The word rabbitfishes is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 23
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (47 words)
airiest, ashiest, babiest, baiters, barbies, barites, bashers, basters, batfish, bathers, bearish, bitsier, braises, breasts, breaths, fairest, fairies, fathers, fibbers, fibrate, fibrise, fibster, fiestas, fishers, fishier, hafters, hastier, herbist, hissier, irisate, rabbets, rabbits, rashest, ratfish, rebaits, rebaths, reshift, resifts, satires, sherifs, shifter, shrifts, sifters, stabber, strifes, tabbies, trashes