title: Effect of 60Co gamma radiation on Biomphalaria glabrata (Mollusca, Gastropoda) embryos: mortality, malformation and hatching.
abstract: A study was carried out on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10, 15, 20 and 25 Gy of 60Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality, malformation and hatching were the parameters used to evaluate the damage induced by ionizing radiation. Estimated LD50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). Susceptibility to malformation induction was higher in the blastula, gastrula and young trochophore stages. Several types of morphogenetic malformations were observed, such as head malformations, exogastrulas, shell malformations, and embryos with everted stomodeum, with nonspecific malformations being the most frequent. The types of malformation induced by radiation probably are not radiation-specific and do not depend on the dose applied. The dose of 15 Gy was sufficient to greatly reduce the number of hatching snails regardless of the embryonic stage irradiated. We conclude that the effect of 60Co gamma radiation on B. glabrata embryos presented a specific pattern.
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares, Comissão Nacional de Energia Nuclear, São Paulo, Brasil.
authors.forename: K
authors.initials: K
authors.lastname: Okazaki
authors.forename: H F
authors.initials: HF
authors.lastname: Andrade Júnior
authors.forename: T
authors.initials: T
authors.lastname: Kawano
mesh_terms: D000818:Animals; D001700:Biomphalaria / Q000528:radiation effects*; D001938:Brazil; D003037:Cobalt Radioisotopes; D004625:Embryo, Nonmammalian / Q000528:radiation effects*; D047108:Embryonic Development; D005720:Gamma Rays; D007928:Lethal Dose 50; D011839:Radiation, Ionizing
chemical_list: D003037:Cobalt Radioisotopes