Molecular and morphological identification of Lernaea spp. in Cyprinid fishes from two districts in Yogyakarta, Indonesia

Background and Aim: Parasitic infection commonly affects freshwater ornamental fishes. Parasites in fish may impede their growth and even cause death, resulting in a decline in fecundity. The prevalence of lernaeosis in aquaculture ponds in Indonesia requires attention because of missing data, especially from Yogyakarta. Therefore, this study aimed to identify the Lernaea species found in fish in Indonesia, particularly in Yogyakarta, molecularly and morphologically, as well as an overview of their distribution and the water condition they inhabit.Materials and Methods: Lernaea species were collected from three different fish species in two districts of Yogyakarta, Indonesia, for precise identification. Lernaea specimens were characterized morphologically and subjected to molecular identification based on 18S rRNA and 28S rRNA genes.Results: Lernaea in this study was morphologically and genetically confirmed as Lernaea cyprinacea, and the infection rate in each fish species was different. Water conditions might have contributed to the differences in infection levels.Conclusion: This study characterized L. cyprinacea isolated from Yogyakarta. Future research should focus on sequencing as much molecular information as possible and carrying out more experimental infections.