An aquatic predator that employs odd appendages and clever tactics to disarm its fishy prey
Nick Baker’s HIDDEN WORLD The popular naturalist, author and TV presenter reveals a secret realm of overlooked wildlife
TENTACLED SNAKE
Many species of snake, from the anaconda to the banded sea krait, have mastered the watery realm. Nothing particularly unusual in that. But there is one that has fascinated me since I first set eyes on it, in a tank in an American zoo.
Its name, tentacled snake (Erpeton tentaculatum) conjures up some pretty far-out images. A snake with tentacles – how weird must that be? The reason this snake seems never to have slithered into the public conscience is that both tentacles and the snake are not in fact as spectacular as they might at first sound. And that is all part of the point.
Inhabiting the weed-choked ponds, ditches and paddy fields of South-East Asia, the tentacled snake does a spectacular job of exactly resembling the plants of its watery home. It’s a skinny little thing, less than 75cm long and decorated with a sombre patterning of brown and grey, occasionally developing a living fuzz of algae to add to its crypsis. In fact, the species is so well camouflaged that I spent several minutes staring at that zoo tank before its inhabitants became apparent.
This is the snake equivalent of a praying mantis. Fully aquatic, it sits motionless amid the tangle of stems, waiting for small fish to blunder into its personal space. So trusting is this creature of its camouflage, that even plucking one out of the water isn’t enough for it to break out of character. It remains stiff and unmoving.
So, about those tentacles. These are certainly not kraken-like suckered limbs that drag unsuspecting fish to their doom, rather a pair of short-scaled projections on either side of the nose, just 13mm long on an adult. They are odd, floppy devices, and until recently they’ve had scientists perplexed. Were they lures to entice curious fish within range? Possibly. Were they further accessories to camouflage? Unlikely.
As it turns out, these appendages are a highly enervated pair of directional ‘fish finders’. And the best bit of their dastardly design is they have evolved to outwit a well-known fish predation avoidance strategy – and even use it to their advantage.
When a fish senses a troublesome movement, it deploys a reflex strategy called the ‘C-start�
