''When Nudibranches Go Wild" could be the tabloid-TV subtitle to the new
Forty minutes in length and requiring viewers to wear the requisite party joke-size polarized glasses, the film is the latest amazing journey in jumbotronic entertainment. When that 65-by-85-foot image wraps around your head and the 100-pound black grouper leaps out of the screen for his dinner, do try not to dive behind your seat.
''Deep Sea 3D" travels around the world via the oceans' floors to show us symbiosis at work in a variety of ecosystems. The relationship between predator and prey constantly shifts depending on the players: Barracuda play nice while smaller fish eat the algae off their backs at ''cleaning stations," only to hunt them down for food later. Sea urchins threaten to overwhelm kelp beds but are kept under control by the wolf eel, which eats them spines and all.
As portrayed here, nature is red in fin and tentacle, and the film plays up that eternal tussle for maximum cinema. When a giant Pacific octopus stalks and pounces on a crab (gracefully ejecting the hard bits after it's done chewing), Danny Elfman's music evokes ''Jaws"-style suspense. A triton snail preys on a starfish in an oddly creepy slow-motion chase scene; a sun star moves over a bed of oysters like the Blob itself (they squeak and skitter out of the way). A basket star extends its skittery arms in an image that could come out of one of Tim Burton's stop-motion nightmares.
It wasn't until Humboldt squids made the toddler at the end of my row start shrieking in terror that it became clear that ''Deep Sea 3D" is probably not for the youngest audiences. (Memo to parents: If your own kids start doing this, it means they are scared. It means take them out.) The film has been made more with children 6 and older in mind, with narration provided by topside stars Johnny Depp and Kate Winslet that's cute but rather less three-dimensional than what we're seeing.
''Deep Sea 3D," which can also be seen on IMAX screens at Jordan's Furniture in Natick and Reading, sounds a note of alarm toward the end, when it informs us that 90 percent of big fish have disappeared from the ocean in the past 50 years. ''We are taking more than the ocean can give," Depp warns us, but the film then shows us how every year, eight nights after the full moon in August, reefs around the planet release eggs.
Part of the fun of 3-D IMAX is allowing one's eyes to shift back and forth between different planes of focus, but as the coral roe fill the screen like millions of tiny balloons taking flight, viewers may find their senses delightfully overloaded. It's a marvelous image, and perhaps an overly reassuring one.
Ty Burr can be reached at firstname.lastname@example.org.