All about Sea Urchins

Sea urchins are small, spiny sea creatures of the class Echinoidea found in oceans all over the world. Their shell, which is also called the "test", is globular in shape and covered with spines. The size of an adult test is typically from 3 to 10 cm. Typical sea urchins have spines that are 1 to 3 cm in length, 1 to 2 mm thick, and not awfully sharp. Diadema antillarum, familiar in the Caribbean, has thin, potentially dangerous spines that can be 10 to 20 cm long. Common colors include black and dull shades of green, olive, brown, purple, and red. Sea urchins are members of the phylum Echinodermata, which also includes starfish, sea cucumbers, brittle stars, and crinoids. Like other echinoderms they have fivefold symmetry and move by means of hundreds of tiny, transparent, adhesive "tube feet". The pentamerous regularity is not obvious at a casual glance but is easily seen in the dried shell or test of the urchin.

Together with sea cucumbers (Holothuroidea), they make up the subphylum Echinozoa, which is defined by primarily having a globoid shape without arms or projecting rays, even if the sea cucumbers and the irregular echinoids have secondarily-evolved dissimilar shapes. Although many sea cucumbers have branched tentacles surrounding the oral opening, these have originated from modified tube feet and are not homologous to the arms of the crinoids, starfish and brittle stars. Within the echinoderms, sea urchins are classified as echinoids. Particularly, the term "sea urchin" refers to the "regular echinoids," which are symmetrical and globular. The ordinary phrase "sea urchin" actually includes several different taxonomic groups: the Echinoida and the Cidaroida or "slate-pencil urchins", which have very thick, blunt spines, and others. Besides sea urchins, the Echinoidea also includes three groups of "irregular" echinoids: flattened sand dollars, sea biscuits, and heart urchins.

How to Repair Your Furniture

The furniture in home always give some problems which deals with too much of stress and strain. Most of the damage can be reduced with very little expertise. You don’t need to be a carpenter to produce long-lasting repairs that save money. All you need to do is be a little alert when dealing with furniture.

When disassembling or assembling furniture, avoid missing of any of the part by keeping it in a bag. Then, even if you have to go out for some other work in between the work, you can save all the parts from losing.

When drilling in to the furniture if you have mistakenly did wrong measurement, which created an extra hole in the furniture then take the sawdust from the table wood and mix it wood glue and create thick paste, which can be used to fill the hole.

When you are supposed to do repairs which requires tiny brads then you keep missing the nail and hit the wood or your nail and bones. To avoid this you can use tape to stabilize your nail and hit the nail till it is steady then remove the tape and finish driving the nail into the wall.

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