The Peacock Mantis Shrimp (Odontodactylus scyllarus) is one of a variety of mantis shrimp species.
They are found throughout the Indo-Pacific Ocean north of Australia from Guam
to Eastern Africa, inhabiting waters between 3 - 40m deep, although have a preferential
depth of 10 - 40m, and at temperatures ranging from 22 - 28oC. The
Peacock Mantis Shrimp is known to create ‘U’ shaped burrows on the bases of
coral reefs on sandy or gravelly substrates (Animal Diversity Web 2013).
The Peacock Mantis Shrimp, along with all other
species of mantis shrimp, have a greatly enlarged second thoracic raptorial appendage
that they use to smash or spear prey, construct and excavate burrows, defend
themselves from predators and fight other individuals (Caldwell 1975). In order
to generate the power for the extreme acceleration of their raptorial
appendages mantis shrimp use a power amplification mechanism consisting of
elastic springs, latches and lever arms. During muscle contractions a click
mechanism holds the limb in place and a specialized
spring stores and releases elastic energy. These specialized mechanisms allow
the Peacock Mantis Shrimp to deliver strikes lasting just a few milliseconds
with an acceleration rate of over 105 m s-2 and at speeds
of over 20m/s (Patek & Caldwell 2005).
The extreme strike speed of the Peacock Mantis
Shrimp has the additional benefit of causing cavitation at the site of impact
between the mantis shrimp and its prey. Cavitation bubbles form in fluids under
low pressure and when these cavitation bubbles collapse, considerable energy is
released in the form of heat, luminescence and sound. The shock waves generated
during the collapse put immense pressure and stress on adjacent surfaces,
ultimately leading to their failure (Brennen 1995). This production of
cavitation bubbles as the mantis shrimp strikes in prey allows its attack to
become two fold; where the first strike is caused by limb impact and the
second, approximately 0.5ms later, is caused by the collapse of the cavitation
bubble (Patek & Caldwell 2005). This combination of forces allows the
mantis shrimp to easily “smash” the shells of the mollusks that they feed on.
References
Brennen. C., 1995, Cavitation and bubble dynamics, New York, Oxford University
Press
Caldwell. R., 1975, Ecology and evolution of
agonistic behavior in stomatopods,
Naturwissenschaften, vol. 62, pp. 214 - 222
Cameron Azad, Peacock Mantis Shrimp, flickr, viewed 29
May 2014
<https://www.flickr.com/search/?q=peacock+mantis+shrimp>
Chiu. F., 2013, Odontodactylus scyllarus, Animal Diversity Web,
viewed 29 May
2014
<http://animaldiversity.ummz.umich.edu/accounts//>
Encyclopedia of Life, 2013,
viewed 29 May 2014
<http://eol.org/pages/2869734/hierarchy_entries/50287908/overview>
Kirsty Faulkner, Peacock
Mantis Shrimp, flickr, viewed 29 May 2014
<https://www.flickr.com/search/?q=peacock+mantis+shrimp>
Patek. S., & Caldwell. R., 2005, Extreme impact
and cavitation forces of a biological
hammer:
strike forces of the peackon mantis shrimp Odontodactylus
scyllarus, The Journal of Experimental Biology, vol. 208, pp. 3655 – 3664
Zefrank, 2013, True
facts about the Mantis Shrimp, Youtube, viewed 29 May 2014 <
https://www.youtube.com/watch?v=F5FEj9U-CJM>
A very interesting and “smashing” way to end your blogging! It’s been fascinating to read all about how animals do “get a step ahead”. Thanks for giving us all a unique insight into the amazing variety of adaptations our animal friends have to offer.
ReplyDelete