What is Saprolegnia? Saprolegnia is ubiquitous in fresh water ecosystems and is the main genus of water molds responsible for significant

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1 Aquatic fungi Nuvee Prapasarakul, D.V.M., Ph.D. Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University Fungal Diseases of Fish, Shellfish and Amphibians Saprolegnia sp. Branchiomyces sp. Icthyophonus hoferi Exophiala spp. Lagenidium callinectes. Halipthoros sp. Sirolpidium zoophthorum Aphanomyces astaci Achlya sp. Taxonomic classification for Saprolegnia Kingdom: Protoctista Division: Oomycota Phylum: Heterokonta Class: Oomycotea Order: Saprolegniales Family: Saprolegniaceae Genus: Saprolegnia Species: declina Humpheryparasitica Coker complex What is Saprolegnia? Saprolegnia is ubiquitous in fresh water ecosystems and is the main genus of water molds responsible for significant 1

2 Life cycle of Saprolegnia Fig. 1 Microscopic finding of Saprolegnia spp. shows nonseptate hyphae Fig. 2 Zoosporangia of Saprolegnia spp. 2

3 A B Fig. 3 Gametangia of Saprolegnia spp.; antheridia and oogonia (a) and oogonia (b) Fig. 4 Primary oospore and oospore of Saprolegnia spp. Fig. 5 Zoosporangium and zoospore 3

4 Condition of Saprolegniasis Broodstock Crowed hatchery condition Epidermal integument Handling High steroid level Other pathogenic and parasites Spawning bed Pollution Water quality Water temperature change Disease signs Saprolegnia invades epidermal tissues Fluffy tufts of cotton-like material Colored white to shades of gray and brown Affected to skin, fins, gills, eyes or fish eggs Fig. 6 Lesion in fish with ulcerated skin caused by Saprolegniasis 4

5 Fig. 7 Fish fungus appears as white patches resemble cotton wool on body and tail Fig. 8 Fish with destroyed tissue and a slimy matted mass Treatment of Saprolegnia Malachite green (but concerned carcinogenicity) 37% formadehyde Hydrogen peroxide High conc of sodium chloride Combination with good management and husbandry techniques Fig. 9 Fungus invade on fish eggs 5

6 Gill Rot (BRANCHIOMYCOSIS) Branchiomyces dimigrans, Pike Branchimyces sanguinis Carp Tench Sticklebacks Branchiomyces sanguinis is generally located in the blood vessels of the gill arch and gill filaments. Branchiomyces demigrans produces hyphae which are able to penetrate into the gill filaments and spread on their surface. The disease breaks out most frequently when the water temperature is above 20 C. Find in fish suffering from an environmental stress, such as low ph (5.8 to 6.5), low dissolved oxygen, or a high algal bloom. Clinical Signs Fish may appear lethargic and may be seen gulping air at the water surface (or piping). Gills appear striated or marbled with the pale areas representing infected and dying tissue. Gills should be examined under a microscope by a trained diagnostician. Damaged gill tissue with fungal hyphae and spores will be present. As the tissue dies and falls off, the spores are released into the water and transmitted to other fish. High mortalities are often associated with this infection. Gill Rot Disease: caused by fungus Branchiomyces dimigrans, Branchimyces sanguinis) 6

7 ICTHYOPHONUS DISEASE Icthyophonus hoferi : Ichthyosporidiosis It grows in fresh and saltwater, in wild and cultured fish, but is restricted to cool temperatures (36 to 68 F). The disease is spread by fungal cysts which are released in the feces and by cannibalism of infected fish. Branchiomycosis of fish: A - branching hyphae of the fungus Branchiomyces sanguinis, B - fungus hyphae spreading in the branchial blood circulation, C - congested and poor-supply areas arise on the gill filaments, D - parts of the gill filaments necrotize, E - necrotic the gill filaments fall Disease Signs Fish with a mild to moderate infection will show no external signs of the disease. In severe cases, the skin may have a "sandpaper texture" caused by infection under the skin and in muscle tissue. Some fish may show curvature of the spine. Internally, the organs may be swollen with white to gray-white sores. Callinectes sapidus Blue crab: Infection of eggs and larvae of the is caused Lagenidium callinectes. As high as 95% infection has been found in populations of crabs off the North Carolina coast. Larvae become sluggish and cannot swim and many times eggs will not hatch. 7

8 Clams and oysters: Sirolpidium zoophthorum: Destroy whole populations Lobsters become infected with species of Lagenidium spp. and Halipthoros spp., resulting in the larvae becoming white and death occurring within hours. Shrimp: A larval shrimp showing hyphae of Sirolpidium inside abdominal appendages. Infested with Sirolpidium spp., Lagenidium callinectes. Pythiosis: Pythium insidiosum Chromomycosis is caused by various pigmented fungi, while phycomycosis results from infection with Mucor or other nonpigmented fungi. Granulomas or abscesses may be found in any organ. Skin ulcers and nodules are also common. 8

9 Cutaneous Pityosis; Swamp cancer Pythium insidiosum: Pythiosis ; ulcerative pyogranulomatous or fibrogranulomatous skin infection in horse, cattle, cat and dogs. Tropical and subtropical areas. Ventral trunk and head Kunkers or leeches: granulomatous coagula consist of necrotic Mc, Eo and hyphae Scanning electron microscopy of Pythium insidiosum's sporangia. Formation of the Pythium insidiosum's sporangia and zoospores (a to h) and release of the flagellated zoopores in water (i). Culture plate of Pythium insidiosum (Sabouraud). Sporangia of Pythium insidiosum on a grass leaf. Cat Pythiosis. Tumoral-like mass caused by Pythium insidiosum. 9

10 Cutaneous dog pythiosis Typical cutaneous pythiosis in an equine. Small white masses, known as "kunkers", are observed in the center of the lesion. Atypical case of equine pythiosis. The infection began in the lower extremity and spread, trough lymphatic vessels, to the horse's chest. Horse pythiosis with bone involvement (from a chronic case of the disease). "Kunkers" removed from the above case. These masses containe viable hyphae of P. insidiosum. Subcutaneous pythiosis in a Texan boy. Orbital pythiosis is common in children and should be differentiated from orbital zygomycosis and aspergillosis and Thai boy with pythiosis in his carotid artery 10

11 Amputated section of a patient leg that had pythiosis.the picture shows the aneurysm in the femoral artery caused by P. insidiosum from a Thai human patient. แล วก จบ เร องของเช อรา