Lymphocystic Disease in Wild Croaker (Micropogonias furnieri) and Flounder (Paralichthys orbignyanus)

Lymphocystis disease has been reported worldwide in several species of freshwater fish and marine fish, naturally infected in the wild environment, or in intensive crops in farms. Nodular warty lesions of irregular surface were observed in the tegument and fins and mouth in a species of croaker (Micropogonias furnieri) caught in Cassino beach Rio Grande RS, Brazil and flounder (Paralichthys orbignyanus) caught in the city of San Clemente, Argentina. The skin lesions fragments were fixed in 20% buffered formalin, and the histological sections were stained with hematoxylin and eosin and Periodic Acid-Schiff (PAS), where microscopic alterations were visualized in the form of hyaline capsule with small basophilic structures in nodules and fibroblastic cells proliferation. The reported cases were based on the disease macroscopic findings characteristic of a lymphocystis disease, along with the histopathology, which confirmed the presence of the disease in the analyzed tissues.