"Catfish" has the same meaning and pronunciation as "鲶", and the Cantonese pinyin is "nim4", which has the same vowel and rhyme scheme as the English word "nim". The Cantonese pinyin is "nim4", which rhymes with the English word "nim", and the tones are so different from Mandarin that it's hard to tell.

If you know how to read Cantonese pinyin for commonly used words, you can draw an analogy between "nim6" and "sweettim4", which have the same vowel and rhyme scheme as "nim" and the same tone as "sweet".

The Cantonese pinyin for "fish" is "jyu4", which is pronounced as "yu" in Cantonese and has the same vowel and rhyme as the Mandarin pronunciation of "fish".