Crioprotetores para o resfriamento de embriões de piracanjuba Brycon orbignyanus (Valenciennes, 1850)

Abstract

ResumoO objetivo deste trabalho foi avaliar a eficiência dos crioprotetores para o resfriamento de embriões de B. orbignyanus. Foram selecionados 1.400 embriões viáveis, na fase de pós-gastrulação e submetidos ao resfriamento a -8ºC com diferentes combinações de crioprotetores permeáveis (Metanol e dimetilsulfóxido -DMSO 9% ou associados 4,5%) combinados à crioprotetores não permeáveis (Sacarose e Glicose, 17%). Para cada tratamento, 200 embriões foram alocados em tubos de vidro "vacutainer" e submetidos ao processo de resfriamento. Após o tempo proposto, os embriões foram retirados e transferidos para incubadoras de quatro litros até a eclosão das larvas. Os resultados com as soluções contendo glicose no resfriamento foram ineficiente, apenas 27% dos embriões sobreviveram no tratamento. Os tratamentos com associação do DMSO não houve sobrevivência. Para o resfriamento de embriões de B. orbignyanus exposto a -8°C por um período de seis horas deve-se utilizar solução crioprotetora contendo sacarose 17% associada ao metanol 9%. Palavras-chave: Biotecnologia, criopreservação, crioprotetor, metanol, sacarose AbstractThe aim of this study was to evaluate cryoprotectants for cooling embryos of B. orbignyanus. 1400 embryos were selected, in the post-gastrulation and subjected to cooling to -8°C with different combinations of intracellular cryoprotectants (methanol and 9% DMSO or associated 4.5%) combined with extracellular cryoprotectants (sucrose and glucose, 17%) diluted in distilled water to complete 100%. For each treatment, 200 embryos were placed in glass tubes and submitted to the cooling process. After the proposed time, the embryos were removed and transferred to four-liter incubation to hatching of the larvae. The results obtained from solutions containing glucose were inefficient. The treatments with association of DMSO showed no satisfactory results. For cooling of B. orbignyanus embryos at -8°C it is suggested to use a cryoprotectant solution containing 17% sucrose associated with 9% methanol.

Survival ofMacrobrachium amazonicumembryos submitted to cooling

“…This characteristic is present in embryos after cooling and was observed by Fornari et al . (2014), although in cooled embryos of piracanjuba ( Brycon orbignyanus ). According to the author, such a characteristic is used as evidence of ice crystal formation, which causes embryonic mortality.…”

Cooling of curimba (Prochilodus lineatus) embryos using different concentrations of dimethyl sulphoxide and methanol

“…Hubálek (2003) considered a concentration of 10% methanol as an ideal composition for the conservation solution of microorganisms. Similarly, several studies used concentrations of 9-10% methanol for fish embryos of species such as Rhinelepis aspera (Fornari et al, 2008), Colossoma macropomum (Pessoa et al, 2013), Brycon obignyanus (Fornari et al, 2014;Paes et al, 2014), Piaractus mesopotamicus (Lopes et al, 2014), and Piaractus brachypomus (Pessoa et al, 2015). In this study, we obtained an 80.85% hatching rate with 10% methanol for 6 h of cooling, and Pessoa et al (2013) observed an 88% hatching rate of Colossoma macropomum embryos treated with a 10% methanol solution.…”

“…Cooling and embryo freezing techniques, as well as cryoprotectant toxicity tests, have been studied in several species of native fish, in both species of economic interest and those endangered; some of the studied species are Piaractus mesopotamicus (Lopes et al, 2014), Piaractus brachypomus (Pessoa et al, 2015), Brycon orbignyanus (Fornari et al, 2014;Paes et al, 2014), and Prochilodus lineatus (Paula et al, 2014;Costa et al, 2017). Studies with ornamental fish species, such as Danio rerio, have also been conducted (Henn and Braunbeck, 2011;Kais et al, 2013).…”

Spermatogenesis and reproductive cycle of male piracanjuba ( Brycon orbignyanus ) raised for use in repopulation programmes

“…Particularly for pelagic‐spawning species such as B . orbignyanus , knowledge on the reproductive cycle of captive broodstock is fundamental for the application of appropriate breeding protocols that can guarantee the supply of individuals for restocking actions (Agostinho et al, 2007; Castro et al, 2019; Fornari et al, 2014; Machado et al, 2019).…”