Catfish farming accounts for nearly 70% of total U.S. freshwater aquaculture production, where the channel catfish, Ictalurus punctatus ♀ × blue catfish, I. furcatus ♂ hybrid constitutes >50% of the harvest. Current technology to produce hybrid embryos is labor intensive and requires the sacrifice of males for in vitro fertilization. This is time-consuming and costly, as blue catfish do not reach maturity for 4-7 years. Catfish sperm are often of inadequate quality/quantity and do not necessarily give high fertility and offspring viability. As a result, we tested the “Testicular-Mediated Paternal Effects Hypothesis for Aquaculture”. In this hypothesis, male reproductive performance indices (i.e., body metrics, testes morphology, sperm quality, sex steroid hormone profiles, and sperm/testes gene expression) are expected to predict crucial industry-relevant performance traits, such as fry growth and survival. These traits are essential during early life stages (i.e., egg to early juveniles) when catfish are prone to high mortality and developmental abnormalities. Throughout this project, we employed a multi-dimensional approach where physiological, cellular, and molecular indices were quantified to comprehensively assess male reproductive performance to improve hybrid catfish production (Fig. 1).
In this presentation, results from the following o bjectives will be reviewed: (i ) investigate how paternal age impacts male reproductive performance and ensuing offspring performance, (ii) measure a series of reproductive performance indices, and then use these indices to forecast the storage potential of sperm for cryo-banking and future production, (iii) evaluate impact of cryopreservation and refrigerated storage on proxies of sperm quality and offspring performance, (iv) determine whether sperm storage/environmental conditions lead to molecular changes affecting breeding success.
Together, our results will lead to a better understanding of the mechanisms underlying reproduction, gonadal function/production, and gamete preservation at cellular, molecular, genetic, organ system, and whole-animal levels. Knowledge gained will reduce production costs and improve reproductive efficiency for a farm animal (catfish).