Origin of right-left sideness could be revealed in the metamorphic process of the most primitive flatfish Indian halibut Psettodes erumei distributed in Asian tropical waters

点击翻译按钮获取中文摘要

It was hypothesized that the most primitive flatfish, Indian halibut Psettodes erumei which has been known as having flexible eye sideness, may have a key to resolve metamorphic mechanism characterized by asymmetrical eye sideness. In order to collect basic biological information on maturation and spawning as well as juvenile habitat sampling of Indian halibut was conducted around Kota Kinabalu Bay, in northwestern Borneo Island, Malaysia during the period of 2009 through 2011. Morphological and histological observations revealed that male is restricted less than 29. 5cm, but female is over 29. 5cm in body length. There was no evidence on seasonality of spawning, suggesting this species would spawn all around year. Field surveys on the distribution of the juveniles suggested the present species may have its nursery ground around 10 to 20m depth area. Molecular biological analyses for two species of flounder of which eye sideness are fixed demonstrated nodal pathway takes an important role ; particularly reappearance of pitx2 at the early phase of metamorphosis definitely regulate eye sisdeness in flatfish.