Inbreeding evidence in a traditional channel catfish (Ictalurus punctatus) hatchery in Mexico

Abstract

Background: Channel catfish are one of the most important aquaculture species raised for food purposes in Mexico. Two temporal samples were obtained from the largest channel catfish breeding hatchery in Mexico to identify changes in genetic diversity and inbreeding that are promoted by traditional hatchery management. Results: The genetic parameter analysis of 11 microsatellite loci showed no significant change in genetic diversity (p > 0.05). However, a significant heterozygosis deficiency was detected (p < 0.001), and genetic structure analysis indicated moderate differentiation between the temporally divided populations (FST = 0.08). A moderate level of inbreeding and a slight increase of the inbreeding coefficient from 0.23 to 0.27 were the result of traditional hatchery practices. To achieve an effective population size, the temporal approach resulted in a limited number of breeders to maintain genetic variability. Conclusions: Although no significant change in genetic diversity parameters was found, the heterozygote deficiency and low effective number of breeders suggest that there is a risk for increased inbreeding. Thus, we propose the need for controlled reproductive management and the establishment of genetic programs in hatcheries. Molecular tools can provide valuable information to facilitate the achievement of these goals.

SNP discovery in wild and domesticated populations of blue catfish, Ictalurus furcatus, using genotyping‐by‐sequencing and subsequent SNP validation

“…; Parra‐Bracamonte et al . ), with levels of heterozygosity and % polymorphic loci generally mirroring previous studies in catfish. A parallel study using historical catfish microsatellite loci alongside larger SNP panels may be needed in the future to aid in direct comparison between these studies.…”

“…Although this study represents the first population genetics assessment in Ictalurid catfish with SNP markers, smaller studies of diversity have been conducted using isozymes, AFLP or microsatellite markers in channel catfish (Hallerman et al 1986;Waldbieser & Bosworth 1997;Tan et al 1999;Mickett et al 2003;Perales-Flores et al 2007). Inbreeding levels here were higher in the domesticated D&B population, but lower in all other populations, when compared with levels reported in farmed populations in Mexico, from 0.17 to 0.27 (Perales-Flores et al 2007;Parra-Bracamonte et al 2011), with levels of heterozygosity and % polymorphic loci generally mirroring previous studies in catfish. A parallel study using historical catfish microsatellite loci alongside larger SNP panels may be needed in the future to aid in direct comparison between these studies.…”

“…A similar study in a single, large Mexican hatchery observed an F ST = 0.08 between temporally divided populations (Parra‐Bracamonte et al . ). Similar values of F ST to those obtained here have been reported using AFLP and isozyme analyses in domesticated channel catfish populations.…”

Assessment of some nongenetic factors that affect egg mass weight of channel catfish, Ictalurus punctatus

“…In general, the male: female ratio is 2:3. Conventionally, selected broodstock is from production farms of the same strain (Parra-Bracamonte et al, 2011).…”

Improving the utility of genetic markers in fish populations

“…Microsatellites have been used as a tool to estimate inbreeding in channel catfish (Ictalurus punctatus) (Parra-Bracamonte et al, 2011) and in common sole (Solea solea) (Blonk et al, 2009). DNA fingerprinting is also a useful tool in estimating rates of inbreeding in aquaculture species during selection (Macbeth 2005).…”