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1.
Parasymmetrorbione bicauda n. g., n. sp. is described from Chinese waters infesting two species of Solenocera Lucas (Decapoda: Penaeoidea). The new genus differs from other orbionine genera by the following combination of features: a pronounced asymmetry of coxal and lateral plate development, biramous uropods, tuberculate lateral plates and a digitate internal ridge on oostegite 1. A key to the eight genera of the Orbioninae R. Codreanu, 1967 is presented. Orbione halipori Nierstrasz & Brender à Brandis, 1923 is also recorded from a new Chinese locality and a new host.  相似文献   

2.
Faunal remains from spoil heaps of two burrows inhabited by small carnivores (fox and badger) are analysed from a taphonomical point of view. This analysis provides characteristics for bone accumulation produced by small carnivores and will be a powerful tool for deciphering site formation about the occupational alternation of small carnivores and humans. Identified species were grouped by size classes. Faunal spectrum is composed by varied species of microfauna (70%), mesofauna (30%). Macromammal remains are under represented (less than 1%) and come from scavenged carcasses. Predators and consumed species are compared on the basis of the skeletal part representation, age classes and recording of predation marks (gnawed and digested bones). Skeletal part representation shows that all taxons exhibit a low-representation of axial skeleton and autopodial bones. Predators show a high representation of hind limb bones and a low representation of the fore limb bones whereas consumed species exhibit a reverse pattern. Mortality curve analysis provides an attritional profile for carnivores and helps for the establishment of the season of occupation of the burrow. Adults largely dominate consumed species. Moreover, predation marks are found in 1% of the carnivores’ bones and from 15% to more than 40% on prey bones. The large-sized prey bones only wear gnawed marks (20%) and anthropic marks (10–20%) whereas microfaunal remains exhibits more digested marks (40%) than gnawing stigmata (5%). Medium-sized animals bones wear both marks and with the same proportions (10–15%).  相似文献   

3.
Proteolytic activity in the stomach, pyloric caeca and intestine decreases with increasing size in the three fish species Mugil auratus, M. capito and M. saliens. Differences between these species are found mainly in the gastric proteolytic activity which appears to be related to diet. This activity is pronounced in M. saliens whose diet is mainly carnivorous. Comparison of regression lines relating gastric proteolytic activity to size reveals differences which distinguish M. auratus from both of the other species. Total proteolytic activity exhibits high variability depending on the types of diet.  相似文献   

4.
Sibling species groups are suitable models for the understanding of inter‐ and intraspecific processes in taxonomy and biogeography. We analysed 262 individuals from the Alps of the Coenonympha arcania/gardetta species complex by allozyme electrophoresis. These taxa showed high variance amongst populations (FST: 0.391) and strong intertaxon genetic differentiation (FCT: 0.376). Although morphologically similar, Coenonympha gardetta and Coenonympha arcania clearly differ in their genetic characteristics; the morphologically intermediate taxa Coenonympha darwiniana darwiniana and Coenonympha darwiniana macromma are genetically well distinguished from each other and the two other taxa. Coenonympha arcania and C. d. macromma most probably share a common ancestor and evolved by cladogenesis, whereas the taxonomic situation of C. d. darwiniana is still unresolved: This taxon might be the result of hybridization between C. arcania and C. gardetta or it might have a common ancestor together with C. gardetta. We suggest species rank for all four taxa. The distribution of genetic diversity of these populations and the differentiation amongst populations suggest rather different biogeographical scenarios: C. arcania most probably is of Mediterranean origin with postglacial range expansion northwards; C. gardetta survived the last ice age in peripheral refugia of the Alps and has spread all over this high mountain system in the postglacial; C. darwiniana and C. macromma survived the Würm in geographic proximity to their actual distribution areas and only have performed moderate uphill translocations during postglacial warming. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 890–904.  相似文献   

5.
Abstract. A newmethod of arranging phytosociological tables by species-relevé groups (blocks) on the basis of the density of rows and columns (relative species frequency and relative species number) is presented. Each block fulfils a given minimum criterion regarding its density. With a density threshold of e.g. 50 %, blocks are formed with only those species that are present in at least 50 % of the block's relevés, while at the same time the block's relevés comprise at least 50 % of the block's species. The procedure starts with the complete table and iteratively masks species and relevés with the smallest densities. This is performed step by step with species and relevés and continues until the given density threshold for all species and relevés is exceeded. Without any further parameters other than the minimum density, species-relevé groups of gradually decreasing size are formed. Data processing is performed with a computer program (ESPRESSO). The main application of the method is found in an effective pre-sorting of relevé data. The blocks formed can be arranged in the final table as desired.  相似文献   

6.
The mono and polyester glycosyl sulfates or phosphate diglycerides account for a group of polar lipids which is found in large amounts in the three fucacae that are studied : Pelvetia canaliculata (L) Decn and Thur, Fucus vesiculosus (L), Fucus serratus (L).These polar lipids have been shown to have complex structures, most of them are unknown in the present nomenclature. Both quantity and composition of these polar lipids are species characteristics, forming the equipment of polar lipids for every species of algae.Glycosyl ester sulfate and phosphate diglycerides are very unstable substances when pure, moreover photolabile and thermodegradable. This extreme fragility caused many difficulties in the determination of molecular structures which require a very high purity of isolated substances.The determination of the structures, studies of quantities and composition, cytological localization of these polar lipids should allow to define clearly their physiological function and importance from the biochemical and ecological point of view.  相似文献   

7.
During the field-work of 2003 in the Narinda peninsula in the Province of Mahajanga (North-West of Madagascar), we found a Palaeopropithecus of large size in the new cave “Raulin Zohy”. This fossil differs in morphology and size from the remains coming from other sites of this area and belonging to a new yet undescribed species. This discovery proves that two species of this genus existed in the costal area of the Province of Mahajanga. This Palaeopropithecus attributed to maximus species allows a reconsideration of the geographical distribution of this subfossil lemur species, and asks an interesting question about the biogeography on the small new species.  相似文献   

8.
The interstitial stygobiont distributions of two rivers in the western High Atlas is analyzed in relation with sediment granulometry. Sixteen stations were sampled along the rivers N'Fis and Zat and their tributaries. Granulometry analyses were performed. Three grain size sediment types constitute the subterranean biotopes and reflect the local hydrodynamical conditions. The main rivers stations, which undergo frequent natural or human disturbances, are characterized by a high content of fine sediment; in contrast, tributaries stations show coarse and well-classified sediments due to more stable biotopes and more regular hydrological conditions. The 92 taxa group 28 stygobiontic species with 11 crustaceans species. PCA. based on 16 stations, three faunistic richness indexes and three granulometric factors display a high correlation between coarse grain-size content and the richness of stygobiontic taxa. A high silt content both limits the interstitial taxa and excludes crustaceans that occur only in coarse gravels. The granulometric preferenda in the species of the amphipod genus Metacrangonyx and isopods Microcerberus. Microcharon and Typhlocirolana are shown on Shepard triangular diagrams. Cohabitation of several species of the same genus could be explained by the occupancy of different ecological niches resulting from the grain-size proportion.  相似文献   

9.
Forty-seven navigation buoys were used to collect quantitative samples of epibenthic fauna in the Lower Estuary and Gulf of St. Lawrence. Stations, as described by their sessile species and biomass composition, were grouped using multivariate analysis. A Gower similarity index, modified to take into account the importance of each species in the ecosystem, was used to compare stations. Results obtained by cluster and principal coordinate analyses showed comparable relations between stations. North Shore and Gaspé Coast stations were separated from those of the Lower North Shore, the Mingan Island sector and the Lower Estuary. Stations from the Lower North Shore were also separated from those of the Mingan Island region and of the Lower Estuary, but at a higher level of similarity. All animal assemblages consisted of the following sessile species: Obelia longissima (Pallas), Hiatella arctica (L.), Mytilus edulis L., Balanus balanoides (L.) and B. crenatus (Bruguière). These species formed over 95% of biomass of all sessile species. Differences between the various station assemblages were mainly due to changes in the relative abundance of these species. The geographical gradient of summer surface water temperature best explains the observed clusters. In the Lower Estuary, the spatio-temporal variations of physico-chemical factors and the surface circulation may influence the number of species and their abundance. The circulation systems of the Lower Estuary and near the Mingan Islands might account for the similarity between their assemblages. The same dominant species, Obelia longissima, characterizes the fauna of these two regions.  相似文献   

10.
Highly repeated DNA sequences from two baboon species (Papio papio and P. cynocephalus) have been compared using restriction endonucleases. The two species share a 343 base pairs tandemly repeated DNA, that is cut once by Bam HI. Papio cynocephalus differs from P. papio by loss of an EcoRI star site in the repeated sequence.  相似文献   

11.
New electrophoretic analysis allowed us to show that the two fastest esterases of T. brassicae are derived from the Est 5′ locus and not from the Est 5 and Est 6 locus. This result changes only slightly the evanescens group place in the phylogenetic tree previously suggested. Esterases have been studied in several other species. Those of T. lacustre and T. piceum are not against the classification of these species in the perkinsi and fasciatum groups, respectively. Those of T. leptoparameron lead us to place this species in the pretiosum group, near T. daumalae. Those of a population of T. dendrolimi reveal a polymorphism clearly higher than what was known in bisexual forms of this species. Lastly, esterases analysed by other authors tend to show that T. chilonis and T. closterae belong to the nubilale group (the appellation of which has to be changed) and that T. ostriniae belongs to the minutum group.  相似文献   

12.
Phytoplankton of the Etang de Berre and Etang de Vaïne (N.W. Mediterranean) The phytoplankton in the brackish Etang de Berre and Etang de Vaïne was studied regularly at 12 stations for two years. The recent diversion of the Durance River into the Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact on its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae, since the salinity is generally less than 3 0/00. However, during summer and fall, as well as in waters near the bottom, the salinity can reach 15 0/00 and marine diatoms are predominant. Because the nutrients in the environment are constantly replenished, phytoplankters are always numerous, ranging in abundance between several million to several hundred million per liter. There is a somewhat irregular seasonal cycle. The average density is about 108 cells/1 in the Etang de Berre, and about double that amount in the Etang de Vaïne. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight.  相似文献   

13.
The planktonic invertebrates found in Lake Volvi are presented. There are 26 species of Rotifera, 1 Bivalve (larva), 13 Cladocera, 5 Copepoda, 1 Branchiura and 1 Diptera (larva). Many of these are new for the Greek fauna, though they are common in Europe. The discovery of some other species extends the knwown bounds of their geographical distribution in Greece. The lack of large-sized forms is considered to be due to strong predation by Alosa macedonica. (Pisces, Clupeidae). A comparison is given to the planktonic invertebrates of other Balkan lakes. There is a remarkable similarity with the fauna of Lake Doïrani.  相似文献   

14.
This study is devoted to the analysis of the psammophyte of the coastal and semi-continental dunes in Tlemcen. Interesting results have been obtained, in particular, on the biological and ecological aspects of the psammophyte. The interpretation from Factoriel analysis of correspondences enabled us to identify the different phytosociological classes (Cakiletea maritimae, Ammophiletea, Quercetea ilicis, Therobrachypodietea and Stellarietea mediae). Some of these classes (Cakiletea maritimae and Ammophiletea) inhabit, exceedingly well, the embryonic dunes. Some species (Therobrachypodietea) colonize the quickset dunes. Lastly, some others (Quercetea ilicis) settle in the more mature and stable dunes. By using the phytosociological and phytodynamical data, we have been able to understand the vegetation and its diversity. To cite this article: H. Stambouli-Meziane et al., C. R. Biologies 332 (2009).  相似文献   

15.
Résumé La présence des gousses et graines de six espèces de Phaseolus déclenche une ponte importante chez A. obtectus et stimule significativement la production ovarienne. Cependant, les meilleures performances ne sont pas observées avec P. vulgaris, hôte habituel, mais avec P. coccineus.Pour toutes ces espèces le tégument de la graine représente une barrière importante pour la pénétration des larves. Chez certaines espèces sauvages, et dans les conditions expérimentales, il permet une protection totale de la graine. Cette protection semble diminuer avec la domestication chez P. vulgaris.Lorsque les graines sont perforées artificiellement, les larves (une par graine) pénètrent sans difficulté, quelle que soit l'espèce. Les graines de P. coccineus et de P. vulgaris permettent le développement complet de la majorité des larves, tandis que dans celles de P. metcalfei et de P. acutifolius ne peut se développer qu'une faible partie de la population larvaire. Certains Phaseolinae peuvent donc stimuler la ponte sans permettre le développement des larves.Les femelles de la F1 provenant de P. coccineus ont des performances reproductrices supérieures à celles des femelles provenant de P. vulgaris (variétés sauvage ou cultivée). P. coccineus pourrait être considéré comme une des plantes-hôtes d'origine.
Summary The presence of pods and seeds of six Phaseolus species induces significant egg-laying in A. obtectus and strongly stimulates ovarian production. However, the best performances are not observed with P. vulgaris, the common host, but with P. coccineus.For all six species, the seed testa is an important barrier against larval penetration. For some wild species, it can give total protection of the seed, but this protection is reduced with domestication in P. vulgaris.For all species, when the seeds are artificially perforated, larvae (one per seed) penetrate easily. Most of the larvae can complete their development in seeds of P. coccineus and P. vulgaris, but only a small proportion of the larval population can develop in seeds of P. metcalfei and P. acutifolius. Thus certain Phaseolinae seeds stimulate egg-laying without allowing larval growth.Females of the F1 reared in P. coccineus have superior reproductive capacities than those reared in P. vulgaris. P. coccineus could be considered as one of the original host-plants of A. obtectus.
  相似文献   

16.
Question: Is it possible to translate vegetation maps into reliable thematic maps of site conditions? Method: This paper presents a new method, called Iteratio, by which a coherent spatial overview of specific environmental conditions can be obtained from a comprehensive vegetation survey of a specific area. Iteratio is a database application which calculates environmental indicator values for vegetation samples (relevés) on the basis of known indicator values of a limited number of plant species. The outcome is then linked to a digitalized vegetation map (map of plant communities) which results in a spatial overview of site conditions. Iteratio requires the indicator values of a minimum of 10–20% of the species occurring. The species are given a relative weight according to their amplitudes: species with a narrow range are weighted stronger, species with a broad range are weighted weaker. Conclusion: The method presented here enables a coherent assessment of site conditions on the basis of a vegetation survey and the indicator values of a limited number of plant species.  相似文献   

17.
A general study on the relations between “phytoplanktonic excretion” and “heterotrophic assimilation” has been carried out in eutrophic systems, natural or artificial. In the complex systems of these relations, two types of heterotrophic responses were obtained according to prevailing algal species. High heterotrophic potentials in NW African upwelling show the role of microorganisms in the disappearance of freshly excreted organic substances and in the composition of the remaining organic matter.  相似文献   

18.
In every species other than mammals xanthine oxidoreductase behaves as a dehydrogenase, never as an oxidase. In three mammalian species, the enzyme acts intracellularly as a dehydrogenase, but its class-specific ambivalence allows its extracellular conversion into an oxidase.

Résumé

En dehors de la classe des Mammifères, l'oxydoréductase de la xanthine ne se comporte jamais comme une oxydase. Chez les Mammifères, une ambivalence de la molécule permet l'expression d'une activité déshydrogénasique (NAD) dans la cellule, et d'une activité oxydasique en dehors de la cellule.  相似文献   


19.
The influence of nitrates (NH4NO3 KNO3 and Ca(NO3)2) on Diatom populations has been studied. These populations were isolated by enclosures with transparent walls, without bottom or lid, placed in an oligotrophic pond. The addition of NH4NO3 generally resulted in a decrease in the number of Diatoms and the disappearance of some species. The addition of KNO3 and Ca(NO3)2 was followed, during some periods, by a very important increase of Achnanthes minutissima, Fragilaria construens and Gomphonema parvulum.  相似文献   

20.
Ten cultures of phytoplankters, including four strains of Skeletonema costatum from different origins, were used to improve some aspects of the bioassay technology. Special attention was paid to the preliminary nutrient limitation of the inocula. When the cells are maintained in nutrient starvation, their carbon, nitrogen, carbohydrates, proteins and above all chlorophyll a contents decrease. The minimum appears after a range of 2–7 days, according to species. The survival of these limited cells and their capacity to give rise to active growing cultures when sub-cultured are different with species, but efficiency in the inocula they provide usually can occur only until the minimum content in cellular components appears. Starved cells and enriched cultures of Chaetoceros lauderi and Skeletonema costatum were used to inoculate several samples of sea water, in order to test the effect of the starvation on the experimental results. It appears that the starved cells increase the sensitivity of the method, but they are more susceptible to substances limiting their growth. In the opinion of the authors the best way would be to use both starved and enriched cells as inocula, but, when this is impossible, cautiously starved cells should be used with unpolluted sea waters.  相似文献   

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