Observation on behavior of adult oriental white stork in nesting period

lntroductionTherearemanystudiesonOrientaIWhiteStorks.Thestudysubjectsincludepopulation,distribution,migration,ecology,historicstatusandconservation,captivepropagation,reproductivebioIogyandbe-haviors,etc.KyDkoArchibaIdandBernardSchmitt(1991)reportedthecomparisonbetWeentheorientaIWhiteStorkandtheEuropeanWhiteStork.TheyalsodescribedspeciaIbehaviorsofiIlCIattering"anddi-videdinto3styIes.ThesearethreatbiIIcIattering",courtshipbilIclattering"andcontactbilIclattering".TheyexpIainedthefem…     

Preparation of Water-Soluble Chitosan and its Suppressive Effect on the Denaturation of Scallop Adductor Muscle Myofibrillar Protein During Frozen Storage

ABSTRACT

In the present study, investigated were the preparation of water-soluble chitosan (WSC) by hydrolysis of original chitosan with commercial α-amylase and the suppressive effect of WSC on denaturation of bay scallop adductor muscle myofibrillar protein (Mf) during frozen storage at ?18°C for 12 months. The WSC (2.5- to 10-g dry weight) was added to 100 g of the Mf, and the changes in the Ca-ATPase activity, solubility, and sulfhydryl content were examined during frozen storage. The addition of WSC significantly reduced the denaturation of the Mf Ca-ATPase. Moreover, a significant increase in Mf solubility and sulfhydryl content was observed in the WSC-treated bay scallop adductor muscles compared with the control (p < 0.05) during frozen storage at ?18°C.     

Properties of scallop mantle collagen: its content,tissue distribution and thermal behavior

ABSTRACT:   To obtain fundamental information for the effective use of scallop Patinopecten yessoensis mantle, which is one of the underutilized marine resources. Some properties of collagen contained in the mantle were examined by chemical and histochemical techniques. Collagen content in the mantle varied annually, ranging from 0.98 to 1.72% of wet tissue, 7.7 to 12.6% of dry tissue and 13.5 to 26.5% of total protein, being relatively in high level of collagen content of invertebrate muscles. Collagen fiber was densely distributed in the inner connective tissue matrix of the mantle pallial, in contrast to the inner fold part which was rich in muscle fibers. The collagen contained in the crude collagen fraction (residue after alkali extraction), prepared from the mantle, was revealed to have considerably low solubility on hot-water extraction, constantly less than 20% of the total collagen at the temperatures in the range of 20–90°C.     

玉米穗部产量性状杂种优势分析

研究了玉米穗部性状的杂种优势,双亲生育期间隔长短与F1穗粒重的关系以及穗部性状亲子相关.结果表明:穗粒重、穗重的杂种优势最大,其次为穗粒数、千粒重、穗长、穗粗,穗行数为最小.F1穗粒重杂种优势与双亲生育期间隔长短无关.杂交种穗粗、穗行数与母本穗粗、穗行数以及中亲值呈正相关,杂交种千粒重与中亲值呈正相关。     

亲虾人工越冬技术研究——大规模亲虾人工越冬的生产性实验

在天津沿海纬度偏高、秋季降温快的条件下,1990年10月12日至1991年3月15日在津塘育苗场进行了大规模亲虾人工越冬的生产性试验。主要研究内容是:亲虾室内自然交尾的技术研究;适用于生产规模的亲虾人工越冬密度、水温等调控技术的研究;促进性腺适时发育成熟的技术研究。     

Comparison of early life history stages of the bay scallop, Argopecten irradians: Effects of microalgal diets on growth and biochemical composition

The culture of bay scallops, Argopecten irradians, is limited by a reliable and affordable supply of spat and the ability to ensure that animals attain market size within a single growing season. The main goals of our study were thus: (1) to develop growth-optimizing algal diets for implementation in hatcheries, and (2) to identify and compare bay scallop postlarval and juvenile dietary requirements, especially of lipids and fatty acids, which if met may enhance production. Nutritional needs of postlarval bay scallops (present study) are compared with those of sea scallops, Placopecten magellanicus, offered the same diets in a previous companion study. To this end, postlarval (initial shell height, SH = 240 μm) and juvenile (initial SH = 10 mm) bay scallops were offered 6–7 microalgal diet combinations at 20 °C, for 3 weeks. A similar growth ranking among diets was observed between the two developmental stages. A combination diet of Pavlova sp. (CCMP 459) and Chaetoceros muelleri was far superior to any other diet tested, yielding growth rates of 58 and 357 μm day^− 1 which were 65% and 25% higher than the next highest performing diet of Tetraselmis striata/C. muelleri in postlarvae and juveniles, respectively. The T. striata/C. muelleri diet, which is limited in the n-3 fatty acid docosahexaenoic acid (DHA), yielded very poor growth of sea scallop postlarvae in a prior study, indicating that bay scallops may have less stringent requirements for DHA than sea scallops. The Pav 459/C. muelleri diet, which also supported the highest growth of sea scallop postlarvae, is characterized by elevated levels of the n-6 fatty acids, arachidonic (AA) in C. muelleri and 4,7,10,13,16-docosapentaenoic (DPA) in Pav 459. The two diets deficient in AA and n-6 DPA, Pavlova lutheri/Thalassiosira weissflogii and P. lutheri/Fragilaria familica, yielded the lowest growth rates in both bay scallop postlarvae and juveniles. Tissue enrichment of these two fatty acids relative to the diet, as well as overall enrichment in ∑n-6 fatty acids was observed across developmental stages and dietary treatments. A similar pattern has previously been observed in sea scallop postlarvae, suggesting a dietary requirement for n-6 fatty acids in pectinids that has often been overlooked in the past.     

Culture of mantle epithelial cells expressing shell matrix proteins from scallop Patinopecten yessoensis

ABSTRACT:   In molluscs, mantle epithelial cells secrete organic matrix proteins to form shells. In this study, we established a culture of mantle epithelial cells by using the mantle pallial layer of scallops. We aimed to identify the mantle epithelial cells expressing scallop shell matrix proteins and establish a culture system of epithelial cells. After the mantle pallial layer was carefully isolated from the mantle tissue, explant culture was performed at 4°C. Most cells that migrated from the explant tissue were round cells. Most of the adhered cells retained round morphology, while some of the cells adhered to the dish and showed morphology similar to that of epithelial-like and fibroblast-like cells. When the cultured cells were immunostained with a polyclonal antibody against the shell matrix protein, the antibody recognized many of the adhered cells. An estimation of the number of epithelial cells revealed that approximately 70% of the adhered cells were epithelial cells. This is the first report to describe epithelial cells in cultured mantle cells, which express shell matrix proteins. This culture system may be a useful method for characterization of the mantle epithelial cells.