In the described Seriola rivoliana outbreak, what deficiency is implicated as the diagnosis?

• A. Taurine deficiency
• B. Selenium deficiency
• C. Vitamin C deficiency
• D. Vitamin A deficiency

Answer: (A)

Taurine is essential for many marine carnivorous fishes, including Seriola rivoliana, because their bodies rely on dietary taurine for important functions such as bile salt conjugation and proper fat digestion. When taurine is deficient, fat is not efficiently emulsified and absorbed, leading to fatty liver and overall poor condition, with growth faltering and metabolic disturbances that are commonly seen in nutritionally deprived or inadequately supplemented diets.

In the described outbreak, signs would align with a nutritional shortfall in a taurine-dependent species fed a diet lacking sufficient taurine or one where processing reduced taurine availability. This makes taurine deficiency the most plausible diagnosis among the options, given the fish’s physiology and the typical presentation of this deficiency. Selenium deficiency, vitamin C deficiency, and vitamin A deficiency each have distinct clinical patterns (oxidative muscle damage, scurvy-like hemorrhages, and keratinization/eye issues, respectively) that do not fit as well with a fat-digestion–related, hepatically centered problem in this species.