圆口

原始的似鳗的淡水或淡水中产卵的圆口纲脊椎动物，它们有长有吮吸嘴，嘴内有锉舌。

Primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue .

缺少下巴或成对附器的似鳗的动物包括圆口纲脊椎动物和某些灭绝的种类。

Eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms .

七鳃鳗隶属于圆口纲，是一类因营半寄生生活而引发机体显著特化的动物。

A commensal organism , especially an insect that lives in the nest or burrow of another species .

最后一个是特意的唇圆口型，这表示更亲密，特别是对婴儿。

The last is extra lip-rounding , which expresses greater intimacy , especially with babies , for example .

第二目，峻鱼，它的鳃类似圆口鱼的鳃，但下鳃活动。

Secundo , the selacians , with gills resembling those of the cyclostomes but whose lower jaw is free-moving .

研究结果表明，与圆口模具相比，扁口模具过渡段压力小，熔体各物理量沿轴向变化较剧烈。

It is shown that the pressure in the transition zone is greater for the flat die than for the round die .

圆口铜鱼的肝胰腺分为2叶，肝胰腺结构较为疏松，肝细胞较大，肝糖元含量很少，肝胰指数为3.8%，蛋白质含量8.8%，脂肪含量22%。

There is less glycogen in the hepatic cells . The hepatopancreas index is 3.8 % . The content of protein and fat is 8.8 % and 22 % respectively .

第一目，圆口鱼，鳃合成为一个转动的圈环，鱼鳃开合有许多小孔，这一目只有一科。类型：人目鳗。

Primo , the cyclostomes , whose jaws are fused into a flexible ring and whose gill openings are simply a large number of holes , an order consisting of only one family .