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1.
Calyptospora n. g. was erected for Eimeria funduli because the sporocyst of that species lacks Stieda and sub-Stieda bodies, has a veil supported by sporopodia, and has an anterior apical opening. A suture may be present, but it does not completely divide the sporocyst into two valves. Because C. funduli has an obligatory invertebrate intermediate host, we established Calyptosporidae n. fam. to accommodate Calyptospora and tentatively to accept Goussia. A new subgenus, Plagula, is erected for species of Goussia with a sporocystic veil not supported by sporopodia. We consider the family more primitive than Eimeriidae, Sarcocystidae, and possibly Lankesterellidae.  相似文献   
2.
Several microphagous grazers co-exist on British rocky shores.The nature of the microbial film which is their prime food sourceis outlined. The radula morphology, hardness, and feeding mechanismsof rhipidoglossan trochids (Gibbula, Monodonta) taenioglossanLittorina, and docoglossan Patella have been compared. Docoglossanscan penetrate hard substrates deeply, taenioglossans can onlypenetrate softer substrates, and rhipidoglossans appear to primarilybrush the surface. A preliminary study found some differencesin diet. Whether feeding mechanisms allow partitioning of themicrofloral film and whether this allows continuing co-existenceof intertidal grazers is discussed.  相似文献   
3.
MUCUS PRODUCTION AND PHYSIOLOGICAL ENERGETICS IN PATELLA VULGATA L.   总被引:2,自引:0,他引:2  
Most energy budgets for marine gastropods lack a measured mucusterm. This is a major omission since mucus is widespread inmolluscan physiological processes. In this paper we outlinemethods for estimating mucus production in the intertidal gastropod,Patella vulgata L. This species uses mucus primarily for adhesionand locomotion. Pedal mucus production rates were measured inaerial environments of 70% relative humidity (RH) and 100% RHand in seawater. Animals in 70% RH did not move, while thosein 100% RH and seawater were mobile. Animals in 100% RH showedthe highest mucus production rate. Those in seawater secretedabout 75% of the mucus produced in 100% RH and those in 70%RH only about 40% of that produced in 100% RH. Significant logarithmicrelationships between mucus production rate and whole dry weightof animal, and mucus production rate and shell length were foundin all cases. The mucus term in the energy budget was calculated as 23% ofingestion both for individuals and for a specific population.This is much higher than the estimate of 4% of Wright &Hartnoll (1981). We have recalculated an energy budget for Patellavulgata to include the substantial mucus term. The recalculatedbudget is structurally different from the original budget. Thissuggests conclusions drawn from budgets not including a measuredmucus term should be regarded with caution. (Received 12 September 1989; accepted 13 December 1989)  相似文献   
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A specific exocytic process, the discharge of spindle trichocysts of paramecium caudatum was examined by means of the electron microscope. This exocytosis is induced by an electric shock simultaneously in nearly all of the trichocysts (ca. 6,000-8,0000 of a single cell. Single paramecia were subjected to the shock and then fixed at defined times after the shock so that the temporal sequence of the pattern of changes of the trichocyst membranes after exocytosis could be studied. The trichocyst vacuoles fuse with the plasma membrane only for that length of time required for expulsion to take place. After exocytosis, the membrane of the vacuole does not become incorporated into the plasma membrane; rather, the collapsed vacuole is pinched off and breaks up within the cytoplasm. The membrane vesiculates into small units which can no longer be distinguished from vesicles of the same dimensions that exist normally within the cell's cytoplasm. the entire process is completed within 5-10 min. These results differ from the incorporation of mucocyst membranes into the plasma membrane as proposed for tetrahymena.  相似文献   
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This study reports the isolation and characterization of seven highly polymorphic microsatellite loci in Chthamalus montagui (Crustacea, Cirripedia). The loci were isolated from a library constructed from genomic DNA enriched for CA repeats. The markers yielded three to 43 alleles per locus (mean 16.7) in samples averaging 49 individuals. Observed heterozygosity ranged from 0.08 to 0.58 (mean 0.39). These microsatellite loci will be valuable tools for population genetic studies of this species.  相似文献   
8.
One hundred and fifty random clones from an enriched genomic library of Atlantic cod were sequenced. Primer pairs were designed for 15 microsatellites containing perfect di‐, tri‐, tetra‐ and hexanucleotide repeats and characterized in 96 unrelated fish. Eight markers were successfully amplified, with the number of alleles ranging from two to nine per locus and observed heterozygosity ranging from 0.341 to 0.977. Loci Gmo‐G13 and Gmo‐G14 had a significant excess of homozygotes. All loci conformed to the Hardy–Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed no significant departure from the null hypothesis between any of the loci.  相似文献   
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Background  

Sweat gland adenocarcinoma is a rare malignancy with high metastatic potential seen more commonly in later years of life. Scalp is the most common site of occurrence and it usually spreads to lymph nodes. Liver, lung and bones are the distant sites of metastasis with fatal results. The differentiation between apocrine and eccrine metastatic sweat gland carcinoma is often difficult. The criteria's are inadequate to be of any practical utility.  相似文献   
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