안성천 (安城川) 버들치 ( Moroco oxycephalus BLEEKER ) 의 개체군 생태조사 - 1. 개체수 퇴정을 중심으로 - = Population ecological studies of Moroco oxycephalus BLEEKER in the Anseung stream - 1. On the Estimation of population size -

다국어 초록 (Multilingual Abstract)

This survey is based on the seven-day researches performed respectively in August and october at the two areas along the upper Anseung stream in Gyeong gi-do, on estimation of the population size of moroco oxycephalus, including the distribution of its body length. They are as follow; Firstly, in Shim mi-dong valley, Moroco oxycephalus was exclusively dominant in number, while in Majun-ri other twelve species were found along with M. oxycephalus. Secondary, in river type the shin mi-dong valley belong to Aa type with pebbles at most of the river-bed and the average temperature of water in August, 1972 was 14 to 15 degrees, Centigrade and that of water in October 8 to 10 degrees C. On the other hand, in Majunri stream which belongs Aa.Bb type in formation with sand at the riverbed, the average temperature of water registered at 18 degrees, Centigrade in August and 15 to 16 degrees, Centigrade in October respectively. Thirdly, each estimation of the population size of M.oxycephalus both in Shin mi-dong valley (120㎡) and Majun-ri stream (1,700 and 5,600㎡) began with release M.oxycephalus., which were collected both in August and October and whose caudal fins were cut off as a marking The catching of M.oxycephalus plus already released ones had hereafter been resumed for five consecutive days until the following figure of the population size was obtained through adaptation of both Petersen method and Bailey`s Amendment; It was 2.00±0.78 fishes per square meter at shin mi-dong, while it was 3. 23±0.23 fishes per square meter at Majon-ri, in October alone. Fourthly, as to growth of M.oxycephalus, it measured On an average 34 to 36㎜ long in August and 46 to 48㎜ long in October in an apparent growth. Fifthly, the October table of the M.oxycephalus length showed a considerable wide range from 37㎜ to 129㎜, however when the multi-peak curve was recurved according to Cassie`s method, the length 28㎜ to 73.5㎜ is estimated to be one year old and that of 61.5㎜ to 129㎜ two years old or more.