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1.
北京出入境检验检疫局从美国进境旅客携带的石榴中检出欧洲球螋。了解欧洲球螋的基本特性,能为相关部门对其检疫鉴定提供参考依据。对欧洲球螋的相关文献进行了查阅和整理,详细介绍了欧洲球螋的分类地位、分布、形态特征及近似种等信息,我国出入境检验检疫部门对球螋属的截获情况,讨论了欧洲球螋的检疫意义。认为欧洲球螋在我国无分布且具有一定的入侵风险,口岸应对该虫引起足够的重视。  相似文献   

2.
Only single cells in the carrier fish species Carassius carassius (Linnaeus, 1758) for koi herpesvirus (KHV) are infected in contrast to large numbers in the susceptible species common carp Cyprinus carpio (Linnaeus 1758). Several species of the family Cyprinidae have been described as virus carrier species, showing no clinical signs of a KHV disease but able to transmit the virus to other susceptible fish. In this study, 72 common carp Cyprinus carpio (Linnaeus, 1758), 36 tench Tinca tinca (Linnaeus, 1758), 36 crucian carp Carassius carassius (Linnaeus, 1758) and 36 common roach Rutilus rutilus (Linnaeus, 1758) were experimentally infected with KHV (isolate “Israel”) by immersion and kept at 20°C. The fish were euthanized at 12 timepoints over a period of 90 days and virus DNA was quantified in tissues by a real‐time TaqMan PCR. Whereas KHV‐DNA was found in Cyprinus carpio for up to 90 days, the virus DNA was detectable only in single individuals of Rutilus rutilus, Tinca tinca and Carassius carassius for up to 25 days after experimental virus exposure. Tissue samples of Cyprinus carpio and Carassius carassius were screened by in‐situ hybridization. Positive signals were found in various organs of the common carp tested crucian carp. In the latter species a much smaller number of virus‐positive stained cells was detected compared to the infected carp.  相似文献   

3.
Manganaro, M., Laurà, R., Guerrera, M.C., Lanteri, G., Zaccone, D. and Marino, F. 2011. The morphology of gills of Haliotis tuberculata (Linnaeus, 1758). —Acta Zoologica (Stockholm) 93 : 436–443. Although the morphology of abalone gills has been studied by some authors, up to date no data are available about the gills of Haliotis tuberculata. This study was carried out, by light and electron microscopy, on 10 wild adult H. tuberculata. Gills lamellae produce an undulated surface increasing the area in contact with water. At the level of skeletal rods, we observed a joint‐like structure that allows a checked movement. The left ctenidium is always decidedly larger than the right, probably because of the enormous size of the shell muscle. The cilia permit oxygenated water that leaves the afferent border and is thrust away at the tips of the lamellae by the extremely long cilia. Ciliary movement may take part in sweeping mucous secretions to capture extraneous particles and remove them from the gills. Three types of mucous cells are distributed along the epithelium of the afferent and efferent zones of the gill filament. They seem to play a role in the cleansing of gills in coordination with the muscle contraction and ciliary movement. The presence of microvilli on particular cells reflects their role associated with the absorption of substances from the environment. A haemolymphatic vessel is located in the central zone of the gill filament. The backbone of the haemolymphatic vessel is a chitino‐like structure, which gives support to the gills.  相似文献   

4.
The first objective of the actual project was to investigate if mucus from Salmo trutta (Linnaeus, 1758) and Thymallus thymallus (Linnaeus, 1758) is suitable for DNA extraction. In the second step, it was analyzed if the avoidance of environmentally hazardous chemicals could lead to sufficiently pure DNA isolation. Finally, it was examined if samples taken from different fish body parts yielded different grades of purity of the extracted DNA. Mucus was collected from 552 individuals of S. truttaand T. thymallusfrom 2012 to 2015. DNA was extracted with two different kits (E.Z.N.A.® Insect DNA Kit and my‐Budget DNA Mini Kit) and two different swabs (my‐Budget roughened laminated sterile cotton swabs and common autoclaved cotton swabs). The results showed that the my‐Budget DNA Mini Kit in combination with the my‐Budget roughened laminated sterile cotton swabs was the most suitable method. It is a non‐destructive and swift technique that results in the concentration of DNA being high and pure.  相似文献   

5.
6.
Candan, S., Suludere, Z. and Bayrakdar, F. 2007. Surface morphology of eggs of Euproctis chrysorrhoea (Linnaeus, 1758). —Acta Zoologica (Stockholm) 88 : 000–000. Filaments covering the egg batches and chorion structure were studied both by light and scanning electron microscopy in the brown‐tailed moth Euproctis chrysorrhoea (Linnaeus, 1758). Females lay eggs in masses on the underside of apple leaves. The egg batches are covered with brown hairs derived from the bodies of the female. Each female lays about 200–400 eggs. The spherical eggs are about 0.84 mm long and 0.47 mm wide. Newly deposited eggs are golden‐yellow and darken after the onset of embryonic development. The micropylar area appears somewhat depressed and has a circular outline. The region is surrounded by a rosette of 10–12 petal‐shaped primary cells, which are completely surrounded by a series of secondary and tertiary cells. The remainder of the egg is largely smooth, but shows aeropyles. These are located in the corners of ill‐defined polygons.  相似文献   

7.
The aquaculture sector has recently focused on alternative food sources due to increased costs and limited resources. Live food sources, such as invertebrates, have important roles in digestion processes of fish. It was aimed to determine the reproduction efficiency of the horse leech, Haemopis sanguisuga, which is expected to be used as an alternative live nutritional source in aquaculture in this study. The study was conducted at ambient temperature in the laboratory conditions for three months. A total of 25 gravid leeches with an average body mass of 6.91 ± 2.20 g were used. The leeches lost up to 75% of their body mass and laid 4.30 ± 1.49 cocoons at 12.0 ± 8.2 days interval during cocoon laying period. Leeches stopped laying cocoon when the temperature fell to 16 °C. The average of offspring hatched from the cocoons was 6.45 ± 2.86. The length–body mass relationship of the offspring was exponential (W = 0.012L2.809, R2 = 0.898). The results from the current study indicate that the basic biological parameter affecting the reproduction efficiency of H. sanguisuga is the size of the broodstock leeches, and reproduction activity weakens the broodstocks.  相似文献   

8.
Orang-utan crania with alterations in bone structure which could be determined morphologically were studied and evaluated. The alterations in bone structure were referred to in the literature up to about 1939 as "rickets"; when vitamin D was given to the animals, the alterations diminished, until they were almost unnoticeable. From about 1941/52, the alterations were diagnosed as "Morbus Paget". Research on orang-utan crania has become possible through comparison of a larger number of single symptoms, occurring in a number of individuals. Out of a larger sample, the study was carried out on 5 individuals, showing these alterations in varying degrees. The individuals also covered various age groups, both sexes and both subspecies of orang-utans. The findings permit a diagnosis of secondary (or tertiary) hyperparathyroidism (= Morbus Engel-von Recklinghausen = fibrous cystic osteitis). The study also showed that orang-utans fall prey to Morbus Engel-von Recklinghausen in a shorter period and suffer more severely than humans. The frequency of orang-utans suffering from this disease, which are kept captive in zoos, is statistically far higher than the occurrence in humans. Orang-utans living under natural conditions do not suffer from the disease at all; according to the study of 500 animals. The authors also believe that there is a psychogenic basis for the occurrence of Morbus Engel-von Recklinghausen in zoo animals; psychological conditions such as apathy, disinterest, etc. are part of the illness, and these symptoms are also shown by animals having no outward signs of fibrous cystic osteitis. The authors believe that improved prophylaxis of orang-utans in zoos would lead to discovery of Morbus Engel-von Recklinghausen in early stages, and allow early therapy to arrest the disease. This is necessary for preservation of the species.  相似文献   

9.
Lenk P  Fritz U  Joger U  Wink M 《Molecular ecology》1999,8(11):1911-1922
The phylogeny and phylogeography of Emys orbicularis was inferred from mitochondrial nucleotide sequences of the cytochrome b gene analysed by DNA sequencing and RNA heteroduplex analysis. Within the family Emydidae the monotypic genus Emys is affiliated with the nearctic taxa Emydoidea blandingii and Clemmys marmorata. The analysis of 423 individuals of E. orbicularis, originating throughout its distribution range, revealed a remarkable intraspecific differentiation in 20 different haplotypes with distinct geographical ranges. Maximum parsimony analysis produced a star-like phylogeny with seven main lineages which may reflect separations in the late Pliocene. The haplotype distribution examined by partial Mantel tests and analysis of molecular variance revealed a substantial effect of glacial periods. This historical perspective suggests the existence of multiple glacial refugia and considerable Holocene range expansion which was modulated by climatic traits. Further support is gained for the occurrence of long-term parapatry in glacial refugia.  相似文献   

10.
The effect of beaver (Castor fiber Linnaeus, 1758) activity on amphibian reproduction was studied in the small river valleys in Novgorod oblast. At sites not subjected to beaver activity, the reproduction rate of amphibians was low. In spring the water in beaver ponds warms up quickly, which attracts amphibians for reproduction. The maximal abundance of tadpoles due to a high reproduction rate was observed in partially drained ponds. However, a high larvae mortality rate was often observed there. Tadpole survival in flooded and empty ponds depends on factors that are not controlled by beavers, such as geomorphology and climate.  相似文献   

11.
We present data for eight polymorphic microsatellite markers isolated from a microsatellite-enriched DNA library for the freshwater snail Radix balthica. Three of them were specific for R. balthica while five also amplified polymorphic products in two congeneric species. Test application on populations from all over the species range has shown that these loci are highly informative for analysing population structure and estimating migration rates. Observed deviations from Hardy-Weinberg equilibrium are attributed to a mixed mating system.  相似文献   

12.
The aim of this study was to identify the potential for optimizing management of sperm quality during commercial reproduction of pikeperch Sander lucioperca. Sperm from different males is often pooled prior to fertilization or stored for short periods (hr) until ovulated eggs become available. A novel approach was applied to assess pooling effects by cross‐wise transfusion of sperm and seminal fluid (SF) of males with differing initial sperm quality. In addition, the effects of two different buffers (glucose and KCl) were tested, as well as a supplementation of melatonin and progesterone (1 mmol L?1) to maintain or improve the quality of freshly stripped and incubated (0.5, 1, 2, 4 and 24 hr) sperm. Sperm motility and curvilinear velocity (VCL) were measured by computer assisted sperm analysis (CASA). The VCL proved to be a more sensitive, reliable parameter compared to motility, since significant differences occurred up to 3.5 hr earlier. Transfusion of SF between low and high quality sperm resulted in a significant decrease in sperm with high initial VCL (seven out of 22 transfusions), whereas VCL of low quality sperm could not be improved. In only one case did a transfusion result in an increased VCL. No treatment prevented a significant quality loss over 24 hr or even enhanced sperm performance. Conclusively, pooling sperm of different qualities as well as short‐term storage has a significant, negative impact on overall sperm quality. Pooling should only be considered when the sperm quality is known.  相似文献   

13.
The reproductive features of Spondyliosoma cantharus were studied in the Gulf of Tunis to contribute to better fisheries management on a regional scale and to broaden knowledge on whether there are actual performance differences compared to others areas. A total of 369 fish were caught by trammel and gill nets in the Gulf of Tunis from January 2005 to June 2006. Sex‐ratio, gonad maturation, size and age at maturity, sexual cycle, condition and reproductive strategy were determined. The male : female ratio was initially skewed in favour of females, with males predominating in larger sizes. Length of females at first maturity was 17.8 cm TL (n = 141), which corresponds to 4 years of age. A recommendation is made to increase the length at capture. Spawning season extends from January to May, with a peak in March–April correlated to the lowest sea surface temperatures (14.8–15.6°C); during this period, a dichromatism arises between males and females. The hepatosomatic index and the condition factor present significant monthly changes in relation to the breeding activity. The bimodal size frequency distribution, the biased sex ratio, and the presence of bisexual gonads outline a protogynous hermaphroditism; diandry should be confirmed.  相似文献   

14.
The Atlantic cod (Gadus morhua) is an important natural resource for northern societies and is now also considered to be a promising candidate for aquaculture. In recent years, much effort has been directed towards the development of genomic tools, and genome initiatives for Atlantic cod have been established. Despite the growing attention devoted to the Atlantic cod genomics, basic aspects of its genome structure and organization remain unknown. Thus, the present work aims to study cytogenetic features of the Atlantic cod as a contribution to the knowledge of this species' genome. The Atlantic cod displays a diploid number of 46 chromosomes, with a karyotypic formula 16 m/sm + 30 st/t. Conventional karyotyping was improved by chromosomal mapping of two classes of repetitive sequences. 18S rDNA clusters were assigned to pairs 2 and 4; small amounts of 18S rDNA clusters were occasionally detected on pair 5. These findings could not be related to the geographical origin of the specimens, but were consistent with the variability of these repeated genes in fish in general. 5S ribosomal gene clusters, apparently corresponding to a single 5S rDNA class, were detected on twelve chromosomes (pairs 11, 12, 14, 17, 20 and 21). The present update of the existing but meagre information on the karyotype of Atlantic cod, plus the first physical mapping of repetitive genes in this species herein, opens the way for an integrated approach that combines genetic and physical mapping with the assembly of the genome of this commercially important species.  相似文献   

15.
The behavioral decisions of wild animals are influenced by the often conflicting needs to both feed efficiently and to avoid predators. Information regarding how lagomorphs such as the mountain hare (Lepus timidus) balance these factors throughout the day-night cycle is largely lacking despite its importance to management.To better understand the type and proportion of various behaviors the mountain hare engages in over the course of a 24-hour period, I monitored the behavior of six mountain hares under controlled conditions from early to mid-winter. The mountain hares spend the majority of their time resting (mean ± standard deviation: 32.4 ± 14.4%) and under canopy (22.4 ± 18.7%), and a smaller proportion of their time feeding (16.2 ± 6.1%). Activity peaks over the course of the 24-hour cycle reflect natural behavior patterns that emphasize the reduction of predation risk. The sunrise phase is characterized by the search for a suitable resting place; the day phase by resting and hiding. The sunset phase is characterized by the search for food, and the night phase by an equal mix of food intake and movement through the home range. These results can help land managers predict how factors such as increasing tourist activity (perceived by the hare as a safety threat) will influence the behavior of free-ranging mountain hares.  相似文献   

16.
Adiaspiromycosis is primarily a necrotizing granulomatous pneumonia caused by a dimorphic fungus of the genus Emmonsia. A young crested porcupine (Hystrix cristata) found dead showed multiple fractures, chronic pleuritis, and granulomatous pneumonia. Microscopically, cystic structures were consistent with adiaspiromycosis by Emmonsia crescens. The diagnosis was confirmed using molecular methods.  相似文献   

17.
Etmopterus spinax Linnaeus, 1758 is a deep-sea lantern shark that emits blue light thanks to thousands of tiny cup-shaped organs made of a pigmented sheath enclosing light-emitting cells topped by an iris-like structure and a lens. In this study, we investigate the ultrastructure of these photophores in order to improve our understanding of the light emission process. The presence of a novel layer, a putative reflector upholstering the pigmented sheath, is highlighted. The intracellular organization of the photocytes is addressed. They appear as regionalized cells: their basal area is occupied by an ovoid nucleus, their medial area is highly vesiculated and their apical area, oriented toward the photophore center, displays small granular inclusions. We hypothesize this granular area to be the intracellular site of photogenesis in E. spinax, as it is also the most fluorescent part of the photocyte.  相似文献   

18.
We present details and characteristics of 123 novel polymorphic microsatellite DNA loci for Bombus terrestris. Thirty-four of these loci have been tested in nine other Bombus species and 25 of them showed polymorphisms in at least one species. These microsatellite DNA loci together with the already established 60 loci will be useful for characterizing wild and managed populations of B. terrestris and other Bombus species as well as for detailed genetic studies in including mapping studies and genome annotations.  相似文献   

19.
The feeding habits of Zeus faber Linnaeus, 1758 were studied by examining digestive tracts in I2 size classes of individuals. It is a stenophagus species which begins life feeding almost exclusively on zooplankton until it is about 80 mm long, then switches gradually from zooplankton to small demersal fish, and finally when > 140 mm switches to feeding exclusively on benthic and demersal fish. Mysids were the most important food component in Z.faber < 141 mm and Cepola macrophthalma (Linnaeus, 1758) in Z.fiber > 140mm. The switch to fish prey was followed by a greater body weight per unit length. Z.faber > 140 mm selected primarily for small-and intermediate-sized C. macrophthalma (and to a lesser extent for Callionymus maculatus Rafinesque-Schmaltz, 1810, Gaidropsarus sp. and Trigla Iyra Linnaeus, 1758). Our results suggested that the ratio of vertical to horizontal dimension of prey, the motion and coloration of prey as well as the visual capabilities and perceptual potentialities of Z. faber may all in a synergetic fashion account for prey type and size selection and the positive relations found between the size of Z.faber and the size and variance of its ingested prey. Possible co-evolutionary relationships between Z.faber and C. macrophthalma are also discussed.  相似文献   

20.
Tungiasis is a parasitic skin disease widespread in resource-poor urban and rural communities in Brazil. Inhabitants of an urban slum in Northeast Brazil were examined for the presence of tungiasis lesions and followed-up twice a week for a period of three weeks. Each time the number, stages, and topographic localization of lesions were recorded on a documentation sheet. The infestation rate (number of newly embedded sand fleas per individual and day) remained stable during the observation period. The infestation rate was significantly related to the intensity of infestation (total number of lesions present) (rho = 0.70, p < 0.0001) and the proportion of viable lesions (rho = 0.28, p < 0.0001). The results indicate that in an endemic area the infestation intensity and the proportion of viable lesions can be used as a proxy to assess the exposure of individuals at risk for tungiasis. Persistently high infestation rates during the transmission season favour the use of prevention measures against invading sand fleas (such as a repellent) rather than a drug to kill already embedded parasites.  相似文献   

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