Another story about the origin of the name "Koottunkal" is a bit funny. I had heard this story in my childhood as a teaser against Koottunkal Family members ("Koottunkans").
Once upon a time,there was a clever man (an ancestor of Koottunkal) lived near the western branch of Vembanadu lake. He was hard working and mainly depended on farming and fishing for a living. Every morning, he would go for fishing at the nearby Vembanadu lake, where fishes and clams were in abundance. He had developed an ingenious way of fishing. His fishing device consisted of a reed basket ("Kutta" in Malayalam) and some pebbles ("Kallu"). He would dip the "Kutta" (reed basket) tied to a rope, to the bottom of the lake and drop the "Kallu" (pebbles) into the "Kutta" intermittently. The noise from the droppings would invite a lot of fishes in search of food into the basket.
Whenever my ancestor dropped a stone to the immersed basket, the fishes that passed by would visit the basket to enquire it and stay there expectantly. Once the assemblage in the basket is found to be sufficient, he would lift the basket with the bounty of fishes in it. So, the name "Koottunkal" was derived from my ancestor's fishing tools - the "Kotta" and "Kallu" -> Kottem Kallum -> Koottunkal