How many letters does the top answer for “any of numerous small tropical fishes having body and head encased in bony plates” have?

The most common answer is boxfish (7 letters).

Crossword clue: any of numerous small tropical fishes having body and head encased in bony plates

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

boxfish 7 letters wn-def

any of numerous small tropical fishes having body and head encased in bony plates

trunkfish 9 letters wn-def

any of numerous small tropical fishes having body and head encased in bony plates