Effects of sperm concentration and egg number on fertilization efficiency with channel catfish (Ictalurus punctatus) eggs and blue catfish (I-furcatus) spermatozoa

The mean sperm concentration of 10 blue catfish (Ictalurus furcatus) was 1.03x10(10) per gram of testis. Testis weighed 3.9 and 17.2 g, with a mean of 6.6 g per fish. Fertilization rate of channel catfish (Ictalurus punctatus) eggs fertilized with 5.00x10(4) to 1.20x10(7) blue catfish spermatozoa per egg was 17 to 87% with an overall mean of 65%. Sperm concentrations of 5.0x10(4)/egg exhibited a lower, 16.6% (P<0.05) fertilization rate than higher sperm concentrations (1.25x10(5) to 1.20x10(8)/egg). Batches of 450, 2,000, 5,000, 8,000 and 11,000 eggs were similarly fertilized with various Sperm concentrations. Mean fertility rate ranged from 25 to 67%, with an overall mean of 53%. The largest egg mass produced the lowest (P<0.05) fertilization rate. A combination of 450 eggs per batch and 5.0x10(5) to 1.20x(8) sperm per egg produced the highest rate of fertilization (67 to 87%).