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1.
Twenty-six species of silica-scaled chrysophytes representing the genera Chrysosphaerella (1 species), Mallomonas (19 species) and Synura (6 species) are reported based on transmission electron microscopy from the springtime flora of the slightly acidic bog-lake Baláta-tó, a Nature Reserve, situated in Southwest Hungary. Ten of them ( Mallomonas alata, M. clavus, M. insignis, M. mangofera, M. oviformis, M. papillosa, M. pillula, M. scalaris, M. transsylvanica and Synura multidentata ) are new records for Hungary. Furthermore, two species, M. pillula and M. scalaris are for the first time found in the Carpathian Basin and M. alata f. hualvensis is a new record for the flora of Europe. Dispersal problems are discussed.  相似文献   

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The European species of Omphale Haliday (Eulophidae: Entedoninae) are revised. The revision includes 37 species, of which eleven are newly described and the remaining 26 species are redescribed. The species are classified into six species groups, with six unplaced species. All species are fully diagnosed and thoroughly illustrated. Identification keys are provided for females and males. Two new morphological features to aid classification and identification are introduced: male genitalia and wing interference patterns (WIPs). The former has been used successfully in the classification of New World Omphale and the latter is used for the first time in a taxonomic revision. Male genitalia in Omphale have considerable interspecific variation, an unusual trait among chalcidoid Hymenoptera, and are demonstrated to be useful for classification of species and species-groups, and they also possess the only autapomorphy for Omphale. WIPs are useful to help separate some species, but cannot be used to define either the genus or species groups. Distributional data are compiled for each species and suggest a pan-european distribution for most species. Gall-midges are the known hosts for 14 species, and the absence of host overlap between species suggests that host specialization is a driving force for speciation. Several Omphale species are known only from females, or have a strong female biased sex ratio, suggesting thelytokous development. Apart from the 37 species included in this revision, the status for nine additional species (names) in species group aetius remain unsolved. For nomenclatorial stability, a neotype is designated for Eulophus lugens Nees (= Omphale lugens (Nees)). Elachestus obscurus Förster and Derostenus sulciscuta Thomson are transferred from Holcopelte to Omphale comb. n. Derostenus radialis Thomson and Achrysocharella americana Girault are synonymized with Omphale theana (Walker), and Omphale teresis Askew is synonymized with Omphale phruron (Walker), syn. n. The status of genus Pholema Graham is revised as it is removed from synonymy with Omphale and instead synonymized with Neochrysocharis Kurdjumov, syn. n., and the type species for Pholema, Pholema microstoma Graham, is transferred to Neochrysocharis, comb. n. Eugerium orbatum Szelényi, previously transferred to Omphale, is synonymized with Asecodes congruens (Nees), syn. n.  相似文献   

4.
The dusky grouper is a large-bodied marine species usually associated with rocky substrates and reefs currently experiencing increasing anthropogenic pressures. Here, we critically evaluate studies conducted during the last few decades on this endangered species, focusing on its biology, ecology, behavior, stock structure and fisheries, and identify future research directions to fill current knowledge gaps. This species plays an important functional role in the rocky bottom habitats in which it lives, usually occupying the highest trophic levels and with the potential role as a keystone species in some ecosystems. It has a complex life cycle characterized by a high longevity, a slow growth rate and a monandric protogynous hermaphroditic mode of reproduction. The species also exhibits spawning aggregation behavior, which makes it more vulnerable to fishing activity. Aside from its ecological importance, this species has high commercial value for professional fishers and is also highly prized by recreational spearfishers. These biological features, associated with increasing fishing pressures throughout most of its geographical distribution, have led to Epinephelus marginatus being included since 2004 in the IUCN Red List of Threatened Species as Endangered. Despite a large amount of research being conducted on this species over the last five decades or so, using a number of different tools and techniques, key questions regarding its biology still remain unanswered. In terms of conservation and management plans designed to safeguard this endangered species, we identified the crucial need to improve fisheries landing statistics for the species and to increase the number of marine protected areas within its distribution beyond the Mediterranean Sea.  相似文献   

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Biological traits can determine species ecological niches and define species responses to environmental variation. Species have a specific functional position in the biological community, resulting in interactions like interspecific competition. In this study, we used biological traits in order to define the life strategies of 205 nektonic species of the Mediterranean Sea. Furthermore, traits related to resource use were analyzed to determine the level of trait and niche overlap and their relationship to life strategies. Focusing on habitats of importance (Posidonia beds, coralligène formations, and lagoons), we investigated strategies and niches of the species present there. Finally, we examined the life strategy of Lessepsian species and investigated the niche overlap between them and indigenous species. Archetypal analysis indicated the existence of three life histories corresponding to strategies already documented for fish (equilibrium, periodic, and opportunistic), with some species also placed in intermediate positions. Niche overlap was evaluated by multiple correspondence analysis and the generation of a single distance metric between all species pairs. This identified species occupying relatively empty (underexploited) ecological niches, like the Lessepsian species Siganus luridus and S. rivulatus, a finding that can also be associated with their establishment in the Mediterranean. Most Lessepsian species were associated with the opportunistic life history strategy, again an important aspect related to their establishment. Also, we documented that most species occurring in important habitats have a relatively high overlap of niches. No significant differences were found in the life strategies across Mediterranean habitats; however, variation in niche overlap and traits related to habitat use was detected. The findings can be useful to determine theoretical competition between species and to identify empty ecological niches. Fisheries science can also benefit from comprehending the dynamics of competing stocks or predict the responses of data‐poor stocks to anthropogenic stressors from known examples of species with shared life strategies.  相似文献   

7.
Abstract. 1. A scheme for monitoring the abundance of butterflies at about eighty sites in Britain is described.
2. Indices of abundance are presented for twenty-nine species for the years 1976–82.
3. There are marked differences between species in the scale of annual fluctuations.
4. Some species show correlations between successive index values; for example the summer generation index of Pieris brassicae is highly correlated with the spring generation index.
5. The annual changes in the index values of many species are highly Correlated. The index values themselves also show positive correlations, but these are less strong.
6. The drought of 1976 is believed to have severely depressed populations of many species in 1977.
7. The data do not indicate any general fall in butterfly numbers over the period at the sites in the scheme.
8. The sites are not representative of the countryside as a whole, but, for a number of species, it is considered that the index values reflect wider trends.  相似文献   

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The land planarian genus Choeradoplana (Plathelminthes, Tricladida) is currently integrated by 13 species. In previous works, morphological variation in its type species, Choeradoplana iheringi, was reported, but no attempt to test whether it is just a single species has been made yet. In order to disentangle the taxonomy of this species and further members of the genus, we sampled new specimens and combined morphological and molecular data and also have evaluated the performance of diverse methods of molecular species delimitation. Our data point to the presence of two cryptic species named C. iheringi, plus two new species, all hidden under the same general appearance. An in-depth morphological study of the specimens allowed detection of diagnostic morphological traits in each species, for which we also propose a molecular diagnosis. This integrative taxonomic study demonstrates once again the usefulness of molecular tools to weigh minor morphological characteristics and thus reveal the existence of species that would otherwise remain cryptic. However, under certain parameters, the molecular methods may over-split species with a high genetic structure, maybe pointing to incipient speciation. This makes critical the use of these methods combined with a comprehensive morphological approach. We also present a comprehensive phylogenetic tree including most Choeradoplana species. The tree, well supported, allows making some preliminary inferences on the evolution of the group and its historical biogeography.  相似文献   

10.
This paper provides the length‐weight and length–length relationships for five fish species in the Zigui section of the lower Three Gorges Reservoir of the Yangtze River. Specimens were collected from December 2014 to January 2017, using various types of fishing gear and electroshock fishing techniques. Length‐weight relationships (LWRs) for one fish species and Length–length relationships (LLRs) for five fish species are unknown to FishBase. New maximum total lengths for four species were also recorded for FishBase. Moreover, standard‐length to total‐length equations for converting size measurements for these five species are presented.  相似文献   

11.
A new biozonation is proposed for the Late Carboniferous strata of the northeastern Paraná Basin (São Paulo and Paraná States), based on well-preserved palynological assemblages recovered from outcrops and core samples retrieved from the Itararé Subgroup. Assemblages include forty-nine species of trilete spores and twenty-five pollen species. The oldest biozone, the Ahrensisporites cristatus Interval Zone (AcZ), in the basal portion of the Itararé Subgroup, includes eleven exclusive spore species, and is assigned a Pennsylvanian (late Bashkirian to Kasimovian) age. The overlying proposed biozone, the Crucisaccites monoletus Interval Zone (CmZ), dated late Pennsylvanian (Kasimovian to Gzhelian), ranges approximately from the top of the lower portion to the middle portion of the Itararé Subgroup, bears only one exclusive species of pollen. Both zones are characterized by the dominance of trilete spores and monosaccate pollen grains, including also few taeniate pollen grains. Furthermore, the basal Protohaploxypinus goraiensis Subzone of the Vittatina costabilis Interval Zone (VcZ) is broadly recognized for the first time in the upper portion of the Itararé Subgroup in the northeastern Paraná Basin. This subzone is attributed to the Early Permian (Early Cisuralian), and is characterized by the dominance of monosaccate pollen grains, a significant increase of taeniate grains (mainly Protohaploxypinus spp.), apart from the appearance of polyplicate pollen (Vittatina spp.). Reference sections and the main characteristics of the two new zones (AcZ and CmZ) are presented, along with a preliminary palynological correlation and discussion on their ages.  相似文献   

12.
Length–weight relationships (LWR) were estimated for 34 fish species belonging to 25 genera and 17 families, specimens were collected near the mouth of the Río Verde, Oaxaca, Mexico. All r2 values are statistically significant (P > 0.0001). The values of ‘b’ ranged from 2.55 and 3.3, within the usual range (2.5–3.5). This study provides the first LWR references for six species, and new maximum length records for eight species.  相似文献   

13.
This study presents length‐weight relationships (LWR) for 19 species captured in the Jacuí Delta in southern Brazil. Most of the species had no previous LWR estimates.  相似文献   

14.
Length–weight and length–length relationships are reported for 18 species of fish and two species of crayfish within the Everglades, FL, USA. This study provides updated relationships for native species, as well as initial relationships for established exotic species in this region. Additionally, 14 length–weight and two length–length relationships are presented to FishBase for the first time.  相似文献   

15.
This study provides length–weight relationships (LWRs) for 33 fish species sampled with several types of fishing gear in six expeditions between 2010 and 2011, during the dry and wet seasons in the middle and lower Cauca River Basin, Northern Colombia. The report represents the first reference on LWRs for 28 species and also provides the new maximum size for 15 species.  相似文献   

16.
The morphology of female genitalia is described for eight species of the genus Mellicta belonging to the M. aurelia species group from different localities within their ranges. The distinctive features, their variability, and possible use for species identification are assessed. It is shown that some characteristics of female genitalia can be used to clarify the position of species within the genus and, in some cases, to outline the species groups. Keys to species of the aurelia group are given.  相似文献   

17.
Early Mesozoic Argentinian darwinuloids, now re-assigned to the genus Penthesilenula (incae group), are described and illustrated. These records seem to constitute the oldest known for the genus. The close similarities between the studied species and those described from eastern Asia enlarge the geographical distribution of Penthesilenula (incae group), which, although restricted to the southern Hemisphere in Recent and Holocene times, may have had a wider distribution in the past. Additional information on the paleoecology, plus a preliminary account on the distribution of darwinulid species from Argentina are also offered. One new species is described: Penthesilenula loana sp. nov.  相似文献   

18.
Five species of the genus Orbipora, including two new species, O. lynnensis sp. nov. and O. ukhakuensis sp. nov., are described from the Middle Ordovician of the Leningrad Region and Estonia. The colonies of the species O. acanthophora Bassler, 1911 and O. solida Bassler, 1911 are measured and figured for the first time. The stratigraphic range and geographic distribution of O. acanthophora are refined. A scheme of possible phylogenetic relationships and distribution maps of the species of the genus are presented.  相似文献   

19.
The present study provides the length‐weight relationship (LWR) for eight species from the estuarine stretch of the Macaé River, Rio de Janeiro State, Brazil. Data were obtained quarterly between June 2011 and March 2012. These LWRs are the first records for six species and present new maximum values of total length for three ones.  相似文献   

20.
A list of species of the water mitegenus Lebertia Neuman, 1880 known from Turkey is provided, based on bibliographical data and results from recent field work, mainly in the Southwestern part of the country. We describe one new species, Lebertia martini sp. n. and report new 28 locality records from 6 provinces for the three previously known species.  相似文献   

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