Predators and Prey (Discovery Channel)
This film was shown on the Discovery Channel very recently (October 1998). It featured a great scene showing an Odontodactyllus specimen hunting and killing a crab. The narrator starts by talking about the evolution of "arms" versus "armor" in nature. For example, how the blue crab's pincers have continued to keep apace with the evolution of harder mussel shells.
The narrator them notes that the same thing happened to mantis shrimps ---- but in this case, the "arms" are the evolution of stronger "hammers" by the shrimplike animals (the show errs in describing them as shrimps). The film begins by showing a front profile of a resting mantis, then a shot of a crab about 1/3 to 1/2 the size of the Odontodactyllus. The mantis stalks the crab, which raises its pincers in a last hopeless gesture of defiance. The mantis then proceeds to hammer repeatedly at the helpless animal, which soon turns over with upraised stiff appendages, whereupon it is dragged into the mantis' lair to be leisurely consumed.
The attack tactics of the mantis contrasted sharply with those used earlier in the show by a cuttlefish against another crab. In the latter case, the cephalopod could not go directly against the strong pincers of its prey, but had to lurk all over the place before finally managing to descend and envelop the crab from the rear. The mantis, on the other hand, simply smashed the sides of the crab and sort of ignored the upraised pincers --- to be honest about it, the thing moved FAST, and struck so quickly that the crab had no chance but to try to make a run for it.
Web Site Author: A. San Juan
Site Created February 3, 1998