"If you guys bit into, say, a gummy worm, and all of a sudden got a mouth full of slime, what would you do?" he asked.
The class responded with disgusted coughs, gags and blahs, making it clear that they now understood the hagfish's defense.
As the Living Planet Aquarium prepares to triple in size with a move to a new location in Draper this December, the type of hands-on, interactive learning that had Castle Dale's 4th graders transfixed will be an important aspect of the new facility's centerpiece: the Deep Sea Gallery, which will include living examples of isopods, eel-like hagfish, spider crabs and other rare creatures.
The Castle Dale students were invited to participate in an experiment that will be featured in the new exhibit by signing their names in the exact same location on two identical styrofoam mannequin heads. One head will be taken to the ocean and submerged to a depth of 1,500 meters, where water pressure will shrink it to a fraction of its original size, while the other will be left unchanged.
The shrunken and normal heads will then be displayed alongside one another for comparison as part of a permanent fixture on ocean depth and water pressure when the new facility opens.
"The great thing about the deep sea is that not a lot of other aquariums do it, so it allows us to do something that's unique to our aquarium," Barela said. "It's an opportunity for kids to have a lot of interaction, and you can really tell a story with it."
The new exhibit will simulate a submarine voyage to the sea floor for investigation of a whale fall. Students will be able to virtually navigate their submarine around the whale and watch actual video from deep sea expeditions.
"Especially where we're not from here, we're from a rural town, this is exciting for the kids," said Castle Dale 4th grade teacher Danielle Tuttle.
The kids were particularly impressed with the creatures that had been discussed, and expressed excitement about returning later this year to see their Styrofoam heads on display.
"My favorite thing was the snake, and I want to see the sharks when I come back," said student Daxton Sorenson, referring to a snake that the students had been invited to pet during the presentation.
For others, the trip was an opportunity to get an up-close look at some rare creatures.
"I've always liked marine life and stuff like that," said student Jaxton Lake, adding that his favorite creature was the tube worm.
But kids aren't the only ones who are enthusiastic about the new facility and the Deep Sea Gallery.
"Most every adult, as a kid, was fascinated with animals and dinosaurs and squids, and a lot of adults kind of forget about that as they grow up," Barela said. "This totally reawakens that."