Resumo

TORRES-TABARES, Alexander et al. Preliminary studies on embryo freezing of yamú (Brycon amazonicus) in different stages of development. Orinoquia [online]. 2012, vol.16, suppl.1, pp.225-236. ISSN 0121-3709.

Reproductive seasonality in fish has limited its commercial farming production due to the restriction in the fingerling availability. The cryopreservation is an alternative to solve this problem since facilitates the fish reproduction throughout the year. Therefore, this study evaluated the yamú embryos (Brycon amazonicus) viability conserved at -14 °C as a possible strategy to improve its production. For this purpose, sexually mature broodstocks were induced to reproduction with carp pituitary extract [females 0.25 (0 h), 0.5 (24 h) and 5 (36 h) mg/kg and males (4 mg/kg)]. The embryos in different stages of embryonic development such as blastulation (2 hours post-fertilization, hpf), gastrulation (6 hpf) and segmentation (8 hpf) were kept at 6 °C during 10 min and then storaged in falcon tubes at -14 °C and subjected (1:1) in a solution of 10 and 15% of dimethyl sulfoxide (DMSO) or methanol (MET). After one hour of storage, the embryos were immersed in a water bath at 27 °C for 10 min and then transferred again to the incubators to evaluate viability and hatching. The viability and hatching depended to the embryonic development stage as well as the storage solution type. The embryos of the control group showed an average viability and hatching of 96.2±0.1 and 96.3±0.7%, respectively. No hatching was observed in the treatments with 2 hpf embryos; in contrast, 8-hpf embryos subjected to MET 15% showed the best hatching results (54.1±4.1%). In conclusion, yamú embryos in later stages of development are susceptible to preserved at -14 °C at least for 1 hour.

Palavras-chave : freezing; cryoprotectants; embryonic development; hatching; viability; yamú.

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