Changes in Solea senegalensis sperm quality throughout the year.

Area of Science:

• Aquaculture
• Reproductive Biology
• Fish Physiology

Background:

• Reproductive success in Senegalese sole (Solea senegalensis) aquaculture is often limited by sperm quality.
• Males produce semen year-round, despite distinct spring and autumn spawning seasons.

Purpose of the Study:

• To conduct an exhaustive annual analysis of Senegalese sole semen quality.
• To identify seasonal variations in sperm parameters and understand limitations in mass production.

Main Methods:

• Monthly sampling of broodstock semen over one year.
• Analysis of cellular parameters including motility, velocity, DNA fragmentation, and apoptosis.
• Assessment of sperm resistance to seawater exposure.

Main Results:

• Progressive motility and linear velocity decreased from spring to summer (highest temperatures) and increased slightly in autumn.
• DNA fragmentation peaked between spawning seasons, while apoptotic cells were highest in late autumn.
• Sperm quality showed a peak in early-to-mid spring, declining significantly during high temperatures.

Conclusions:

• Senegalese sole sperm quality exhibits significant seasonal fluctuations, negatively impacted by high temperatures.
• Individual male reproductive cycles vary, potentially leading to unequal genetic contributions in aquaculture.
• Addressing seasonal sperm quality variations is essential for optimizing Senegalese sole broodstock management and aquaculture production.