Embryos cooling of piabanha, Brycon insignis (Steindachner, 1877) using different cryoprotectors

• Grant number: 19/26304-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2020
• End date: December 31, 2020
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Fisheries Engineering
• Principal Investigator: Eduardo Antônio Sanches
• Grantee: Janaína Sayuri Imafuku Valandro
• Host Institution: Universidade Estadual Paulista (UNESP). Campus de Registro. Registro , SP, Brazil

Abstract

The Piabanha (Brycon insignis) is a reophilic fish, which over the years has suffered from anthropogenic impacts caused in the region. Because of this, the species joined the list of Brazilian endangered fish, being considered by ICMBio as endanger species (EN). Thus, the gene banks (gametes or embryos) cooled and/or cryopreserved are alternatives for maintaining the genetic variability of future populations. So, the aim will be evaluate the different cryoprotector efficiency at B. insignis embryos cooling. To obtain the embryos, 6 females and 12 males will be used. The fertilized eggs will be placed in 120 liter incubators until the blastopore closure, where 1,650 viable embryos will be separated individually for the experiment. The embryos will be submitted to a completely randomized experimental design with 11 treatments containing the combination of an intern cryoprotectant (0.1M) and an extern one (1.0M): T1: propylene glycol + glucose; T2: propylene glycol + sucrose; T3: propylene glycol + fructose; T4: methanol + glucose; T5: methanol + sucrose; T6: methanol + fructose; T7: Dimethyl sulfoxide + glucose; T8: Dimethyl sulfoxide + sucrose; T9: Dimethyl sulfoxide + fructose; T10: positive control (embryos incubated without cooling); T11: Negative control (embryos cooled in water without cryoprotectant) with three replicates each. The plots will be allocated in Falcon type tubes, along with cryoprotectants (15mL). The tubes containing the cryoprotectant embryos will be cooled for 10 minutes in a container containing water at 15 °C. Subsequently, they were allocated for a further 10 minutes in a container with water at 5°C and then stored in a freezer at -5°C for six hours. After six hours the embryos will be transferred directly to individual incubators to complete their development. Next, hatching rates will be evaluated, as well as the percentage of normal larvae, in order to verify the effect of cryoprotectants on early larval development. The results will be subjected to analysis of one-way ANOVA at 5% significance.