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Protandrism was confirmed in Crepidula fecunda Gallardo 1979 by histological analysis of the gonad. Individuals were classified as immature (12 mm or less in shell length), male (13–26 mm), intersex (25–28 mm), and female (over 26 mm). There was an evident loss of mobility with growth— large females became completely sessile. The presence of epithelial glands in mobile individuals was associated with the need for lubrication during crawling, whereas the proliferation of subepithelial glands in sessile females was associated with adhesion. Mobility of immature and male individuals was related to grazing activities on biofilms, and in males was also associated with copulation. Grazing activity of motile individuals was carried out so that the radula teeth did not come into direct contact with the substratum, but rather harvested the biofilm surface. Sessile females used the radula to rasp the area under their shells, thus cleaning the substratum in preparation for oviposition. Since this process required that the radula enter into direct contact with the substratum, it suffered abrasion of radular teeth and loss of radular denticles, producing important alterations in its appearance in mature females. A complex interaction was observed between size, mobility, histological changes in the foot, activity, and tooth‐wear of the radula, which have been related to the sessile habit, sex change, and the oviposition process in this species. 相似文献
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EVALUATION ON NUTRITIVE VALUE OF PORTUNUS TRITUBERCULATUS 总被引:2,自引:0,他引:2
MODUon0NP.trituberculatushasanupswellingshuttiedsecephalothoraxcrust0nWhosescheearemanydiversefinegranuleswhichbererneroughandconcentIatalinthegillaas.IthasthIeewartybulgesandtwosharpodhonitSforeheadPaiAiy-U,l986).Thechelipedisdeveloped,itSmerusisshuuleshaped,thefotirthpairofpereiopodsareuseoars,itScarpopoditiswideandshort,thedaCty0poditisslab-shaped,eachjoint'sedgehasshorthahaforswirTuning,themalebodyisbluishgreen,andthebolebodyisadeeppmple.Maleanddrileglands')locateatthedorsalordorsola… 相似文献
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This study on the nutritive indexes (total nitrogen, amino acids, crude fats, inorganic elements, unsaturated fatty acids)
of meat, male and female reproductive gland ofPortunus trituberculatus showed that their nutritive value is in the order meat>female reproductive gland>male reproductive gland and that they do
not raise the total cholesterol (TC) and triglyceride (TG) contents of the serum of the animals which eat them but increase
the contents of high density lipoprotein cholesterol (HDL-C) in the animal's blood. These findings implied that people who
have high blood lipid and aortic atheroma can safely use them as food. This study showed thatP. trituberculatus has high nutritive value. 相似文献
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Marine mammals and marine birds perform diving to forage underwater. Recent technological advances have led to rapid progress in our understanding of diving behavior, but additional research is required into feeding behavior to determine the timing of prey ingestion, prey mass, and prey type. To achieve a comprehensive understanding of the foraging and diving behavior of these endotherms, it is essential to integrate information on feeding behavior with other data. The challenges involved in developing an appropriate research method have been addressed, and several methods have been tested and used in the field, including the stomach temperature method, the esophagus method for marine birds, the stomach temperature telemeter method for seals, and the beak magnet sensor method. In the present study, I review these methods, suggest the necessity of their further development in field studies, and propose a new practical method that involves the measurement of jaw movements underwater as an indicator of the feeding behavior of seals. 相似文献
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采用组织学方法对锯缘青蟹(Scylla serrata)大颚器进行研究。大颚器位于大颚肌几丁质腱的后侧基部,发育过程可分为4期:I期大颚器很小,肉眼难以辨认,腺细胞数量少,细胞界限不清晰;Ⅱ期大颚顺形状不确定,腺细胞开始形成腺泡;Ⅲ期大颚器通常呈肾形,腺泡多;Ⅳ期大颚器体积最大,呈柱状,腺细胞发达,未见退化现象。锯缘青蟹体长、卵母细胞直径、生精小管直径与大颚器腺细胞直径具有良好的线性关系。实验结果提示了锯缘青蟹大颚器与生长、生殖活动密切相关。 相似文献
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