Pethia didi Pethia didi Pethia didi is a species of cyprinid fish which has only been recorded in the vicinity of Myitkyina and Indawgyi Lake in the north of Myanmar. This is a small fish which can reach a length of SL. It is generally brownish with a dark vertical bar just behind the operculum and a round dark blotch on the caudal peduncle. The species "P. tiantian" – with a range close to "P. didi" – is similarly marked, but "P. didi" can be distinguished by its truncated lateral line, deeper body and longer dorsal fin, with two rows of dark
Operculum (gastropod) ornaments. The largest opercula of "Turbo marmoratus" have been used as paperweights. Operculum (gastropod) The operculum, meaning little lid, (plural: opercula or operculums) is a corneous or calcareous anatomical structure like a trapdoor which exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it