Lake sturgeon (Acipenser fulvescens) is a species of conservation concern that has been stocked in several Great Lakes (North America) rivers. Lake sturgeon were extirpated in the Ontonagon River in Lake Superior and stocking began in 1998. In 2017, gametes were collected from spawning lake sturgeon (9 females, 36 males) caught at the nearby Sturgeon River spawning ground, generating nine family groups using a 1:4 mating design (n = 862). In 2018, gametes were collected from 3 females and 15 males, generating three family groups, and additional collections of drifting fry from the Sturgeon River were reared in the hatchery, resulting in 84 hatchery-produced and 675 wild-caught fry for stocking in the Ontonagon River. The objective of this study was to compare paternal representation and genetic diversity between the two stocking strategies. Parentage analysis based on genetic data from 12 microsatellite loci determined none of the family groups in the hatchery had equal paternal representation (p < 0.001), while wild-produced offspring had equal paternal representation. Despite the larger number of breeders contributing to the wild-caught larvae, there was no significant difference in genetic diversity between the wild-caught larvae and representative hatchery-produced offspring.
Walleye, Sander vitreus, has several distinct genetic lineages throughout North America as a consequence of Pleistocene glaciation. Stocking walleye across genetic boundaries in the mid-20th century has led to the introduction of non-native strains that persist to this day. In West Virginia, the identification of the native Eastern Highlands strain led the West Virginia Division of Natural Resources (WVDNR) to employ broodstock screening to assist in the conservation of the native strain. To develop a baseline native ancestry prevalence in walleye populations throughout the state, 1532 broodstock were sampled across 17 sampling locations over a 6-year period. To evaluate the effectiveness of the current broodstock two-SNP qPCR assay protocol and identify whether more SNPs need to be implemented, 284 walleye were sequenced and ancestry-genotyped across 42 fixed SNPs between the two strains. When comparing the current protocol to the older microsatellite protocol, advancement in the ability to identify native-strain individuals was observed. Genotyping previously assigned walleye broodstock across multiple fixed SNPs revealed that the current ancestry assignment protocol, on average, assigned individuals that display 96% Eastern Highlands native ancestry to the native strain and accurately identified >93% of all pure Eastern Highlands walleye. Throughout the state of West Virginia, the New and Kanawha River systems contained a high prevalence of native ancestry, with the Ohio River and sampled impoundments displaying varying levels of ancestry. SNPs with >98% prevalence in individuals assigned to the Eastern Highlands strain were identified during the course of the study and can be implemented in future screening protocols. Our results highlight the utility of genomic approaches as tools to assist fisheries management goals and their capability to accurately identify native ancestry to assist in conservation efforts.
Despite catfish being the dominant freshwater aquaculture product in the United States, catfish texture and sensory evaluation are understudied compared with other aquaculture species, and very few studies have been conducted to evaluate these traits in catfish. Texture, sensory, carcass yield, flavor, visceral fat deposition, gonadal development, and fillet color analyses were conducted on four size classes, small (1.75 kg), for channel catfish (n = 456) (Ictalurus punctatus), blue catfish (n = 78) (I. furcatus), and hybrid catfish (n = 195) (channel catfish ♀ × blue catfish ♂). Within genetic type comparisons indicated that the texture traits, hardness, and chewiness and the sensory trait toughness increased with increasing size in hybrid catfish and channel catfish but were the most pronounced in channel catfish. Overall, channel catfish had the firmest fillets based on several attributes. Blue catfish were found to have differences among texture traits between the extra‐large size class and the three remaining size classes, but overall size had less of an effect compared with the channel catfish and hybrid catfish. A trend of paternal predominance was observed as the hybrid catfish was more similar to the blue catfish than the channel catfish. Hybrid catfish had the highest fillet percentage. This study is the first large‐scale analysis of texture and sensory traits within two catfish species and their interspecific hybrid at different sizes and highlights the differences in commercially important texture and sensory traits.