Abstract: Identifying the optimal bone structure for age determination is a basis for examining fish age composition and surveying fish biological and ecological traits. Based on the 132 specimens of Chinese minnow, Phoxinus oxycephalus, collected from the JiulongPeak of the Huangshan Mountain during April 2012, the annulus characteristics on the scale, operculum, vertebra and otolith were identified and, according to the “true age” determined from length frequency distributions, the precision and accuracy of the observed ages determined by operculum, vertebra and lapillus otolith were compared in this study. No distinct annulus marker was observed on the scales taken from both lateral body and caudal peduncle and on the asteriscus otolith, but annuli could be observed on operculum, vertebra and lapillus otolith. According to the average error percent of aging, both precision and accuracy in the age determined by operculum, vertebra and lapillus otolith varied across agegroups. Overall, the highest precision was observed for vertebra and the lowest for lapillus otolith; however, the accuracy showed an opposite pattern. These results suggest that lapillus otolith is the optimal structure for aging P. oxycephalus, of which the relatively low precision in age determination and its potential effect on the accuracy may be mitigated by improving the quantity of observed structures and by optimizing the aging method.

Key words: net photosynthetic rate, impervious pavement, chlorophyll fluorescence, urban tree, pervious pavement