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!
Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel
The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Materials Sciences
05.12.2016 | Power and Electrical Engineering