Fish : A fish is a animal vertebrate aquatic, most often covered withscales, which breathes with the help of gills and moves with fins. We currently know more than 30.000 species, which form a very heterogeneous group. Most of them live in seas and oceans, at more or less deep levels, generally called the saltwater fish.
Mediafixer freshwater fish are much less numerous; some of them (eels, Salmon) spend part of their life at sea. Fish are first classified according to their skeleton, cartilaginous (requin, dogfish, stingray) or bony (the majority), then according to the position of their fins in relation to each other. Their body shape - streamlined, dorso-ventrally compressed (stingray) or laterally (flatfish, with eyes on one side only, to the right or to the left, such as the brill, Sun, turbo), or elongated and serpentiform -, the number and shape of their fins, the width of the mouth, the presence of teeth, thorns, spurs, barbels, the thickness of the skin, the outline of the lateral line, pigmentation also make it possible to differentiate them.
Fish have a few specific characters linked to their way of life. They have approximately the same density as water. They usually have a gas bladder that serves as their float. We speak of a swim bladder.
In the aquatic environment, having practically no weight, their skeleton is light and simple (we then speak ofedges and not bone, much denser and heavier). Fish grow throughout their lives (so their size is theoretically unlimited), and that's why they don't age. Therefore, you do not cook an older fish any longer, because it does not change texture or flavor with age and bulk.
Cold blooded animals, their body temperature is variable. They have, in general, eyes without eyelids, which have become unnecessary because their eyes are constantly bathed in water. Fish have two articulated jaws.
Large-scale breeding of so-called " noble ”Because of their scarcity has lowered the price and increased consumption. This is the case with salmon, trout, gilthead sea bream, bar, turbot. Conversely, common fish have become scarce due to overexploitation (cod, hake, thon, whiting). Nowadays, in France, the supply of seafood is in deficit, one in three products comes from abroad. This globalization of inputs is made possible thanks to the improvement of fishing and livestock production techniques.

A change in lifestyles and better consideration of knowledge of dietetics have considerably changed the rate of consumption of seafood products. Thus, Friday is no longer the obligatory and unique day of fish consumption. We consume it more often. Nutritionists also recommend eating a seafood product two or three times a week.
Three elements determine the purchase: the season, freshness and the proportion of parts groceries.
Today we find fish caught almost all year round on the African or Nordic coasts. However, it is advisable to choose those that are taken in nearby waters in high season, as they are tastier and less expensive.
Freshness is the first quality of a fish, which is never better than when it comes out of the water. However, means of transport and refrigeration today make it possible to consume, far from fishing grounds, fish of a flavor flawless.
Conservation techniques are also very old, whether it is cold (already used by the Romans), desiccation (especially for the herring and cod) Of the smoking (Salmon) or crating or barrel. Finally, the possibilities of consumption have been widened thanks to new methods of conservation: metal cans, jars, flexible bags, vacuum, under modified atmosphere. Freezing and deep-freezing on board ships have been decisive factors in bringing in new species.
The amount of edible parts, in net weight relative to the total gross weight, varies considerably, from 35 to 80%, depending on the species, the preparation and the final presentation. It is therefore necessary to provide 250 g of raw fish, to obtain a net portion of about 150 g.

Diet: all fish are very rich en proteinbut also phosphorus. as magnesium. as copper. as fer. as iodine as well as in vitamin B, and, with regard to so-called "fatty" fish. as vitamin A et vitamin D.
In all cases, they have a content of lipids low or very medium, which decreases further after spawning (reproduction).

Seafood : Seafood includes all mollusks (periwinkles, whelks, Oysters, Mussels), shellfish (clams, clams, clams), shellfish (spider crabs, shrimp, langoustines, cake) et with animals marine groceries short (sea ​​urchins). The expression is mainly used for the presentation of a assortment served in appetizers on some ice pounded and kelp frais, accompanied de butter and Rye bread.
A voucher seafood platter  perfect should include, per person: six Oysters flat, six cupped oysters, three clams, three clams, three clamsFew Mussels, six periwinkles and four whelks, four bunch prawns or ten grey shrimpTwo langoustines, with, possibly, a half cake and some sea ​​urchins.
Seafood, always assorted, enter into many preparations culinary (bite, skewer, casserole, omelette stuffed, Risotto, etc.).
Sometimes we add crabe and St. Jacques shells to scallops.