Saprolegnia and other oomycetes.

Abstract

The biology, life cycle, genetic characteristics, diagnosis, taxonomy, geographical distribution, host range, economic importance, control, prevention and treatment of Saprolegnia and other Oomycetes in fishes were discussed.

Deciphering microbial landscapes of fish eggs to mitigate emerging diseases

“…Saprolegnia also forms secondary zoospores and secondary cysts that, for some species, contain boathooks that are presumed to aid in attachment to the fish skin or promote floating (buoyancy) in water ( Van den Berg et al, 2013). Losses resulting from Saprolegniosis average 10% in eggs and young fish, but losses of up to 50% have been reported Hoshiai, 1992, 1994;Bruno et al, 2011;Van den Berg et al, 2013).…”

“…This disease is characterized by white and grey patches of mycelial growth on the skin and fins of adult fish, and cottonlike filamentous mycelium on eggs. In fish, death often occurs from disruption of the osmotic balance (haemodilution) following destruction of large areas of the epidermis by massive, invasive hyphal growth (Bruno et al, 2011). Fish eggs, on the other hand, are thought to be killed by hyphal breaching of the chorionic membrane regulating the osmosis of the embryo.…”

“…Among the fungi, Fusarium solani is causing mass mortality in eggs of endangered sea turtles in Cape Verde (Sarmiento-Ramirez et al, 2010), and Batrachochytrium dendrobatidis and Batrachochytrium salmandrivorans are involved in major amphibian declines worldwide Martel et al, 2013). Among the fungal-like oomycetes, Aphanomyces astaci, Aphanomyces invadans and Saprolegnia species are causing significant reductions in crayfish, fish and amphibian populations (Fernandez-Beneitez et al, 2008;Phillips et al, 2008;Krugner-Higby et al, 2010;Bruno et al, 2011;Van den Berg et al, 2013), respectively. Saprolegniosis is a major disease problem in different wild and farmed fish species, including salmonid species such as Atlantic salmon, rainbow and brown trout, and non-salmonid species including perch, eels and catfish (Bruno et al, 2011).…”

“…Among the fungal-like oomycetes, Aphanomyces astaci, Aphanomyces invadans and Saprolegnia species are causing significant reductions in crayfish, fish and amphibian populations (Fernandez-Beneitez et al, 2008;Phillips et al, 2008;Krugner-Higby et al, 2010;Bruno et al, 2011;Van den Berg et al, 2013), respectively. Saprolegniosis is a major disease problem in different wild and farmed fish species, including salmonid species such as Atlantic salmon, rainbow and brown trout, and non-salmonid species including perch, eels and catfish (Bruno et al, 2011). This disease is characterized by white and grey patches of mycelial growth on the skin and fins of adult fish, and cottonlike filamentous mycelium on eggs.…”

Pathogenicity and oxidative stress in Nile tilapia caused by Aphanomyces laevis and Phoma herbarum isolated from farmed fish

“…Intensive aquaculture conditions can promote the transmission of fish diseases (including fungal diseases), causing economic losses, hence study of these diseases has become increasingly important over the past 20 yr. Zoosporic fungi are classic secondary invaders of fish epithelial surfaces, becoming increasingly infectious under conditions of poor water quality or general immunosuppression. Oomycetes of the order Saprolegniales are responsible for infections of various wild and farmed fish species (Willoughby & Pickering 1977, Bruno & Wood 1999, Hussein & Hatai 2002. Within the Saprolegniales, species of Achlya, Aphanomyces and Saprolegnia are major pathogens of many fish or shellfish species (Jeney & Jeney 1995, Daugherty et al 1998.…”