长江中游四大家鱼仔鱼营养状况的初步研究

The Preliminary Studies on Nutritional Condition of Larval Grass Carp, Silver Carp, Black Carp and Bighead from the Middle Reaches of the Yangtze River

通过形态观察、食性分析及消化系统组织学检测 ,对长江中游四大家鱼仔鱼的营养状况进行了初步评价。仔鱼具有匀称、消瘦和很消瘦三种体型 ;空肠率较高 ,草鱼、鲢、青鱼和鳙分别为 4 5 1 6%～72 1 3% ,30 %～ 4 0 91 % ,31 2 5%～ 67 65%和 87 50 % ;依据肝胰脏和肠的组织学特征 ,可以将天然仔鱼的营养水平划分为很好、较好和饥饿三种。 1 998年采自九江江段的样本中 ,遭受饥饿的草鱼、鲢、青鱼和鳙分别为 4 0 %、4 8 1 5%、4 6 1 5%和 60 %。

The nutritional condition of the larval grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix), black carp (Mylopharyngodon piceus), and bighead (Aristichthys nobilis) from the middle reaches of the Yangtze River was evaluated based on morphological observation, food analysis and histological examination. There were normal, emaciated and severe emaciated body shapes in wild larvae. The percentage of individuals with no food in guts was very high in larvae: 45.16%～72.13% in grass carp, 30%～40.19% in silver carp, 31.25%～67.65% in black carp, and 87.5% in bighead. The nutritional condition of wild larvae could be divided into three grades: good, normal and starvation, based on the histological characteristics of liver, pancreas and intestine. In the sample from Jiujiang section of the Yangtze River, the percentage of starved individuals was 40% in grass carp, 48.15% in silver carp, 46.15% in black carp, and 60% in bighead.