There’s a touch tank sequence in the Pixar movie “Finding Dory,” which opens nationwide this weekend and it’s the oceanographic equivalent of Hell.
Marauding 5-year-olds are the demons: Fingers pink and stubby as uncooked sausages thrust into the shallow water, groping for sea creatures that writhe and scream as they flee. Little hands come down like piledrivers to terrorize the octopus and blue tang who have wrongly ended up in this sandy torture pit.
So we went to Discovery Place to get the straight dope, both to learn about touch tank etiquette and to reassure children who are afraid they’re terrorizing invertebrates.
Riana Clark, lab coordinator at Discovery Place for the Explore More Collection, oversees the touch tank and can explain the difference between a portly spider crab and a spider decorator crab. She can also lay out three key rules for proper touch-tanking:
1) “Don’t pick them up at all. Even if you picked one up at the beach, don’t do it here. A starfish has feet like suction cups. So if it’s attached to a surface, and you suddenly pull him loose, it’s like breaking his foot.”
2) “These animals don’t have brains like ours, except for crabs.” (Discovery Place doesn’t keep fish in that tank, let alone octopi.) “But they have a network of nerves, and they do feel. So we ask you to use two fingers, not a whole hand, and touch them gently.”
3) “Wash your hands first, so the oils on your skin don’t come off in the water. We monitor the water daily, so we know it’s clean.”
The unspoken rule number four – don’t hog the tank – goes without saying, especially as you can watch what’s happening on an underwater camera or through the glass sides of the aquarium.
So how do we know whether an animal’s overstressed?
Cuvierian tubules are one tipoff. Wikipedia defines those “as clusters of fine tubes located at the base of the respiratory tree in some sea cucumbers...that can be discharged through the anus when the sea cucumber is stressed.” (Those then become adhesive, tangling predators.)
Clark looks for animals that hide in corners or burrow beneath the underwater camera, then removes those to rest them. The museum has multiple members of each species in the tank, all recognizable by markings, so no starfish or sea urchin gets displayed more than once a week.
Sometimes the museum varies the routine by bringing in non-stinging jellyfish for visitors to touch, if they dare. “People really respect the rules then,” she says. “Nobody’s picking one of those up.”