DAO 84:251-255 (2009)  -  DOI: https://doi.org/10.3354/dao02048

ABSTRACT: Four samples of Trisopterus luscus exhibiting unusual black spots on their musculature were obtained from catches made on different days and were rejected as unsuitable for consumption. Bipolar eggs somewhat resembling those of the nematode genus Huffmanela (Nematoda: Trichosomoididae) were identified as the cause of these black spots. Microscopic analysis revealed the presence of dark-shelled trichinelloid embryonated eggs dispersed throughout the muscle tissue, 73 to 94 × 40 to 59 µm in size, with large polar plugs 14 to 22 µm wide. However, the morphology and distribution of the observed eggs were not compatible with any previously described Huffmanela species. Intracellular nematodes were also observed in muscle cells. In 2 samples, sectioned nematode specimens were observed in other locations as well: the lymphatic vessel of intestine submucosa and the dermal lymphatic vessel. This could be due to nematode migration inside the infected fish. The presumed identification of Huffmanela sp. in a new host (Trisopterus luscus), and in a new location (Atlantic Ocean) supports the belief that these parasites could be widely distributed, particularly in marine fishes. In view of these factors, together with the observed egg morphology, it is possible that these specimens represent a new, unidentified Huffmanela species.

KEY WORDS: Huffmanela · Trisopterus luscus · Portuguese coast · Black spots · Nematode