Agricultural encyclopedia terminology - oyster details

< h1 class="pgc-h-arrow-right" > detailed</h1> description

The general term for oyster shellfish (Ostrea). Commonly known as oysters, sea oysters. It belongs to the mollusc phylum, bivalves, pearl oysters, oyster family. The meat is delicious and nutritious, and its soft parts contain 45% to 57% protein, 7% to 11% fat, 19% to 38% liver sugar, and the iodine content is higher than that of milk and eggs. In addition, it also contains a variety of vitamins and trace elements such as iron, copper, and manganese. In addition to fresh food, meat can also be made into dried "oyster sauce" or canned, and the soup of processed oysters can be refined into "oyster sauce". According to the "Compendium of Materia Medica", oysters can be used for medicinal purposes, and eating more can purify the skin, cure weakness, and detoxify erysipelas. Its shells can be used as raw materials for burning lime, cement, acetylene and livestock feed. Oysters are one of the earliest and most comprehensively studied species of marine economic animals. In the 18th century, the classification of oysters began to be studied, and in the 19th century, the biology and embryology of oysters began to be studied. T..C. Nelson, England, 1918–1938, C. Yongge, 1926 M. Yonge studied the feeding and digestion mechanisms of oysters; J. Orton, 1921-1937 H. Orton) studied the reproductive behavior, shell formation and growth patterns of European oysters. In 1956, Zhang Xi and Lou Zikang of China studied the reproduction and growth of the monk hat (pleated) oyster. Scholars from various countries have also studied artificial hybridization, genetic breeding, triploidity, ecology, physiology and antigenicity of oysters. Species and distribution The world's major economic varieties are the edible oyster (Ostrea edulis Linnaeus), the European oyster (O. angulata Lamarck), Greek oyster (O. lurida Carpenter), Grassostrea virginica Gmelin, C. long oysters gigas Thunberg) and the Australian oyster [C. commercialis (Iredale and Roughley)] et al. There are 20 species in China, and the main species that have been farmed is the pleated oyster (O. plicatula Gmelin), O. O. Omi Oyster rivularis Gould), Dalian Bay Oyster (O. talienwhanensis Cross), O. scaled oysters (O. denselamellosa Lischke) and the introduction of long oysters, etc. With the exception of a few areas in the polar and boreal regions, oysters are found along the coasts of the world, inhabiting mid-tide zones up to tens of metres of water depth. The species ecology varies from place to place. The horizontal distribution is mainly governed by temperature and salinity. The geographical distribution and vertical distribution of the main cultured oyster species in China are shown in the table.

The distribution of mainly farmed oysters in China

Morphological structure The external morphological characteristics of oysters can be identified from the shape of the shell, the arrangement of the scales, the presence or absence of radial ribs, and the length of the ligament grooves. Pleated oyster shells are small, thin, and varied in size, but mostly triangular or elongated (Figure 1). The right shell is thin and brittle, flat as a lid, with concentric ring-like scales on the surface, multi-layered, no radiating ribs, the shell surface is mostly yellowish, mixed with cyan and purple-brown stripes, and the fixed left shell is larger, deeply sunken, with thick radial ribs. The color is mostly lighter than the right shell. The inner surface of the shell is off-white, the ligament grooves are narrow and long, and the anterior depression is extremely deep.