Aquatic Animal Health MCQs 50 Score: 0 Attempted: 0/50 Subscribe 1. The scientific name of the common carp is: (A) Clarias batrachus (B) Cyprinus carpio (C) Labeo rohita (D) Pangasius hypophthalmus 2. The study of fish diseases is called: (A) Ichthyology (B) Limnology (C) Fish pathology (D) Aquaculture science 3. White spot disease in shrimp is caused by: (A) Virus (B) Bacteria (C) Fungus (D) Protozoa 4. Ichthyophthiriasis (Ich) in fish is caused by: (A) Bacteria (B) Protozoa (C) Fungus (D) Nematode 5. The causative agent of bacterial gill disease is: (A) Flavobacterium branchiophilum (B) Aeromonas hydrophila (C) Vibrio vulnificus (D) Edwardsiella tarda 6. Which is the most common method of fish anesthesia? (A) MS-222 (Tricaine) (B) Lidocaine (C) Ether (D) Alcohol 7. Dropsy in fish is mainly characterized by: (A) Skin lesions (B) Abdominal swelling and scale protrusion (C) Gill discoloration (D) Loss of appetite 8. The main route of disease transmission in aquaculture is: (A) Airborne (B) Waterborne (C) Soil contamination (D) Insect bites 9. The optimum pH range for most aquaculture species is: (A) 4–5 (B) 5.5–6.0 (C) 6.5–8.5 (D) 9–10 10. Edwardsiellosis in fish is caused by: (A) Edwardsiella ictaluri (B) Aeromonas salmonicida (C) Vibrio harveyi (D) Streptococcus iniae 11. Which parasite causes “anchor worm” infection in fish? (A) Lernaea (B) Ichthyobodo (C) Trichodina (D) Gyrodactylus 12. Hematopoietic necrosis virus (IHNV) mainly affects: (A) Tilapia (B) Salmonids (C) Catfish (D) Shrimp 13. The gas bladder in fish is responsible for: (A) Digestion (B) Buoyancy regulation (C) Blood circulation (D) Immune defense 14. Saprolegniasis is caused by: (A) Bacteria (B) Virus (C) Fungus (D) Protozoa 15. The causative agent of vibriosis is: (A) Aeromonas hydrophila (B) Vibrio species (C) Edwardsiella tarda (D) Mycobacterium marinum 16. The term “osmotic stress” in fish refers to: (A) Thermal imbalance (B) Salinity imbalance (C) pH fluctuation (D) Overfeeding 17. Koi herpesvirus (KHV) primarily affects: (A) Salmon (B) Tilapia (C) Koi and common carp (D) Catfish 18. The best method for preventing aquatic animal diseases is: (A) Antibiotics (B) Vaccination (C) Biosecurity and good management (D) High stocking density 19. Which of the following is a crustacean pathogen? (A) WSSV (B) Myxobolus cerebralis (C) Flavobacterium columnare (D) Ichthyophthirius multifiliis 20. The process of gradually adjusting fish to a new water environment is called: (A) Acclimatization (B) Osmoregulation (C) Conditioning (D) Quarantine 21. The gills in fish primarily function for: (A) Digestion (B) Excretion of nitrogen (C) Gas exchange (D) Reproduction 22. What is the main symptom of Mycobacteriosis in fish? (A) Pop-eye and weight loss (B) Rapid growth (C) Egg deformity (D) Skin thickening 23. A major risk factor for fungal infections in fish is: (A) High oxygen levels (B) Poor water quality and injuries (C) High temperature alone (D) Excessive aeration 24. The causative agent of red disease in eels is: (A) Vibrio species (B) Pseudomonas species (C) Edwardsiella species (D) Aeromonas species 25. Which of the following is a viral disease of shrimp? (A) Taura syndrome virus (B) Columnaris (C) Gill rot (D) Trichodinosis 26. The primary nitrogenous waste excreted by fish is: (A) Urea (B) Uric acid (C) Ammonia (D) Nitrate 27. The term “quarantine” in aquaculture means: (A) Breeding of fish (B) Separating and monitoring new stock before introduction (C) Increasing feed intake (D) Reducing light exposure 28. Epizootic ulcerative syndrome (EUS) is mainly caused by: (A) Virus (B) Bacteria (C) Fungus (Aphanomyces invadans) (D) Protozoa 29. What does HACCP stand for in aquatic food safety? (A) Hazard Analysis and Critical Control Points (B) Hazard and Animal Care Control Plan (C) Health and Aquatic Culture Control Program (D) High Action Control for Clean Products 30. The best practice to control parasitic diseases in aquaculture is: (A) Overfeeding (B) Regular liming and water treatment (C) Increased salinity always (D) Use of antibiotics only 31. Streptococcosis in fish is caused by: (A) Streptococcus iniae (B) Vibrio cholerae (C) Aeromonas hydrophila (D) Pseudomonas aeruginosa 32. The swim bladder disorder in ornamental fish is mainly due to: (A) Viral infection (B) Overfeeding and poor water quality (C) Vitamin E deficiency (D) High salinity 33. The role of probiotics in aquaculture is to: (A) Increase ammonia levels (B) Improve water quality and gut health (C) Reduce feed intake (D) Increase stress 34. “Melanomacrophage centers” in fish are indicators of: (A) Good health (B) Immune response and chronic disease (C) High oxygen levels (D) Reproductive activity 35. Which chemical is commonly used to disinfect fish ponds? (A) Potassium permanganate (B) Formalin (C) Chlorine (D) All of the above 36. Fish louse is scientifically known as: (A) Argulus (B) Gyrodactylus (C) Trichodina (D) Dactylogyrus 37. The major cause of ammonia toxicity in ponds is: (A) Low pH (B) Overfeeding and poor waste management (C) Excess lime application (D) Low oxygen levels 38. The main purpose of aeration in fish ponds is: (A) Increase temperature (B) Supply oxygen and remove toxic gases (C) Reduce fish growth (D) Control predators 39. Gill rot is mainly caused by: (A) Fungi (B) Bacteria (C) Protozoa (D) Viruses 40. The causative agent of “whirling disease” in salmonids is: (A) Myxobolus cerebralis (B) Flavobacterium columnare (C) Vibrio alginolyticus (D) Saprolegnia spp. 41. Fish health management includes: (A) Disease diagnosis (B) Environmental monitoring (C) Biosecurity (D) All of the above 42. A major symptom of gas bubble disease is: (A) Fin rot (B) Gas emboli in fins and eyes (C) Weight loss (D) Yellowing of skin 43. The main purpose of fish vaccination is to: (A) Treat bacterial infections (B) Prevent specific diseases (C) Kill external parasites (D) Improve water color 44. Which factor is most critical for fish immune response? (A) Light intensity (B) Water temperature (C) Water color (D) Pond depth 45. Sea lice are mainly a problem in: (A) Freshwater ponds (B) Salmon farming (C) Catfish ponds (D) Shrimp farming 46. The most sensitive life stage of fish to toxins is: (A) Adult (B) Juvenile (C) Egg and larval stage (D) Broodstock 47. The main purpose of quarantine tanks is to: (A) Increase breeding rate (B) Prevent disease introduction (C) Improve water taste (D) Lower stocking density 48. Which is an example of a monogenean parasite in fish? (A) Dactylogyrus (B) Lernaea (C) Argulus (D) Saprolegnia 49. Nitrite poisoning in fish is also known as: (A) Red disease (B) Brown blood disease (C) White spot disease (D) Black gill disease 50. The first step in fish disease diagnosis is: (A) Immediate medication (B) Clinical observation and history (C) Pond draining (D) Water salting