Sperm cryopreservation of tiete tetra Brycon insignis (Characiformes): effects of cryoprotectants, extenders, thawing temperatures and activating agents on motility features

Abstract

The aim of this study was to test the effects of cryoprotectants [dimethyl sulphoxide (DMSO) and methylglycol], extenders (0.9% NaCl, 5% glucose, Beltsville Thawing Solution™ and Merck III™), thawing temperatures (30 and 60 °C) and activating agents (0.29% NaCl and 1% NaHCO3) on the cryopreservation process of tiete tetra Brycon insignis sperm. Sperm was loaded in 0.5 mL straws, frozen in nitrogen vapour at −170 °C and stored in liquid nitrogen. Post‐thaw sperm quality was evaluated in terms of subjective motility rate, quality motility score (0=no movement; 5=rapidly swimming spermatozoa), duration of motility and vitality (eosin–nigrosin staining). Post‐thaw sperm motility rate was greater in methylglycol (76–88%), compared with DMSO (23–59%). In general, the highest quality motility scores were observed when sperm was thawed at 30 °C and triggered in 1% NaHCO3 (3.5–4.3). Duration of motility was longer when triggered in 1% NaHCO3 (95–120 s) compared with 0.29% NaCl (69–107 s). Sperm vitality was not affected by any of the parameters tested and varied from 51% to 69% intact sperm. Brycon insignis sperm frozen in methylglycol combined with any of the extenders tested and using the methods described above yields motility above 57% and that should last long enough to fertilize oocytes.

Fresh, equilibrated and post-thaw sperm quality of Brycon orbignyanus (Valenciennes, 1850) and Prochilodus lineatus (Valenciennes, 1837) treated with either salmon GnRHa and domperidone or pituitary extract

“…Motility rate (expressed as % of motile sperm) was subjectively estimated in intervals of 5% following the addition of 500 µL of an activating agent, composed of a NaCl solution at an osmolality of 120 ± 10 mOsm/kg (60-70 mM NaCl), according to our previous results . Motility velocity score (a subjective analysis of sperm velocity) was determined using an arbitrary grading system ranging from 0 (no movement) to 5 (rapidly swimming sperm), according to Viveiros et al (2011). Because motility analysis was carried out in the field, we could not use our Computer-Assisted Sperm Analyzer (CASA); all we could transport from the lab was the light microscope.…”

<b>Cryopreservation of semen of Thailand tilapia (<i>Oreochromis</i> spp.) fed diet with different oil sources

“…However, along with the dilutor, it is necessary to add cryoprotectants to prevent cryoinjuries caused during the process (MARIA et al, 2006). The cryoprotectants DMSO (Dimethyl sulfoxide) and methanol have shown satisfactory results for Prochilodus lineatus (FELIZARDO et al, 2010;MURGAS et al, 2007) and several native species (VIVEIROS et al, 2009;PAULA et al, 2012), but not for Colossoma macropomum (MENEZES et al, 2008). According to Godinho et al (2003), Nile tilapia has obtained the best result with the use of methanol.…”

“…The cryopreservation allows the sperm storage at −196°C for unlimited time, preserving its original conditions (CARNEIRO, 2007; VIVEIROS; GODINHO, 2009;DZIEWULSKA et al, 2011.…”

Cryopreserved sperm for oocyte fertilization of dourado Salminus brasiliensis

“…This fact can be associated with a lower osmotic difference between activator to cytoplasm, preserving the integrity of the cytoplasmic membrane of spermatozoa (MURGAS et al, 2007). A similar result was observed for the activation of cryopreserved semen of Leporinus elongatus (MURGAS et al, 2007) and for Brycon insignis (VIVEIROS et al, 2011). Nevertheless, CAROLSFELD et al (2003) have not found a difference between dourado semen activated with water or 1% NaHCO 3 .…”