Decapoda
From CreationWiki, the encyclopedia of creation science
| Decapod |
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| Scientific Classification |
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| Infraorders |
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Suborder: Dendrobranchiata (Prawns) Suborder: Pleocyemata
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Decapoda is an order of diverse crustaceans, which includes shrimp, lobster, crab, and crayfish. They have 5 pairs of legs as suggested by their name Decapod which means "ten legged". Most decopods lives in the sea, but some are found living on the land. Although the body shapes are quite different, they all share the similarity of having 5 legs on each side. In case of crab and lobster, they have claws, but shrimps do not. They have 5 pairs of legs, but their claws are degenerated.
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Anatomy
The decapoda body is composed of a series of hard segments called somites that are joined together by a flexible joint. Decapoda has two sets of jaws and some appendages near the mouth. The limbs starts with a pair of developed arms and claws. Behind these, there are 4 pairs of walking legs and claws.
Ex)Shrimp's 20 body parts:
1.Antennule - small antenna
2.Rostrum - pect
3.Brain - the organ inside their head that controls your body's activities
4.Bladder - the part of their body where urine is stored until it leaves your body
5.Stomach - the organ inside their body where food is digested before it moves into the intestines
6.Testis - The part that produce sperm
7.Heart - the organ in their chest that pumps the blood around your body
8.Intestine - the part that body through which food passes
9.Abdominal Muscle - The muscle which is for the chest
10.Anus - the hole from which faeces leaves their body
11.Telson - A part of tail
12.Tail Fan - A part for swimming
13.Uropod -A part of muscle
14.Swimming legs - legs for swimming; shrimp has 3 pairs of swimming legs
15.Carapace - the protective shell on the back of some animals such as tortoises or crabs.
16.Walking legs - legs for walking; shrimp has 2 pairs of walking legs.
17.claw - the two pointed parts at the end of its legs which are used for holding
18.Mouthpart - joint for the mouth
19.Antenna - the two long, thin parts attached to its head that it uses to feel things with
20.Eye - parts of body with which they see
Eye
The unique design of the decapod eye has been intensely studied to help understand how it allows some organisms to see in low light and murky waters. Rather than bending (refracting) the light to focus the image on the retina, several of the long-bodied decapod crustaceans (shrimps, prawns, crayfish and lobsters) possess “reflecting” compound eyes.[2] Unlike the more common compound eyes of insects, which have hexagonal facets, this unique eye design incorporates square facets that are arranged radially forming an optic array with a 180° field of view.[3] The geometric assemblage of facets has all of the hallmarks of intelligent design and defies attempts to explain it through natural mechanisms.[4]
Simply put, these facets are tiny square-shaped tubes with walls that act as mirrors to reflect the incoming light. The walls of each facet are perfectly aligned so that the reflected light is focused toward the receptor layer flawlessly so that they all merge at the same point. The design creates an intensified, superpositioned image because the light from many facets combines to form a single image.[5] As many as 3000 reflective facets are found in some species such as the Norway lobster (Nephrops norvegicus), and increases in sensitivity up to 1000 above the more common apposition type eye (where light remains within a single facet/ommatidium).[6]
The ability of the decapod’s eye to intensify an image that is captured from a broad field of view has intrigued engineers since the mechanism was first made known. Investigating biological systems or processes for potential use in technology is rapidly expanding field known as biomimicry. Several technological developments are now based on the unique geometric design of the decapod eye (see Lobster eye biomimicry).[2]. Researchers have developed a cosmic imaging device for use on space satellites,[7] and a handheld imaging system was built that can view through walls of various thicknesses and materials, and identify contents.[8]
Ears that hear and eyes that see—the LORD has made them both. Proverbs 20:12
Reproduction
The anatomy of male and females crabs is distinct. A male has a triangle shaped abdominal flap and a female has a broad oval shaped abdominal flap. When a breeding season is become, female crab open its propagative organ and storing male crabs sperm; female crabs can store male sperm until its eggs are ready to be released. After released, female crab keep the eggs to protect.[1]
Ecology
Decapodas ecology is divided into two types. The one is small decapodas which type is living as animal plankton form. The second is well known decapodas which is living as common crustaceas form; for example Shrimp, lobster, crab. Their habitat is 4000 m deep ocean and usually they are living near by the South Pole and the North Pole. Big shrimp and crab are the important natural resources for our daily sea food. On other hand, small types of decapodas are important food resources for the other sea animails; food chain. Nowadays decapoda life, which documents, analyzes, and works to conserve decapoda populations around the world, estimates that nearly 9 percent of the world's decapoda species are threatened with extinction and even more are in decline because of water pollution.
Gallery
 European Lobster |
