Danio annulosus Danio annulosus Danio annulosus is a species of Chain danio fish in the family Cyprinidae in Danio genus. The species is named and described jointly by Sven O Kullander, M.D Mizanur Rahman, Michael Noren and Abdur Rob Mollah in 2015 in association with the Department of Zoology, Swedish Museum of Natural History, Sweden and the Department of Zoology, University of Dhaka, Bangladesh. The study and paper on Danio annulosus was published in ZooTaxa both online and in print in the same year (2015). It was collected from a small pool at the bottom of the Shuvolong Falls in the Kaptai
Danio margaritatus with a markedly blunt snout, measuring just 2–2.5 cm standard length. The body is about three times as long as it is high. In general shape, it resembles "Danio erythromicron" more than any other known species. This species shows some sexual dimorphism: males have a bright-blue background color (dull blue-green in females), and their fins are more brightly colored. The tail end of their bodies (the caudal peduncle) is also higher than in females. The body is sprinkled with small, pearly dots. The back is bronzy green, and the belly in females is yellowish-white. The gill covers are transparent, letting