(Animalia)+Mantis+Shrimp

=Mantis Shrimp, //Squilla empusa//=


 * Kingdom || Animalia ||
 * Phylum || Arthropoda ||
 * Class || Malacostraca ||
 * Order || Stomatopoda ||
 * Family || Squillidae ||
 * Genus || Squilla ||
 * Species || //Squilla empusa// ||

Phylum: Arthropoda
The phylum Arthropoda is the largest phylum of Kingdom Animalia; the number of species belonging to the phylum is greater than all of the other phyla of Animalia combined, and the number of species yet to be described are thought to be in the tens of millions. The phylum includes insects, crustaceans, arachnids, and centipedes. The signature feature of the species of Arthropoda are the strongly segmented bodies; bilateral symmetry (meaning they are symmetrical, e.g. like humans), a body covered by an exoskeleton made of chitin (a polysaccharide) with multiple other proteins, lipids, and calcium carbonate; lacking cilia; and an open circulatory system in which their bodily fluids directly feed organs with oxygen and nutrients.

Common features include fusion of segments in a process called tagmosis that forms body regions called tagmata, such as the head, thorax, and abdomen (though not all arthropods have these three divisions). Arthropods usually grow through molting (process called ecdysis), lay eggs, and usually possess a pair of compound eyes, or at least 1 simple ocelli (a type of eye that looks like a small black orb, usually).

//Squilla Empusa//
The //Squilla empusa//, a species covered by the umbrella-common name of "mantis shrimp," looks like a cross between a large shrimp or lobster and a preying mantis, that lives in the dark, muddy bottoms of the lower inter-tidal zone of the Chesapeake Bay, down to 500 feet deep. It can also be found anywhere between Cape Cod to the Gulf of Mexico, and the coast of Brazil to the Mediterranean Sea. The species is very hardy, being resistant to medium to high salinity waters.

The //S. empusa// make their homes in burrows in the mud, and the burrows have many openings that are 0.6 to 1 metre apart. They are nocturnal predators that eat soft-bodied marine animals. They hunt using their two distinct, forward claws that "spear" their prey, and after doing so, they return to their burrows to feast in safety. They grow to be up to 30cm long.

Morphological and Physiological Features
//S. empusa// have two extremely distinct features. The first is their two forward claws. Mantis shrimp on a whole are known for their forward appendages, that can be either heavy, calcified claws or like large jackknives that unfold, with a number of spines along the claw (called smashers and spearers respectively). The //S. empusa// mantis shrimp belongs to the latter group, possessing two claws with around 6 spines each. The //S. empusa// uses its claws to snap at and impale its prey - indeed, the spearing motion of mantis shrimp in general are one of the fastest movements known in the animal kingdom. The claws possess a velocity of up to 10m/s when striking, and the motion can take less than 8ms to execute - mantis shrimp have been called "thumb splitters" by sailors because of their astonishing ability to strike to quickly and violently. There have also been reports of "smasher" type mantis shrimp cracking glass with its strikes.

The second distinct feature of the //S. empusa// is their vision - Stomatopods in general are known to have some of the most well-developed optical systems, being capable of seeing over 100000 colours thanks to their 16 different types of photoreceptors (12 for colour, 4 for UV light). However, //S. empusa// are a bit unique in that they are a bit more "primitive" in a way - it cannot see colour light, and can only see polarized light. However, its eyes have adapted to its dark and muddy habitat perfectly fine; in such conditions, little light hits the muddy bed, and colour is not necessary. Instead, the //S. empusa//'s ability to see deep into the ultraviolent spectrum is extremely helpful in locating prey. This, combined with the mantis shrimp's 3 overlapping fields of vision (trinocular vision), makes the //S. empusa// a highly effective predator in its habitat.