The Australian redclaw crayfish has great potential for aquaculture intensification and global market expansion. However, traditional production methods, subfertility, and high embryo mortality could curtail industry growth. This study evaluated sperm quality using optimized conventional and sensitive tools in redclaw crayfish. Healthy and robust male redclaw (n = 33) were collected from the Ross River Dam, Northern Queensland, and immediately subjected to electroejaculation to yield spermatophores for sperm quality assessment. Sperm concentration, count, morphology, viability, DNA fragmentation, and total potential fertile sperm cells (TPFSC) were determined. Under phase contrast microscopy, spermatozoa were visible with an elliptical shape of varying diameters and a tail-like structure. The mean ± SEM of sperm concentration, TPFSC, DNA fragmentation, and sperm viability was 42.5 x 104 ± 5.1 x 104 cells/ml, 23.6 x 104 ± 3.4 x 104 cells/ml, 17.2 ± 2.5 %, and 65.2 ± 3.9 %, respectively. Spermatophore weight was positively associated (p < 0.05) with sperm concentration and TPFSC and inversely associated with sperm DNA fragmentation (p < 0.05). Sperm viability was negatively associated with body mass (p < 0.05) but not spermatophore weight (p > 0.05). In conclusion, the weight of spermatophores provides a guide to sperm quality prior to spermatozoa extraction and may serve as a preliminary indicator of sperm quality. In addition, this study validated species-specific diagnostic tools for sperm quality assessment that may help improve productivity through selective breeding programs in redclaw aquaculture.
Biomarkers, crustaceans, DNA fragmentation, electroejaculation, fertility, spermatophore