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乌鳢的消化器官与其机能适应性的讨论 总被引：4，自引：0，他引：4
本文从乌鳢消化器官的形态学与组织学方面,就各消化器官与其机能的适应性作了初步探讨。各器官均与其食性和捕食方式相适应。 相似文献
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Polonium-210 (210Po) has been analysed in the soft parts of two bivalves species, the scallop Chlamys varia and the common mussel Mytilus edulis, from the Bay of La Rochelle and Ré Island, on the French Atlantic coast. Between those sites, the highest 210Po concentrations have been found in whole scallop soft parts from La Rochelle, reaching 1,181 +/- 29 Bq kg(-1) dry weight (dwt), a size effect being related to the highest 210Po concentration in the smallest scallops. The results show a significant difference in concentrations for similar size individuals between species in each site (C. varia > M. edulis) and between sites for each species (Ré Island > Bay of La Rochelle). Very high 210Po concentrations have been found in the digestive gland of C varia, ranging 3,150-4,637 Bq kg(-1) dwt. Thus, the digestive gland contains up to 60% of the radionuclide. Subcellular investigations have shown that approximately 40% of the 210Po contained in the digestive gland is in the cytosolic fraction, suggesting a high bioavailability of the 210Po from this fraction to the trophic upper level. Calculations will show that approximately 4 kg of scallops flesh intake would be necessary to reach the annual incorporation limit of 1 mSv. 相似文献
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Since the early 1960s, the application of aluminum alloy sacrificial anodes to mitigate marine corrosion has been well known. The aim of this work was to study aluminum bioconcentration in Mytilus edulis by an in vitro test performed in two tanks: the first containing non-contaminated water (NCW) and the second containing aluminum-contaminated water (CW) (530 μg L−1) released by sacrificial anode. The mussels were collected and examined over a period of 8 weeks. A comparison between the aluminum concentrations in the digestive glands of mussels from the CW and NCW tanks shows that the highest value (1700 mg/kg d.w.) was found in the CW mussels collected after 13 days. In NCW, the mean aluminum concentration in digestive glands during the test was 281 mg/kg d.w. The rapid concentration decrease in digestive glands is probably due to the inhibition of filtering activity due to valve closure at the high concentration as well as the induction of the detoxification response. 相似文献
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长蛸唾液腺和消化腺的组织学与组织化学研究 总被引：4，自引：0，他引：4
以组织学和组织化学方法，研究了长蛸的唾液腺和消化腺。前唾液腺腺细胞含团状蛋白性质的分泌颗粒。后唾液腺有两种腺管，I型腺管由I型腺细胞和黏液细胞组成。I型腺细胞团状分泌颗粒及丰富的RNA，且脂酶活性；黏液细胞分泌酸性黏多糖。Ⅱ型腺管的腺细胞内含一桃形丝状物。肝细胞含大量的分泌颗粒，呈现强的蛋白酶及弱的非特异性酯酶和脂酶活性。胰脏腺细胞呈非特异性酯酶和弱的蛋白酶和脂酶活性。 相似文献
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本文对东方对虾消化道及肝胰脏进行大体解剖和组织学观察,并将其结构与功能同其它主要十足动物作比较。 前肠和后肠内壁有几丁质层覆盖,中肠则没有。食道壁向四个角落内褶,在其表皮层之下的结缔组织中充满皮肤腺,环肌层连续,纵肌成束分散排列:胃的组织学结构除没有皮肤腺分布外,大体与食道相似。中肠从胸部延伸到第六腹节前区,约占消化道总长的60％,其上皮是一层柱状细胞,环肌层薄,纵肌成束分散排列;中肠前,后盲囊分别从中肠的前端和后端发出。后肠是一短管,内壁突出四个大的垫状隆脊,肛门开口于尾节腹面,和食道一样后肠壁分布大量皮肤腺:后肠上皮由单层柱状细胞组成,环肌层连续,纵肌在后肠前段成束分散排列于环肌之下,在后段则在环肌层之上。肝胰脏由许多分支肝小管构成,肝小管内壁为单层柱状上皮,中央为管腔:肝管细胞分为分泌细胞、吸收细胞、纤维细胞和原始细胞四种。原始细胞是一种未分化的细胞,分布于肝小管末端。 相似文献
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运用石蜡切片法、透射电镜技术及组织化学方法，对栉孔扇贝的消化盲囊进行了研究。结果表明消化盲囊的腺上皮由消化(吸收)细胞和分泌细胞组成，消化(吸收)细胞顶端有微绒毛，细胞内有酸性磷酸酶、碱性磷酸酶、脂酶和酯酶活性，还含有糖原和脂肪。是进行食物的细胞内消化和营养物质吸收的主要场所，并有储存能量的功能；分泌细胞内含粗面内质网、高尔基体和分泌颗粒，具有酸性磷酸酶和碱性磷酸酶活性。并含有丰富的RNA和蛋白质，有分泌消化酶的功能；消化盲囊导管上皮细胞顶端有纤毛和微绒毛，细胞内有酸性磷酸酶、碱性磷酸酶及脂酶活性，也能分泌消化酶。消化(吸收)细胞浅部的细胞质及其释放到盲囊腔中的胞质团中含铁；各部位不含钙。 相似文献
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The aim of the present work was to determine the activities of selected antioxidant enzymes (SOD, Se-GPX, CAT) in two species of bivalves, Scapharca inaequivalvis and Tapes philippinarum, from two sites of the lagoon of Venice that are characterized by different pO(2) (Marghera and Chioggia). The specimens were collected at four times during a 1-year period. In the two species studied, enzyme activities were found to be present in both digestive glands and gills, but with some species-specific differences that may also represent a different adaptation to seasonal variations. The presence of high SOD activities in the gills of both species may be related to their physiological role in respiration. Scapharca inaequivalvis is less sensitive than T. philippinarum to environmental changes, perhaps due to the presence of hemoglobins in this species. Moreover, in the digestive gland of T. philippinarum we found a significant negative correlation between the activities of SOD and GPX that may indicate the presence of oxidative stress. Some correlations between temperature/dissolved oxygen and antioxidant enzyme activity were present in specimens sampled in Marghera. Only GPX adequately responded to changes in dissolved oxygen and temperature, while the decrease in the activity of SOD and CAT in winter may be directly responsible for an enhanced susceptibility of mussels to oxidative stress during this period. We can conclude that the observed differences between Chioggia and Marghera are due to different concentrations of dissolved oxygen. Marghera is an appropriate location to study seasonal variations in water temperature. In fact, in this site, the differences between hot and cold months are quite evident. 相似文献
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Among extant vertebrates, only birds have a respiratory system associated with pneumatic diverticula. However, several extinct clades also had pneumatic diverticula, including the sauropod dinosaurs. Among sauropods, Saltasaurini are characterized by extreme postcranial pneumaticity, which extends as far down the spinal column as the posterior caudal vertebrae. In this paper the pneumatic foramina in both the neural arches and the centra are described in detail, and the relative proportion of air spaces in the caudal vertebrae is established, revealing that the skeleton of Rocasaurus muniozi was more pneumatized than that of Neuquensaurus australis, with Saltasaurus loricatus intermediate. The level of pneumatization varies between the three saltasaurine taxa: in Neuquensaurus, only the neural arch is pneumatized, whereas in the other two saltasaurines both neural arches and centra are pneumatized. This allows us to hypothesize that the timing of pneumatization varied between the three species, with Rocasaurus muniozi pneumatized earliest in ontogeny. This ontogenetic pattern is correlated with evolutionary derivation: the most derived taxa show pneumatization in both the neural arch and the centrum. 相似文献