First Report of Aeromonas schubertii Infection in Striped Snakehead Channa striata (Bloch, 1793) Fingerlings in Malaysia

This study aimed to determine chloramphenicol residues and bacterial contamination (Aerobic Plate Count-APC, Escherichia coli count, Salmonella sp., and Vibrio cholerae) in farmed African catfish (Clarias gariepinus) that are marketed in Banyuwangi, Indonesia. A total of ninety samples of C. gariepinus were collected from several markets in Banyuwangi, namely, Kertosari, Blambangan, and Banyuwangi Kota. Using standard procedures, APC, E. coli count, Salmonella sp., V. cholerae, and chloramphenicol residues were determined. 36.37% of samples from Kertosari markets; 23.33% of samples from Banyuwangi Kota markets; and 16.67% of samples from Blambangan markets contained chloramphenicol residues, but less than 0.3 ppb. Only 40% of samples from Kertosari markets, 36.67% of samples from Banyuwangi Kota markets, and 26.67% of samples from Blambangan markets were contaminated by E. coli, but were less than 3 MPNg-1. The highest APC was from Banyuwangi Kota, followed by Kertosari and Blambangan. No samples were contaminated by Salmonella sp. and V. cholerae from any of the markets, and there was no significant difference between all markets in APC, E. coli count, or chloramphenicol residues. All farmed catfish marketed in Banyuwangi were safe to eat because no samples exceeded the maximum chloramphenicol residue and bacterial contaminant standards. Further studies are needed to detect other antibiotic residues used in aquaculture, including tetracycline, sulphonamide, enrofloxacin, and nitrofuran.

Chloramphenicol Residues and Bacterial Contamination in Farmed African Catfish (Clarias gariepinus) from Banyuwangi Traditional Markets: A Risk Assessment

Ulkhaq,

Kenconojati,

Budi

et al. 2024

Molecular Fish Sexing on Taisho Sanshoku Koi (Cyprinus carpio) Based on ArS.9-15 Gene Amplification using PCR Method

Novindasari,

Nurrahmi,

Andrian

et al. 2024

Taisho Sanshoku is a variant of Koi fish (Cyprinus carpio) that has high demand due to its high economic value and relatively expensive price. This study aimed to determine the sex of the Taisho Sanshoku Koi fish by molecular sexing using the PCR method to amplify the ArS.9-15 gene. This study was initiated by rearing a 4–6 month-old of 10 Taisho Sanshoku Koi fish in a fish tank with a filter and oxygen aeration. The fish were fed with fish pellets for 1–3 days. The Koi fishes were then anesthetized using Koi anesthesia containing β-hydroxyethyl phenyl ether. Each fish's peripheral blood was collected as much as 0.5 mL per fish and then stored in tubes containing Ca-EDTA anticoagulant. The genomic DNA was extracted from peripheral blood samples and used as a template DNA for PCR amplification targeting ArS.9-15 gene. Agarose with 1.5% concentration and CybrSafe staining was used in electrophoresis for visualization of the PCR results then visualized in a dark chamber using a UV transilluminator. The Taisho Sanshoku Koi fish's sex was determined using descriptive analysis based on the electrophoresis results. According to the PCR results, the female Taisho Sanshoku Koi fish only produced one 800 bp DNA band, whereas the male fish produced two 800 bp and 1,100 bp DNA bands. The outcome of molecular fish sexing of the 10 Taisho Sanshoku Koi fish reported that 60% were male and 40% were female.

Primary and Secondary Sexual Characteristics of Kuhli Loach (Pangio kuhlii)

Budi,

Restanti,

Suciyono

et al. 2024

Kuhli loach (Pangio kuhlii) a popular ornamental freshwater fish species with economic potential, originating from Sumatra, Kalimantan, Java, and Malaysia. The kuhli loach's appeal lies in its vibrant colors and distinctive eel-like body. This study aims to explores the sexual primary and secondary characteristics of the kuhli loach. Conducted at Universitas Airlangga in Banyuwangi, Indonesia, the study involved a thorough analysis of 50 kuhli loaches, evenly split between males and females. Morphological observations revealed significant differences (p < 0.05), such as the elongated body and expanded abdominal region in females, suggesting adaptations for reproduction. Internal examinations, including peritoneal dissections and histological analysis, unveiled distinct stages of spermatogenesis in males and ovarian development in females, providing insights into the reproductive cycle. Meristic and morphometric analyses identified noteworthy differences in pectoral fin rays, suggesting potential roles in reproductive behavior, while other traits exhibited similarity between genders. This study contributes to the understanding of kuhli loach ecology and reproductive biology, highlighting the importance of addressing sustainability concerns arising from the continuous exploitation of wild populations. This study serves as a foundational step towards advancing reproductive improvement in fish and supports the conservation of this unique ornamental fish species, with implications for aquaculture practices and economic considerations.