He used banana slugs as a teaching organism because they were easy to collect & biologically interesting! They have a single #lung which opens externally via a #pneumostome which allows #gasexchange. Their slime helps them stay hydrated, in reproduction & predator defense!

#Bananaslugs have a single #lung which opens externally via a #pneumostome. The pneumostome is heavily vascularized to allow #gasexchange. To stay hydrated, it excretes a slime around their bodies & can #aestivate. Slime also contains pheromones to attract other slugs for mating.