1. Parasitic Diseases in fishesBy
Dr. Mohamed Sayed Mohamed Marzouk
Professor of Fish Diseases and Management , Faculty of Veterinary Medicine,
Cairo University

2. Parasitic Diseases of cultured fishes
What is meant by Parasite ? ً
Classification of different parasites
Protozoa (unicellular).
Helminthes (multi-cellular)
Crustaceans

3. Protozoa According to habitate: According to shape: External.
Internal (Blood and Tissue).
According to shape:
Cilliates (Icthyophthirius, Chilodonella, Trichodina).
Flagellates (Ichthyopoda, Trypanosoma, Cryptobia, Hexamita).
Sporozoa (Myxosoma).

4. External protozoa 1. Exteranl cilliated protozoa:
Ichthyophthirius multifillis
Chilodonella spp.
Trichodina spp.

5. 2. Exteranl flagellated protozoa:
Ichthyoboda (Costia) necatrix and pyriformis
Piscinoodinium spp.
Amyloodinium spp.
Cryptobia spp.
3. Internal flagellated protozoa
Hexamita spp.
Trypanoplasma spp.

6. Ichthyophthirium multifilis trophozoit (Stained )

7. Ichthyophonus multifillis (unstained)

8. Stained Trichodina from skin mucus scraping

10. Pathogenesis of external protozoa Skin cellular irritation
Protozoal invasion
Skin cellular irritation
1. Abnormal swimming
2. Excessive mucus
Skin cellular destruction
1. Haemorrhages
3. C.T capsules (White spots).
2. Erosions and ulcers

11. Life cycle of Ichthyophthiriosis

12. Clinical signs
Abnormal swimming ( Flashing, circling, sluggish and itching ).
Surfacing and gasping ( Asphyxia ).
Excessive skin mucus ( patchy then generalized ).
Pathognomonic white spots (Ichthyophthiriosis), Yellow
shine or Rust (Oodiniosis).
Skin haemorrhages, erosions and ulcerations.
Emaciation and death.

13. White spot disease

14. Cryptocarion irritans infection in marine fish

15. Surfacing and gasping in gill infection

16. Diagnosis of External parasitic Diseases
1. History ( new introduced fish, water parameters,………
2. Clinical signs and lesions.
3. Demonstration and identification of the causative parasites
Skin and gill mucus scraping (wet mount).
Stained skin and gill mucus smears.

17. Treatment of External parasitic Fish Diseases
External chemical treatment
Dip treatment
Bath treatment
Flush treatment
Indefinite bath treatment
Non-chemical treatment
Increase water temperature in White Spot disease
Change water facility
Use of ultraviolet radiation in re-circulating system

18. Types of Chemical treatments
1. Disinfectants:
Pot. Permenganate.
Malachite green.
Formaline.
Na Cl.
Acriflavin.
Methylene blue.

19. 2. Pesticides:
Chlorinated Hydrocarbones.
Organophosphates.

20. Control of Fish diseases in infected fish farms
In infected earthen ponds:
Drainage
Dryness
Disinfection using quick lime
In infected concrete or fiberglass fish tanks:
Disinfection with strong antiseptics

21. Hexamita intestinalis
Hexamitiosis
Systemic infection caused by an internal flagellated protozoa
Causative protozoa
Hexamita truttae
Hexamita salmonis
Hexamita intestinalis

22. Hexamita is normal inhabitant of intestine
Mode of infection and transmission:
1. Infection through ingestion.
2. Transmission is from dead fish and contaminated water body.
Pathogenesis
Hexamita is normal inhabitant of intestine
Large numbers
Small numbers
Systemic form
Intestinal destruction
No signs
Intestinal irritation
Hole in head
Excess mucus
Off food & emaciation

23. Clinical signs: 1. Off food. 2. Emaciation and tucked up abdomen.
3. Mucus shreds from the vent.
4. High mortality in severe cases.
5. Hole in the head in systemic form (Fistula behind the head
exuding white material).

24. Diagnosis Clinical signs and lesions (Non-confirmative)
Laboratory ( Confirmative)
Sampling ( Intestinal mucus )
Quantitative (Count/ MF)
Qualitative
= Negative
5 – = Mild
= Moderate
30 – = Severe
More than 100 = Marked

25. Can be used in food fishes Not to be used in food fishes
Treatment and control
2. Hexamiticides
1. Expulsion
Sulfonamides
Saline purgative
(MgSO4)
Aresenical (Carbersone).
Murcurial (Calomel).
Can be used in food fishes
Not to be used in food fishes

26. Fish Helminthosis Helminthes of fishes
Helminthes infection or infestation ?
Helminthes of fishes
Platy helminthes
Round worms
Trematodes
Cestodes
Larvae
A dults

27. Encysted metacercaria
Fish Trematodes
1. Monogenea
2. Digeanea
Adults
Gill flukes
Skin flukes
Encysted metacercaria

28. Gill flukes 1. Dactylogyridae 2. Cichlidogyridae
Cichilidogyrus tilapiae (C. tilapiae)
Dactylogyrus vastator (D. vastator)

29. D. vastator

30. C. tilapiae

32. G. elegans

34. Haemorrhagic granuloma of Lernea copepode

35. 2 egg sacs
Anchor
Lernea cyprinicae

37. Fish lice ( Argulus sp.) attached to fish skin

38. Ventral view of Fish Lice

39. Thank You