おはよう!

I think this is accurate. No need correction. but if you want to speak naturally,

今日は私の庭の池にひめはやを追加します。or just 入れます。(いれます）

私はそれらを捕獲しました.　

I think it means you caught them. If you add more information, the sentence would be understandable. For example. "I caught them in the river yesterday."     昨日、私はそれらを川で捕まえました。

捕獲しました. is accurate as well of course. but probably it is used in News often.  you can just say つかまえました。

つかまえる　catch ( dictonary form)

つかまえた　caught( past )

つかまえました　caught ( polite form)

I hope this helps. Thank you for reading.