AUTHOR=De Benedetto Giovanni , Gervasi Claudio , Riolo Kristian , Abbate Jessica Maria , Natale Sabrina , Di Paola Davide , Falleti Rosa , Iaria Carmelo 

TITLE=First report of Stephanostomum cesticillus (Molin, 1858) Looss, 1899 in Merluccius merluccius (Linnaeus, 1758) from the Tyrrhenian Sea (Southern Italy)

JOURNAL=Frontiers in Marine Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1178977

DOI=10.3389/fmars.2023.1178977

ISSN=2296-7745

ABSTRACT=<p>The genus <italic>Stephanostomum</italic> consists of digenean trematodes found in many marine teleosts. In this study, <italic>Stephanostomum cesticillus</italic> (Molin, 1858) Looss, 1899 metacercariae were identified in European hake (<italic>Merluccius merluccius</italic>, Linnaeus, 1758) caught in the Tyrrhenian Sea. The metacercariae were found encapsulated in the muscle, close to the spine and gills. Out of 131 specimens, 111 (P = 84.7%, mI = 25.1 mA = 21.3) were infected by digenean trematode metacercariae. Morphological and histological evaluations were carried out. The members of this genus are characterised by a double crown of spines close to the oral sucker. For identification of the parasite, molecular analysis was performed via 28S and 18S ribosomal DNA (rDNA) genes. Partial rDNA sequences of <italic>Stephanostomum</italic> highly matched to <italic>S. cesticillus</italic> for the percentage of similar identity from the nucleotide database of BLAST. The present survey reports the presence of <italic>S. cesticillus</italic> metacercariae in <italic>M. merluccius</italic> for the first time. Our results improve current knowledge on hake parasites to better understand the distribution of <italic>S. cesticillus</italic> in <italic>M. merluccius</italic> caught in the Mediterranean Sea and shed light on the life cycle of the parasite adding other possible hosts.</p>