(proverb)you can or should take advantage of anything that comes your way(谚)抓到网里便是鱼；来者不拒；不择手段
a big fish
an important or influential person大人物，大腕儿
a big fish in a small (或 little) pond
a person seen as important and influential only within the limited scope of a small organization or group小塘里的大鱼；矮子堆里的高个
drink like a fish
drink excessive amounts of alcohol过量饮酒；牛饮
a fish out of water
a person in a completely unsuitable environment or situation出水之鱼；逆境中人
have other (或 bigger) fish to fry
have other (or more important) matters to attend to另有要事；另有他图
like shooting fish in a barrel
used to convey the extreme ease with which something can or has been accomplished瓮中捉鳖，易如反掌；举手之劳
neither fish nor fowl (nor good red herring)
of indefinite character and difficult to identify or classify非驴非马，不伦不类
there are plenty more fish in the sea
used to console someone whose romantic relationship has ended by pointing out that there are many other people with whom they may have a successful relationship in the future海里好鱼多的是；天涯何处无芳草
fish out
To deplete (a lake, for example) of fish by fishing.捕尽：用捕或钓的方式把（如湖）鱼捕尽
fish in troubled waters
To try to take advantage of a confused situation.混水摸鱼：在一片混乱中攫取好处
fish or cut bait【非正式用语】
To proceed with an activity or abandon it altogether.在两者中作出选择：要么继续干下去，要么全部放弃
like a fish out of water
Completely unfamiliar with one's surroundings or activity.如鱼离水的，感到生疏：对自己所处的环境或所干的事完全不熟悉的
neither fish nor fowl
Having no specific characteristics; indefinite.非驴非马的，不伦不类的：没有明显的特征的；不确定的
柯林斯高阶英汉双解学习词典释义
N-COUNT
鱼
A fish is a creature that lives in water and has a tail and fins. There are many different kinds of fish.
If you say that someone is fishingfor information or praise, you disapprove of the fact that they are trying to get it from someone in an indirect way.
If you tell someone that there are plenty more fish in the sea, you are comforting them by saying that although their relationship with someone has failed, there are many other people they can have relationships with.
PHRASAL VERB
(从…中)取出，拿出，拖出
If you fish something out from somewhere, you take or pull it out, often after searching for it for some time.
1. any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills;
"the shark is a large fish""in the livingroom there was a tank of colorful fish"
2. the flesh of fish used as food;
"in Japan most fish is eaten raw""after the scare about foot-and-mouth disease a lot of people started eating fish instead of meat""they have a chef who specializes in fish"