Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Marine Pathology - all > Quaglio - Fungal Diseases > Flashcards

Quaglio - Fungal Diseases Flashcards

1
Q

What are the common fungal diseases affecting fish?

A

Saprolegniasis (Saprolegnia spp.), Epizootic Ulcerative Syndrome (EUS) caused by Aphanomyces invadans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Saprolegniasis, and what causes it?

A

A fungal disease caused by Saprolegnia spp., a water mold. Common in freshwater fish. Often a secondary infection following physical trauma or poor water quality.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the clinical signs of Saprolegniasis?

A

White, cotton-like growths on skin, gills, or fins; lesions that may lead to secondary bacterial infections; lethargy and loss of appetite in infected fish.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does poor water quality contribute to Saprolegniasis?

A

Stress from high ammonia, low oxygen, or poor hygiene compromises immunity, increasing susceptibility to fungal infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the predisposing factors for Saprolegniasis?

A
  • Physical injuries (e.g., handling, netting)
  • Immune suppression due to stress or poor nutrition
  • Cold water temperatures favor fungal growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is Saprolegniasis treated in aquaculture?

A
  • Salt baths or potassium permanganate treatments
  • Improving water quality and minimizing handling stress
  • Application of antifungal agents like formalin or malachite green
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Epizootic Ulcerative Syndrome (EUS), and its causative agent?

A

A severe fungal disease caused by Aphanomyces invadans. Affects freshwater and estuarine fish. Associated with ulcerative lesions and high mortality.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the symptoms of EUS?

A
  • Deep, red ulcerative lesions on the body and fins
  • Necrosis of underlying muscle tissue
  • Secondary bacterial infections leading to systemic septicemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What environmental factors favor EUS outbreaks?

A
  • Poor water quality with high organic matter
  • Stagnant or polluted water bodies
  • Seasonal changes, especially during monsoon periods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is EUS transmitted?

A

Spores of Aphanomyces invadans released into water. Infection occurs through open wounds or abrasions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is EUS diagnosed?

A
  • Clinical signs of deep ulcers and necrotic tissue
  • Microscopic identification of fungal hyphae in lesions
  • Histopathology showing mycotic granulomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are mycotic granulomas, and their significance in fungal infections?

A

Granulomas are inflammatory responses to fungal invasion. Seen in chronic cases, indicating immune system response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What treatments are effective for EUS?

A
  • Broad-spectrum antifungal treatments (e.g., formalin baths)
  • Antibiotics for secondary bacterial infections
  • Improving water quality and reducing organic load
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the prevention strategies for fungal diseases in fish?

A
  • Regular monitoring and maintaining good water quality
  • Avoiding overcrowding and minimizing fish injuries
  • Prompt removal of dead or infected fish to reduce fungal spread
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the histological findings in fungal infections?

A
  • Hyphae invading tissues, surrounded by inflammatory cells
  • Necrotic lesions and granulomas in chronic cases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the impact of fungal diseases on fish populations?

A
  • Causes high mortality, especially in stressed populations
  • Reduces fish growth and marketability
  • Can lead to significant economic losses in aquaculture
17
Q

How do fungal infections differ from bacterial infections in fish?

A

Fungal infections often present as cotton-like growths or deep ulcers. Bacterial infections are typically associated with hemorrhages and systemic signs.

18
Q

What are the common laboratory methods for diagnosing fungal infections?

A
  • Wet mount preparation of lesions for hyphae
  • Staining techniques like PAS or Gomori methenamine silver
  • Culturing on Sabouraud dextrose agar
19
Q

What role does stress play in fungal disease outbreaks?

A

Stress weakens fish immunity, making them more susceptible. Common stressors include poor water quality, overcrowding, and handling.

20
Q

How does temperature affect fungal growth?

A

Lower temperatures favor growth of water molds like Saprolegnia spp. Rapid temperature changes can stress fish, increasing susceptibility.

21
Q

How do fungal diseases contribute to secondary infections?

A

Fungal lesions provide entry points for opportunistic bacteria. Secondary infections complicate treatment and increase mortality.

22
Q

What biosecurity measures help control fungal diseases?

A
  • Quarantine new fish stocks
  • Regularly disinfect equipment and tanks
  • Avoid using contaminated water sources
23
Q

What is the lifecycle of Saprolegnia spp.?

A

Asexual reproduction through zoospores released into water. Zoospores infect damaged tissues or organic debris.

24
Q

Why are fish eggs particularly susceptible to fungal infections?

A

Lack of protective mucus layer. High organic matter in spawning areas promotes fungal growth.

25
Q

How are fungal diseases managed in hatcheries?

A
  • Regular use of antifungal treatments (e.g., formalin or malachite green)
  • Maintaining optimal water quality and aeration
  • Frequent removal of dead eggs or larvae
26
Q

What is the role of formalin in fungal disease management?

A

Acts as an antifungal agent. Effective in treating Saprolegniasis and EUS. Used in baths at prescribed concentrations.

27
Q

How can fungal infections be prevented during fish transportation?

A
  • Minimize handling and physical injuries
  • Use clean, aerated water and avoid overcrowding
  • Treat transport water with antifungal agents if needed
28
Q

How do fungal infections impact wild fish populations?

A

Can lead to large-scale mortality during environmental stress events. Impacts biodiversity and ecosystem stability.

29
Q

How does Aphanomyces invadans differ from Saprolegnia spp.?

A

Aphanomyces invadans causes deep tissue necrosis and granulomas. Saprolegnia spp. primarily causes superficial cotton-like growths.

30
Q

What is the economic significance of fungal diseases in aquaculture?

A
  • Results in high mortality rates and loss of fish stock
  • Increases treatment and management costs
  • Reduces overall productivity and profitability

Marine Pathology - all (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions