Stress and/or poor water management may lead to brown spot disease in

• A. Frogs
• B. Seaweed
• C. Alligators
• D. All of the above

Answer: (D)

Stress and poor water management weaken an aquatic animal’s defenses and create conditions that let pathogens take hold. Brown spot disease is a discolored, lesion-like response that can appear when the environment is stressful: high ammonia or nitrite, low dissolved oxygen, fluctuating temperatures, improper pH, or overcrowding. When these stressors are present, various organisms exposed to the same poor conditions can show brown patches or spots on tissue or surfaces.

In frogs, skin lesions can develop under water-quality stress. In seaweed, discolored brown patches can arise from microbial activity promoted by nutrient imbalance and poor water conditions. In alligators kept in restricted or poorly managed water systems, skin or tissue changes consistent with brown spot disease can occur as well. Because the underlying issue is water quality stress that compromises health across different aquatic life, all of the listed organisms are potentially susceptible.