His seemingly obsessive concern for the eggs is for good reason.它对鱼卵看似过度担忧其实有充分的理由

concern for:对 ... 的关心； 忧虑

His concern for the poor is only a pose.

他对穷人的关心只不过是做做样子罢了。

The teacher showed particular concern for the disabled child.

老师特别关心那个残疾儿童。

she's in charge here and if his efforts don't match to her standards, she'll get rid of him.这里是母鱼当家作主，要是它认为公鱼的努力不够，就把它一脚踢开

in charge:负责；主管

I am in charge of financial affairs.

我职掌财务。

I gather that he is the one in charge.

我猜想他是负责的人。

get rid of:摆脱； 除去

Let's get rid of this moldy old furniture.

咱们把这件老掉牙的旧家具扔掉吧。

The fat boy went on a diet to get rid of his excess weight.

这个胖男孩节制饮食以减轻过量的体重。

So he focuses all his efforts on keeping them clean and healthy.它用全副心力保持鱼卵的洁净和健康

focus on集中在

You should focus your attention on your work.

你应该把注意力放到工作上。