Nature Nerd

With the world’s fastest punch, dazzling colors, incredible eyes, and unique body structure it’s no wonder these little powerhouses have been getting attention all over the internet.  From comics, to inspiring next generation body armor, and new types of cameras, they are tremendously intriguing.  

Mantis shrimp are in an order of crustaceans called stomatopods, with 17 families and over 400 species.

Weaponizers 

In general they are divided into two groups based on their method of attack, smashers and grabbers.  Mantis shrimp’s most defining feature are their raptorial appendages. Their first pair of legs are specialized predatory weapons, similar legs are found on their insectoid namesake, praying mantises, as well as a few other kinds of insects.  

Grabbers are ambush predators, lying in wait to grab a fish that comes in range. Their raptorial appendages are extremely similar to praying mantis, and superbly adapted for spearing and grabbing fish.

Smashers are more active predators that pursue their prey and use their raptorial appendages to club and smash clams and crabs.  This club, to withstand the extreme forces inflicted by smashing, has several layers of mineralized fiber to reinforce their exoskeleton.  Each layer of this is aligned and arranged at an angle to the layer below, this created a spiral structure perpendicular to the point of impact, dissipating the force.  

This structure is currently being researched to develop for use in body armor.

The raptorial appendage’s speed is way faster than is possible by muscle movement alone, so how do they achieve such power? They store potential energy with a system of pivots, springs and trigger latches.  They work on the same principle as a crossbow, build up potential energy in something by applying force to it, hold it there with a latch, and use a trigger to release it.  The structure that they use for this isn’t found anywhere else in the biological world, it is called a hyperbolic paraboloid spring, a saddle shaped mechanism. 

When the trigger is released, along with the potential energy, the dactyl can accelerate to 50 mph in only 3 thousandths of a second, as quickly as a .22 caliber bullet, and that’s with the added resistance of being underwater!  To put this in perspective, the average time it takes you to blink is 3 tenths of a second, the mantis shrimp’s punch is one hundred times faster than that, and it imparts forces thousands of times more than it’s own body weight.  

You might think the devastation would be over by now, you’d be wrong.  The club moves so fast that it can create a cavitation bubble, this is caused by the speed of the dactyl altering the pressure in the water creating an extremely low pressure area which makes the water vaporize, literally boiling the water.  However, due to the relatively high pressure of the surrounding water the bubble collapses back onto itself creating a shockwave.  This shockwave has a fraction, yet still significant amount, of the force of the actual impact.  

Extreme Eyes

Mantis shrimp eyes are so different from ours that it’s hard to even comprehend.

Dogs and a lot of other animals have 2 types of color receptor cells called cones, this is called dichromacy.  Most humans have 3 types of cones trichromacy, allowing us to see wavelengths from 400-too nanometers, this is what we call the visible spectrum, about a million colors.  There are many animals with 4 cones, most insects reptiles and birds, tetrachromacy, and even some that have 5 including pigeons and some butterflies, pentachromacy.  The mantis shrimp however blows these all away.  They have a mind boggling 16 types of cone cells.

They can also see polarized light using a specialized band across their eyes.  And if that wasn’t enough, each eye has 3 focal points which gives them unparalleled depth perception and what I’m going to call hexanocular vision.

any animal with an exceptionally unique and interesting feature is something to be amazed by, but the mantis shrimp truly is like an alien on earth, absolutely fascinating.  

Check out some mantis shrimp in action. And if you like these kinds of videos check out other videos by both of these channels.  

Maratus jactatus Jurgen Otto / Via Flickr: 59431731@N05

First some set up:

The Maratus genus is within the family of jumping spiders, which with over 5000 described species is the largest family of spiders, even including a species in Central America that is mainly herbivorous.  Thats right, there is a species of spider that mostly eats what are called Beltian bodies, which are nubs that form on acacia leafs as a product of a symbiotic relationship between the plant and ants.  So not only is this species a herbivore, which is named after the panther in the Jungle Book and its author, Bagheera kiplingi, it's also a thief.

Their name gives away their hunting strategy.  Unlike most spiders people are familiar with, and the iconic webs they create (which are incredible in their own right, I'll have to post about those also), jumping spiders are ambush or assault predators.  They use their excellent vision, some of the best in the arachnid world, and 4 pairs of eyes to keep track of everything around them.  The main front facing set is actually internally movable to track their prey with binocular vision, while the other sets are stationary and give a 360 degree view of their surroundings.  

In this photo you can see a jumping spider which has attacked, overpowered and envenomated a grasshopper nymph, all while being anchored by a line of silk which it will use to haul itself back to a perch and begin the process of consuming its prey. 

© 2010 Jeevan Jose, Kerala, India

On now to the main character

Peacock spiders, the Maratus, genus are noteworthy for the spectacular coloration and courtship dances of the males.  Jurgen Otto, the prominent entomologist who has studied and described many of the Maratus species, has an utterly incredible Flickr album, 

showing the diverse range of stunning colors. What makes this little guys even more impressive is just how little they really are.  Most are only around 5mm, a dance line could fit comfortably on one of the knuckles of one of my fingers. And what an incredible dance line it would be.  Check out this video of one of the most recently discovered species Maratus jactatus, with the amazing nickname sparkle muffin! This species is found in Queensland Australia.  

Like a lot of animals, the males are the more eye catching of the sexes, so as to win favor of discerning females.  Peacock spiders have a few features in addition to their brilliant colors to aid in this.  Their third paris of legs are elongated and used prominently in their dance, they also inflate their body to increase the area of color, and they elongate their spinnerets to add a flair to their flamboyance.  It is this raising and expansion of their opisthosoma and its resemblance to their avian namesake gives them their common name.

Does this change your perception of spiders?  Does it make you curious to know other things about spiders, or anything else? What other animals do you want to know more about?