Filter Feeding System in Whales’ Mouths
Puzzle 4 of Deep Sea Journey Hard Pack
Question is: Filter Feeding System in Whales’ Mouths
and the answer is: BALEEN
Word Meaning:
BALEEN — (physiology, uncountable) keratinous material that makes up the plates in the mouth of the baleen whale (Mysticeti), which it uses to trap its food; formerly used in corsetry.
Definitions from Wiktionary.