Accepted: 08 June 2016 1818): Adults and Embryos Published: 10 June 2016 ISSN: 2379-0881 under Laboratory Conditions Copyright © 2016 de Freitas Tallarico et al. Lenita de Freitas Tallarico1,2*, Patrícia Aoki Miyasato1, and OPEN ACCESS Eliana Nakano1 1Laboratório de Parasitologia/Malacologia, Instituto Butantan, Brazil Keywords 2Faculdade Nossa Cidade – Estácio, Brazil • Ecotoxicology • Schistosoma mansoni • Embryos Abstract • Breeding; Moluscicides The freshwater snail Biomphalaria glabrata has been studied by many features. The life cycle and reproduction are well described, besides research in the development of molluscicides, maintenance of schistosomiasis cycle and most currently as environmental pollution bioindicators. The knowledge of the best conditions of snails breeding and cultivation are the most relevant information and contribute to the success of the studies with those organisms. The parameters for analyses of snails are described in tables to simplify the employment during the research and comply with the requirements for the preparation of laboratory testing standards. In this paper a review of the recommendations for B. glabrata rearing is described. INTRODUCTION and 2). Snails are simultaneous hermaphrodite and different reactions in both sexes do not occur, they can reproduce Freshwater snails of the genus Biomphalaria (Preston, throughout the year under controlled conditions and have a short 1910) are widely studied due their importance in public life span, with an egg-to-egg monitoring during two months [5]. health, as intermediate hosts of Schistosoma mansoni Sambon 1907 trematode parasite and for being good bioindicator for The B. glabrata breeding is important for several approaches environmental studies, as described by Tallarico [1]. According to World Health Organization the control of schistosomiasis is of population of snails, both for the study of schistosomiasis, such in scientific researches. It is necessary to keep an abundant international concern, on their own or jointly with other measures, as the development of new molluscicides or parasite cycle is to reduce morbidity within to decrease general parasite maintenance, as well as for toxicity of chemical compounds transmission in the snail and associated aquatic stages by use of moluscicides and environmental changes [2]. Another important intermediate host to Schistosoma mansoni cycle, our laboratory and environmental analyses. In addition to maintaining the statement by WHO explains that invertebrates are recommended for toxicity tests in evaluating of any chemical agent in the potential toxic effects, either for humans, animals and plants [3]. Furthermore, toxicological assays employing Biomphalaria species have revealed its importance as a biomarker providing endpoints for the aquatic life risk assessment and protection [1]. Adaptation to adverse environmental conditions is an important aspect of Biomphalaria [4]. This genus shows wide geographical distribution, low dispersion and is easily collected in the freshwater. For the maintenance of snails, little space A) B) is enough and the exposure systems require relatively small quantities of test samples for analysis [5]. Images courtesy: Márcio M. Yamamoto Among the genus Biomphalaria, the species B.Glabrata (Say, Figure 1 Adults of Biomphalaria glabrata (Say, 1818). (A) Wild-type 1818) is the most used in laboratory conditions [6] (Figures 1 snail. (B) Non-pigmented, albino snail. Cite this article: de Freitas Tallarico L, Miyasato PA, Nakano E (2016) Rearing and Maintenance of Biomphalaria glabrata (Say, 1818): Adults and Embryos under Laboratory Conditions. Ann Aquac Res 3(1): 1013. de Freitas Tallarico et al. (2016) Email: Central has been summarized in the tables. RESULTS AND DISCUSSION Some particular requirements are necessary to optimize the conditions for the growth and maintenance of B. glabrata, both snails as embryos. Fertility, growth, mortality rates and shell size are essential indicators of the physiological state of A) B) the snails and it is important to have all the information about them [8]. Furthermore, many aspects for a proper rearing of Figure 2 Maintenance of Biomphalaria glabrata (Say, 1818) in snails are necessary, such as food, temperature, oxygen, pH, conductivity, and mate selection [1]. Another relevant topic is containers. laboratory conditions. (A) Containers for rearing. (B) Individual conditions. The normal embryonic development of B. glabrata is has used B. glabrata to evaluate toxic and mutagenic effects of the characterization of the reproductive cycle under defined chemical and physical agents using mortality index, alterations in detail and easily recognizable. The observation of embryos may in embryonic development and chromosome aberrations as bewell visible defined due by the Camey transparency and Verdonk of capsules [9], the stages spawning are described and eggs biomarkers [5,7]. are placed one by one in a single layer. The complete embryonic The knowledge of the best conditions of snails breeding development and hatching of young snails can be observed after and maintenance are relevant information to the success of the B. can reach sexual maturity and begin to spawn [5,7,10]. seven to nine days at around 25ºC, and after about 30 days they glabrata rearing is described. culture. In this paper a review of the recommendations for MATERIALS AND METHODS quality and ambient requirements for the maintenance and rearingIn this of B.work, glabrata the best adults conditions and embryos about describedreproduction, by several water authors are presented in Table (1) and the requirements for importance of the rearing of Biomphalaria glabrata and its achievement toxicological studies are listed in Table (2), [6- In this work, a literature review was conducted on the 8,11-18]. Some complementary or divergent considerations are and world database indexed on the internet were consulted addressed in articles and will be described below. forapplication this preparation. in scientific research.Molluscs, Allschistosomiasis, available printed toxicology, literature Biomphalaria, rearing and cultivation were the descriptors used. the most commonly used are plastic and glass. For rearing of infectedThe animals,container the material use of glassfor culturingaquaria is canadvisable, be diversified, since the ButantanIn addition, - São information Paulo, Brazil, collected were forincluded. more thanAll the thirty information years of decontamination process with this type of material is more safe breeding snails in the Parasitology Laboratory of the Instituto Table 1: Detailed summary of the existing literature data concerning recommended maintenance and culturing conditions of the freshwater snail Biomphalaria glabrata (Say, 1818) [6-8, 11-15]. Parameters Culturing conditions Test species: Biomphalaria glabrata Known - adult snails with at least two months old and with a minimal shell Age of organisms: diameter of 10mm Amount of liquid per stock vessel: 20 L Stock vessels: Number of stock vessels: Container50 of 50 x 23 x 17 cm Maintenance water: Filtered and dechlorinated water Water exchange: ± 15 days (if necessary) Aeration: pH: 7.0 ( ± 0.2) Constant aeration during the maintenance Photoperiod: 12 h light and 12 h darkness Room temperature Light quality: 25°CAmbient ( ± 2) light Feeding: Three times a week; test snails were not fed 24 h before test start Food: Duration of culture: TwoOver large6 months fresh lettuce leaves without the talus, and fish food flakes Weekly, remove the egg masses deposited in container CultureDaily control: rotation: Ambient temperature, amount of food, quality of food Sensitivity control: Quarterly assays with a reference substance Ann Aquac Res 3(1): 1013 (2016) 2/4 de Freitas Tallarico et al. (2016) Email: Central Table 2: Review of the existing literature data concerning the requirements for the toxicity assays with Biomphalaria glabrata (Say, 1818) adults and embryos [7,12,16,17]. Parameters Requirement Adults Embryos Mortality in seven days before test start: 10% 10% Assay duration: 7 days 7 days Exposition duration: 24 h 24 h Observation time: Daily Daily Solution renewal: Static assay Static assay Temperature: Photoperiod: 25°C12 h light( ± 2) and 12 h darkness 25°C12 h light( ± 2) and 12 h darkness Dilution water: Reconstituted soft water Reconstituted soft water Feeding: None None Aeration: No No Test vessels: 180 mL 20 mL Test solution volume: 178 mL 10 mL Number of replicate test vessels: 3 3 Number of replicate test vessels in the control: 3 3 Number of organism per replicate: 10 100 Organism stage at the start of bioassay: 2 months stagesBlastulae (0-15 h after the first egg cleavage), Gastrulae (24-39 h), Trocophore (48-87 h) and Veliger (96-111 h) Endpoints: Mortality Mortality and Malformation Assay acceptability: ); 7 ); 7 days with 95% Results expressions: Control Mortality ≤ 10% 50 Control Mortality ≤ 10% 50 Median lethal concentration (LC Median effect concentration (EC days with 95% confidence intervals confidence intervals is recommended to prevent the snails escape and to the presence of insects in containers. 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