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1.
John A. Raven 《Plant Ecology & Diversity》2013,6(3):477-485
Summary The life cycle of the Batrachospermales (freshwater florideophyte red such as Batrachospermum, Lemanea) is a shortened variant of the ‘normal’ marine florideophyte life cycle. The perennial Chantransia diploid phase is microscopic and encrusting. Each winter it produces one or more semi-erect haploid gametophytes by vegetative meiosis. Gamete production and fertilization is followed by production of diploid carposporophytes; these produce diploid carpospores which disperse, and regenerate the Chantransia phase. The question of the extent to which the Chantransia phase contributes resources to the gametophyte was approached by physiological-hydrodynamic modelling. These computations suggest that the photosynthetic rates in situ on an area basis are 20 times greater for the gametophyte than the Chantransia phase; this agrees with the observed ratios of peak biomass. The conclusion is that the Chantransia phase has a negligible role in provisioning the growing gametophyte, and that the role of the Chantransia phase is to occupy space with living biomass throughout the year, including exposure at summer drawdown, and (perhaps) by dispersal via production of monospores. A similar conclusion is arrived at on the basis of biomass data for the role of the perennial ‘mushroom’ phase of the semelparous marine Fucalean brown alga Himanthalia elongata in relation to the short-lived but much larger reproductive receptacles. 相似文献
2.
Pharyngodon medinae García-Calvente, 1948 (Nematoda: Pharyngodonidae) is redescribed from Podarcis pityusensis (Bosca, 1883) (Sauria: Lacertidae) of the Balearic Islands (Spain) and confirmed as a member of the genus Skrjabinodon Inglis, 1968. A systematic review of S. medinae and closely related species is also given. Parathelandros canariensis is referred to Skrjabinodon as a new combination and Parathelandros Magzoub et al., 1980 is dismissed as a junior homonym of Parathelandros Baylis, 1930. 相似文献
3.
The male of Brumptomyia angelae, sp. nov., a new species of Phlebotominae (Diptera, Psychodidae) of the Atlantic forest of the state of Paraná, Brazil, is described and illustrated. This new taxon is closely related to Brumptomyia ortizi Martins, Silva & Falc?o 1971, Brumptomyia nitzulescui (Costa Lima, 1932), and Brumptomyia troglodytes (Lutz, 1922). The male genitalia of these three latter species have also been drawn. 相似文献
4.
Population density (number of propagules/l) of Pythium in the irrigation water has been studied in the reservoirs of the Poniente Almeriense (Almería, Spain). These reservoirs are habitually used in the watering of the greenhouse crops of the district. From October 1994 to August 1997, 17 sampling campaigns were carried out, 23 reservoirs were visited and three of them were sampled during three years. 300 ml of superficial water were sampled and analyzed in the laboratory by means of filtration with paper Whatman number 1, placed on Ponchet selective medium and incubated at 20 degrees C. Data of the physical-chemical characteristics of the water (temperature, pH, CE, anions and cations) were taken. The geographical and seasonal distributions of the population were correlated with the analyzed characteristics. The more frequent densities were among 0-100 propagules/l. A population's seasonality was observed, with a maximum in winter and a minimum in summer. When Cl- concentration was higher, the number of propagules/l was smaller. 相似文献
5.
A new species of Kritskyia inhabits the urinary bladder of the "curimba", Prochilodus lineatus in the floodplain of the high Paraná river. The new species resembles others members of Kritskyia in the following features: haptor lacking anchors and with 14 hooks marginal, posterior male copulatory organ non articulated with the accessory piece and vagina a sclerotized tube. However, it differs from the known species mainly by the shape of the copulatory complex. This is the third endoparasitic monogenean species reported from freshwater Neotropical fish. 相似文献
6.
《International Journal of Insect Morphology and Embryology》1991,20(1-2):1-13
Ultrastructure of stemmata (larval eyes), stemmatal nerves, and the optic neuropils of 5th-instar larvae of cotton bollworm, Heliothis armigera (Hübner) (Lepidoptera : Noctuidae), were examined with scanning and transmission electron microscopes. Six stemmata are on each side of the head. Each stemma consists of 7 retinula cells arranged into 2 tiers. Stemmata I and II have 4 distal retinula cells and 3 proximal cells, the other 4 stemmata (III–IV) have 3 distal cells and 4 proximal cells. Stemmata I and IV have a short proximal rhabdom and the rhabdomere of each proximal cell has its microvilli projecting in only one direction. On the other hand, each stemma (in stemmata II–V) has a long proximal rhabdom and the rhabdomere of each proximal cell has microvilli pitched in several different directions relative to the horizontal plane. An axon projects proximally from each retinula cell body. The stemmatal nerve is composed of the 42 retinular axons from all of the 6 stemmata on the same side of the head. Each stemmatal nerve projects to the ipsilateral optic neuropil. Axons from each stemma are in a fasicle (within the stemmatal nerve), which consists of 7 axons, 3–4 of them are thick and terminate synaptically in the proximal neuropil; the others are thinner and terminate in the distal neuropil. Organelles, particularly lysosomes, undergo ultrastructural transformations relative to ambient light levels. The functional significance of abovementioned structures are discussed in light of current knowledge. 相似文献
7.
W. C. Osman Hill 《Zoomorphology》1969,65(3):274-286
Musculature innervated by the N. facialis inTheropithecus gelada (Rüppell) is patterned on broad lines in agreement with related genera of catarrhine monkeys, but presents some specializations and divergences in detail. Noteworthy is the extension to the labial margins superficially of the combined levator labii superioris and zygomaticus in the upper and the pars mandibularis of trachelo-platysma in the lower lip. A specialization of the medial fibres of levator labii superioris forms a sling-like structure within the upper lip and serves to implement the lip-flip gesture characteristic of the genus. Its antagonist is the orbicularis oris. Special features of all other facialis muscles are considered.Abbreviations
ABD
Anterior belly of digastricus
-
AE
Arteria facialis
-
ALS
Arteria labialis superior
-
ANL
Arteria lateralis nasi
-
AP
Auricularis posterior
-
APA
Arteria auricularis posterior
-
AS
Arteria auricularis superior
-
A.Se.
Arteria septi nasi
-
A.Sy.
Arteria symphysialis
-
BP
Buccal pouch
-
LAO
Depressor anguli oris
-
FTA
Fronto-temporo-auricularis
-
GLI
Glandulae labialis inferiores
-
GLS
Glandulae labialis superioris
-
LAO
Levator anguli oris
-
LG
Artery to labial glands
-
LLAN
Levator labii superioris alaeque nasi
-
LLS
Levator labii superioris
-
M
Masseter
-
MM
Musculus mentalis
-
NP
Notoplatysma
-
O
Occipitalis
-
OO
Orbicularis oris
-
O.Oc
Orbicularis oculi
-
P
Procerus
-
SH
Sterno-hyoideus
-
TP
Trachelo-platysma
-
VL
Vena labialis communis
-
VP
Venous plexus of dorsum nasi
-
ZM
Zygomaticus minor
-
Zy
Zygomaticus 相似文献
8.
Valentin Popa Louis Morneau Céline Piché André Deshaies Eric Bauce Claude Guertin 《ZooKeys》2013,(348):97-124
Twig beetles in the genus Pityophthorus Eichhoff, 1864 include more than 300 species worldwide, with maximum diversity in tropical and subtropical regions. To date, approximately 50 species of Pityophthorus have been recorded in Canada, and these species are associated mainly with coniferous trees. Since 1981, no comprehensive study on this difficult taxonomic group has been conducted in Quebec, Canada, most likely due to their limited significance as forest pests. Based on data gathered from five years of field sampling in conifer seed orchards and compiled from various entomological collections, the distribution of Pityophthorus species in Quebec is presented. Approximately 291 new localities were recorded for the Pityophthorus species. Five species-group taxa, namely Pityophthorus puberulus (LeConte, 1868), Pityophthorus pulchellus pulchellus Eichhoff, 1869, Pityophthorus pulicarius (Zimmermann, 1868), Pityophthorus nitidus Swaine, 1917,and Pityophthorus cariniceps LeConte&Horn, 1876 were the most widespread. In contrast, Pityophthorus consimilis LeConte, 1878, Pityophthorus intextus Swaine, 1917, Pityophthorus dentifrons Blackman, 1922, Pityophthorus ramiperda Swaine, 1917, and Pityophthorus concavus Blackman, 1928 display a notably limited distribution. In addition, the first distribution records of Pityophthorus intextus and Pityophthorus biovalis Blackman, 1922 are furnished, and the subspecies Pityophthorus murrayanae murrayanae Blackman, 1922is reported from Quebec for the second time. Moreover, distribution maps are provided for all Pityophthorus species recorded in the province of Quebec. 相似文献
9.
Dr. D. R. Nässel 《Cell and tissue research》1975,163(4):445-464
The Lamina ganglionaris (first optic neuropile) of the decapod crustacean Pandalus borealis has its optic cartridges (synaptic compartments) arranged in horizontal rows. Each optic cartridge contains seven receptor axon terminals and the branching axis fibres of five monopolar second order neurons. Four types of monopolar neurons are classified. Their cell bodies are arranged in two layers. The inner layer contains the cell bodies of exclusively one of these types, and each cartridge is invaded by two neurons of this neuron type (type M 1:a and M 1:b). The outer layer contains the cell bodies of the remaining three types (M 2, M3 and M4). One gives rise to a large radially branched axis fibre in the centre of the cartridge. The other two have wide branches which may make inter-cartridge contacts, one proximally and the other distally in the plexiform layer, which is clearly bistratified. The receptor axons terminate in two levels corresponding to these strata. Two sets of tangenital fibres form networks in the proximal and the mid-portion of the lamina. Both networks have fibres with primary branches in the vertical plane and secondary branches in the horizontal plane. The fibres of the networks are derived from axons that pass from the second optic neuropile, the medulla externa. 相似文献
10.
Giuseppe Marramà Giorgio Carnevale Andrea Engelbrecht Kerin M. Claeson Roberto Zorzin Mariagabriella Fornasiero Jürgen Kriwet 《Pal?ontologische Zeitschrift》2018,92(2):283-313
Here, we review and discuss the records and taxonomy of the Ypresian (Eocene) chondrichthyans from the famous Bolca Konservat-Lagerstätte in northeastern Italy. Despite the outstanding diversity and the numerous studies focusing on the actinopterygian faunas from Pesciara and Monte Postale, the current knowledge about the systematics, taxonomy and phylogenetic relationships of the cartilaginous fishes from these Eocene sites remains elusive and largely inadequate. The celebrated Eocene Bolca Lagerstätte has yielded several exquisitely preserved articulated remains of chondrichthyan fishes in which delicate structures and soft tissues are preserved, as well as isolated teeth. The cartilaginous fish assemblage of Bolca comprises at least 17 species-level taxa belonging to 10 families in 6 orders, including selachians (Carcharhiniformes, Lamniformes), batoids (Torpediniformes, Myliobatiformes, Rajiformes) and holocephalans (Chimaeriformes). The occurrence of holocephalans represented by an isolated fin-spine of the chimeroid Ischyodus in the Bolca assemblage is reported here for the first time and represents the first record of chimeroids in the Eocene of Italy and also southern Europe. The Bolca chondrichthyan assemblage is remarkably different from those of other contemporaneous Boreal or Tethyan deposits, suggesting that its taxonomic composition is largely influenced by the palaeoenvironmental context. However, this synoptic review also highlights the importance of detailed revisions of all chondrichthyan remains from the Bolca Konservat-Lagerstätten. 相似文献
11.
In this paper, we study a sample of cranial, mandibular and dental remains of two species of the machairodontine felid genus Machairodus from the Early Vallesian (MN 9, around 10 Ma) site of Los Valles de Fuentidueña (Segovia, Spain): the tiger-sized Machairodus aphanistus, and the smaller and more primitive M. alberdiae; a species which is only known from this site. The fossils of these two sympatric populations are compared with the most abundant samples of M. aphanistus from the Late Vallesian (MN 10), younger sites of Batallones-1 and Batallones-3 (Torrejón de Velasco, Madrid, Spain). The results support the specific separation of M. alberdiae from M. aphanistus based on several differences in teeth size and proportions. Besides this, we observed differences among the analysed samples of M. aphanistus, indicating a differentiation between the older and more primitive form from Los Valles de Fuentidueña, and the younger and more derived one from the two Batallones sites. These differences fit well with the morphological evolution of this lineage towards the more derived Turolian Amphimachairodus giganteus. Finally, a relatively structured, patched habitat, combining the presence of open landscapes with shrubby and wooded areas, is inferred to explain the sympatric distribution of these two large machairodontines in Los Valles de Fuentidueña. 相似文献
12.
The structure of the ovipositor sclerites and muscles was investigated in Spaziphora hydromyzina (Diptera, Scathophagidae). 相似文献
13.
Alfredo E. Zurita Francisco Cuadrelli Rodrigo L. Tomassini Martín de los Reyes Carlos Luna Pablo Toriño 《Comptes Rendus Palevol》2017,16(3):303-311
Within the Late Neogene Glyptodontidae of the Pampean region of Argentina, “Urotherium antiquum” was described on the basis of some associated osteoderms of the dorsal carapace, which in addition include a partial skull and left hemimandible. The diagnostic characters are located on the exposed surface of the osteoderms of the dorsal carapace which somewhat resembles those of the Pleistocene genus Neuryurus. Although the relationship of “U. antiquum” to the remaining Glyptodontidae has never been clarified, some cladistic analyses suggest a close phylogenetic affinity with the clade composed of Plohophorus + (Glyptodon + Doedicurus). A careful comparison of “U. antiquum” to well-characterized taxa with similar stratigraphic and geographic provenance reveals that no significant skull differences are observed from Plohophorus figuratus Ameghino. It seems likely that the alleged ornamentation pattern that characterizes this species was produced by a taphonomic alteration of the exposed surface of the osteoderms, a process broadly distributed in glyptodonts having a “rosette” ornamentation pattern. Finally, some characters present in the osteoderms of the type specimen of “U. antiquum” suggest that it may be a juvenile specimen. In summary, “U. antiquum” should be considered a junior synonym of P. figuratus. 相似文献
14.
《Comptes Rendus Palevol》2014,13(5):421-441
The paralic flora and fauna from the Late Jurassic of Chassiron (Oléron Island, western France) are described. The Tithonian-aged bonebeds of Purbeck facies of this locality have yielded a rich and diverse vertebrate assemblage including fishes, amphibians, reptiles and mammals, alongside numerous plant and invertebrate remains. The Chassiron locality thus appears as a peculiar Konzentrat-Lagerstätte in which most of the palaeoecosystem's biological components (both aquatic and terrestrial) have been preserved. The depositional environment was probably subject to salinity fluctuations, as indicated by the co-occurrence of freshwater and euryhaline organisms. This is one of the richest localities and the first mammal-bearing site known from the Jurassic of France. 相似文献
15.
Yu. D. Nechipurenko A. D. Guzaev M. V. Khodykov Ya. V. Stirmanov A. A. Ivanov A. S. Krylov A. L. Zhuze 《Biophysics》2017,62(3):356-360
Monomeric bis-benzimidazole (MB) is an analog of the Hoechst 33258 dye. The enthalpy and entropy of MB binding were evaluated by analyzing the calorimetric data on MB reverse titration with poly(dA) · poly(dT). A mathematical model was developed to estimate the thermodynamic parameters of binding on the basis of calorimetric data. The results agree well with spectrophotometric data on the binding of analogous compounds. The model was used to estimate the parameters of binding with poly(dA) · poly(dT) for dimeric bis-benzimidazole (DB), which consists of two bis-benzimidazole monomers linked via a flexible chain. The ligand was assumed to produce different types of complexes with the polymer. 相似文献
16.
Mizoguchi SM Portela-Castro AL Martins-Santos IC 《Genetics and molecular research : GMR》2007,6(3):650-656
Three populations of the genus Crenicichla, namely Crenicichla iguassuensis, Crenicichla sp 1 and Crenicichla sp 2, from the Igua?u River, were analyzed cytogenetically, and their nucleolus organizer regions, constitutive heterochromatin distribution and chromomycin A3 markings were studied. Karyotype analyses showed a diploid number of 48 chromosomes, made up of 2 metacentric pairs, 2 submetacentric pairs, 7 subtelocentric pairs, and 13 acrocentric pairs for the three Crenicichla species and no sexual chromosome differentiation. Nucleolus organizer regions showed strong interstitial marking on the first chromosome pair, coincident with a constriction presented by Giemsa and positive marking by chromomycin. Although constitutive heterochromatin patterns were also similar, with pericentromeric markings, small differences in the three species could be observed. Crenicichla sp 2 presented some chromosomes with bitelomeric markings absent in Crenicichla iguassuensis and Crenicichla sp 1. 相似文献
17.
A revised checklist of the Scathophagidae, Fanniidae and Muscidae recorded from Finland is presented. Phaonia
amicula Villeneuve, 1922 is noted from Finland for the first time. 相似文献
18.
Summary Acclimation to low salinity induces changes in the ultrastructure of the gill cells of the marine euryhaline amphipod, Gammarus oceanicus. The gills are composed of a single cell type. In 100% artificial sea water, these cells contain moderate numbers of mitochondria which are randomly distributed in the cytoplasm. The plasma membrane is extensively invaginated at the apical, lateral, and basal surfaces. Acclimation to 20% artificial sea water induces a further invagination at the apical cell membrane to form an elaborate apical labyrinth. The extracellular spaces between the folds in the basal cell membrane dilate to 1500 Å or more. Mitochondria are more abundant and in many cells they undergo a change in conformation. The mitochondria are crowded into thin leaflets of cytoplasm between the dilated basal invaginations or into the narrow space between apical and basal cell membranes. Consequently, they lie in close contact with the plasma membrane over much of their surface.Supported in part by grants from the United States Public Health Service, 5 RO1 AM13455-03 and PHS FR-07085-04, and by a grant from the National Research Council of Canada administered by Dr. G. P. Morris. 相似文献
19.
J Moens 《Archives internationales de physiologie et de biochimie》1975,83(3):443-451
The ionic regulation of the haemolymph of larvae of Aeshna cyanea (Müller) was studied by means of two types of experiments. In the first the change in internal ionic composition was followed as a function of the time spent in a given experimental medium. These experiments led to the conclusion that: 1. the haemolymph composition does not change when larvae are starved in tap water for 10 days; 2. the haemolymph ionic concentrations (Na and Cl) have initial marked increase when the animals are kept in hypertonic media of diluted sea water; after 80 hours however, both concentrations stay constant. In a second series of experiments the internal ionic concentration was compared to a series of different concentrations of external media. From this, the relation between the internal and external ionic concentration was elaborated : in hypotonic media the internal Na and Cl concentrations stay constant, in hypertonic media there is a parallelism between the increase of the external concentration and haemolymph concentration, the internal Na concentration being always slightly hypertonic, the Cl concentration markedly hypotonic. Finally, when larvae are placed in glass distilled water, the internal Na and Cl concentrations begin to decrease after 60 hours. 相似文献
20.
Espíndola EL Matsumura-Tundisi T Rietzler AC Tundisi JG 《Revista brasileira de biologia》2000,60(2):179-194
With the purpose of analyzing the horizontal distribution of the zooplankton community of the Tucuruí Reservoir in the State of Pará, Brazil, collections were made at 16 stations during August 1988. The stations cover the regions called Caraipé (C), Ara?agi (B) and Arar?o (A), and represent the different compartments of this ecosystem in regard to the morphometry and the presence or absence of "flooded forest". Our findings showed the existence of three compartments with different limnological characteristics determined as a function of the system's morphometry, a factor that may have influenced the horizontal circulation of the reservoir's water and, consequently, led to physical, chemical and biological differences at each of the sampled stations. All the stations presented physical and chemical stratification and layers of total anoxia or reduced concentrations of oxygen dissolved at depths corresponding to the limit of the euphotic zone. With regard to the zooplankton, a differentiated distribution that was mainly quantitative was found among the compartments (density of organisms and proportion among the species) in the case of Cladocera and Copepoda, and basically qualitative in the case of Rotifera. On the other hand, the greatest densities of organisms for all the groups were recorded at the Caraipé stations. As for the spatial distribution, some species were more restricted or more abundant at given stations. Among the Cladocera, there was a greater abundance of Moina minuta, Bosmina hagmani and Bosminopsis deitersi at the Ara?agi stations, while C. cornuta intermedia, C. cornuta rigaudi and C. cornuta cornuta were more plentiful in the Caraipé and Diaphanosoma birgei in the Arar?o. Among the Rotifera, Trochosphaera aequatoriales and Lecane proiecta, Ascomorpha ecaudis, besides Polyartha cf vulgaris were restricted, respectively, to the Caraipé, Ara?agi and Arar?o stations, while the others, such as Keratella americana and Collotheca sp., were more broadly distributed. As regards Copepoda Calanoida, the dominating species was found to be Notodiaptomus maracaibenses, followed by Notodiaptomus henseni and Argyrodiaptomus azevedoi. The most abundant Cyclopoda species was Thermocyclops minutus, although Thermocyclops decipiens, Mesocyclops longisetus, Mesocyclops meridianus e Metacyclops sp. were also found. 相似文献