Toxicity of cryoprotectants on Prochilodus lineatus (Valenciennes, 1837) (curimba) embryos in an experimental incubator (Characiformes: Prochilodontidae)

Abstract

This paper investigated the effect of cryoprotectant substances on Prochilodus lineatus embryos in an experimental incubator. The prospective study applied combinations of polyvinyl alcohol, hydroxyethyl cellulose, gelatin and fetal bovine serum with dimethyl sulfoxide and ethylene glycol in a new experimental incubator. The morphology of embryos, larval viability and the efficiency of experimental incubators in maintaining the quality of embryos were evaluated. This study demonstrates the efficient association between hydroxyethylcellulose and dimethyl sulfoxide as greater viability (p<0.05) was found for embryos (72.9 ± 23.9%). It should also be noted the permeation of cryoprotectants in embryos through the changes found in chorion diameter, embryo diameter and embryo volume comparing the treatments versus control group (water) (p<0.05), this results can help in future cryopreservation protocols. Although the temperature and oxygenation differed between the usual and experimental incubators (p<0.05), the results showed a high fertilization rate (79.6 ± 13.2%) for experimental incubators (p<0.05) which is sufficient for the maintenance of embryos in a cryoprotective environment and effectively allows experimentation for long periods with cryoprotectant substances. Cryopreservation of fish embryos has not been accomplished yet and new approaches are required for understanding the permeability of teleost embryos, especially in Brazilian native species.Este trabalho avaliou o efeito de substâncias crioprotetoras sobre embriões de Prochilodus lineatus em uma incubadora experimental. O estudo aplicou combinações de álcool polivinílico, hidroxietilcelulose, gelatina e soro fetal bovino com dimetilosulfóxido e etilenoglicol em uma nova incubadora experimental. Foram avaliadas a morfologia dos embriões, a viabilidade larval e a eficiência das incubadoras experimentais na manutenção da qualidade dos embriões. Este estudo demonstra a associação eficiente entre hidroxietilcelulose e dimetilsulfóxido pela maior viabilidade (p<0,05) encontrada para os embriões (72,9 ± 23,9%). Deve-se notar também a permeação dos crioprotetores nos embriões através das alterações encontradas no diâmetro córion, diâmetro do embrião e no volume do embrião comparando os tratamentos ao grupo controle (água) (p<0,05), estes resultados podem ajudar em futuros protocolos de criopreservação. Embora a temperatura e a oxigenação diferiram entre as incubadoras comuns e as experimentais (p<0,05), os resultados mostraram elevada taxa de fertilização (79,6 ± 13,2%) para incubadoras experimentais (p<0,05), o que é suficiente para a manutenção de embriões em ambiente crioprotetor e permite efetivamente a experimentação por longos períodos com substâncias crioprotetoras. A criopreservação de embriões de peixes ainda não foi realizada e novas abordagens são necessárias para a compreensão da permeabilidade dos embriões de teleósteos, especialmente em espécies nativas brasileiras.

Improved solution for vitrification ofProchilodus lineatusembryos based on the reduction in risk factors: Toxicity, osmotic responses and ice-nucleation

“…It is common for experiments to use two or more types of internal and external cryoprotectants in association (Adams et al., ; Ninhaus‐Silveira et al., ; Paula et al., ). Despite the advantages suggested by literature, such as increase in liquid viscosity, cryoscopic point reduction and ability to form a vitreous solid (Kirichek et al., ), these mixtures make it difficult to understand the alterations induced by each cryoprotectant, which even at low concentrations may promote irreversible histological damage.…”

“…Prochilodus lineatus , called “curimba” or “curimbatá” belongs to the Prochilodontidae family and is widely distributed in Paraná, Paraguay and Paraíba do Sul basins (Brazil, South America) (Reis, Kullander & Ferraris‐, ), having great ecological and commercial importance. Its reproduction is conditioned to migratory movements, but it can easily reproduce in captivity by means of hormonal induction (Ninhaus‐Silveira, Foresti, & Azevedo, ; Ninhaus‐Silveira, Foresti, Azevedo, Agostinho, et al., ; Paula et al., ). This species presents rapid embryonic development (13–21 hr), and eggs that have large perivitelline space and a large yolk, are non‐adhesive and pelagic (Rizzo, Godinho & Sato, ; Ninhaus‐Silveira, Foresti, Azevedo, et al, 2006).…”

Effects of cooling rates on the quality of Prochilodus lineatus (Valenciennes, 1836) sperm

“…Well‐established artificial reproduction methods and high reproduction rates are established for this species, being the highlight of several cryopreservation studies (Felizardo et al, ; Miliorini et al, ). In addition, this species has been used as a model for fish reproduction research (Paula et al, ; Viveiros, Nascimento, Orfão, & Isaú, ).…”

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

“…Cooling consists of maintaining the eggs at low temperatures, but above the freezing point, which reduces metabolic activity, thus prolonging their viability in the external environment. This process Cooling of curimba (Prochilodus lineatus) embryos using different concentrations of dimethyl... Machado et al has been used as a strategy for conservation and maintenance of gametes for limited time frames of a few hours or even for several days (Paes, 2013;Paula et al, 2014). Embryos are subjected to low temperatures for a specific time, as a way of preserving them during transport to remote sites, such as when they are taken to a laboratory for incubation (Ahammad et al, 2003).…”

“…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).…”