Mantis Shrimp

Mantis shrimp Temporal range: 400–0 Ma PreЄ Є O S D C P T J K Pg N
Odontodactylus scyllarus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Subclass:	Hoplocarida
Order:	Stomatopoda Latreille, 1817
Superfamilies and families [1]
Bathysquilloidea Bathysquillidae Indosquillidae Gonodactyloidea Alainosquillidae Hemisquillidae Gonodactylidae Odontodactylidae Protosquillidae Pseudosquillidae Takuidae Erythrosquilloidea Erythrosquillidae Lysiosquilloidea Coronididae Lysiosquillidae Nannosquillidae Tetrasquillidae Squilloidea Squillidae Eurysquilloidea Eurysquillidae Parasquilloidea Parasquillidae

The mantis shrimp, or stomatopod, is a type of marine crustacean of the orderStomatopoda. The majority of Stomaopoda species grow to around 10 centimetres (3.9 in) in length. A few can reach up to 38 cm (15 in). The largest mantis shrimp ever caught had a length of 46 cm (18 in) and was caught in the Indian River nearFort Pierce, Florida of USA. A mantis shrimp's carapace (the bony, thick shell that covers crustaceans and some other species) covers only the rear part of the head and the first four segments of the thorax. Varieties range from shades of brown to vivid colours, as there are more than 450 species of mantis shrimp. They are among the most important predators in many shallow, tropical and sub-tropical marinehabitats. However, despite being common, they are poorly understood as many species spend most of their life tucked away in burrows and holes.

Called "sea locusts" by ancient Assyrians, "prawn killers" in Australia and now sometimes referred to as "thumb splitters" – because of the animal's ability to inflict painful gashes if handled incautiously – mantis shrimps sport powerful claws that are used to attack and kill prey by spearing, stunning, or dismemberment. In captivity, some larger species are capable of breaking through aquarium glass with a single strike.

Power full punch

Mantis shrimps are mere inches long but can throw the fastest punch of any animal. They strike with the force of a rifle bullet and can shatter aquarium glass and crab shells alike. Now with the aid of super-speed cameras, we are beginning to truly appreciate how powerful this animal is

Eyes

The mantis shrimp has one of the most elaborate visual systems ever discovered.

Compared to the three types of colour receptive cones that humans possess in their eyes, the eyes of a mantis shrimp carry 16 types of colour receptive cones. It is thought that this gives the crustacean the ability to recognize colours that are unimaginable by other species.^[13]

The midband region of its eye is made up of six rows of specialised ommatidia - a cluster of photoreceptor cells. Four rows carry up to 16 different photoreceptor pigments, 12 for colour sensitivity, others for colour filtering. The vision of the mantis shrimp can perceive both polarised light and multispectral images. Their eyes (mounted on mobile stalks and capable of moving independently of each other) are similarly variably coloured and are considered to be the most complex eyes in the animal kingdom.

Each compound eye is made up of up to ten thousand side-by-side ommatidia. Each eye consists of two flattened hemispheres separated by six parallel rows of specialised ommatidia, collectively called the midband. This divides the eye into three regions. This configuration enables mantis shrimp to see objects with three parts of the same eye. In other words, each eye possesses trinocular vision and thereforedepth perception. The upper and lower hemispheres are used primarily for recognition of form and motion, like the eyes of many other crustaceans.

Rows 1–4 of the midband are specialised for colour vision, from ultra-violet to longer wavelengths. Their UV-vision can detect five different frequency bands in the deep ultraviolet. To do this they use two photoreceptors in combination with four different colour filters. They are not currently believed to be sensitive to infrared light. The optical elements in these rows have eight different classes of visual pigments and the rhabdom (area of eye that absorbs light from a single direction) is divided into three different pigmented layers (tiers), each for different wavelengths. The three tiers in rows 2 and 3 are separated by colour filters (intrarhabdomal filters) that can be divided into four distinct classes, two classes in each row. It is organised like a sandwich; a tier, a colour filter of one class, a tier again, a colour filter of another class, and then a last tier. Rows 5–6 are also segregated into different tiers, but have only one class of visual pigment (a ninth class) and are specialised for polarisation vision. They can detect different planes of polarised light. A tenth class of visual pigment is found in the upper and lower hemispheres of the eye.

The midband only covers about 5°–10° of the visual field at any given instant, but like most crustaceans, mantis shrimps have their eyes mounted on stalks. In mantis shrimps the movement of the stalked eye is unusually free, and can be driven in all possible axes of movement – up to at least 70° – by eight individual eyecup muscles divided into six functional groups. By using these muscles to scan the surroundings with the midband, they can add information about forms, shapes and landscape which cannot be detected by the upper and lower hemisphere of the eye. They can also track moving objects using large, rapid eye movements where the two eyes move independently. By combining different techniques, including movements in the same direction, the midband can cover a very wide range of the visual field.

Some species have at least 16 different photoreceptor types, which are divided into four classes (their spectral sensitivity is further tuned by colour filters in the retinas), 12 of them for colour analysis in the different wavelengths (including six which are sensitive to ultraviolet light) and four of them for analysing polarised light. By comparison, most humans have only four visual pigments, of which three are dedicated to see colour, and the human lenses block ultraviolet light. The visual information leaving the retina seems to be processed into numerous parallel data streams leading into the central nervous system, greatly reducing the analytical requirements at higher levels.

At least two species have been reported to be able to detect circularly polarised light. Some of their biological quarter-wave plates perform more uniformly over the visual spectrum than any current man-made polarizing optics, and it has been speculated that this could inspire a new type of optical media that would outperform the current generation of Blu-ray disc technology.

The species Gonodactylus smithii is the only organism known to simultaneously detect the four linear and two circular polarization components required to measure all four Stokes parameters, which yield a full description of polarization. It is thus believed to have optimal polarization vision.

                                                  Mantis Shrimp can see every thing

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