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991.
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Abstract. Under controlled laboratory conditions of 28–30o C and 16:8 L:D photoperiod, an attempt was made to develop an age-grading technique for Anopheles culicifacies males. Mating activity was maximal when females were 5–12 days old and males were 5–7 days old. The numbers of total and mature spermatocysts declined significantly with age, and the proportion of the testes occupied by the sperm reservoir increased as virgin males grew older. Mating resulted in the loss of spermatozoa and accessory gland substance from the reproductive system. Loss of mating ability of older virgin males seemed to be age-related, because the reproductive system contained ample supplies of accessory gland substance and spermatozoa. Morphological changes of the reproductive system, due to mating and age, were used to infer the age and reproductive history of unknown males in a laboratory evaluation. 相似文献
993.
Based upon thermocouple implantation, thermal preferenda and voluntary maxima for the head and body were studied in three individuals of Ophisaurus attenuatus attenuatus collected in Texas. Calculated grouped data for the head and body mean preferred temperature were 31.2°C (range 29.O° -34.7°C) and 31.8°C (range 30.3° -34.5°C) respectively. Gaping or panting were found to be absent in the O. a. attenuatus examined in this study. 相似文献
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SAMUEL S. BOWSER STEPHEN P. ALEXANDER WILLIAM L. STOCKTON TED E. DELACA 《The Journal of eukaryotic microbiology》1992,39(6):724-732
The seemingly delicate, strand-like pseudopodia of Astrammina rara , a carnivorous benthic foraminiferan, adhere to and withstand the rigorous movements of meiofaunal prey. Previous electron microscopic studies identified two novel structures that might account for the unusual tensile properties of these pseudopodia: 1) an extensive, coiled microtubule cytoskeleton and 2) a fibrous extracellular matrix vesting the pseudopodial surface. In the present study, we found that pseudopodial networks microsurgically removed from A. rara's cell body captured Artemia metanauplii as efficiently as intact organisms, and therefore used them to test the role of microtubules and extracellular matrix components in augmenting pseudopodial strength. Agents that specifically disassemble micro-tubules (1 mM colchicine or 20 μM nocodazole) or generally disrupt pseudopodial integrity (heat, 10 mM formaldehyde, 1 mg/ml saponin) failed to inhibit prey capture. All of these treatments left the extracellular matrix intact as revealed by immunofluorescence and scanning electron microscopy. The elastic and tensile properties of the extracellular matrix, isolated by solubilization of pseudopodial cytonhsm using the nonionic detergent Triton X-100, were similar to those of intact pseudopodial networks when assayed with calibrated microneedles or a flexible rubber substrate. These observations indicate that A. rara uses a fibrous extracellular matrix to augment cytoplasmic tensile properties. 相似文献
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ODOR INTENSITY: MIXTURES AND MASKING 总被引:4,自引:4,他引:0
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