title: Toxicity of cryoprotectants agents in freshwater prawn embryos of Macrobrachium amazonicum.
abstract: The process of cooling and cryopreservation of prawn embryos is a viable alternative for a continuous supply of larvae for freshwater prawn farming ponds. However, studies involving the application of those techniques as well as on toxicity of cryoprotectants in freshwater prawn embryos are scarce. Thus, this study aims to test the toxicity of methylic alcohol (MET), dimethyl sulfoxide (DMSO) and ethylene glycol (EG) on Macrobrachium amazonicum embryos. For the present experiment, pools of embryos were taken from 15 M. amazonicum females and were divided into three groups and tested in duplicate at concentrations of 10, 5, 3; 1, 0.5 or 0.1%. Toxicity tests were conducted for 24 h in Falcon® pipes to obtain the lethal concentration for 50% of the larvae (LC50). After the set period for testing, random samples of embryos were removed for morphological analysis under stereoscopic microscopes. Results were analysed using analysis of variance (ANOVA) and Tukey's test at a 5% significance level and Trimmed Spearman-Karber Analysis to determine LC50-24 h. DMSO toxicity tests revealed that 5% and 10% concentrations showed the highest toxicity and differed from the control (P ≤ 0.05), 24h-LC50 was 437.4 ± 14.4 µL. MET was less toxic among the tested cryoprotectants and concentrations did not allow the determination of its LC50-24h. For tests with EG, concentrations of 3, 5 or 10% solutions resulted in a 100% mortality to tested embryos; EG was the tested cryoprotectant with the highest toxicity, with an LC50-24h average of 81.91 ± 35.3 µl.
authors.affiliation: Dept of Biology,State University of Ceara,UECE,Fortaleza,CE,60740-000,Brazil.
authors.forename: Arthur Vinícius Lourenço
authors.initials: AV
authors.lastname: Ferreira
authors.affiliation: Dept of Biology,State University of Ceará,UECE,Fortaleza,CE,Brazil.
authors.forename: Elias José Teles
authors.initials: EJ
authors.lastname: Castro
authors.affiliation: Dept of Biology,State University of Ceará,UECE,Fortaleza,CE,Brazil.
authors.forename: Mariana Silva Alves
authors.initials: MS
authors.lastname: Barbosa
authors.affiliation: Postgraduate Program in Veterinary Science,UECE,Fortaleza,CE,Brazil.
authors.forename: Míriam Luzia Nogueira Martins
authors.initials: ML
authors.lastname: de Sousa
authors.affiliation: Laboratory of Ecology of Mangroves,Federal Institute of Education,Science and Technology of Ceará,IFCE,Acaraú,CE,Brazil.
authors.forename: Manoel Paiva
authors.initials: MP
authors.lastname: de Araújo Neto
authors.affiliation: Dept of Fishing Engineering,Federal University of Ceará,UFC,Fortaleza,CE,Brazil.
authors.forename: Aldeney Andrade Soares
authors.initials: AA
authors.lastname: Filho
authors.affiliation: Dept of Biology,State University of Ceará,UECE,Fortaleza,CE,Brazil.
authors.forename: Celia Maria
authors.initials: CM
authors.lastname: de Souza Sampaio
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000633:toxicity*; D004121:Dimethyl Sulfoxide / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000502:physiology; D019855:Ethylene Glycol / Q000633:toxicity; D005260:Female; D005618:Fresh Water; D007814:Larva / Q000187:drug effects; D000432:Methanol / Q000633:toxicity; D033541:Palaemonidae / Q000187:drug effects* / Q000196:embryology*; D018675:Toxicity Tests / Q000379:methods
chemical_list: D003451:Cryoprotective Agents; D019855:Ethylene Glycol; D000432:Methanol; D004121:Dimethyl Sulfoxide
keywords: Amazon River prawn; Dimethyl sulfoxide; Ethylene glycol; LC50; Methylic alcohol