Which of the following is NOT a clinical sign of Vibrio infection?

The correct answer identifies spinal deformities as not typically associated with Vibrio infections. Vibrio, a genus of bacteria known for impacting aquatic species, particularly fish, is primarily linked to a variety of clinical signs that manifest due to the infection's effects on the skin, gills, and overall health of the fish.

Signs such as darkening of skin, skin ulcers, and respiratory distress are common manifestations of Vibrio infections. The darkening of skin occurs due to changes in pigmentation as a stress response or due to underlying disease processes. Skin ulcers indicate localized tissue damage, which can result from the bacteria's destructive activity. Respiratory distress is also a common symptom, as Vibrio species can impair gill function, leading to difficulty in breathing.

In contrast, spinal deformities are not directly linked to Vibrio infections and are more likely associated with other conditions, such as genetic anomalies, nutritional deficiencies, or other types of infections or diseases that affect bone development. Understanding the specific signs and symptoms associated with Vibrio infections can aid in differentiating it from other potential health issues in aquatic animals.