首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The collection of land caenogastropod snails in the genus Cyclophorus Monfort, 1810 housed in the Natural History Museum, London (NHM), includes 52 type lots. Lectotypes have been designated for 43 available species-level names to stabilize existing nomenclature, two previously designated lectotype, two holotypes, one paratype, one syntype, one possible syntype and two paralectotypes are also listed. A complete catalogue of the Cyclophorus types in NHM, London is provided for the first time.  相似文献   

2.
 Several patterns of feeding behaviors have been documented in benthophagous fishes. The foraging behavior of the maiden goby, Pterogobius virgo, was studied at Kurahashi Island in the Seto Inland Sea, Japan. Pterogobius virgo foraged mostly on polychaetes by volume from among several available prey items by digging in the sandy bottom. The digging behavior comprised swing of only pectoral fins or of both pectoral fins and body. Pectoral fin swing exposed the cryptic prey within the bottom, and fins and body swing exposed the prey and washed the sediment away. The swings were repeatedly and continuously conducted at a site during the daytime, making a pit several centimeters deep in which the fish was located. After the prey was exposed, the fish immediately and rapidly picked up the prey. Polychaetes were abundant prey in the sediment, occurring in the layer 3–5 cm deep from the bottom surface in the study area. In this goby, spot-fixed fin digging, the first documentation of feeding habits in gobies, may be effective for feeding on the most valuable prey, i.e., polychaetes, which may be otherwise unavailable for this fish. Received: April 24, 2001 / Revised: April 26, 2002 / Accepted: May 7, 2002  相似文献   

3.
4.
Polydactylus kuru (Bleeker, 1853), originally described from Jakarta, Java, Indonesia, has been regarded as a valid species. However, examination of two syntypes of Polynemus kuru revealed their close similarity to three syntypes of Polynemus sexfilis Valenciennes in Cuvier and Valenciennes, 1831, in the synonym of which the former is herein included. Polydactylus sexfilis, which is widely distributed in the Indo-Pacific region, is redescribed on the basis of a newly-designated lectotype and two paralectotypes, and a wide range of non-type material. The species is characterized by six pectoral filaments, 15 or 16 pectoral fin rays, 61–67 pored lateral line scales, 8–10 scales above the lateral line, 12–14 below, 11–14 and 15–18 upper and lower series gill rakers, respectively (27–31 total), teeth present on vomer and a long second dorsal fin ray (mean 26% [range 21–30%] of standard length). Received: July 7, 2000 / Revised: August 29, 2000 / Accepted: September 30, 2000  相似文献   

5.
Zhang Q  Sodmergen 《Protoplasma》2003,221(3-4):211-216
Summary.  Following 4′,6-diamidino-2-phenylindole staining of mature pollen grains of Chlorophytum comosum, fluorescence microscopy confirmed that cytoplasmic nucleoids (DNA aggregates) were present in the generative cells, which indicated the possibility of biparental cytoplasmic inheritance. Electron and immuno-electron microscopy showed that both plastids and mitochondria were present in the generative cells, and both organelles contained DNA. These results indicate that mitochondria and plastids of C. comosum have the potential for biparental inheritance. Similar results were obtained with mature pollen grains of C. chinense. Therefore, we conclude the coincident biparental inheritance for mitochondria and plastids in the members of the genus Chlorophytum. Received June 28, 2002; accepted September 26, 2002; published online April 2, 2003 RID="*" ID="*" Correspondence and reprints: College of Life Science, Peking University, Bejing 100871, People's Republic of China.  相似文献   

6.
Ophiodothella caseariae sp. nov. from leaves of Casearia tremula in Venezuela is described and illustrated. Received: February 19, 2002 / Accepted: April 30, 2002  相似文献   

7.
The ketolide antibiotics are semi-synthetic derivatives of erythromycin A with enhanced inhibitory activity in a wide variety of microorganisms. They have significantly lower MICs than the macrolide antibiotics for many Gram-positive organisms. Two ketolides, telithromycin and ABT-773, were tested for growth-inhibitory effects in Haemophilus influenzae. Both antibiotics increased the growth rate and reduced the viable cell number with IC50 values of 1.5 μg/ml. Protein synthesis was inhibited in cells with a similar IC50 concentration (1.25 μg/ml). Macrolide and ketolide antibiotics have been shown to have a second equivalent target for inhibition in cells, which is blocking the assembly of the 50S ribosomal subunit. Pulse and chase labeling assays were conducted to examine the effect of the ketolides on subunit formation in H. influenzae. Surprisingly, both antibiotics inhibited 50S and 30S subunit assembly to the same extent, with no specific effect of the compounds on 50S assembly. Over a range of antibiotic concentrations, 30S particle synthesis was diminished to the same extent as 50S formation. H. influenzae cells seem to have only one significant target for these antibiotics, and this may help to explain why these drugs are not more effective than the macrolides in preventing the growth of this microorganism. Received: 21 February 2002 / Accepted: 30 April 2002  相似文献   

8.
Cochliobolus heterostrophus Pol2 and Pol5 mutants are pleiotropic, and each mutant gene is responsible for alterations of both unrelated phenotypes: reddish-brown pigmentation and polyoxin resistance. The three pigments accumulated in these mutants were isolated. Structural characterization by spectroscopic analyses indicated that these three pigments were polyhydroxyanthraquinones: emodin, chrysophanol, and citreorosein. Emodin is known to be an antidote against benzimidazole fungicide, although no antidoting activity against polyoxin was observed. Received: February 12, 2002 / Accepted: April 27, 2002  相似文献   

9.
Tricholoma matsutake isolates IFO6933 and IFO30604 have been maintained on slants for 46 and 26 years, respectively, and widely used for studies of matsutake in vitro without any contact with potential host plants. In the present study, we demonstrate that both isolates are able to form a typical ectomycorrhiza in association with Pinus densiflora. The result shows that T. matsutake is hardly attenuated in its symbiotic potential and that the fungal cultures maintained for years are useful in further analysis in vitro. Received: August 22, 2002 / Accepted: January 29, 2003  相似文献   

10.
Paternal mouthbrooding bagrid catfishes in Lake Tanganyika   总被引:1,自引:0,他引:1  
 This article gives the first information about paternal mouthbrooding in bagrid catfishes, based on analysis of specimens collected while SCUBA diving in Lake Tanganyika, Africa. Lophiobagrus aquilus and L. cyclurus, endemic to the lake, were nocturnally active, and in the daytime were found concealed singly or in pairs beneath rocks. Among 39 L. aquilus and 52 L. cyclurus collected, 8 and 1 solitary males, respectively, were incubating eggs or young in the buccal cavity. Paired males and females and solitary females never took care of the offspring. In both species, females of pairs showed much higher gonadosomatic index values and had larger oocytes in the ovaries than did solitary females. This fact suggests that pair formation takes place at a time near the gonadal maturation of the female and that the pair separate after spawning. We tentatively propose an evolutionary transition route of care patterns in bagrid catfishes. Received: January 25, 2002 / Revised: April 13, 2002 / Accepted: April 17, 2002  相似文献   

11.
 Extremely small animals including fishes have been reported with discussion of the causes and consequences of their miniaturization. Here we demonstrate, for the first time, very early (i.e., 23–60 days old and 42–67 days old) sexual maturity in two groups of gobioid fishes (Schindleria and Paedogobius, respectively) in warm water, based on the otolith increments. The generation time of Schindleria is the shortest known among vertebrates under natural conditions. We discuss the occurrence and evolutionary significance of the progenesis found in gobioid fishes. Received: September 27, 2001 / Revised: January 26, 2002 / Accepted: February 20, 2002  相似文献   

12.
 Phylogenetic relationships among eight Trematocara species and a single Telotrematocara species included in the Tanganyikan cichlid tribe Trematocarini were investigated on the basis of morphological features. The monophyly of the tribe is supported by the presence of hypertrophied sensory pores on the head, tendon “c” of adductor mandibulae section 1, a single scale row between the upper lateral line and body axis, great depth of the anteriormost infraorbital (reversed in Trematocara caparti and T. stigmaticum), and the absence of a lower lateral line. Trematocara is paraphyletic unless Telotrematocara is treated as a junior synonym. Received: December 10, 2001 / Revised: March 18, 2002 / Accepted: April 4, 2002  相似文献   

13.
Changes in the spring arrival dates of migrant birds have been reported from a range of locations and many authors have focused on long-term trends and their relationship to temperature and other climatic events. Perhaps more importantly, changed arrival dates may have consequences for the breeding dates of birds which strongly influence breeding success. In this paper we take the opportunity provided by a monitoring scheme of the white stork (Ciconia ciconia) to examine several features of the timing of arrival and breeding in relation to chick production in Slovakia during the period 1978–2002. First arrival dates ranged from 5th March to 30th April, and hatching dates varied between 26th April and 8th July. Generally, early arriving pairs started breeding earlier and a shorter interval between the arrival of the first partner and breeding, expressed here as hatching date, resulted in higher breeding success.  相似文献   

14.
Pterothrissus gissu is a rare albulid fish that is distributed in deep water off Japan. This fish is known to pass through a leptocephalus larval stage, but only metamorphosed (after reaching the fully grown stage) specimens have been available. In this study, the premetamorphosis (before fully grown stage) leptocephalus larva of P. gissu is first described from 45 specimens (117.2–194.5 mm SL) collected by a pelagic otter trawl in the Kuroshio–Oyashio transition region of the western North Pacific in May 1995. Premetamorphosis leptocephalus larvae are characterized by having poorly developed fin rays except for the caudal fin, a translucent body, branched melanophores beneath the eye, and punctuate melanophores on the dorsal edge of the gut from the throat to the anus. Previously fully grown leptocephali were estimated to reach about 130 mm SL based on the size distributions of metamorphosing specimens. However, the present specimens show that fully grown leptocephali of P. gissu exceed 180 mm SL. Received: March 21, 2001 / Revised: March 19, 2002 / Accepted: April 15, 2002  相似文献   

15.
The Food and Drug Administration has become aware of several instances where supposedly sterile medical surgical products made of Chinese cotton have been found to contain viable Pyronema domesticum. The aim of this research was to determine the gamma and electron beam radiation resistance values for the two dormant phases (ascospores and sclerotia) of P. domesticum. The resistance values were obtained by developing a standardized system to cultivate, purify, and harvest biological indicators containing sclerotia or ascospores. Ascospores were more resistant to radiation than sclerotia. The D 10 values for sclerotia were 0.79 and 1.09 kGy for strains 32030 and 14881, respectively. The resistance value for wild type ascospores was 2.83 kGy. The current standard for assuring radiation sterilization of medical devices is ISO 11137. This standard was developed to address the propensity for highly radiation-resistant organisms such as P. domesticum. Prior to the standard, biological indicators such as Bacillus pumilus, having a nominal D 10 value or 1.7 kGy, were used to determine the sterility of many medical devices. Journal of Industrial Microbiology & Biotechnology (2002) 29, 51–54 doi:10.1038/sj.jim.7000267 Received 09 October 2001/ Accepted in revised form 08 April 2002  相似文献   

16.
 Age and growth of a paralepidid, Lestrolepis japonica, were determined from sagittal otoliths of specimens collected from April 2001 to February 2002 in Kagoshima Bay, southern Japan. Marginal growth increments indicated that the annulus was formed once a year, in August and September. Four groups were recognized, having none, one, two, or three annuli, respectively. Age in months was assigned to each individual on the basis of August as the birth month. The maximum recorded age was 48 months. Growth was expressed by von Bertalanffy's equation, L t  = 171.91{1 − exp[−0.148(t + 0.403)]}, t being the age in months and L t the standard length (mm) at age t. Received: July 15, 2002 / Revised: November 18, 2002 / Accepted: December 10, 2002  相似文献   

17.
Summary.  Eight analogs 4a-7a and 4b-7b of philanthotoxin (PhTX) from wasp venom and nephilatoxin-8 (NPTX-8) from spider venom whose tyrosine or asparagine linker is replaced by squaryl (sq) amino acid or 4-amino squaryl (4-asq) amino acid have been synthesized in an efficient manner via coupling of N-acyl squaryl amino acid intermediate 19 or 26 with the corresponding polyamine part. Preliminary bioassay using crickets revealed that the analogs substituted by glutamate-type squaryl amino acid-containing NPTX 7a and 7b showed more potent paralytic activities than that of NPTX-8. Received April 25, 2002 Accepted June 21, 2002 Published online December 18, 2002 Acknowledgement This work was supported by a grant from Research for the Future Program from the Japan Society for the Promotion of Science (JSPS). Authors' address: Yasufumi Ohfune, Graduate School of Science, Osaka City University, Sugimoto, Osaka 558-8585, Japan, Fax: +81-6-6605-3153, E-mail: ohfune@sci.osaka-cu.ac.jp  相似文献   

18.
While studying antibiotic-resistant plasmids from multi-drug-resistant nosocomial Staphylococcus aureus strains, we isolated a small (2.889 kb) chloramphenicol-resistant (Cmr) plasmid, which was designated as pMC524/MBM. The molecular size of pMC524/MBM was close to that of pC194 (2.910 kb), a well-known Cmr staphylococcal plasmid. Unlike pC194, this plasmid can replicate and express itself efficiently and stably in Escherichia coli. However, Cm is needed for stable maintenance of pMC524/MBM in different hosts. In this study, the nucleotide sequences of these two plasmids were compared after sequencing of pMC524/MBM [EMBL Accession No. AJ312056 SAU312056]. Although these two plasmids have striking nucleotide sequence homology, the Plus Origin, Minus Origin, the replication protein (Rep), and the chloramphenicol acetyl transferase (Cat) have considerable variations. Possibly, these changes have modulated pMC524/MBM into an efficient shuttle-plasmid. Received: 8 April 2002 / Accepted: 27 July 2002  相似文献   

19.
A male lectotype and several paralectotypes of Chloroperla lugens Klapálek, 1923 are designated. The species is transferred to genus Isoperla and is the valid name for Isoperla alpicola Brinck, 1949.  相似文献   

20.
The harbour porpoise (Phocoena phocoena) is widely distributed in the North Sea. During both the SCANS 1994 and 2005 surveys, porpoises were commonly encountered in offshore waters, for example in the central German Bight. However, information on year-round abundance and distribution of harbour porpoises in that area on a monthly basis was lacking. Between 2002 and 2004, we undertook 26 aerial line-transect surveys in a 2,600 km2 area in the central German Bight, 100 km north of the Island of Borkum (Eastern Frisia). Data were analysed with DISTANCE software. A total of 406 porpoises were sighted. Sighting rates (=sightings/km transect) peaked in July 2002, February, May and September 2003, and in January and April 2004. Absolute densities (g(0) corrected) ranged between 0.14 and 1.54 animals/km2 (peak in April 2004). Proportion of calves varied between 3.4 and 27.3%. Our results show a highly irregular appearance of harbour porpoises in the study area with no apparent seasonal trends in occurrence but peaks in single months. We propose that the area is used as a transit route with harbour porpoise moving in from regions of high density in summer (Northern Frisia) and early spring (Eastern Frisia).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号