Freaky-Looking Giant Sea Louse Surfaces from the Deep, Astounds Everybody Except Scientist

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If you’re a true aficionado of daikaiju—Japanese for “giant sea monster cinema”—you probably remember the memorable scene from the otherwise unremarkable Godzilla 1985, in which the protagonist, intrepid investigative reporter Goro Maki (portrayed by Ken Tanaka) battles in a death match against a giant sea louse. Or maybe you don’t, since the segment was trimmed considerably in the U.S. version. Apparently, the filmmakers made a judgment call that Americans, who took years to get used to the idea of eating raw fish, weren’t quite ready for Bathynomus giganteus, an actual plus-size deep-sea crustacean that is a distant cousin of the smaller and considerably less gross terrestrial woodlouse.

You can only imagine, then, the epic gross-out experienced by oil rig workers in the Gulf of Mexico when one of these creepy deep-sea critters hitched a ride to the surface on a robotic submarine that was doing a survey of the ocean bottom. The story quickly became a minor Internet sensation, in part because an employee of the company that owns the robot posted the photo above of the creature on, and this closeup head shot as well (which, BTW, undoubtedly would make a fabulous profile pick for your Facebook profile, hint hint.) But while B. giganeus’s appearance is a bit disconcerting, the seven-legged, four-jawed creature, which is common in the Gulf, actually is no danger at all to Japanese investigative reporters, or other humans for that matter, since it’s a scavenger that dines on fragments of various dead sea creatures. Yum yum.

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One reason for the hysteria: Both the original Reddit posting and This UK Daily Mail article describe the “giant woodlouse” as a strapping two-and-a-half feet long. But environmental biologist Craig McClain, assistant director of science for the National Evolutionary Synthesis Center in North Carolina, expresses some skepticism about that measurement—and the generally hyperbolic media coverage of the find– in this delightfully snarky post in Deep Sea News. McClain notes that the largest specimen documented in scientific literature is 1.6 feet in length, which would make the recently captured B. giganeus “the mother of all giant Isopods.”

Of course I also have a problem with people referring to this beloved creature as a terrifying sea beast, terrifying sea creature, a sea roach or cockaroach (a comparison even worse comparing it to a crab), and monster or prehistoric creature that led one person to say ““KILL IT!  KILL IT WITH FIRE!  OH GOD OH GOD GET IT AWAY!”  Giant Isopods are magnificent creatures nothing short of an spectacular evolutionary trajectory.

B. giganeus, however, is an example of a intriguing phenomenon called deep-sea gigantism, in which some creatures from the depths tend to be larger than their shallow-water counterparts. In his blog post, McClain explains that this evolutionary adaptation may enable deep sea creatures to cope with the relative scarcity of grub in their environment.

Alternatively, the larger size also increases fasting potential because greater fat reserves can be maintained. Larger size also confers a greater foraging area, important for either a scavenger or a predator.  Both of these are important adaptations in the food-limited deep sea.

In their 2009 textbook Introduction to the Biology of Marine Life, John F. Morrissey and James L. Sumich offer an alternative explanation, that gigantism may also be related somehow to the effects of extreme pressure at great depths upon cells and metabolic rates.

BTW, if you’re still pondering Godzilla movies, you may be interested in this fascinating article, “The Biology of B-Movie Monsters,” by University of Chicago organismal biology and anatomy professor Michael C. LaBarbera.


  1. ngcbrad
    April 7, 2010, 12:11 am

    nightmares are coming for me tonight