A hungry mantis shrimp may be the last thing that a passing fish sees before it is snatched from the water by the predator. Maya deVries from the University of California, Berkeley, says 'Spearer mantis shrimps stay in their sandy burrows and they wait for a fast-moving prey item to come by, but then they come out of nowhere and grab the prey with their long skinny appendages.'
However, little was know about how these vicious predators unleash their lightning-fast attacks. According to deVries, the spearing shrimp are closely related to smasher mantis shrimps, which pulverise the shells of crustaceans and molluscs with a single explosive blow from their mighty claws. Having decided to find out how the crustaceans unleash their deadly assaults, deVries says, 'We thought that the spearers would be just as fast – if not faster – than the smashers because they have a smaller time window in which to capture their prey.' deVries and her colleagues publish their discovery that Lysiosquillina maculata spearer mantis shrimps power their mighty spears with muscle alone while smaller Alachosquilla vicina spearer mantis shrimps use a more conventional catapult mechanism in The Journal of Experimental Biology at http://jeb.biologists.org.
Working with her PhD advisor, Sheila Patek, deVries took a short trip along the corridor to Roy Caldwell's lab to film some of his L. maculata mantis shrimps. Coaxing the nocturnal lobster-sized crustaceans to assault frozen prawns, deVries recalls that the animals were reluctant to attack; 'They probably didn't like the bright lights', she says. However, when the duo analysed the speed of the strikes, they were surprised that the spearer's harpoon speed was much slower than that of their smashing cousin's. Explaining that smashers can unleash strikes at speeds ranging from 10 to 23m/s, the duo were taken aback that L. maculata could only muster 2 m/s.
Smasher mantis shrimp store catapult energy in skeletal springs that they unleash during a deadly assault; therefore deVries analysed the trajectories of several L. maculata claws in action, and realised that the hefty crustaceans were not using the same mechanism. 'The spear has all the same components [as the smashers]', explains deVries, but she adds that the shape of some of the structures are subtly different and the spring did not deform to store energy prior to an attack – possibly because it is too stiff – preventing L. maculata from firing a ballistic attack. 'If the L. maculata movement is similar to other ambush predators that have muscle-driven strikes, it is possible that these guys are creating strikes with muscle movement', says deVries.
Next, deVries and Patek tested the reactions of another, smaller mantis shrimp, Alachosquilla vicina, to find out whether all spearing mantis shrimps have opted for muscle-powered strikes. Elizabeth Murphy filmed the animals snapping up brine shrimp however, it was obvious that the diminutive crustaceans were using a spring-loaded catapult to spear their nimble prey. The team could clearly see energy-storing deformations in the spring structure before the mantis shrimp unfurled their deadly assaults at 6m/s.
But the team were still puzzled by L. maculata's sluggish performance. Maybe the lab-based animals had become too unfit to produce explosive attacks? Traveling to Australia to film L. maculata hunting in the wild, the team were relieved to see that the animals' reactions were well within the range of speeds that they had measured in the lab. Adult L. maculata use muscle-powered attacks all the time.
Having confirmed that it is possible for the large shrimp to produce lightening-fast strikes without using a spring mechanism, deVries says 'We're trying to get more L. maculata in the lab to look at the complete size range in one species to see how the strike scales and to find out if there is a size threshold above which you can't have a spring-loaded strike anymore.'
IF REPORTING ON THIS STORY, PLEASE MENTION THE JOURNAL OF EXPERIMENTAL BIOLOGY AS THE SOURCE AND, IF REPORTING ONLINE, PLEASE CARRY A LINK TO: http://jeb.biologists.org/content/215/24/4374.abstract
REFERENCE: deVries, M. S., Murphy, E. A. K. and Patek, S. N. (2012). Strike mechanics of an ambush predator: the spearing mantis shrimp. J. Exp. Biol. 215, 4374-4384.
This article is posted on this site to give advance access to other authorised media who may wish to report on this story. Full attribution is required, and if reporting online a link to jeb.biologists.com is also required. The story posted here is COPYRIGHTED. Therefore advance permission is required before any and every reproduction of each article in full. PLEASE CONTACT firstname.lastname@example.org
Kathryn Knight | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences