Hydrobiological Research

Effect of oxytetracycline on serum response of rainbow trout, Oncorhynchus mykiss

Muhammed Enis Yonar — 2025-01-25

In this study, the effect of oxytetracycline (OTC), which is widely used in the treatment of fish diseases, on serum response was investigated. We conducted two experiments, the first with intraperitoneal (IP) injection and the second with immersion (IM) bath administration of OTC. For this purpose, fish was injected with IP 20 mg/kg fish weight dose of OTC every day for 4 days. After 24 hours the last treatment serum was collected. In trial second, fish were exposed to 50 mg/L concentration of OTC for 48 hours. The several immune parameters (lysozyme, myeloperoxidase, and total protein activities) and bactericidal activity against Yersinia ruckeri were studied. The present results show that immune parameters (lysozyme, myeloperoxidase and total protein activities) were significantly reduced after injection administration of OTC. However, in the immersion administration of OTC in fish, while the difference in lysosome and total protein activities was not significant, the decrease in myeloperoxidase activities was found to be significant compared to the control group. The serum bactericidal activity of all groups showed a significant increase in comparison with the control untreated group.

Can the irisin levels in blood circulation on association with feeding habits in Mastacembelus mastacembelus and Cyprinion macrostomus

Fatma Caf — 2025-01-25

Irisin is a peptide that is effective in regulating dietary habits, food intake, body weight, and glucose balance. There is limited research on the irisin hormone in freshwater fish. This research aimed to investigate the serum irisin levels in an omnivorous fish of C. macrostomus (Cyprinion macrostomus) and a carnivorous fish of M. mastacembelus (Mastacembelus mastacembelus). Hormone levels were measured using the ELISA (Enzyme-Linked Immunosorbent Assay) method. The serum level of irisin hormone was analyzed using the ELISA kit (Phoenix Pharmaceuticals Inc., Burlingame, CA, USA). The results were compared between the two species and between the sexes of each species. Additionally, the levels of iris were compared with the body weight and length of both M. mastacambelus and C. macrostomus. The adult C. macrostomus (n=22) showed lower irisin levels than the adult M. mastacembelus (n=22) in both of male and female fish. Serum irisin level was higher in M. mastacembelus (1127 ± 71.6 ng/mL), which was fed predominantly carnivores and had large muscle mass, than C. macrostomus (513 ± 27.1 ng/mL), which was fed omnivores and had low muscle mass. We conclusion that irisin levels may vary depending on the feeding habits and weight of the fish.

Endoparasitic infections and host-parasite interactions of cyprinid fish in Murat River: A focus on Rhabdochona denudata and Neoechinorhynchus zabensis

Nimetullah Korkut — 2025-01-25

This study investigated the endoparasitic fauna of four cyprinid fish species (Cyprinion macrostomum, Capoeta umbla, Chondrostoma regium, and Squalius cephalus) inhabiting the Murat River, with a focus on the ecological distribution and variation of two identified parasites: Rhabdochona denudata (Nematoda) and Neoechinorhynchus zabensis (Acanthocephala). R. denudata was found in both C. macrostomum and C. umbla, while N. zabensis was exclusively detected in C. umbla. No endoparasitic infections were observed in C. regium or S. cephalus. Morphological examination confirmed taxonomic characteristics of both parasites, including prostomal teeth and sexual dimorphism in R. denudata, and proboscis structures and unique lemniscus nuclei in N. zabensis. Prevalence and infestation density of R. denudata were higher in C. umbla than in C. macrostomum. Seasonal variations in infestation levels were observed, with the highest prevalence of R. denudata recorded in autumn and N. zabensis in spring and summer; however, these differences were not statistically significant. A significant positive correlation was found between host size and R. denudata infestation levels, with larger hosts exhibiting higher infestation rates. These findings provide insights into host-parasite interactions and contribute to the understanding of parasitic diversity and ecology in freshwater ecosystems.