The lunge-feeding technique of whales requires engulfing a volume of prey-laden water as large as their own body, while swimming at high speeds, to allow for the capture of small fish and krill in their baleen.
However, lunge-feeding baleen whales must also breath in the process – how do whales manage not to choke?
A recent study by Gil et al. dissected deceased fin whales and discovered an anatomical structure that seems to be making the lunge-feeding and no choking process possible. Coined “oral plug” in the study, this large musculo-fatty structure passively seals the oropharyngeal channel and is not observed in other animals.
This “oral plug” is a part of the soft palate and can only shift posteriorly and dorsally. Its position indicates that its movement, shift, allows swallowing thanks to the following steps:
- Elevation of the oral plug allows food transfer to the pharynx and protects the upper airways from food entry.
- The laryngeal inlet in the floor of the pharynx is sealed by laryngeal cartilages, and the muscular laryngeal sac moves upward into the laryngeal cavity, completely occluding the airway.
- The pharynx is dedicated to the digestive tract during swallowing, with no connection between upper and lower airways.