List: word usually written using kana alone

irregular okurigana  usually written using kana alone  noun  noun (generic) 

• pea crab (any crab of the family Pinnotheridae)

usually written using kana alone  noun  noun (generic) 

• rove beetle

usually written using kana alone  noun  noun (generic) 

• biting louse (any louse of order Mallophaga), chewing louse

usually written using kana alone  noun  noun (generic) 

• sea hare (esp. species Aplysia kurodai)

rarely used kanji form  usually written using kana alone  noun  noun (generic) 

• Drosophila melanogaster (species of fruit fly)

rarely used kanji form  usually written using kana alone  noun  noun (generic) 

• lovebird (esp. Lilian's lovebird, Agapornis lilianae)

usually written using kana alone  noun  noun (generic) 

• hardy amaryllis (Lycoris squamigera), resurrection lily, surprise lily, magic lily

usually written using kana alone  noun  noun (generic) 

• river dolphin

rarely used kanji form  usually written using kana alone  noun  noun (generic) 

• rock dove (Columba livia), rock pigeon

usually written using kana alone  noun  noun (generic) 

• garden tiger moth (Arctia caja)