What question did this study set out to answer?

To identify and document the presence of Paragyliauchen sp. and associated bacterial species in imported Centropyge bicolor.

February 28, 2026Open Access

Detection and Identification of Paragyliauchen sp. (Trematoda) and Bacteria in Diseased Centropyge bicolor from the European Marine Aquarium Trade

Key Points

To identify and document the presence of Paragyliauchen sp. and associated bacterial species in imported Centropyge bicolor.
Clinical examination of Centropyge bicolor for signs of disease.
Necropsy to investigate internal parasites and morphological features.
Molecular analyses to confirm species identification of the trematode.
Bacterial identification using MALDI-TOF MS from different tissues.
Identification of Paragyliauchen sp. in the intestinal lumen of Centropyge bicolor.
Detection of three bacterial species: Shewanella putrefaciens, Brevundimonas diminuta, and Aeromonas caviae.
First documentation of Paragyliauchen genus presence in C. bicolor in Europe.

Abstract

During the examination of a bicolor angelfish (Centropyge bicolor) imported from the Philippines and intended for sale on the Polish market, clinical signs of weakness and respiratory distress were observed. Mild hyperemia was noted along the lateral sides of the body and around the mouth. Necropsy revealed the presence of five orange-colored trematodes in the intestinal lumen, with an average body length of 3.12 mm. Based on morphological features and molecular analyses, the parasite was identified as Paragyiauchen sp. The following gene loci were amplified: the gene-encoding component of the large ribosomal subunit (28S rRNA), the gene-encoding NADH dehydrogenase subunit 1 (ND1), the gene cluster 5.8S rRNA-ITS2-28S rRNA and the gene cluster ITS2-28S rRNA. Bacterial species identification using MALDI-TOF MS revealed the presence of three species: Shewanella putrefaciens and Brevundimonas diminuta isolated from the head kidney, and Aeromonas caviae isolated from the liver. This study documents the first detection of representatives of Paragyliauchen genus in C. bicolor imported to Europe and highlights the potential risk of introducing new parasites and opportunistic bacterial pathogens through the ornamental fish trade. These findings emphasize the need for parasitological and microbiological screening of imported ornamental fish.

Ask AI

Helpful

Bookmark

View Full Paper