Molecular characterisation of the monogenea parasites of blue mackerel (Perciformes: Scombridae) in Australian waters.

This study describes the occurrence and molecular identification of Monogenea from blue mackerel (Cuvier) (Perciformes: Scombridae), an edible fish, from Australian waters. Previous studies have provided either morphological or genetic results, whereas this study combines both methods of species identification. A total of 50 fish sourced from the waters off the south-eastern Australian coastline were examined and 71 Monogenea were recovered from the gills. The overall prevalence, mean intensity, and mean abundance were 64%, 2.22, and 1.42, respectively Monogenea were initially classified morphologically as five species belonging to two families. Family Mazocraeidae was represented by a (Kuhn, 1829) Sproston, 1945, Nasir & Fuentes Zambrano, 1983 and (Goto, 1894) Rohde & Watson, 1985 and family Gastrocotylidae by Unnithan, 1968 and Nasir & Fuentes Zambrano, 1983. Molecular identification of Monogenea was conducted through sequencing of the mitochondrial cytochrome c oxidase subunit 1 (1) gene. The host was barcoded (1) to confirm the specific identity. There was no comparable sequence available in GenBank for . Also, limited sequences were available in GenBank for the gastrocotylid Monogenea identified in this study. However, phylogenetic analyses of 1 sequences of the Monogenea identified in this study clustered according to their familial groups. and were identified for the first-time on in Australian waters. This study provides the first sequencing of 1 gene for . The outcomes of the study provide a basis for future Monogenea research in Australian waters, as well as for other spp.