The effects of osmolality on sperm quality in Jenynsia multidentata (Cyprinodontiformes: Anablepidae).
Sperm quality tests on fish are classically used for evaluating cryopreservation procedures, and they are also promising to assess aquatic toxicity and biomarkers of xenobiotic effects on reproduction. Osmotic shock from the storage medium is one of the main factors affecting sperm quality during evaluation. Thus, the objective of this study was to evaluate the effects of different osmolalities (240-460 mOsm/kg) for at least 4 days on the sperm quality parameters of the viviparous fish Jenynsia multidentata. The level of significance was (P < 0.05). The plasma osmolality of J. multidentata is 326 ± 3.9 mOsm/kg. The motility of fresh semen was higher in osmolalities of 280 and 300 mOsm/kg but did not differ between osmolalities from 240 to 320 mOsm/kg. Above 380 mOsm/kg, the motility observed was 0%. Over the time period studied motility increased with increasing osmolality, and the most constant and long-lasting rates were between 300 and 320 mOsm/kg. On the 4th day of evaluation, higher membrane integrity rates were observed between 280 and 360 mOsm/kg, higher mitochondrial membrane potential was observed between 300 and 460 mOsm/kg, and higher DNA integrity rates were observed between 260 and 380 mOsm/kg. Moreover, osmolalities ≥460 and ≤240 resulted in the lowest motility and DNA integrity levels. Over 4 days, the plasma membrane integrity was significantly lower at ≤260 and ≥400 mOsm/kg, and the mitochondrial membrane potential was significantly lower only in osmolalities ≤240 mOsm/kg. Therefore, we conclude that for sperm quality preservation in J. multidentata, an osmolality of 300-320 mOsm/kg of the most suitable diluent is necessary. Furthermore, we conclude that the storage of sperm in a hyposmotic (<260 mOsm/kg) or hyperosmotic (>400 mOsm/kg) solution affects not only motility but also other sperm quality parameters.
Post-graduate in Physiological Sciences: Comparative Animal Physiology, Institute of Biological Sciences, Federal University of Rio Grande, Av. 8 km Italy, Campus Carreiros, Rio Grande, RS, 96203-900, Brazil.
Janaína Camacho
JC
da Silva
Post-graduate in Physiological Sciences: Comparative Animal Physiology, Institute of Biological Sciences, Federal University of Rio Grande, Av. 8 km Italy, Campus Carreiros, Rio Grande, RS, 96203-900, Brazil.
Antonio Sergio
AS
Varela Junior
Post-graduate in Aquatic Environments Continental Biology, Federal University of Rio Grande, Av. Italy 8 km, Rio Grande, RS, 96203-900, Brazil.
Jôsie Shwartz
JS
Caldas
Post-graduate in Physiological Sciences: Comparative Animal Physiology, Institute of Biological Sciences, Federal University of Rio Grande, Av. 8 km Italy, Campus Carreiros, Rio Grande, RS, 96203-900, Brazil.
Clarissa da Silva
Cda S
Freitas
Post-graduate in Physiological Sciences: Comparative Animal Physiology, Institute of Biological Sciences, Federal University of Rio Grande, Av. 8 km Italy, Campus Carreiros, Rio Grande, RS, 96203-900, Brazil.
Joziel Gonçalves
JG
Botelho
Post-graduate in Physiological Sciences: Comparative Animal Physiology, Institute of Biological Sciences, Federal University of Rio Grande, Av. 8 km Italy, Campus Carreiros, Rio Grande, RS, 96203-900, Brazil.
Elton Pinto
EP
Colares
Department of Animal Pathology, Faculty of Veterinary Medicine, Federal University of Pelotas, University Campus, PO Box 354, Pelotas, 96001-970, Brazil. corcinicd@gmail.com.|Pós-Graduação em Ciências Fisiológicas: Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Av. Itália km 8, Campus Carreiros, Rio Grande, RS, 96201-900, Brazil. corcinicd@gmail.com.
Carine Dahl
http://orcid.org/0000-0001-5683-7801
CD
Corcini
D000818:Animals; D002462:Cell Membrane; D003532:Cyprinodontiformes / Q000502:physiology*; D004247:DNA; D008297:Male; D053078:Membrane Potential, Mitochondrial; D009994:Osmolar Concentration; D013048:Specimen Handling; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*
D004247:DNA
Biomarker; Cryopreservation; Live-bearing; Sperm; Thinner; Viviparous