Research Highlight: Small but Mighty

Although small in stature, the mantis shrimp packs a powerful punch. The 2.5-5-centimeter (one- to two-inch-) long crustacean uses its club-like appendage to strike prey at speeds up to 50 miles per hour. Specimens have even been known to shatter aquarium glass in a single strike.

To dig deeper into this knockout punch, researchers from Scripps Institution of Oceanography at the University of California San Diego and the University of California Berkeley examined the feeding behavior of the “smasher” mantis shrimp to understand if the unique appendage evolved out of an appetite for hard-bodied prey.

Similar to the Galapagos cactus finch’s uniquely designed beak that’s used to feed on prickly pear, scientists have long thought that the mantis shrimp evolved its smasher to crush the hard-bodied shells of hermit crabs and snails, which are abundant in mantis shrimp habitats.

Scripps postdoctoral researcher Maya deVries tested the idea by studying the Caribbean coral reef flat smasher, Neogonodactylus bredini, in its natural environment–seagrass and coral rubble–along a reef flat in Colón, Panama. She then set up laboratory feeding experiments and conducted stable isotope analysis to further investigate their dietary preferences.

In both the lab and field tests, the smashers consumed a broad range of both soft- and hard-bodied prey, with a larger proportion of the diet towards soft-bodied prey such as fish, alpheid shrimps, and worms. The stable isotope analysis on the mantis and the prey species revealed similar results suggesting that they have a broader diet than was previously thought.

“Along with similar results found in other animals, from fish and bats to insects and snails, our results also suggest that highly specialized morphology may more often correspond to a generalist diet than is currently recognized,” said deVries, lead author of the study, which was recently published in the online edition of the journal Oecologia. “This result is surprising given that we so often see form and function going hand-in-hand in nature.”

The study shows that a powerful appendage, at least for the mantis shrimp, isn’t solely associated with an appetite for hard-bodied prey. The hammer-like club is in fact beneficial for both feeding and fighting off predators and competitors.

The research was funded by the American Museum of Natural History Lerner-Gray Fund, the Berkeley and National Sigma Xi Scientific Honors Society Grants-In-Aid-of-Research, the Fulbright Student Research Grant, the Society of Integrative and Comparative Biology Grants-In-Aid-of- Research, the Smithsonian Tropical Research Institute’s Short-Term Fellowship Award, the UC Berkeley Department of Integrative Biology Endowment, and the UC Museum of Paleontology Graduate Student Research Award.

­– Annie Reisewitz

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