Crayfish

Generality

The prawns are macruri crustaceans, therefore provided with a long, stretched abdomen and with a fan-shaped codal fin; in reality, the term "shrimp" is extremely generic because it covers a wide range of species belonging to different genus, family, superfamily and suborder .

It can therefore be deduced that "crayfish" means many animals (sometimes with different sizes and colors) that are mainly linked to:

1. Eukaryota Domain, Animalia Kingdom, Phylum Eumetazoa, Malacostraca Class and Decapoda Order
2. Small dimensions.

NB . By carefully observing the various Decapodi Macruri crustaceans, therefore also scampi, lobsters and lobsters, it is clear that each of them possesses all the morphological requirements typical of shrimp; however, in the common language (and not in the zoological classification), it is precisely the DIMENSIONS and some anatomical peculiarities to distinguish the shrimp (or shrimp, if even smaller) from the rest of the Decapodi Macruri crustaceans.

Distinction between crayfish

The most commercialized shrimps for HUMAN feeding are those of salt water even if, in certain areas, those of fresh water play a very important food role. Shrimps are also part of the feeding of numerous aquatic and underwater species, therefore, their capture can be aimed at supporting specific fish farms (such as salmon).

Ultimately, the shrimp can be classified by:

1. Habitat (fresh or salt water prawns)
2. Origin (Italian or Mediterranean prawns and ocean prawns).

Edible salt water shrimp

The "properly said" shrimps live on all the bathymetric, colonize almost the entire planet and often result morphologically different from each other; listing all the shrimp species would be of no help to the readers, therefore we will try to illustrate more clearly the most interesting breeds compared to the usual prawns (Argentine, blue, Californian, etc.) present in the supermarkets' freezers or on the market benches fish.

• Shrimp Shrimp: genus Penaeus (family Penaeidae), the species are very numerous and widespread. The Italian / Mediterranean shrimp shrimp has a light color, between white and gray, which in any case fluctuates according to the seabed. It lives in depths between 5 and 50m of depth and reaches 20cm per 100g of weight. It is very precious and (in Italy) it is known as Gambero Imperiale or Spannocchia.
• Indopacific prawns or prawns: genus Metapenaeus (family Penaeidae); there are some species and ALL of them are larger than the aforementioned category. They are generally products of oceanic fishing, mainly from the Indian and the Pacific.
• Sea shrimps:
• Boreal prawns: Latin name Pandalus borealis (family Pandalidae); it colonizes both the Atlantic Ocean and the Pacific and lives between 0 and 9 ° C up to 400m of depth. It has a considerable food and commercial importance.
• Prawns Rockpool Prawn: Latin name Palaemon elegans (family Palaemonidae); 12-13cm long, it is transparent and lives mainly in light. It is present in the Mediterranean and the Atlantic Ocean.
• Common prawn prawns: Latin name Palaemon serratus (family Palaemonidae); about 6cm long, it is whitish and lives mainly in the shade or in the dark. It is present in the Mediterranean and the Atlantic Ocean.
• Posidonia prawns: Latin name Palaemon xiphias (family Palaemonidae); lives in Madeira, on the Canary Islands and in the Mediterranean Sea; it is present between 0.5 and 10 m of depth in the middle of the Posidonia oceanica and rarely in the algal grasslands.

Freshwater crayfish

As far as inland waters are concerned, several edible crayfish (although not all native) can be found on the Italian territory:

• Italian crayfish : there are several species: Austropotamobius pallipes, Astacus astacus and Austropotamobius torrentium; they are fairly concentrated native shrimps in the cold water of series A (streams, lakes, hill rivers, etc.). They are prevalent in the region of Friuli Venezia Giulia but it is not rare to find them in the hilly streams of the Apennines; they are also widespread in some lakes in northern Italy and in the center. Crayfish need clean, cold and unpolluted waters.
• Allochthonous shrimps : different species are present: Procambarus clarkii ("Killer" shrimp), Orconectes limosus, Pacifastacus leniusculus and Astacus leptodactylus; the best known are the "Killers". They are prawns originating from the lower valley of the Mississippi River (USA) but are currently widespread in many other areas of the planet (Sudan, Tahilandia, some European nations, etc.). In Italy they are often confused with European crayfish but are distinguished from them by some morphological details and a GREATer adaptability. These prawns resist polluted waters and are often colonized in low-lying lake creeks, in drains and in all temperate low-altitude waters.
• Fresh and brackish water shrimps: Palaemon antennarius (family Palaemonidae ) and Atyaephyra desmaresti (family Atyidae); they are both native shrimps but, unlike the Italian crayfish, they have small dimensions and a transparent or brownish-striped color. They colonize practically all the watercourses of the peninsula but do not reach the most impetuous streams. The Atyaephyra desmaresti also tolerates salt water well and is very present on the coasts of the northern Adriatic where salinity is not excessive. In coastal fishing and near the mouths, in spring, it is often caught together with some sea shrimp breeds.

storage

Shrimps are highly perishable foods; they, like many other crustaceans, contain high amounts of free amino acids which, together with muscle proteins (both for its own enzymatic degradation and for bacterial degradation), contribute significantly to the release of nitrogen and the onset of an unpleasant ammonia smell. To overcome this drawback, the shrimps are cut down in temperature on board fishing vessels and some species can undergo pre-cooking.

Shrimps are also subject to food addition with sulphites; these preservatives are used to slow down the process of browning of the head and loss of body color. Therefore, contrary to what one might deduce, the freshest prawns always have a dark head (a process that takes place in a very short time) while those treated with sulphites, despite having a bright color, may have been fished or thawed long before . A shrimp with sulphites reaches first the rot that the browning of the head.

Shrimp in the kitchen

Shrimps lend themselves to countless preparations: raw food, an ingredient for sauces to accompany first courses or sauces, grilled dishes, pan-fried dishes, fried dishes and steamed dishes. The main things to consider are:

1. Shrimps should be cleaned by eliminating the intestine, not for hygienic reasons but for gustatory pleasantness
2. Shrimps need RAPID cooking, prolonged ones inexorably ruin the food
3. Grilled shrimps should keep the carapace that maintains its softness, just as the medium ones to be fried should be shelled to speed up the frying process.

It is necessary to take into consideration that shrimps are the object of a widespread allergic form; therefore they are foods that are not recommended for pregnant women, nurses and infants.

How to Clean Prawns

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Nutritional characteristics

Shrimps are foods of animal origin; they supply modest amounts of energy, most of which come from high biological value proteins. There is also little fat and a CONSISTENT portion of cholesterol. Carbohydrates are present but irrelevant.

As far as vitamins are concerned, prawns provide good amounts of riboflavin (vit. B2), niacin (vit. PP) and, in some species, also an equivalent retinol called astaxanthin (very powerful antioxidant).

Shrimps are also rich in sodium, iron, potassium, phosphorus and calcium.

The shrimp carapace contains a non-digestible polysaccharide, chitin ; this, which treated with basic solutions originates chitosan, is part of the wide range of dietary supplements aimed at slimming. Its effect should be chelating on fats but the results are not significant or null.

Nutritional composition for 100 grams of edible portion Fresh prawns:

Edible part 45% water 80, 1g Protein 13, 6g Lipids TOT 0.6g Cholesterol 150, 0mg TOT Carbohydrates 2, 9g Starch 0.0g Soluble sugars 2, 9g Dietary fiber 0.0g Power 71, 0kcal Sodium 146, 0mg Potassium 266, 0mg Iron 1, 8mg Football 110, 0mg Phosphorus 349, 0mg Thiamine 0, 08mg Riboflavin 0, 10mg Niacin 3, 2mg Vitamin A 2, 0μg C vitamin 2, 0mg Vitamin E - mg

Nutritional composition for 100 grams of edible portion Shrimps, shelled, frozen:

Edible part 100% water 81, 2g Protein 16, 5g Lipids TOT 0, 9g Saturated fatty acids 0, 27g Monounsaturated fatty acids 0, 27g Polyunsaturated fatty acids 0, 37g Cholesterol 150, 0mg TOT Carbohydrates 2, 9g Starch 0.0g Soluble sugars 2, 9g Dietary fiber 0.0g Power 85, 0kcal Sodium 375, 0mg Potassium 75, 0mg Iron 2, 6mg Football 128, 0mg Phosphorus 150, 0mg Thiamine tr Riboflavin 0, 02mg Niacin 0.5mg Vitamin A tr C vitamin tr Vitamin E - mg

Bibliography:

1. Fauna in Italy - A. Minelli - Ministry of the Environment and Protection of the Territory - pag. 188
2. Food composition tables - National Research Institute for Food and Nutrition (INRAN)