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1.
Ichthyological Research - Stolephorus insignus sp. nov. is described from 10 specimens from Taiwan, the Philippines, and the Moluccas, Indonesia. The new species is closely related to S. apiensis... 相似文献
2.
The morphology of the digestive system was useful to distinguish the larvae of Stolephorus baganensis and Thryssa kammalensis before the full development of their dorsal and anal fins. The relative positions of these fins, the length of the anal fin, and body depth, were good criteria for identifying individuals >10·0 mm L S . For both species, the relative growth of the ten morphometric characters studied was best explained by linear piecewise regressions indicating inflection in allometry at specific standard lengths. Most of these sudden changes in growth rate occurred between 6·9 and 10·0 mm L S for S. baganensis and between 5·8 and 8·9 mm L S for T. kammalensis . Double-centred principal component analysis (PCA) confirmed important changes in the external morphology of both species during this transition period. Prior to this period, the main parameters characterizing the global morphological changes of both species were the length and position of dorsal and anal fins whereas they were body depth and eye diameter (only in S. baganensis ) for larger specimens. Complete development of scales did not appear as a suitable criterion to define the end of the larval period, which, instead, was set at the size at which larvae presented an adult-like pigmentation (respectively 35·0 mm L S and 55·0 mm L S in S. baganensis and T. kammalensis ). 相似文献
3.
Immunomodulatory peptides derived from marine organisms are potential sources of new immunomodulating drugs. This study aimed to investigate the optimal enzymatic hydrolysis conditions of immunoregulatory peptides from Stolephorus chinensis. The relative proliferation rate (RPR) of RAW264.7 macrophages was set as the screening index. The immunoregulatory peptides from S. chinensis was prepared via process optimization, ultrafiltration, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (RP-HLPC). The amino acid sequence of the immunoregulatory peptide from S. chinensis (IPSC) was identified to be Tyr-Val-Met-Arg-Phe (YVMRF; MW 715.4 Da) using Edman degradation and mass spectrometry. In addition, the macrophages became larger with more pseudopods after IPSC treatment, indictating that IPSC stimulated RAW 264.7 differentiation. IPSC also increased productions of nitric oxide (NO), interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α). Our results provide a theoretical basis for preparing immunomodulatory functional food from S. chinensis in future. 相似文献
4.
Fish eggs of successive stages of embryonic development, which were identified as belonging to specimens of Commerson's anchovy Stolephorus commersonnii through comparative molecular techniques, were collected from Leqing Bay, Zhejiang, China. Some eggs were reared artificially to obtain samples of successive developmental stages of larvae. The fertilized eggs of S. commersonnii are ellipsoidal and non-adhesive. The surface of the egg membrane is smooth and the perivitelline space is narrow. There is a single oil globule in the irregularly segmented yolk. Newly hatched larvae are transparent and devoid of pigments. Development of the larvae occurs in the following sequence: 8?h after hatching, the anus unfolds; 12?h after hatching, the pectoral fins emerge; 24?h after hatching, the liver and branchial arches emerge, and the alimentary canal differentiates into the oesophagus and intestinal canal; 30?h after hatching, the eyes become pigmented; 36?h after hatching, the upper and lower jaws become distinct; 42?h after hatching, the stellate melanophores emerge; 72?h after hatching, the postlarval developmental stage begins with the emergence of the dorsal fin. Based on the morphology of eggs and larvae of S. commersonnii, a taxonomic key to fish eggs of the Clupeidae and Engraulidae off China is established to provide an efficient and convenient way to identify the egg specimens. The fish eggs of the Clupeidae and Engraulidae off China could be identified to some extent by the buoyancy, shape and diameter of eggs, the number of layers in the egg membrane, the size of the perivitelline space, the number and diameters of oil globules, and the distribution of pigments. Meanwhile, their prelarvae could be identified by the number and diameters of oil globules, the distribution of pigments, the location of the anus and the number of myomeres. 相似文献
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As a basis for comparative studies of mating systems, we estimated genetic diversities and inbreeding coefficients for six perennial species of Ainsliaea and two shrubby species of Pertya (Asteraceae). These related species are known to vary from frequent cleistogamy to xenogamy by bumblebee pollination, and we examined allozyme variation in these species to describe mating system variation in further detail. Significant heterozygote deficit was found in five species, while no heterozygote deficit was found in three species. A cleistogamous species showed no genetic polymorphism. Multilocus average of inbreeding coefficients among seven species ranged from –0.12 to 0.78. These findings indicated that related species can vary from predominant selfers to predominant outcrossers under perennial life cycles. 相似文献
7.
D. C. Fernández R. Laird C. Herle H. Goulet H. Cárcamo 《Biocontrol Science and Technology》2018,28(7):702-717
We report a long-term survey summarising the seasonal variation in species composition of Peristenus species, and their levels of parasitism in an assemblage of Lygus spp., over more than 10 years in southern Alberta in western Canada. Plants sampled include alfalfa (Medicago sativa L.), canola (Brassica napus L.), and stands of different weed and grass species commonly found on crop field edges. Three native Peristenus species (Peristenus dayi, Peristenus mellipes, and Peristenus howardi) were recorded in 2003–2011 and 2013–2015. In laboratory trials, P. mellipes emerged 13 days earlier than P. howardi. Degree-days for field-collected individuals suggested a sequential occurrence during the growing season: P. dayi appears early in the season, followed by P. mellipes, and later on by P. howardi. Studies of species composition and phenology of native parasitoids of insect pests provide valuable baseline information when considering introduction of exotic agents, and contribute to the management and improvement of conservation biological control by endemic natural enemies in agricultural systems. 相似文献
8.
The major intention of the present study was to investigate whether an approach combining the use of niche-based palaeodistribution modeling and phylo-geography would support or modify hypotheses about the Quaternary distributional history derived from phylogeographic methods alone. Our study system comprised two closely related species of Alpine Primula. We used species distribution models based on the extant distribution of the species and last glacial maximum (LGM) climate models to predict the distribution of the two species during the LGM. Phylogeographic data were generated using amplified fragment length polymorphisms (AFLPs). In Primula hirsuta, models of past distribution and phylogeographic data are partly congruent and support the hypothesis of widespread nunatak survival in the Central Alps. Species distribution models (SDMs) allowed us to differentiate between alpine regions that harbor potential nunatak areas and regions that have been colonized from other areas. SDMs revealed that diversity is a good indicator for nunataks, while rarity is a good indicator for peripheral relict populations that were not source for the recolonization of the inner Alps. In P. daonensis, palaeo-distribution models and phylogeographic data are incongruent. Besides the uncertainty inherent to this type of modeling approach (e.g., relatively coarse 1-km grain size), disagreement of models and data may partly be caused by shifts of ecological niche in both species. Nevertheless, we demonstrate that the combination of palaeo-distribution modeling with phylogeographical approaches provides a more differentiated picture of the distributional history of species and partly supports (P. hirsuta) and partly modifies (P. daonensis and P. hirsuta) hypotheses of Quaternary distributional history. Some of the refugial area indicated by palaeodistribution models could not have been identified with phylogeographic data. 相似文献
9.
L. A. S. Johnson 《Plant Systematics and Evolution》1976,125(3):155-167
Eucalyptus is recognised as containing somewhat more than 450 species, but this number could reasonably be either decreased or increased considerably by slight variations of species concept. Recognition of taxa, at least in the wild, is less difficult than supposed but their ranking depends on degree and nature of discontinuities or steepened gradients of correlated variation, in this group of diploid sexual outbreeding trees of the dominant stratum. Some 8–10 rather distinct lines marked by different character constellations are discernible inEucalyptus s. lat. (incl.Angophora), and it is clear that the floral operculum is of diverse nature and multiple origin. The advisability of recognising several distinct genera depends on the wideness of polyphylesis in relation to other Myrtaceous genera, and (unfortunately) on practical convenience.Presented at the symposium Speciation and the Species Concept during the XIIth International Botanical Congress, Leningrad, July 8, 1975. 相似文献
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An attempt is made to identify sibling species within the Brachionus plicatilis complex (Rotifera). Allozyme and morphological data for nine strains from all over the world are provided. Although the analysis of morphological data classified individuals from nine strains into two groups, cluster analysis using genetic distance data obtained from allozyme data revealed at least three groups. A male choice design is described for the first time in rotifers and was used to test for male mating preferences among sympatric strains belonging to three distinct species. The results suggest that the B. plicatilis complex is actually composed of more than three sibling species. 相似文献
12.
Cornelis C. Berg 《Brittonia》1990,42(1):59-65
Four new species are described and illustrated:Coussapoa fulvescens, C. tolimensis, andC. valaria from Colombia, andPourouma napoensis from Ecuador. 相似文献
13.
Willard W. Payne 《Plant Systematics and Evolution》1976,125(3):169-178
The shrubby to herbaceous genusAmbrosia is centred in the arid regions of N. America. Its remarkable variability appears to be related to occurrence as pioneers and weeds in unstable habitats, extensive migrations and hybridization, seed-longevity, inbreeding, polyploidy and dysploidy. Volatile oils underline that the genus is a natural assemblage. Sesquiterpene lactones profiles parallel migration routes and characterize geographical races in several groups, but patterns of chemical and morphological differentiation sometimes are not congruent. Seed proteins are ± individual-specific and useful as parameters of genetic polymorphism. In connection with other approaches analyses of chemical constituents can greatly help to clarify problems of species, speciation and evolution.Presented at the symposium Speciation and the Species Concept during the XIIth International Botanical Congress, Leningrad, July 8, 1975. 相似文献
14.
Pedro Fiaschi 《Brittonia》2014,66(2):134-150
Three new species of Oxalis sect. Polymorphae are here described and illustrated: Oxalis artemioides, O. calcicola, and O. monochasiata. These species have narrow geographic distributions, each being known from just one location. Oxalis artemioides differs from other species of the section by the glabrous stem, narrow terminal leaflets (8–10.5 × 2 mm), and inflorescences with elongated dichasial branches bearing flowers only in the distal portion. Oxalis calcicola differs from other species by having the young stem with adpressed-retrorse trichomes, inflorescences shorter than adjacent leaves, short dichasial branches (0.5–3 mm long) with flowers densely grouped along the entire length, and glabrous pedicels. Oxalis monochasiata is remarkable because of its monochasial inflorescence and the two-ovulate carpels, both features unique within Oxalis sect. Polymorphae. The new species are compared to similar species of the section, and information on distribution and habitat, phenology, and conservation status according with IUCN criteria are provided. Geographic distribution maps, lists of examined materials and an identification key for species of this section are also presented. 相似文献
15.
Ontogenetic trends in the wood structure of Nepalese Rhododendron were studied in 15 specimens of two tree and four subtree species. Average growth ring width was constant from pith to bark in spite of occurrences of extremely narrow, false, or discontinuous rings. Vessel density, vessel area, vessel element length, and multiseriate ray height generally had an initial increase or decrease to 1.5 cm radius and near plateau or slight decrease or increase outward. Multiseriate ray density and area percentage were variable between specimens without a clear pattern. Ontogenetic trends from pith to fully mature wood in trees plus subtrees were inferred by treating the measurements in the present study with those of mature individuals in a previous study. Comparison of trends in trees plus subtrees and those in shrubs lead to ecological or systematic groupings. Vessel features showed that alpine shrub species have distinctly small, numerous vessels composed of short vessel elements. Multiseriate ray features indicated a systematic difference between the trees plus subtrees of subgenus Hymenanthes and the shrubs of subgenus Rhododendron. Vessel features of alpine shrubs may be an adaptation against frequent freeze-thaw cycles or the result of growth stress imposed by the severe alpine environment. 相似文献
16.
Rojas-Alvarado AF 《Revista de biología tropical》2002,50(3-4):969-1006
More new species, new combinations and new distributions are made in the large and difficult genus Elaphoglossum in Neotropic. Ten new species are described, this are: Elaphoglossum adrianae A. Rojas, E. betancuri A. Rojas, E. caridadae A. Rojas, E. glabromarginatum A. Rojas, E. kessleri A. Rojas, E. macdougalii A. Rojas, E. paramicola A. Rojas, E. paxense A. Rojas, E. pseudoherminieri A. Rojas and E. solomonii A. Rojas. Three species are combined, this are: Elaphoglossum beitelii (Mickel) A. Rojas, E. curvans (Kunze) A. Rojas and E. eutecnum (Mickel) A. Rojas. Finally, 86 species are reported from other countries and some species names are synonymized. 相似文献
17.
Jenynsia lineata species complex,revision and new species description (Cyprinodontiformes: Anablepidae)
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P. F. Amorim 《Journal of fish biology》2018,92(5):1312-1332
The Jenynsia lineata species complex comprises J. lineata from Montevideo, Uruguay and Jenynsia multidentata, from coastal basins of Brazil, Uruguay and Argentina up to 1200 m a.s.l. Taxonomic divisions within this group were tested using three different species delimitation methods, which found the two existing names to be synonyms and revealed a new cryptic species. Jenynsia darwini sp. nov. is distinguished from all congeners by having a unique combination of character states, including the shape of the dorsal postcleithrum (three times higher than wide v. less than two times higher than wide) and female colour pattern in the half of the caudal peduncle with rows of chromatophores segmented in unaligned spots (v. aligned spots forming lines). The new species also differs from J. lineata by having 26 nucleotide substitutions in the mitochondrial gene cytochrome c oxidase I (coI). Phylogenetic analysis of the genus based on morphological characters proposed by previous studies corroborates monophyly of the subgenera Plesiojenynsia and Jenynsia, with the new species being allocated to the subgenus Jenynsia as the sister group of J. lineata. 相似文献
18.
B. J. M. Zonneveld 《Plant Systematics and Evolution》2001,229(1-2):125-130
Genome size (C-values) and pollen viability staining were applied as new criteria to investigate the species of the genus
Helleborus Linnaeus (Ranunculaceae). All species have the same chromosome number (2n=32). However, the nuclear DNA content, as measured
by flow cytometry with propidium iodide, could be demonstrated to range between 19 pg to 35.7 pg. The different genome sizes
of the species coincided to a large extent with earlier determined section boundaries based on morphology. Flow cytometry
can be a convenient method to discriminate between some species.
Received April 17, 2001 Accepted May 7, 2001 相似文献
19.
Mitotic chromosomes of 12 species of Catasetum were assessed to contribute with the karyotypic study of the subtribe Catasetinae (Orchidaceae), expanding the knowledge of this group in terms of chromosomes and supporting its taxonomic and evolutionary analysis. The species are maintained in cultivation in the greenhouse of the Department of Plant Biology/IB/UNICAMP and in the “Orquidário Frederico Carlos Hoehne” of the Botanical Garden of São Paulo. Chromosome counts ranged from 2n = 54 to 2n = 108. Karyotypes were prepared for all species studied, in which there was a predominance of metacentric chromosomes and some submetacentric ones. The chromosome size ranged from 0.5 to 4.9 μm, the total chromosome length ranged from 34.7 to 78.7 μm and the asymmetry index TF% ranged from 21.2 to 42.3. The results obtained so far favor the taxonomy of the genus, allowing to distinguish species with very similar external morphology. 相似文献
20.
Abstract. We describe two new species of Blepharoneura (Diptera: Tephritidae) from Venezuela and Trinidad and redescribe Blepharoneura atomaria (Fabricius), comb.n. Each of the morphologically similar sympatric species feeds on a different tissue of Gurania spinulosa Cogn. (Cucurbitaceae): seeds ( B.manchesteri , sp.n.), male flowers ( B.atomaria ), and female flowers ( B.perkinsi , sp.n.). With the help of elementary school children and teachers we developed new methods for detecting and describing wing patterns. We present frequency distributions of character states and describe a denticulate area within the distiphallus that may function as a holdfast. For each species we provide notes on the ecology and behaviour of larvae and adults. 相似文献