Growth Rate and Fecundity of Bleak ( Alburnus Alburnus (L.) in the Sand-Pit Lake Chepintsi (Bulgaria)

摘要

The population status of bleak (Alburnus alburnut (L.) in sand-pit lake Chepintsi near Sofia by using some biological factors as growth rate, condition and fecundity was investigated. The maximum age, length and body mass of bleak were 3 years, 12.7 mm and 20 g, respectively. The first, second and third age group were 5.77%, 63.46%, 30.77% respectively. The linear and body mass growth rate were described by the equations: SL=1.3487+2.6601R (r=0.88); W=0.1499L 1.8499 (r=0.95), respectively. The condition coefficient of bleak (k) was the lower than that for other populations from different water bodies. Also the populations from different water basins were compared by the body mass at the same length. Fecundity was 7 168 eggs, the average was 1 707?￠????12 284 eggs. The fecundity-length and fecundity-weight relationship were described by the equations: F=387.32L+4365.7 (r=0.46); F=1368.4W-3151.9 (r=0.59) respectively.