Determination of some seminal plasma indices, sperm density and sperm motility in the Persian sturgeon Acipenser persicus

Some biological aspects of semen were investigated in the Persian sturgeon, Acipenser persicus, by determination of seminal plasma indices (ionic composition and osmolality), sperm density and their relationships with sperm motility. The osmolality of seminal plasma ranged from 42.00 to 111.00 mOsmol Kg-1. The concentrations of Sodium (Na+), Potassium (K+), Chloride (Cl-), Calcium (Ca2+) and Magnesium (Mg2+) ions were 62.44±6.82, 6.92±0.88, 21.11±5.41, 0.79± 0.03 and 0.52±0.03mM L-1, respectively. The sperm density was 8.34±1.38×109 spz/ml. The Sodium/Potassium and Calcium/Potassium ratios were 9.02 and 0.13, respectively. The following significant positive correlations were found between seminal plasma indices; osmolality - Cl- (r2= 0.492, P0.05). No relationship was observed between sperm density and its motility at the concentrations tested (r2= 0.015, P>0.05). The ionic composition and osmolality of seminal plasma reveals an inter-species specific as well high secretory activity of sperm duct. The clear differences observed in A. persicus should be considered when cryopreservation methods for sperm are developed in Acipenseridae species

Di-(2-ethylhexyl)-phthalate disrupts pituitary and testicular hormonal functions to reduce sperm quality in mature goldfish

International audienceDi-(2-ethylhexyl) phthalate (DEHP) interferes with male reproductive endocrine system in mammals, however its effects on fish reproduction are largely unknown. We evaluated sperm quality and investigated reproductive endocrine system in mature goldfish (Carassius auratus) exposed to nominal 1, 10, and 100 mu g/L DEHP. To examine DEHP estrogenic activity, one group of goldfish was exposed to 17 beta-estradiol (5 mu g/L E-2) for comparison. Following 30 d of exposure, sperm production was decreased and suppressed in DEHP and E-2 treated goldfish, respectively. Sperm motility and velocity were decreased in goldfish exposed to 100 and 10 mu g/L DEHP at 15s post-sperm activation, respectively. Compared to control, 11-ketotestosterone (11-KT) levels were decreased at 10 and 1 mu g/L DEHP at day 15 and 30, respectively. In E-2 treated goldfish, 11-KT levels were decreased compared to control during the period of exposure. E-2 levels were increased in goldfish exposed to E-2, but remained unchanged in DEHP treated goldfish during the period of exposure. StAR mRNA levels encoding regulator of cholesterol transfer to steroido-genesis were decreased in DEHP and E-2 treated goldfish following 15 and 30 d of exposure, respectively. Luteinizing hormone (LH) levels were decreased in DEHP and E-2 treated goldfish following 15 and 30 d of exposure, respectively. In DEHP treated goldfish, gnrh3, kiss) and its receptor (gpr54) mRNA levels did not change during the experimental period. In E-2 treated goldfish, gnrh3 mRNA levels were decreased at day 7, but kiss1 and gpr54 mRNA levels were increased at day 30 of exposure. The mRNA levels of genes encoding testicular LH and androgen receptors remained unchanged in DEHP and E2 treated goldfish. In contrast to E2 treated goldfish, vitellogenin production was not induced in DEHP treated goldfish and mRNA levels of genes with products mediating estrogenic effects remained unchanged or decreased. In conclusion, DEHP interferes with testis and pituitary hormonal functions to reduce sperm quality in goldfish and does not exhibit estrogenic activity

Dose inseminante para fertilização artificial de ovócitos de dourado Insemination dose for artificial fertilization of dourado oocytes

Objetivou-se determinar a dose inseminante adequada para uso na fertilização artificial de ovócitos de dourado (Salminus brasiliensis). Os ovócitos foram distribuídos em delineamento inteiramente casualizado, e fertilizados com uma das relações espermatozoides/ovócito 6,0×10³; 6,0×10(4); 6,0×10(5); 6,0×10(6) ou 3,0×10(7), cada uma com quatro repetições. Considerou-se unidade experimental uma incubadora de volume útil de 2,5 L, contendo 2,0 mL de ovócitos não-hidratados. As taxas de fertilização foram mensuradas 8 horas após o início da fertilização. Com intuito de verificar possíveis efeitos da diluição seminal na movimentação dos espermatozoides, realizou-se a mensuração do tempo de duração da motilidade espermática dos espermatozoides de dourado, ativados por meio de diferentes relações de diluição: 6,8×10-5; 6,8×10-4; 6,8×10-3; 6,8×10-2; 3,4×10-1 e 1,0 mL de sêmen por mL de água. O tempo de duração da motilidade foi avaliado em delineamento inteiramente casualizado composto de seis tratamentos e três repetições. As taxas de fertilização apresentaram relação quadrática com o número de espermatozoides por ovócito. As relações de diluição do sêmen tiveram efeito inversamente proporcional sobre a duração da motilidade espermática. A relação que proporcionou melhores taxas de fertilização artificial de ovócitos de dourado (Salminus brasiliensis) foi de 30.722 espermatozoides por ovócio.<br>The objective of the present study was to determine the proper insemination dose of dourado (Salminus brasiliensis) oocytes. The oocytes were placed in a randomized complete design and fertilized with one of the spermatozoa.oocytes-1 ratio, 6.0×10³, 6.0×10(4), 6.0×10(5), 6.0×10(6), 3.0×10(7) SPZ:OOC, each one with four replications. An experimental unit was considered to be an incubator with a 2.5L useful volume containing 2.0 mL non-hydrated oocytes. The fertilization rates were measured eight hours after the start of fertilization. In order to ascertain the possible effects of seminal dilution on the spermatozoa motility, the duration time of the spermatic motility of the dourado spermatozoa was measured when activated by different dilution ratios 6.8×10-5; 6.8×10-4; 6.8×10-3; 6.8×10-2; 3.4×10-1 and 1.0 mL semen.mL water-1. The motility duration time was assessed in a randomized complete design, with six treatments and three repetitions. The fertilization rates showed a quadratic relationship with the number of spermatozoids per oocyte. The semen dilution ratios had an inversely proportional affect on the spermatic motility time. The spermatozoa:oocytes ratio that provided the best artificial fertilization rates of dourado (Salminus brasiliensis) oocytes was 30,722 spermatoids per oocyte