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3‐Monochloropropane‐1,2‐diol (3‐MCPD), 2,3‐epoxy‐1‐propanol (glycidol), and their fatty acid esters are heat‐induced food toxicants that have widely been investigated. This review study presents an overview of current knowledge about the dietary toxicity of 3‐MCPD, glycidol, and their fatty acid esters. A literature search in two databases from January 2012 to December 2023 yielded 75 eligible articles for this review. The majority (73%) of the articles focused on 3‐MCPD‐ and 3‐MCPD fatty acid ester‐induced toxicities. Nephrotoxicity (32%) was the most studied toxicity, whereas the least studied were carcinogenicity (4%) and hematotoxicity (4%). The metabolism of glycidol and its esters to 3‐MCPD in the gastrointestinal tract remained a subject of contention as studies reported opposing findings. There was also new evidence of 3‐MCPD‐induced reproductive toxicity, hematotoxicity, and nephrotoxicity and 3‐MCPD‐ and glycidol‐induced neurotoxicity and genotoxicity. Findings suggest animal species‐dependency in 3‐MCPD's carcinogenicity expression. Meanwhile, the 3‐MCPD toxicity mechanism in obese rats is poorly understood. The review recommends further studies into the 3‐MCPD toxicity mechanism in obese rats and the possible conversion of glycidol to 3‐MCPD in gastrointestinal tracts. [ABSTRACT FROM AUTHOR]

Reintroduction is an important tool for the recovery of imperiled species. For threatened Pacific salmonids (Oncorhynchus spp.) species, hatchery‐origin (HOR) individuals from a nearby source are often used to reestablish populations in vacant, historically occupied habitat. However, this approach is challenged by the relatively low reproductive success that HOR Pacific salmonids experience when they spawn in the wild, relative to their natural‐origin (NOR) counterparts. In this study, we used genetic parentage analysis to compare the reproductive success of three groups of adult Chinook salmon (Oncorhynchus tshawytscha) reintroduced above Cougar Dam on the South Fork McKenzie River, Oregon: HOR Chinook salmon from an integrated stock; first‐generation, wild‐born descendants (hereafter F1s) of Chinook salmon produced at the same hatchery; and NOR Chinook salmon that are presumed to have been produced below the dam, on the mainstem McKenzie River, or elsewhere and volitionally entered a trap below Cougar Dam. We found that F1s produced nearly as many adult offspring as NORs, and 1.8‐fold more adult offspring than HORs. This result suggests that, for the South Fork McKenzie reintroduction program, a single generation in the wild increases fitness for the descendants of HOR Chinook salmon. Although these results are encouraging, care must be taken before extrapolating our results to other systems. [ABSTRACT FROM AUTHOR]

Here, we provide evidence that the freshwater parasitic copepod, Salmincola californiensis, acts as a vector for Aeromonas salmonicida. While investigating the effects of S. californiensis on Chinoook salmon (Oncorhynchus tshawytscha), we tangentially observed that fish infected with the copepod developed furunculosis, caused by A. salmonicida. This occurred despite being reared in pathogen-free well water in a research facility with no prior history of spontaneous infection. We further investigated the possibility of S. californiensis to serve as a vector for the bacterium via detection of fluorescently labelled A. salmonicida inside the egg sacs from copepods in which the fish hosts were experimentally infected with GFP-A449 A. salmonicida. We then evaluated copepod egg sacs that were collected from adult Chinook salmon from a freshwater hatchery with A. salmonicida infections confirmed by either culture or PCR. The bacterium was cultured on tryptic soy agar plates from 75% of the egg sacs, and 61% were positive by PCR. These three separate experiments indicate an alternative tactic of transmission in addition to direct transmission of A. salmonicida in captivity. The copepod may play an important role in transmission of the bacterium when fish are more dispersed, such as in the wild., (© 2023 John Wiley & Sons Ltd.)