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1.
A new species of amblycipitid catfish is described based on five specimens (88.0–164.5mm in standard length: SL) collected from the vicinity of Duan, Guangxi Zhuangzu Autonomous Region, southern China. The new species, Xiurenbagrus gigas, is different from all other known amblycipitid catfish, but similar to X. xiurenensis by having two patches of vomerine teeth. The new species can be distinguished from X. xiurenensis by having a larger head (head length: 27.9–34.9% vs. 21.8–26.4% SL; head depth: 14.4–17.9% vs. 12.4–14.1% SL; head width: 22.4–29.4% vs. 18.1–20.3% SL), lower adipose fin (4.6–6.0% vs. 6.5–8.3% SL), shorter distance from dorsal origin to adipose origin (25.7–32.0% vs. 32.9–38.9% SL), longer dorsal fin (21.2–24.9% vs. 16.2–19.1% SL), longer pectoral fin (18.4–20.7% vs. 13.5–16.8% SL), longer pelvic fin (13.1–14.3% vs. 8.8–11.8% SL), and more gill rakers (7–9 vs. 5). Xiurenbagrus gigas, the largest known species in the family Amblycipitidae, is distributed in the Xijiang River, the longest tributary of the Zhujiang (Pearl) River basin.  相似文献   

2.
Taxonomic analysis of a group of morphologically similar ponyfishes (Perciformes: Leiognathidae) establishes a complex comprising three valid species: Leiognathus aureus Abe and Haneda, 1972, widely distributed in the western Pacific Ocean (Taiwan, Philippines, Thailand, Singapore, Indonesia, and northern Australia); L. hataii Abe and Haneda, 1972, currently known only from Ambon, Indonesia; and L. panayensis sp. nov. Kimura and Dunlap, currently known only from Panay Island, the Philippines. The L. aureus complex can be defined by the following combination of characters: mouth protruding forward, not downward; small but sharp conical teeth uniserially on jaws; a black line between lower margin of eye and lower jaw articulation; and lateral line incomplete, ending below posterior part of dorsal fin base or on anterior caudal peduncle. Leiognathus hataii differs from both L. aureus and L. panayensis in having a large dark blotch below the spinous dorsal fin base and fewer counts of scales (lateral line scales 50–58 vs. 64–85 in the latter two species; scales above lateral line 7–10 vs. 12–18; scales below lateral line 22–26 vs. 30–41). Leiognathus panayensis is distinguished from L. aureus in having a deeper body (41–51% SL vs. 35–45% SL in the latter), long posterior limb of maxilla (21–25% HL vs. 15–23% HL), wholly scaled belly (vs. naked along preanal median keel), and a dark blotch on nape (vs. absent).  相似文献   

3.
4.
A new genus and new species of Canthocamptidae: Glaciella yalensis (Copepoda: Harpacticoida) from the surface of Yale Glacier, Nepal is described. This new species was collected from cryconite-pit on the surface of the glacier and is closely related to genus Maraenobiotus, but easily distinguishable from its species in the following: 1) segments and setae on endopodites of legs 2–4 in the male differing shape, 2) exopodites of male legs 3–4 with modified setae, 3) caudal seta in female absent. Body color of this copepod is red in live specimens.Contributions No. 86 Itako Hydrobiological Station, Ibaraki University.  相似文献   

5.
A new hairtail, Trichiurus nickolensis, is described on the basis of ten specimens collected off northwestern Australia, off the Northern Territory, and in the Gulf of Carpentaria, Queensland. The new species strongly resembles T. brevis Wang and You in Wang et al., 1992, off Hainan Island, South China Sea, and T. russelli Dutt and Thankam, 1966, off the Waltair Coast, Andhra Pradesh, India, in having the highest point of the supraoccipital crest situated directly above the posterior margin of the eye and a relatively short caudal peduncle. Trichiurus nickolensis differs from those two species in being strongly pigmented on the anterior section of the dorsal fin membrane (vs. slightly pigmented), and having a dorsal head margin that appears concave in lateral view, rises gently from snout tip to above middle of orbit, and then extends more steeply to dorsal fin origin (vs. rising gently from tip of snout to dorsal fin origin). The new species also has a greater number of dorsal fin rays (III, 138–143 vs. III, 127–132 and III, 127–131 in T. brevis and T. russelli, respectively) and total vertebrae (160–166 vs. 147–155 and 149–153), and shorter preanal length (mean 30% TL vs. 33% TL and 35% TL), head length (11% TL vs. 12% TL and 13% TL) and upper jaw length (4% TL vs. 5% TL and 5% TL).  相似文献   

6.
Fifteen Erysiphaceous taxa found on 20 host plant species in Patagonia are documented. A new species Oidium maculatae (type host: Viola maculata) is described. Berberis linearifolia, Buddleja globosa, Prosopis alpataco and Viola maculata, are new host plants for Erysiphales. Three new combinations on fungi and host plant species were founded: Erysiphe howeana – Fuchsia magellanica; E. patagoniaca – Nothofagus pumilio and N. antarctica. The genus Sawadaea and the species S. bicornis on Acer negundo and A. pseudoplatanus, are new records for South America. New host plants recorded for Argentina: Consolida ajacis, Galega officinalis and Plantago lanceolata. New host plants recorded for Patagonia: Galium aparine, Melilotus albus, Petunia × hybrida, Potentilla anserina, and Spiraea × bumalda. Oidium longipes is a new record for Argentina and Golovinomyces riedlianus is a new record for Patagonia.  相似文献   

7.
Summary Freeze-fractured preparations of septate junctions between epidermal cells of annelids (Lumbricus terrestris and Tubifex spec.) have been investigated. In Lumbricus the protoplasmic face (PF) of the plasma membrane is characterized by variously arranged rows of particles. Apically the rows take an undulating course and often are separated by wide distances. In the basal part of the junction the rows run closely together and more or less in parallel. The diameter of the particles measures 80–120 Å, the distance between two particles (centre to centre) is 150–250 Å. Additionally striking rows of large particles (long diameter 150–200 Å). Are to be observed mainly near the basal part of the junction. In Tubifex both faces of the plasma membrane could be studied in detail. The protoplasmic face (PF) contains rows of distinct individual particles (mean diameter 100–150 Å, centre to centre distance approx. 250 Å) whereas the particles of the extracellular face (EF, mean diameter 200–250 Å) usually form continuous strands in which the individual particles seem to fuse. The density of arrangement of the strands varies considerably. Additionally ladder-shaped membrane structures have been observed in plasma membranes of this species.  相似文献   

8.
Euphrasia includes perennial or annual green parasitic plants, and has a disjunct bipolar distribution except for one transtropical connection across the high mountains of Oceania. The disjunction is coupled with strikingly contrasting patterns of morphological diversity between the southern and northern hemispheres, making it an exciting model to study processes of evolutionary diversification which shaped present floras. We inferred the relationships among 51 species representing 14 of the 15 sections of the genus based on nrDNA ITS and cpDNA trnL intron, trnL-trnF and atpB-rbcL intergenic spacers. Maximum parsimony and Bayesian inference support monophyly of the genus and of several intrageneric groups characterized by morphology, ploidy level, and geographic range. Molecular phylogenetic dating using Bayesian “relaxed” clock methods suggests that the earliest Euphrasia radiations occurred minimum 11–8 Mya with bipolarity being achieved 7–5 Mya. Biogeographic analyses using explicit model-based approach inferred Eurasia as an ancestral area for the genus. The most parsimonious reconstruction found by a dispersal-vicariance analysis requires 17 dispersals to account for the current biogeographic pattern and supports Eurasian origin for Euphrasia. Both long-distance dispersal and across land vicariance can be invoked to explain the diversification in the genus, which experienced rapid radiations driven by new ecological opportunities of the late Pliocene and Pleistocene but also retained a set of local endemic or relict species of an earlier origin.  相似文献   

9.
Atactorhynchus duranguensisn. sp. (Acanthocephala: Atactorhynchinae) is described from the intestine of Cyprinodon meeki Miller, an endemic freshwater fish from a far-inland locality of Mexico. Diagnostic features include: body small, stout, ventrally curved; small cylindrical proboscis armed with 16 alternating vertical rows of four or five hooks; anterior two or three hooks conspicuous, stout and larger than other hooks, and have large, rod-shaped roots with a markedly and abruptly enlarged base; three posterior hooks of each row are smaller and rootless; single-walled proboscis receptacle; lemnisci equal in length, elongate and robust; and cement gland syncytial, larger than testis. The new species is smaller than A. verecundus Chandler, 1935, the only previously described species in the genus. The shape of the proboscis of the new species is strikingly different from that of A. verecundus, which is widest at the apex. Likewise, the greatest width of the trunk of the new species is in about the middle, differing from that of A. verecundus where the trunk is widest posteriorly. The new species also can be distinguished from A. verecundus because of its much smaller hook lengths and slightly smaller proboscis. In addition, the proportion of large apical proboscis hooks in relation to the small basal hooks is different: the basal hooks of A. verecundus are about half the size of the anterior hooks and but only about a quarter of the size in A. duranguensis. Unlike A. verecundus, the base of the roots are markedly and abruptly enlarged in the new species. Finally, the eggs of the new species are smaller (23–27 × 8–10 m) than those of A. verecundus (27–30 × 12–13 m).  相似文献   

10.
Summary The plant species composition of the chaff piles of three species of harvester ant (Messor spp.) and the contribution of the chaff to the organic pool were studied from August 1985 to July 1987. There were distinct differences in the plant species composition of the chaff of the three species. We attribute this to the different diets of the three species, which reflect the relative sizes of their individuals and their foraging strategies. The amount of chaff accumulated varies greatly between the three species (Messor rugossus: 127–196 g · ha–1 · y–1;Messor ebeninus: 2823–4437 g · ha–1 · y–1;Messor arenarius: 2165–2535 g · ha–1 · y–1), although the number of nests per hectare is virtually the same. We found that the amount of chaff is related to the rate of activity and the size of the individuals of each of the three ant species. The total chaff accumulated during the study period was 19.2 kg · ha–1, which is an important contribution to the organic matter in the soil in the Negev desert ecosystem.  相似文献   

11.
Differences between clones of the diatom Cylindrotheca fusiformi were studied with respect to growth rate, total lipid content and fatty acid composition. Sixty clones were isolated and cultivated under batch conditions. All clones were grown under identical conditions (temperature 22±1°C, light intensity 100 μmol photon m−2 s−1, salinity 28, F/2 medium) and were harvested in the late exponential growth phase for lipid and fatty acid analysis. The results show a wide variation in growth, total lipid content and fatty acid profiles among clones (p<0.05). The major fatty acids in the 60 clones were 14:0 (4.6–9.1%), 16:0 (18.2–32.0%), 16:1n-7 (21.6–33.1%), 20:4n-6 (4.1–13.5%) and 20:5n-3 (6.2–17.2%), with the highest proportion of 20:4n-6 in clone CF13 (13.5%), and the highest proportion of 20:5n-3 in clone CF5 (17.2%). The results support the view that some microalgal fatty acid variation is not restricted to interspecific variation and external factors, but also varies from clone to clone within the same species.  相似文献   

12.
Nuclear DNA content (2C) is used as a new criterion to investigate all species of the genus Gasteria Duval including the three recently described species Gasteria polita van Jaarsv., G. pendulifolia van Jaarsv. and G. glauca van Jaarsv.. The 122 accessions investigated have the same chromosome number (2n=2x=14), with exception of three tetraploid plants found. The nuclear DNA content of the diploids, as measured by flow cytometry with Propidium Iodide, is demonstrated to range from 32.8–43.2 pg. This implies that the largest genome contains roughly 1010 more base pairs than the smallest. Based on DNA content the species could be divided in five groups: G. rawlinsonii Oberm. with 32.8 pg, 13 mostly inland species with 34.3–36.0 pg, five coastal species with 36.5–39.0 pg and Gasteria batesiana Rowley with 43.2 pg. The thirteen species with 34.3–36.0 pg could be divided further, in a group of eight species occupying mainly very restricted areas with 34.3–35.1 pg and a second group of five species with 35.2–36.0 pg mainly occupying large areas. These five groups did not coincide very well with the two sections and four series of Gasteria based on a cladistic analysis by van Jaarsveld et al. (1994). Based on its long leafy branches, location in the centre of Gasteria species distribution and its by far lowest DNA content, G. rawlinsonii might be the most primitive member of the genus. Nuclear DNA content as measured by flow cytometry is shown to be relevant to provide additional information on the relationships between Gasteria species.  相似文献   

13.
In the present study phylogenetic relationships of the genus Stereocaulon (lichenized ascomycetes) were examined using DNA sequences from the ITS1–5.8 S–ITS2 rDNA gene cluster and from the protein-coding β-tubulin gene. In addition to the fruticose species traditionally classified in Stereocaulon, representatives of the crustose species that have recently been transferred to the genus were included. Muhria, a monotypic genus that is morphologically similar to Stereocaulon, differing only in apothecia ontogeny, was also incorporated. The analyses included 101 specimens from the ingroup representing 49 taxa. Sequences from both DNA regions were analysed simultaneously using direct optimization under the parsimony optimality criterion. The results support the inclusion of the crustose species and Muhria in Stereocaulon, while the current infrageneric classification is not supported. As Muhria is securely nested within Stereocaulon the new combination Stereocaulon urceolatum comb. nov. (syn. Muhria urceolata) is made. Further, species concepts need to be re-examined, as some species do not appear as monophyletic entities in the phylogeny.  相似文献   

14.
A new species of the fish genus Grammonus (Ophidiiformes: Bythitidae) is described based on a ripe female, 98 mm in standard length (SL). It was caught at the bottom of a cave at a depth of 20 m under lightless conditions in Ie-shima Island, one of the Ryukyu Islands. A comparison to the seven described species of Grammonus shows the greatest similarity to the widely distributed G. robustus, but G. yunokawai n. sp. differs from it by having fewer vertebrae (41 vs. 44–47), a greater predorsal length (41.5 vs. 32.0–39.0% SL), higher posterior margin of maxilla (8.4 vs. 5.6–7.3% SL), and greater interorbital width (10.5 vs. 5.9–7.6% SL). Supplementary material to this paper is available in electronic format at  相似文献   

15.
Phylogenetic relationships of ten wild species and several cultivars ofForsythia were reconstructed based on the chloroplast (cp) DNA variation. A total of 216 cpDNA variants, 44 of which were potentially phylogenetically informative, was detected using 24 restriction endonucleases. Phylogenetic analysis usingFontanesia andAbeliophyllum as outgroups revealed four well defined species groups in the genus: 1)F. suspensa, 2)F. europaea — F. giraldiana, 3)F. ovata — F. japonica — F. viridissima, and 4)F. koreana — F. manshurica — F. saxatilis. The amount of support for each monophyletic group was evaluated by various methods including character number, decay analysis, parsimony bootstrapping, Neighbour-Joining (NJ) — bootstrapping, NJ-jackknifing, and the topology-dependent permutation tail probability (T-PTP) test. The data do not support the hybrid origin ofF. intermedia fromF. suspensa andF. viridissima. The disjunctly distributed European species,F. europaea, was identified as a sister species of the ChineseF. giraldiana and it was probably derived through recent long distance dispersal.  相似文献   

16.
A new cottid, Icelinus pietschi sp. nov., and a rare species, Sigmistes smithi Schultz, were collected from intertidal zones in the southern Kuril Archipelago. Icelinus pietschi, represented by five specimens (34.8–42.2 mm SL) from Iturup Island, is distinguished from other species of Icelinus by having the dorsal scale rows terminating before the posteriormost base of the second dorsal fin, spines absent on the dorsal surface of the head, a single common opening of the terminal pores of the mandibular canal, a cirrus on the base of the nasal spine, and a slightly bifid uppermost preopercular spine without denticles dorsally. Six examples (36.8–42.9 mm SL) from Urup Island of Sigmistes smithi, previously known only rarely from the middle of the Aleutian Archipelago, constitute the first record of the species from the western North Pacific. Received: September 26, 1999 / Revised: May 25, 2000 / Accepted: August 29, 2000  相似文献   

17.
Based on the results of morphological and DNA sequence (partial D1–D3/D7–D8 nuLSU and partial nuSSU-ITS1-5.8S rDNA) data, three species of Plasmopara are revised and reclassified. A species of Plasmopara parasitic on Scorzonera, invalidly published several times, is assigned to a new genus and species under Novotelnova scorzonerae. Plasmopara euphrasiae sp. nov. is segregated from P. densa, and P. centaureae-mollis is revised and relegated to synonymy of Bremia centaureae. All taxa are described and illustrated.  相似文献   

18.
A new phototrophic sulfur bacterium has been isolated from a red layer in a laminated mat occurring underneath a gypsum crust in the mediterranean salterns of Salin-de-Giraud (Camargue, France). Single cells were coccus-shaped, non motile, without gas vacuoles and contained sulfur globules. Bacteriochlorophyll a and okenone were present as major photosynthetic pigments. These properties and the G+C content of DNA (65.9–66.6 mol% G+C) are typical characteristics of the genus Thiocapsa. However, the new isolate differs from known species in the genus, particularly in NaCl requirement (optimum, 7% NaCl; range, 3–20% NaCl) and some physiological characteristics. Therefore, a new species is proposed, Thiocapsa halophila, sp. nov.Dedicated to Prof. Dr. Norbert Pfennig in occasion of his 65th birthday  相似文献   

19.
20.
Olaveson  M. M.  Nalewajko  C. 《Hydrobiologia》2000,433(1-3):39-56
Our study separates the effects of elevated protons (at pH <3) and elevated metals (Al, Cd, Cu, Fe, Ni, Zn) on the growth of E. mutabilis Schmitz, a pioneering phototroph in acid mine drainage (AMD) and E. gracilis Klebs, a closely-related species rarely found in severely AMD-impacted sites. Both species were acid tolerant, growing optimally at pH 2.5–7. At pH values typical of AMD (pH 2.5–4) in the absence of elevated metals, E. gracilis outcompeted E. mutabilis (growth rates of 1.0 and 0.8 div d–1, respectively). Relative metal toxicities were evaluated based on the Effective Exposure causing 50% growth reduction (= EE50). With total metal additions similar to AMD levels, E. mutabilis demonstrated significantly greater tolerance to all metals, except Cu. E. gracilis showed two-fold higher tolerance to Cu2+ than E. mutabilis (EE50 of 91.6 vs. 45.7 pmol cell–1). The EE50 for Zn2+ was similar for both species (368 pmol cell–1 for E. gracilis and 423 pmol cell–1 for E. mutabilis). With Cd and Ni, E. mutabilis tolerated an order of magnitude higher exposure than E. gracilis(EE50 of 1.6 vs. 0.2 pmol Cd2+ cell–1; EE50 of 942 vs. 87 pmol Ni2+ cell–1). Al and Fe were tolerated at high total metal concentrations (up to 100 mM) by E. mutabilis, but toxicity was evident with E. gracilisat much lower levels. E. mutabilis grew at double the Al3+ exposure tolerated by E. gracilis (EE50 of 398 vs. 188 pmol Al3+ cell–1). There was an 18-fold difference in Fe tolerance levels between E. mutabilis and E. gracilis with EE50s of 8773 and 502 pmol Fe2+ cell–1, respectively. We conclude that differential metal tolerance, particularly to Fe2+, accounts for the mutually exclusive distribution of E. gracilis and E. mutabilis in AMD-impacted habitats.  相似文献   

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