Location: Aquatic Animal Health Research
Project Number: 6010-32000-027-039-A
Project Type: Cooperative Agreement
Start Date: Aug 15, 2024
End Date: Aug 14, 2028
Objective:
As the largest aquaculture industry in the United States, catfish farming accounts for about 75% of total U.S. finfish aquaculture production, in which the channel catfish female by blue catfish male hybrid constitutes nearly 60% of the harvest. The major bottleneck for hybrid catfish breeding is high-quality sperm production as blue catfish reach sexual maturity in 4 to 7 years, and sperm is collected through a lethal testis removal procedure. The fact that semen can only be stripped once from these males requires a substantial economic investment in sperm. In contrast, female channel catfish reach sexual maturity earlier (after 3 years), and their eggs can be readily hand-stripped for artificial fertilization, allowing the animal to survive and provide eggs during the next spawning season. These paternal complications suggest that sperm production, in terms of quality and quantity, is a major bottleneck for hybrid catfish embryo production, making healthy sperm more valuable than eggs in reproduction. The objective on this project is to alleviate this problem through the development of sperm cryopreservation protocols for commercial-scale applications to conserve sperm in case of disease outbreaks, reduce male broodstock numbers, facilitate breeding, and conserve genetic variability in domesticated populations; thereby drastically improving hatchery efficiency and profitability.
Approach:
To avoid catastrophic outcomes due to extremely low male fertility, there is a critical need to determine underlying mechanisms associated with low hatch and develop a set of sperm quality biomarkers as an indicator of reproductive health. If unmet, catfish farmers are unlikely to have a definitive metric for blue catfish sperm quality, perpetuating their reliance on pooling semen from a vast number of males, making male gamete management extremely resource-consuming and genetic enhancement, through selective breeding, almost impossible. In this proposal, we will use basic and applied research techniques to gain a better understanding of critical processes underlying male reproductive health and gamete preservation at molecular, cellular (sperm), tissue, organ system, and farm-animal levels. Together, this will increase hatching rates and offspring performance by optimizing the selection, collection, and storage conditions of healthy sperm to make hybrid catfish hatcheries more efficient and profitable.
