In September, Kieran spotted a water scorpion, Ranatra brevicollis, in Alameda Creek in Sunol. We brought it home and it lived for seven months in our fishbowl “pond.” These curious creatures are like an underwater praying mantis — they have evolved very similar raptorial front legs for grasping prey. Ours kept well fed on tiny scuds swimming about in the tank. Though it’s common name is “water scorpion,” this insect cannot sting you. It gets its name from the long breathing tube extending from the tip of its abdomen. This snorkel allows it to breathe while dangling beneath the water, waiting for a meal. After it finally died this month, we plucked it out of the tank for a closer look.
I sketched the aquatic insect after we first found it.
The sharp beak it uses to pierce the exoskeleton of its prey is visible here.
Like a praying mantis, the water scorpion has evolved raptorial arms.
The breathing “tube” is two long filaments with bristles on them.
Steven E. F. Brown 