Changes in lipids and biochemical properties of actomyosin from pre- and post-spawned hake (Merluccius hubbsi Marini)

The total lipid contents of muscle, the liver somatic index and the total lipid contents of actomyosin in hakes changed with the gonadal condition of the fish. Non-polar lipids in actomyosin from pre-spawned hake were 145% higher than in actomyosin from post-spawned hake; polar lipids were 30% higher. The relative percentage of phospholipids changed from 32% in pre-spawned hake to 48% in post-spawned hake. The Mg²⁺-ATPase activity in actomyosin increased from the pre-spawned to the post-spawned conditions, and this could be related to a higher phospholipids to neutral lipids ratio in post-spawned hake. Gradual decreases in both Ca²⁺-ATPase activity and myosin: actin ratio during the gonadal development of fish were found, suggesting a partial loss of myosin functionality of the actomyosin complex.