Melanized fungi in bony fish species with Head and Lateral Line Erosion (HLLE) with a review of the literature on fungal fish diseases

Abstract

Background. An outbreak of black fungi in Palette surgeonfish (Paracanthurus hepatus) and Threespot angelfish (Apolemichthys trimaculatus) with severe case of Head and Lateral Line Erosion (HLLE) in the saltwater aquarium of Burgers’ Zoo in Arnhem, The Netherlands is reported. Results. Etiologic agents were waterborne species of Exophiala, Scolecobasidium and Trematosphaeria. The Scolecobasidium species appeared to be a new species and is introduced as S. burgersense. As numerous Exophiala and Scolecobasidium species are known to cause fish diseases, a review of the literature was undertaken. Literature review. This showed that these genera of melanized fungi, particularly Chaetothyriales and Venturiales, and to a less extent Pleosporales, are preponderant in infecting both marine and freshwater bony fish. In contrast, sharks and other cartilaginous fish species are almost exclusively infected by hyaline fungi, primarily Fusarium species and some others by the Hypocreales. Conclusion. Fungal fish disease are exceptional, limited to just a few orders in the fungal Kingdom. The predilection of melanized fungi differs significantly from that of hyaline fungi. Outbreak of black fungi in Palette surgeonfish (Paracanthurus hepatus) and Threespot angelfish (Apolemichthys trimaculatus) with severe case of Head and Lateral Line Erosion (HLLE) in the saltwater aquarium of Burgers’ Zoo in Arnhem, The Netherlands is reported. Etiologic agents were waterborne species of Exophiala, Scolecobasidium and Trematosphaeria. The Scolecobasidium species appeared to be a new species and is introduced as S. burgersense. A review of the available literature showed that these genera of melanized fungi, particularly Chaetothyriales and Venturiales, and to a less extent Pleosporales, are preponderant in infecting both marine and freshwater bony fish. In contrast, sharks and other cartilaginous fish species are almost exclusively infected by hyaline fungi, primarily Fusarium species and some others by the Hypocreales.