Sperm cryopreservation of lane snapper Lutjanus synagris(Linnaeus, 1758)

Abstract

This study aims developing and evaluate a protocol of semen cryopreservation of the lane snapper Lutjanus synagris. Firstly, sperm motility rate, motility time, density and spermatocrit were appraised to characterize the sperm quality of the lane snapper. The effect of three extenders with distinct ionic compositions and pH values combined with seven concentrations of cryoprotector dimethylsulfoxide (0; 2.5; 5.0; 7.5; 10.0; 12.5 e 15.0%), five cooling rates (110, 90, 60, 45 e 30°C -min ), nine equilibration time (1; 2,5; 5; 10; 15; 20; 25; 30 e 60 minutes) e five dilutions ratio (1:1; 1:3; 1:6; 1:10 e 1:20) on the sperm motility rate and motility time were analyzed. Fertilization test was accomplished to evaluate the viability of the cryopreserved sperm. The higher sperm motility rate and motility time (P<0.05) was achieved by combining extender with pH 8.2 with 10% concentration of dimethylsulfoxide and cooling rate 60°C Criopreservação do sêmen do ariocó Lutjanus synagris (Linnaeus, 1758) ResumoEste estudo teve a finalidade de desenvolver e avaliar um protocolo de crioconservação do sêmen do ariocó Lutjanus synagris. Para caracterizar o sêmen foram avaliados a taxa de motilidade, a duração da motilidade, a concentração espermática e o espermatócrito. Em seis experimentos foram analisados os efeitos de três diluentes, com distintas composições iônicas e valores de pH distintos, combinados com sete concentrações de dimetilsulfóxido (0; 2,5; 5,0; 7,5; 10,0; 12,5 e 15,0%), cinco velocidades de congelamento (-110, -90, -60, -45 e -30°C/min), nove tempos de equilíbrio (1; 2,5; 5; 10; 15; 20; 25; 30 e 60 minutos) e cinco proporções de sêmen:diluente (1:1; 1:3; 1:6; 1:10 e 1:20) sobre a taxa de motilidade e a duração da motilidade espermáticas. Posteriormente um teste de fertilização foi realizado para avaliar a viabilidade do sêmen crioconservado. O tratamento que propiciou maior taxa de motilidade e duração da motilidade espermáticas (P<0,05) foi aquele proporcionado pelo emprego do diluente com pH 8,2 com dimetilsulfóxido a 10%, em uma velocidade de congelamento de -60°C/min, com tempo de equilíbrio de 1 minuto e na proporção de 1:3 (v/v). O sêmen crioconservado apresentou taxa de fertilização superior a 69% validando o presente protocolo para o ariocó. A crioconservação do sêmen do ariocó é uma alternativa viável, sendo possível manter uma apropriada qualidade espermática.

<b>Short-term storage of lebranche mullet <i>Mugil liza</i> (Valenciennes, 1836) semen <i>in natura</i> and diluted with CF-HBSS

“…The semen of M. liza presented reduced portion of plasma. The same was observed in other marine fish species, such as: Mugil cephalus (Chao, Chen, & Liao, 1975); Lutjanus synagris (Sanches & Cerqueira, 2010Sanches, Oliveira, SEerralheiro, & Cerqueira, 2013;Sanches, Oliveira, Serralheiro, & Cerqueira, 2015) and Lutjanus analis (Sanches & Cerqueira, 2011;Sanches et al, 2013). Even with a small amount of plasma and without sperm diluents, the lebranche mullet spermatozoa showed the same motility time of that of fresh semen during 48h cooling.…”

“…For diluted semen, the increase in motility time during semen refrigeration was also confirmed for Scophthalmus maximus (Chereguini et al, 1997), L. synagris (Sanches & Cerqueira, 2010) and L. analis (Sanches & Cerqueira, 2011). Diluents maintain sperm immobility and are developed for restore continuously osmotic changes in cells during the refrigeration procedures, correcting successive imbalances in ionic concentrations of solutes that accompany changes in temperature.…”

“…Even with a small amount of plasma and without sperm diluents, the lebranche mullet spermatozoa showed the same motility time of that of fresh semen during 48h cooling. This is an unusual result for refrigeration process in natura, which generally exhibits little success and loss of seminal quality in a few hours (Sanches & Cerqueira, 2010). A rapid loss of seminal quality was verified in semen refrigeration of Centropomus undecimalis (Tiersch, Wayman, Skapura, Neidig, & Grier, 2004); Lutjanus synagris (Sanches & Cerqueira, 2010) and Lutjanus analis (Sanches & Cerqueira, 2011), which presented total sperm immobility after only 24h of refrigeration; in Latris lineata (Ritar & Campet, 2000) and Anguilla anguilla (Peñaranda et al, 2010) total loss of motility was observed after 48h of refrigeration.…”

Application of piezoactuators in the technology of low-temperature preservation of fish reproductive cells

“…Cryobiologists around the world are working to improve the survival rate of defrosted sperm of different fish species, as well as their fertilizing ability. For this purpose, optimal compositions of cryoprotective media, freezing and thawing regimes, and various kinds of stimulating effects are being selected [8][9][10][11].…”