【摘要】 <正> 沙鳢Odontobutis obsura(Temm.et Schl.)(本地土名为沙乌鳢)为梁子湖分布较广的鱼类之一,如聂开、南塘口、南湾、凃家碯、张桥湖、磨刀矶、长岭、港口、樊口、葫飘口、小集、岳山、金脸盆、土地堂、南北极等地均有出产。但是,由于沙鳢在梁子湖产地分散,产量不多,所以在当地经济价值并不甚大,而且也不作为一种重要的捕捞对象。因此,在梁子湖没有专门捕捉沙鳢的渔民,也缺少捕获它们的专门网具和操作方法。另外一些地区,特别在杭州它却是比较名贵的鱼类。更多还原

【Abstract】 The fresh-water goby, Odontobutis obscura (Temm. et Schl.) (belonging to the family Eleo- tridae), is very common in South-Eastern China. It lives in the bottom of lakes, streams and rivers. The food consists mainly of shrimps and small fishes. Sexes can be easily distingulshed from the shape and color of the urogenital papillae. At the beginning of the brecding scason, the male occupies a site as a nest, such as crevices between stones or rocks, large bivalved shells, brocken crockery, etc., at the depth of 1—2 m. and produced sound to attract females. The breeding season lasts from early April to early June (18—25℃.), about 60 days. Eggs are laid usually in early morning about 6—7 a. m. Each female spawns 1—3 times during the season according to its age. Eggs are lightly yellow in color, ovoid in shape, 2.10×1.63 mm. on averge. The number of eggs varies from 556 to 1647. The male guards in the nest and flaps constantly its fins in order to keep the water in the nest flowing. The incubation period lasts 25 days if the water temperature ranges from 15.5° to 28.5℃. and it lasts 19 days if the temperature is riased from 19°to 31℃. The development of cmbryo may be divided into 15 stages. Eggs hatch also in the early morning. The newly hatched fry about 0.70—0.75 cm. in length swims freely in the water and feeds on cyclops. The number of ossified annules on radials of the pectoral fins can be used for age determination. The ossified annules formed in the radials seems to occur in the late winter. Both sexes show a similar growth rate and longevity. They reach sexual maturity at the age of two years when they grow 9.20 cm. in length on average. Individuals 4 years old which grow. in length are the largest of the catch in the lake.更多还原