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) w as 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 (Icta lurus punctatus) eggs fertilized with 5.00x10(4) to 1.20x10(7) blue ca tfish spermatozoa per egg was 17 to 87% with an overall mean of 65%. S perm 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 wer e similarly fertilized with various Sperm concentrations. Mean fertili ty rate ranged from 25 to 67%, with an overall mean of 53%. The larges t egg mass produced the lowest (P<0.05) fertilization rate. A combinat ion of 450 eggs per batch and 5.0x10(5) to 1.20x(8) sperm per egg prod uced the highest rate of fertilization (67 to 87%).