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991.
The macroinvertebrate communities of 16 karst springs in the Southern Limestone Alps (Slovenia, SE Europe), were studied from
May to September 1999, together with the major chemical parameters of the water and selected physical characteristics of the
springs. The springs are located in an area of 800 km2, between 410 and 955 m a.s.l., and drain into two rivers whose catchments are separated by mountain ranges up to 2864 m.
The Soča river drains into the Adriatic Sea and the Sava into the Black Sea. Springs showed relatively large fluctuations
in discharge and small variations in temperature (normally about 1 °C) during the period of study. Seventy macroinvertebrate
taxa were collected. Chironomidae (Diptera), Limnephilidae (Trichoptera), Enchytraeidae (Oligochaeta), Tricladida (Turbellaria)
and Belgrandiella kuesteri (Gastropoda) were the most widespread taxa, collected from the majority of sampling sites. The environmental characteristics
showed a great heterogeneity, and there was a large variation in the taxonomic composition and relative abundance of taxa
between springs and during seasons. The coexistence of taxa with highly divergent ecological requirements is characteristic
of the spring communities studied. They range from stygobionts and spring-restricted species to ubiquitous species. The differences
observed in spring fauna in the two river catchments were probably dictated by differences in local environmental parameters
and not by the geographical location in the different river catchments. 相似文献
992.
Summary One of the cell types occurring in the connective tissue of gastropods and bivalves is thepore cell. Cells of this type have a characteristic morphology in that their plasmamembrane has many invaginations bridged by cytoplasmic tongues. In the well developed granular endoplasmic reticulum and in these invaginations fine granular material, sometimes arranged in crystalline patterns, is present. InLymnaea stagnalis this material has been identified as haemocyanin on a morphological basis. Histochemical and ultrastructural results on pore cells of 2 snail species(Biomphalaria glabrata, Planorbarius corneus) having haemoglobin in their blood indicate that the pore cells in these species synthesize haemoglobin. Possible other functions of pore cells are briefly discussed. 相似文献
993.
The 525 strains of heterotrophic bacteria isolated from natural and cultured populations of the mussel Mytilus trossulus and the surrounding seawater were identified to a genus level on the basis of phenotypic analysis and the fatty acid composition of cell lipids. Gram-negative isolates were dominated by six genera of the family Enterobacteriaceae and by the genera Pseudoalteromonas, Vibrio, Photobacterium, Cytophaga/Flavobacterium/Bacteroides, Pseudomonas, and Moraxella. Gram-positive isolates were mainly represented by the genus Streptomyces. The taxonomic compositions of natural and cultured populations of the mussel M. trossulus in Peter the Great Bay were similar. 相似文献
994.
Thaoge M.L. Adams M.R. Sibara M.M. Watson T.G. Taylor J.R.N. Goyvaerts E.M. 《World journal of microbiology & biotechnology》2003,19(3):305-310
With the aim of improving the safety and nutritional quality of traditional African weaning porridge, the reduction of the viscosity of a high solids fermented pearl millet porridge by addition of sorghum malt (amylase rich flour, ARF) was investigated. The effect of fermentation, cooking, malt addition and recooking on the microflora of, and the survival of an inoculated pathogen were determined. Addition of 5% (w/v) sorghum ARF to the gelatinized millet porridge gave an acceptable viscosity of 2500–3000 cP at a high solid content of 30%. Fermentation inhibited the growth of microorganisms in the porridge and recooking the fermented porridge after sorghum ARF addition further eliminated (<102 c.f.u./g) the moulds and coliforms that were introduced with the sorghum ARF. The recooked, fermented millet plus sorghum ARF porridge prevented the proliferation of the inoculated Escherichia coli and reduced it to <102 c.f.u./g within 18 h. The porridge could supply children under 3 years with the daily required protein using 1.4 feedings per day and required energy with 4 feedings a day. 相似文献
995.
Morphological and histochemical examination of the blood and connective tissue of the freshwater snail Lymnaea stagnalis injected with various types of foreign particulate materials has shown the existence of free as well as fixed phagocytic cells. The morphology of the fixed phagocytes is described, and the phagocytic system of the snail is compared with that of other molluscan species. 相似文献
996.
Xinzhen Wang Ruiyong Jing Junjie Liu Zhenhua Yu Jian Jin Xiaobing Liu Xiaojuan Wang Guanghua Wang 《中国病毒学》2016,31(2):188-191
Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s12250-015-3673-5 and is accessible for authorized users. 相似文献
997.
998.
Exposure to contaminants below lethal concentrations may affect the performance of organisms, resulting in measurable differences in behavior. We measured the response of the benthic invertebrate Gammarus pulex (Crustacea, Amphipoda) to sublethal concentrations of three pharmaceuticals, fluoxetine, ibuprofen and carbamazepine, and the cationic surfactant cetyltrimethylammonium bromide (CTAB). Responses in behavior during exposure were analyzed using the multivariate method of Principal Response Curves (PRC). The PRC results show that exposure to low pharmaceutical concentrations (range 1–100 ng/l) resulted in increased ventilation, whereas exposure to control or to high concentrations (1 μ g/l–1 mg/L) resulted in increased locomotion. Exposure to CTAB resulted in decreased locomotion and increased ventilation at increasing concentrations. The results of our experiments indicate that increased ventilation can be used as a general sign of stress, but not necessarily an early warning signal for mortality. 相似文献
999.
The fluviatile Rhinogobius sp. 1 (hereinafter R. sp. 1) (Japanese name kibara-yoshinobori or English name yellow belly medium-egg type) is broadly distributed in the Ryukyu
Islands ranging from Amami-oshima Island to Iriomote Island. However, based on the molecular evidence, this species has probably
had multiple origins from amphidromous species. We compared the coloration of specimens at Amami-oshima I. with that of the
other specimens (islands) in the Ryukyu Is. Amami-oshima I. specimens of R. sp. 1 were different from the specimens of other populations in having five to six cross lines on the caudal fin. We examined
the early life history of fluviatile Rhinogobius at Amami-oshima I., based on rearing experiments, and estimated the age of wild specimens by counting otolith increments.
Spawned egg capsules of “Rhinogobius sp. 1” at Amami-oshima I. were larger than those of amphidromous species. Their developmental stage in newly hatched larvae
was similar to that of Okinawan R. sp. 1 in having a straight notochord; however, it had a flexed notochord earlier than that of Rhinogobius sp. 2 (hereinafter R. sp. 2) (aobara-yoshinobori or blue belly medium-egg type). The ontogenetic trajectory of “Rhinogobius sp. 1” in Amami-oshima I. was similar to Okinawan R. sp. 1 (30 days in larval duration) but different from R. sp. 2 (15 days). In amphidromous relatives of R. sp. 2, developmental timing during larval period was earlier than in the amphidromous relatives of R. sp. 1. It has been suggested that the phenomenon of fluvial landlocking has been accompanied somewhat by egg size increase
(on the basis of a few examples). However, the ontogenetic trajectories of fluviatile Rhinogobius species may be a reflection of those of ancestral amphidromous species.
Received: March 18, 2002 / Revised: November 7, 2002 / Accepted: December 10, 2002 相似文献
1000.
Twenty-four weeds commonly found in commercial potato fields in Quebec were evaluated for their host suitability to the root-lesion nematode, Pratylenchus penetrans, under greenhouse conditions. Brown mustard (Brassica juncea) and rye (Secale cereale) were included as susceptible controls and forage pearl millet hyb. CFPM 101 (Pennisetum glaucum) as a poor host. Pratylenchus penetrans multiplied well on 22 of the 24 weed species tested (Pf/Pi ≥ rye or brown mustard). Cirsium arvense, Leucanthemum vulgare and Matricaria discoida were classified as very good hosts with a Pf/Pi ranging from 1.60 to 2.54, while Ambrosia artemisiifolia and Cyperus esculentus were classified as poor hosts with a Pf/Pi from 0.01 to 0.15. Amaranthus powellii, A. retrqflexus, Raphanus raphanistrum, Rorippa palustris, Cerastium fontanum, Spergula arvensis, Stellaria media, Chenopodium album, Vicia cracca, Elytrigia repens, Digitaria ischaemum, Echinochloa crusgalli, Panicum capillare, Setaria faberii, S. pumila, S. viridis, Polygonum convolvulus, P. scabrum and P. persicaria were intermediate hosts with Pf/Pi values ranging from 0.33 to 2.01. The plant species and the botanical family had a significant impact on nematode reproduction. The Brassicaceae family resulted in the greatest reproduction of P. penetrans, and the Cyperaceae resulted in the least. The plant life-cycle (annual vs. perennial) had no impact on nematode population. 相似文献