Abstract
Misgurnus anguillicaudatus (Cantor 1842) is the most common loach in the world, habitually, available in Asian regions like China, Korea, India, and Japan. It lives in streams and rice paddy fields, preferably with a soft muddy bottom. The body of a typical loach is elongated with five pairs of barbs surrounding the mouth, and a single short-based dorsal fin. This species is omnivorous and source of diet usually varies from fish and insects, to plant detritus. The fish spawn multiple times per year during a spawning season that lasts from mid-April until mid-October. M. anguillicaudatus diploid individuals (2n=50) are common in wild populations. Different polyploidy populations have been reported in various locations in China. It has a delicious taste with high nutritional value, used as a traditional Chinese medicine. The most serious problem in both loach hatcheries and farms is bleeding in head, opercula, and lower jaw, swollen muscles, anus, liver, and spleen, and empty intestines. Characterization and expression profiles of tissue-specific immune genes are highly useful in understanding gene functions, tissue physiology, and transcriptomics of M. anguillicaudatus.