Exploring the presence of Lernaea cyprinacea in Carasobarbus luteus fishes via molecular diagnosis

Background

Lernaea species, which are part of the genus Lernaea, are widespread parasites capable of infecting a wide range of freshwater fish. Their classification is exceedingly challenging and contentious due to a significant amount of intraspecific variability in morphology and substantial similarities between different species.

Aim of study

The aim of this study was to gather data and molecular diagnosis to the Lernaea species that infect Carasobarbus luteus in in the Shatt al-Hilla, Iraq.

Materials and methods

In this study conducted in Shatt- Hilla, Iraq between September 2023 and April 2024, 26 sample of Lernaea species were obtained from 150 fish sample exam belonging to Carasobarbus luteus. The larvae of Lernaea species were studied by molecular analysis done by primer design for 18S RNA and 28S RNA, PCR amplification, sequencing, and comparing gene loci of 18S RNA and 28S RNA of larvae isolated from Lernaea species.

Results

The sequencing of 18S RNA and 28S RNA revealed that all larval Lernaea from all infected fishes represented exactly one species of Lernaea cyprinacea parasite based upon comparing and identifying a percentage of the Gene Bank database. The genetic characteristics of L. cyprinacea in this study are available in the Gene Bank database, and they were deposited in the Gene Bank. Their accession numbers were demonstrated as LC830719, LC830720, LC830721, and LC830722.

Conclusion

This is the first molecular diagnostic research on L. cyprinacea parasite from Carasobarbus luteus in Iraq. It found all larval Lernaea were of one species. PCR assays and DNA analyses are important in the detection of parasites on fish.