Love the anagram idea... but why is one plural and all the others singular?

Liked anagram idea, but all are animals. Should have been mammals for the first one

A puzzle made entirely of anagrams is really difficult. On the animal group there is a mixture of singular and plural. On the fish group “angler” is not a fish, I suspect you mean anglerfish. Oh and spiders aren’t insects.
Applaud your effort in making such a tough grid but it’s too tough!

I'd agree - make it Loin rather than Loins

Critique taken on board and amended where possible, however one can always move on to another grid if you're finding it too tough!