The increasing reliance on imported fish products in Kazakhstan raises concerns about the presence of fish-borne parasitic infections, particularly zoonotic helminths that pose risks to public health. This study aimed to assess the diversity and prevalence of helminths in commercially imported marine fish using both traditional and molecular diagnostic methods. A total of 670 specimens representing 17 fish species were collected from retail markets in Astana, Almaty, and Karaganda. Macroscopic inspection and muscle compression techniques were used to detect larval parasites, followed by DNA extraction and PCR amplification targeting the ITS-2, 5.8S, 18S rRNA, and mitochondrial COX gene regions. Sequencing and phylogenetic analysis confirmed the presence of cestodes (Eubothrium crassum, Hepatoxylon trichiuri, Nybelinia surmenicola), acanthocephalans (Echinorhynchus gadi), and nematodes, with a predominance of zoonotic species from the Anisakidae family, including Anisakis simplex, A. pegreffii, Pseudoterranova decipiens, and Contracaecum osculatum. The highest levels of infection were detected in Atka mackerel (97.1%), herring (96.0%), mackerel (92.0%), and blue whiting (88.1%), while the lowest rates were recorded in smelt (6.8%), flounder (10.2%), and haddock (16.0%). This is the first molecular-based survey of fish helminths in Kazakhstan and highlights the need to integrate genetic screening into food safety control systems to better protect consumers and improve parasite monitoring of imported seafood.

In Kazakhstan, meat–fat-tailed sheep breeding is crucial for breed development and high-quality mutton production. Understanding variations in candidate genes may improve selection for meat quality and growth traits. Therefore, this study aimed to investigate the relative mRNA expression levels of the DGAT1, CAST, IGF-1, POU1F1 genes using qRT-PCR in tissues from three 12-month-old male Degeres sheep, identify SNP variations by PCR and Sanger sequencing, and assess their associations with growth traits in 18-month-old female Degeres sheep (n = 380). Relative mRNA expression revealed tissue-specific expression patterns of the studied genes, with DGAT1 showing the highest expression in abdominal fat (p < 0.001), CAST in the abomasum (p < 0.01), IGF-1 in the liver (p < 0.001), and POU1F1 in the testis (p < 0.05). The findings uncovered a previously reported synonymous SNP (c.1461 C > T) in the DGAT1 gene and polymorphism information content (PIC) exhibited low polymorphism. Moreover, the identified SNP deviated from Hardy–Weinberg equilibrium (HWE) and was significantly associated with chest width (p = 0.001), with the “TT” genotype exhibiting greater chest width. Therefore, further studies with larger sample sizes are required to validate its potential use in marker-assisted selection (MAS) to optimize sheep breeding.