鱼的象征意义据说源于中国传统文化的英语是： It is said that the symbolic meaning of fish derived from traditional Chinese culture.
解析： “据说”翻译为 It is said that …，内容处理为“that”引导的主语从句，“源于”翻译为derive from。此处介绍鱼象征意义的历史，所以时态不再使用一般现在时，而是使用一般过去时。“中国传统文化”翻译为traditional Chinese culture。
其他相关解析
1、鱼是春节前夕餐桌上不可或缺的一道菜，因为汉语中的“鱼”字的发音与“余”字发音相同。
译文： Fish is an indispensable dish for the dinner table on the Spring Festival Eve, because the pronunciation of “fish” is the same as that of “surplus” in Chinese.
解析：本句主干为“鱼是不可或缺的一道菜，因为……”，主句为Fish is an indispensable dish，后面的因为处理为because引导的原因状语从句。而“春节前夕餐桌上的”则修饰“一道菜”，处理成介词词组for the dinner table on the Spring Festival Eve作后置定语。“鱼”和“余”则按照中文原因打双引号。
2、正由于这个象征性的意义，春节期间鱼也作为礼物送给亲戚朋友。
译文： It is because of this symbolic meaning that fish is also given as a gift for relatives and friends during the Spring Festival period.
解析：“正由于…”是对原因部分的强调，所以原文处理为“it is + 强调部分 + that + 句子剩余部分”的强调句，“象征性的意义”译作symbolic meaning。
3、中国人有节省的传统，他们认为节省得愈多，就感到愈为安全。
译文：Chinese people have the tradition of thrift, believing that the more they save, the safer they feel.
解析：本句的主干为“中国人有节省的传统”，翻译为Chinese people have the tradition, “节省的”译作of thrift跟在tradition后面补充tradition的内容。
由于英语习惯为一个主句一个谓语，且后半句的“他们”指前文的“中国人”，所以此处处理为现在分词作状语，believing that …“愈…，就愈…”处理为“the + 比较级 + 句子， the + 比较级 +句子”，即 the more they save, the safer they feel。
4、今天，尽管人们愈来愈富裕了，但他们仍然认为节省是一种值得弘扬的美德。
译文： Today, though people are getting increasingly richer, they still consider thrift as a virtue which deserves to be promoted.
解析：“尽管……”处理为though引导的条件状语从句，因为英语中关联词仅出现一次，所以后面的“但”不需要再翻译为英语中的but。文中“值得弘扬的”处理为定语从句跟在virtue后面对其进行修饰，译作which deserve to be promoted.