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1.
A.M. Avis 《African Zoology》2013,48(4):351-355
Diogenes brevirostris was found to be tolerant to low salinities (0,5 - 4,0 %) at a wide range of temperatures (12 to 27°C). Tolerance to temperature and salinity were inversely related. At low salinities (0,5 and 1,0 %) the rate of mortality increased with temperature throughout the range, whereas at higher salinities (1,5 and 4,0 0/00) temperature had no effect on mortality. These results are discussed in relation to the distribution of D. brevirostris in estuaries. It appears that temperature and salinity tolerance are not solely responsible for limiting distribution of these crabs to estuary mouths.  相似文献   

2.
《African Zoology》2013,48(1):118-123
The aquatic oxygen consumption of the estuarine brachyuran crab, Cyclograpsus punctatus, was investigated after a 24-hour acclimation period at different temperature (12.5, 20, 30°C) and salinity (9, 17.5, 35, and 44°) combinations . Salinity had no significant effect on oxygen consumption at 12.5 and 20°C in both large and small crabs. At 30°C and 44°, however, the rate of oxygen consumption declined in large crabs (from 0.233 to 0.176 mg O2 g wwt/h) and increased in small crabs (0.300 to 0.469 mg O2 g wwt/h). There was also a significant increase in the oxygen consumption (0.300 to 0.536 mg O2 g wwt/h) of small crabs at the high temperature/low salinity combination. Temperature had a significant effect on the rate of oxygen consumption at all salinities, with Q10 values ranging from 1.16 to 2.85. In all cases the mass-specific oxygen consumption rate of small crabs was higher than that of large crabs. The results suggest that the confinement of this species to the lower reaches of estuaries may, in part, be due to physiological constraints on juveniles and small individuals.  相似文献   

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Morphological information on the reproductive system allows the understanding of ecological and behavioural aspects of different species as well as supports the development of conservational strategies. Unfortunately, for many species, not enough relevant and precise information is available. In the present study, we describe for the first time the macroscopic and histological aspects of female genital organs and external female genitalia of Saimiri macrodon, Saimiri cassiquiarensis and Saimiri vanzolinii. We perform a comparison between these three peripatric species and investigate the possibility of their reproductive morphology to act as a factor of reproductive isolation. We have found that these species share many similarities in most of the analysed organs. Although some important differences were identified that may play an important role in the evolution of the components of the reproductive system of these species, those differences are not enough to compose a mechanism of reproductive isolation for these three species of Saimiri. The results of this study may be used to support the development of biotechnological approaches of reproduction and strategies for conservation programmes and management of threatened species of this genus, particularly S. vanzolinii, considered to be a vulnerable species to extinction.  相似文献   

6.
Abstract

Morphological studies were carried out on adult postmetamorphic females of three native South American genera of Lernaeidae (Crustacea: Copepoda: Cyclopoida) and these were compared with the imported species Lernaea cyprinacea. Two of the native species represent new genera, which are described as Amazolernaea sannerae gen. et sp. nov. and Bedsylernaea collaris gen. et sp. nov. The third native species had already been described as Perulernaea gamitanae Thatcher and Paredes, 1985. Amazolernaea sannerae from the cichlids Cichla monoculus and speckled pavon C. temensis was characterized as having four similar petal-like anchors, a long slender neck, thoracopods 1 and 2 close together, and a genital pore located equatorially in the well-developed hindbody. Bedsylernaea collaris differs from all known lernaeids in having a large inflated head region with one bulbous anchor on either side, a slender neck, a stout hindbody with a large pregenital prominence, a genital pore that is anterior to the midpoint on the hindbody, and collar-like extensions on the anterior extremity of the hindbody. Perulernaea gamitanae has two large and two small unbranched anchors, a long neck with prominent glands, and an elongate hindbody with a genital pore that is posterior to the midpoint. In contrast, all valid species of Lernaea have four frequently branching anchors, a neck region and hindbody that are not well defined, a short abdomen, and a genital pore at or near the posterior extremity.  相似文献   

7.
The anatomy of the neck and forelimb of Chrysochloris asiatica is described and illustrated. The sequence of events during digging and modifications for fossorial action are described. Modifications include the appearance of a third bone in the forearm; the shortening and fusion of bones in the manus; enlarged processes on the scapula, humerus and ulna for greater muscle attachment; enlarged neck muscles and a dip in the spine in the cervical region to accommodate these and the enlarged shoulder muscles; an enlarged occiput for insertion of the powerful neck muscles; a greatly enlarged triceps and movement of the shoulder girdle to a position anterior to that normal in mammals. The possibility of the third forearm bone being the ossified tendon of a flexor muscle is discussed, without any conclusion being reached as to its true origin.  相似文献   

8.
Norileca indica (Milne Edwards, 1840) is fully redescribed based on ovigerous females collected from Maputo Bay, Mozambique, from the branchial cavity of the fish host Selar crumenophthalmus Bloch, 1793. An identification key to the species of Norileca Bruce, 1990 is given. Furthermore, a fragment of the mitochondrial cytochrome oxidase I (COI) gene from N. indica was sequenced for the first time. This is the first molecular characterisation of a species of Norileca.  相似文献   

9.
The attachment of the piscine gill parasite, Ergasilus mirabilis Oldewage & van As, 1987 is described by means of scanning electron microscopy and light microscopy. A variety of sensory structures occur on and around the host contact surface of the parasite and proliferation of gill tissue occurs at the site of attachment. It would appear that this proliferation of host tissue results from the feeding behaviour of the parasite rather than the actual attachment thereof.  相似文献   

10.
This paper points out a situation in which a particular phalangeal modification in the genus Hemidactylus has been constantly interpreted in an erroneous manner. Conclusions about the actual situation result from the study of a wide range of genera and the modifications discussed may be utilized to set aside a particular assemblage of gekkonine geckos on the basis of the possession of a particular set of synapomorphies. The functional significance of this particular suite of modifications is considered and its probable evolutionary origin outlined. It is pointed out that particular phalangeal modifications are better indicators of phylogenetic affinity than are simple phalangeal counts.  相似文献   

11.
本文旨在研究微生物发酵豆粕对仔猪生长及血清指标的影响,并且根据肠道组织形态学的微观变化,评价了不同处理的豆粕对早期断奶仔猪肠道形态的影响.选用60头35日龄断奶体重为(8.62±0.21)kg的同窝杜×长×大仔猪,分为试验组和对照组,每组3个重复,每个重复10头,分别饲喂以普通豆粕为对照组,微生物发酵豆粕为试验组的日粮.试验结果表明:饲喂微生物发酵豆粕使仔猪料重比降低8.39%(P<0.05),腹泻指数降低39.96%(P<0.01),血清尿素氮含量降低39.47%(P<0.01),血清IgG含量降低6.35%(P<0.05).豆粕经微生物发酵后减轻饲粮中大豆蛋白对肠道的过敏损伤,使肠道维持良好的结构形态,从而促进营养物质的消化吸收.  相似文献   

12.
The Plesionika material, collected by the National Comprehensive Oceanography Survey from the East China Sea in 1959, has been found to contain three species: P. izumiae Omori, 1971, P. marita orientalis Chace, 1985, and P. ortmanni Doflein, 1902. The ranges, population numbers, population density, and ratios of males, non‐ovigerous females and ovigerous females of P. izumiae were found to vary seasonally.  相似文献   

13.
探讨家蚕不同饲料营养与抗性生理的关系对家蚕的病理生理及蚕病预防研究具有重要意义。自4龄起蚕开始用柘树叶和桑叶分组饲养,调查家蚕的生长发育状况,并连续10 d分别检测蚕体内与抗性相关的酶活性。结果表明:柘叶饲养组不仅蚕体重和体长的增长小于桑叶饲养组,而且上蔟率、结茧率、全茧量及茧层量均显著低于桑叶组;柘叶饲养组蚕体内的碱性磷酸酯酶、乙酰胆碱酯酶及羧酸酯酶活性平均值分别为0.070 8、14.129 0、632.557 1 U/mL,桑叶饲养组蚕体内的碱性磷酸酯酶、乙酰胆碱酯酶和羧酸酯酶的活性平均值分别为0.076 4、15.189 0、628.055 1 U/mL,与桑叶饲养组相比,柘叶饲养组蚕体内的碱性磷酸酯酶和乙酰胆碱酯酶活性显著降低,而羧酸脂酶的活性显著提高(P<0.05)。由此认为,家蚕采用拓叶饲养会在一定程度上影响蚕体的生理代谢,降低蚕体对不良环境的抵抗能力。  相似文献   

14.
The aim of this study was to investigate the morphology and ultrastructure of the pronephros of Testudo hermanni as observed in the earlier part of its development. This paired structure appears during renal ontogenesis and originates from the first somites localised in the cephalic part of the embryo. The first pronephric evidence is noted at stage 12. The kidney is composed of large glomeruli that are devoid of a capsule and protrude into the coelomic cavity. A ciliated nephrostome provides access to short renal tubules, lined with a well-developed brush border. Two nephric ducts on the lateral sides of the embryo are connected to the tubules. The cytological characteristics of the pronephric structure suggest that it might be functional, at least in the first part of development. The pronephros of Testudo hermanni regresses after a short time around stage 18, while the mesonephros is already well differentiated. Its plesiomorphic characteristics, similar to those observed in amphibians, might be related to the phyletic position of chelonians within the reptiles.  相似文献   

15.
采用人工紫外线辐射(UV-B)增强处理多年生牧草品种冷地早熟禾(Poa crymophila Keng).、垂穗披碱草(Elymus nutans Griseb).和中华羊茅(Festuca sinensis Keng)种子,测定其发芽率、苗长、胚根/胚芽比值,以研究UV-B辐射对牧草种子萌发及出苗的影响。结果表明:紫外线增加0.50 W.m2时,对三种牧草种子的发芽率、苗长和胚根/胚芽的影响均不明显;增加1.00 W.m2时,对三种牧草种子的发芽率有影响但均不显著;对3种牧草种子的苗长和胚根/胚芽的影响显著;增加1.25 W.m2时,3种牧草中的发芽率差异不显著,而幼苗和胚根/胚芽值差异均显著。3种牧草的影响程度由大到小依次为:中华羊茅、垂穗披碱草、冷地早熟禾,说明增加UV-B辐射不会影响到高寒草地上主要禾草的种子萌发。  相似文献   

16.
经对宁夏4个地区1085只家兔和35只野兔的调查,发现有3种双腔属(Dicrocoelium)吸虫:矛形双腔吸虫(D.lanceatum)、东方双腔吸虫(D.orientalis)和中华双腔吸虫(D.chinensis)。其中后2种为宿主新纪录。它们在家兔中的感染率依次为4.2%、1.8%、0.4%,在野兔中的感染率依次为14.3%、5.7%、5.7%。中华双腔吸虫呈纺锤形,体长5.702~6.934mm,体宽1.091~1.549mm,长宽比4.9:1,睾丸并列,阴茎囊椭圆形并达腹吸盘前缘,卵黄腺起自于睾丸之后、卵巢之前水平处;其余2虫种的形态与记载的基本一致。  相似文献   

17.
The copper concentration detected in the water and sediments of the Natalspruit River, Bronkhorstspruit River and Nooitgedacht Dam exceeded certain stated limits for the protection of aquatic life. Despite considerable individual variation, the general ranking of copper concentrations in the various tissues was carapace < muscle < gonads < midgut gland < gills. Seasonal variation was detected in the bioaccumulation of copper in crabs sampled from the Natalspruit River. However, this phenomenon did not occur in crabs from the other two water bodies. A significant increase in copper concentrations was detected with a decrease in size, indicating that the size of the crabs is an important influencing factor in the bioaccumulation of copper. It was also found that more copper accumulated in the ovary than in the testis per unit weight. The bioaccumulation factors (BF) calculated for the different tissues with respect to the water were highest in the gills and midgut gland (785,00 – 1257,50 and 432,00 – 1340,00, respectively). The BF with respect to the copper concentration in the sediments was comparatively low for all the tissues (<0,10 – 2,74). It appears that P. warreni is able to regulate the copper concentrations in its various tissues and is therefore not a suitable indicator of the presence of copper in the aquatic environment.  相似文献   

18.
Peripheral blood smears from four adult reindeer (Rangifer tarandus) were examined after staining with Romanowsky's stain and cytochemical stains, including alpha-napthyl butyrate esterase (alpha-NBE), Sudan black B (SBB), chloroacetate esterase (CAE) and alkaline phosphatase (ALP). Romanowsky-stained eosinophils, neutrophils, lymphocytes and monocytes resembled those of cattle, sheep and goats. Basophils had two different staining patterns with Romanowsky's stain. Basophils that we termed "grey basophils" were similar in appearance to grey eosinophils in Greyhound dogs, with medium blue-grey to lavender-grey cytoplasm containing varying numbers of clear vacuoles or granules and variable numbers of small, intensely basophilic, perinuclear granules. The second basophil staining pattern was more typical of ruminant basophils, with uniform, pale to dark basophilic cytoplasmic granules. Basophils stained positive for alpha-NBE, SBB, CAE, and ALP. Eosinophils stained positive for SBB, and were negative for alpha-NBE, CAE, and ALP. Neutrophils were negative for SBB, CAE, and ALP. Monocytes stained positive for alpha-NBE, were rarely positive for CAE and SBB, and were negative for ALP. Transmission electron microscopy revealed matrix within all granulocytes granules, including those of basophils.  相似文献   

19.
南岭山脉三节叶蜂科昆虫种类和区系   总被引:1,自引:0,他引:1  
游群 《草业学报》2009,18(5):130-135
南岭山脉共有三节叶蜂28种,隶属于膜翅目叶蜂总科,其中南岭山脉特有种3种。区系分析表明,东洋种22种,占78.57%;其余6种为东洋古北兼有种,说明南岭山脉的三节叶蜂以东洋种占优势。南岭山脉三节叶蜂在我国动物地理区划中共有9个区系组合;其中最多的是华中+华南种,其次是华中种,两者之和已达物种总数的60.72%。南岭山脉不同自然保护区、不同海拔、不同植被类型间三节叶蜂的Jaccard相似性系数均小于0.5,属极不相似或中等不相似。  相似文献   

20.
为了明确芥子油苷对2种色型豌豆蚜生长、存活及体内保护酶的影响.本研究采用豌豆蚜(Acyrthosiphon pisum)全纯人工饲料薄膜饲养技术,通过添加不同浓度(CK:0 μmol·g-1;A1:0.94 μmol·g-1;A2:1.87 μmol·g-1;A3:2.86 μmol·g-1)的芥子油苷,测定了豌豆蚜的...  相似文献   

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