とか and など in same sentence

Question

This sentence includes both とか and など.

金魚の食べ物は虫とか水草などです。

Is there a difference in meaning between the two? Is there a reason to use both like this?

Answer 1

「AとかBなど」+ です・だ・が・を・に etc.
("A and/or B, etc.", "things like A and B")

Both of とか and など are used to give examples. とか is more colloquial/conversational than など.

You can also use:

「AやBなど」+ です・だ・が・を・に etc.
「AとかBとか」+ です・だ・が・を・に etc. ← casual
「AやB」+ です・だ・が・を・に etc.
「AとかB」+ です・だ・が・を・に etc. ← casual

But not

×「AやBや」+ です・だ・が・を・に etc.
×「AなどBなど」+ です・だ・が・を・に etc.
×「AなどB」+ です・だ・が・を・に etc.