Royal Clown Loach Imperial Flower Loach, Elongate Loach, Queen Loach Size 5 cm Feed with chopped mussels The Royal Clown Loach is a very large loach with a life span of about 20 years. In its natural habitat it can grow up to 30" (76.2 cm) in length. Newly imported specimens are usually between 7 - 12" (18 - 30 cm) long, but it will grow, so anticipate it needing a very large tank to house it.