Question

“Gill rot” disease of fish is due to

• A. $Bacilluspolymyxa$
• B. $Bacillussubtilis$
• C. $Branchiomycessanguinis$
• D. $Aeromonasspecies$

Answer 1

The correct option is C $Branchiomycessanguinis$

Gill rot disease
Gill rot is a fungal disease caused by $Branchiomycessanguinis$. It affects the gills of the fishes and later spreads to the skin. It is characterised by mottled or blotchy appearance due to underlying dead tissues.

$Aeromonas$
$Aeromonashydrophila$ causes MAS (Motile Aeromonas Septicemia) in fishes. It is characterised by reddening of the skin, fluid accumulation in gill pockets and the abdominal cavity.

$Bacilluspolymyxa$
Polymyxin B, an antibiotic derived from the bacterium $Bacilluspolymyxa$ is used for the treatment of drug resistant Gram-negative infections. It is used as a probiotic in aquaculture.

$Bacillussubtilis$
$Bacillussubtilis$ is a nonpathogenic organism. It is used as a probiotic in aquaculture, especially for shrimps.

Final answer
b. $Branchiomycessanguinis$.