Scallops

[Zeinab elnagdi]

Scallops are edible bivalves similar to oysters and clams. They are found both in bay waters and in the sea. They do not attach themselves to a permanent anchorage, but move themselves through the water by opening and closing their shells. As a result, the muscle that controls the 'hinge' of the shell is much larger than that of oysters or clams. The whole of the organism is edible, and in Europe, they are eaten in their entirety like oysters. In the US, only the shell muscle is eaten and it is this white cylinder of flesh that is commonly thought of in America as a scallop. Scallops are both fished and farmed. Since they cannot survive out of water, they are shucked from their shells on board the fishing boat. The bay scallop is much smaller than the sea scallop, and the edible muscle is less than an inch in diameter; usually a half-inch (about a centimeter) or smaller. The sea scallop's muscle can be as large as two inches (about 5 centimeters) in diameter. Sea scallops are sometimes cut into smaller shapes to pass as bay scallops. [فقط الأعضاء المسجلين والمفعلين يمكنهم رؤية الوصلات . إضغط هنا للتسجيل]      منتديات اكوازوو

للمزيد من مواضيعي

   الموضوع الأصلي : هنا    ||   المصدر : منتديات اكوا زو للاستزراع السمكى   ||   الكاتب: Zeinab elnagdi    ||  مواضيعي

 

 

[Zeinab elnagdi]

Scallop Aquaculture Scallop farmers require a reliable source of spat for grow-out. Scallop spat from the wild The scallop grower has a wide variety of options for culturing this species. The natural settling behavior of larval scallops can be exploited by putting out collectors which simulate the conditions in which scallops will normally chose to set. Collectors are made by stuffing bundles of nylon monofilament fishing net material into bags with a mesh size of 2-3 mm. These bags are anchored in the seas a few meters above the bottom in a location where scallop larvae may be expected to settle. They are set out in the fall shortly before the larvae reach the pediveliger stage. The collectors are usually left in the water until the following summer. The larvae will have grown to 8-10 mm diameter, and will be large enough to handle. The bags are then opened and the small scallops sorted from other shellfish, small starfish, worms and other material that will have accumulated. Success varies from year to year and place to place. Hatchery culture The alternative to collecting wild spat is to raise the larvae in a hatchery. Adult scallops are brought into the hatchery and conditioned by feeding a mixture of several species of phytoplankton. Part of the success of a hatchery lies in growing sufficient phytoplankton and in feeding it to the scallops at an optimum quality. Water quality control is also important at all stages of the hatchery operation. Eggs released by the females are captured on fine mesh screens and transferred to large tanks where the water is changed regularly and the tanks kept scrupulously clean. After hatching, the larvae are also fed mixtures of cultured algae. Settling is done on rigid plastic sheeting or fiberglass panels suspended in the tanks, they may be allowed to settle in collector bags which are then transferred to the field for nursery grow out. Culture of post-settled scallops Post settled larvae may be held on screen-bottom trays. Warm water containing cultured algae is pumped to them. The most successful technique is one called an upweller. Screen-bottom trays or cylinders containing the spat are suspended in a tank into which water is pumped. The outlet from the tray or cylinder is led through the side of the tank. The upward water flow provides abundant food and washes away feces and other wastes. The outflowing water drains into a reservoir where the algae are replenished and the water is recirculated. At commercial scales, collectors, with the small scallops still attached by their byssus, are placed in small mesh bags and hung out in the sea on long lines to grow like their wild counterparts. The secret is to grow the spat as economically as possible and maximize their growth rate. Intermediate grow-out When juvenile scallops are 5-10 mm in diameter they are ready for transfer to intermediate grow-out. At this stage they are about one year old. This is usually done in fine mesh lantern nets or pearl nets. These are suspended on long lines deep enough in the water to be below the action of surface waves . [فقط الأعضاء المسجلين والمفعلين يمكنهم رؤية الوصلات . إضغط هنا للتسجيل]      منتديات اكوازوو

 

 

التوقيع

لم أستطع إنتظار النجاح ، لذا قررت الذهاب إليه

[reham abdelwahab]

[فقط الأعضاء المسجلين والمفعلين يمكنهم رؤية الوصلات . إضغط هنا للتسجيل] [فقط الأعضاء المسجلين والمفعلين يمكنهم رؤية الوصلات . إضغط هنا للتسجيل] Bay scallop spawning at the Martha's Vineyard shellfish hatchery [فقط الأعضاء المسجلين والمفعلين يمكنهم رؤية الوصلات . إضغط هنا للتسجيل]      منتديات اكوازوو

 

 

التوقيع

[فقط الأعضاء المسجلين والمفعلين يمكنهم رؤية الوصلات . إضغط هنا للتسجيل] لست سوى طفلة وما اسعدني من طفله فقد تحررت من قيد الانوثه وتركت النضج ورائي واقفلت بابي بوجه عشاقي ومعجبي وعلقت لافتتي على نافذة قلبي الصغير وانا اكتب بالخط العريض "لست سوى طفله " طفله تنظر من خلف الابواب الموصده ومن خلف الغيوم .. تنظر لعل الامل يأتي من بعيد لعل الشمس يومآ تشرق من جديد لعل الحب يداوي جرحآ استوطن قلب " الطفله "