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1.
The presence of the two morphs, “typical” and “large mouth”, in the Antarctic fish species Trematomus newnesi (Perciformes, Notothenioidei) was recorded for the first time in nearshore waters of the South Shetland Islands (Potter Cove)
and western Antarctic Peninsula (Petermann Island). The two morphs were distinguishable in specimens of 60–241 mm total length
(TL); about 30% of the specimens constituted intermediate forms. In addition to the previously known characters separating
the morphs, we found that the “relative size of the eye” can also be used to identify smaller and larger fish of the typical
morph. The ecological significance of the two morphs remains unclear. Ratios of diagnostic characters for identification of
the species at two size ranges (60–131 and 132–241 mm TL) are provided. 相似文献
2.
Specimens of eelpouts were found in the northern Sea of Japan that were externally similar to Lycodes yamatoi Toyoshima, 1985, but their coloration differed from the coloring known for this species. Comparative analysis of meristic
characters and sequence comparison of mtDNA COI and cytb gene fragments did not reveal distinctions between specimens with
different types of coloration. All studied specimens belong to L. yamatoi. The live color pattern of L. yamatoi is characterized by high variation, with two main types of coloration, “dark” and “bright.” 相似文献
3.
Lotfi Rabaoui Randa Mejri Sabiha Tlig-Zouari Lilia Bahri Oum Kalthoum Ben Hassine Costas S. Tsigenopoulos 《Hydrobiologia》2011,678(1):99-111
The Mediterranean fan mussel Pinna nobilis is an endangered invertebrate due to overexploitation and habitat deterioration. In this species, two distinctive morphs,
the “combed” and “straight and wide” forms, have been recorded and it is not known whether this morphometric variability is
attributed to genetic or environmental factors. In this study, we used mitochondrial COI sequences to describe the genetic
variability of five Pinna nobilis populations sampled along the northern, eastern, and southern Tunisian coastline, and to examine whether there is a genetic
differentiation between the two forms of this species. DNA sequences of 675 bp from the mitochondrial COI gene have revealed
10 different haplotypes among 49 examined specimens. Haplotype diversity was high, ranging between 0.40441 and 0.80952, and
showed a decreasing North-East gradient, which seems to be explained by the hydrogeography of the study area. The mitochondrial
COI marker did not suggest a genetic distinctiveness between the two Pinna nobilis shell forms, “combed” and “straight and wide”. Although the morphometric plasticity of the fan mussel could be due to the
influence of environmental factors, further genetic studies using nuclear markers are envisaged to investigate whether this
differentiation is associated to gene flow restrictions. 相似文献
4.
Showe-Mei Lin 《Journal of applied phycology》2006,18(3-5):671-678
Four flattened Gracilaria species have been reported from Taiwan: G. spinulosa, G. vieillardii, G. textorii and G. punctata, identified based on branching pattern, the presence or absence of spines, and characters that often vary seasonally. Gracilaria spinulosa was originally described from the type locality, Tainan. Species with toothed margins are usually referred to G. “vieillardii”; those with smooth margins to G. “textorii”, and those with smooth margins and dark spots scattered over the blade to G. “punctata”. Molecular analyses show that specimens with marginal teeth cluster in three different groups: a G. “vieillardii” clade, a G. spinulosa clade, and a clade sister to G. spinulosa. An undescribed species comprises the third clade, which is distinguished by its relatively large gonimoblast cells and weakly developed tubular nutritive cells. The three clades can be separated by the character of the tubular nutritive cells, the size of gonimoblast cells and certain vegetative features. Plants with entire margins form a single clade characterized by cystocarps with basal tubular nutritive cells and their absence in the cystocarp cavity. They are nested in the Hydropuntia complex and are referred to as Gracilaria “punctata” here. The records of G. textorii and G. punctata from Taiwan require reinvestigation in comparison with the Japanese species. 相似文献
5.
6.
George D. Koufos Louis de Bonis Dimitris S. Kostopoulos Laurent Viriot Theodora D. Vlachou 《Pal?ontologische Zeitschrift》2004,78(1):213-228
Two skulls, two mandibles and some postcranials ofMesopithecus from the locality “Vathylakkos 2” of Axios Valley (Macedonia, Greece) enlarge our knowledge about the genus and its differentiation.
The new material together with an old skull from the same locality is compared with the Pikermi, “Ravin des Zouaves 5” (Axios
Valley), and Maramena (Serres basin) samples. It is concluded that the VathylakkosMesopithecus resemblesM. pentelicus from Pikermi, as wellM. delsoni from “Ravin des Zouaves 5” and it is referred asMesopithecus sp. aff.M. pentelicus. The biochronological age of “Vathylakkos 2” has been considered as MN 12, while recent magnetostratigraphic data indicate
an age of about 7.5 Ma. This age confirms the position of the VathylakkosMesopithecus between Pikermi and “Ravin des Zouaves 5”. Some dental indices compared with those of the RecentCercopithecus suggest that the Vathylakkos sample is monospecific.
相似文献
7.
Here, we have characterized four pH-dependent states: alkaline state, “B” (pH 9.0), native state, “N” (pH 7.4), acid-induced
state, “A” (pH 2.2) and molten globule state, “MG” (pH 1.8) of Rhizopus niveus lipase (RNL) by CD, tryptophanyl fluorescence, ANS binding, DLS, and enzyme activity assay. This “MG” state lacks catalytic
activity and tertiary structure but it has native-like significant secondary structure. The “R
h” of all the four states of RNL obtained from DLS study suggests that the molecular compactness of the protein increases as
the pH of solution decreases. Kinetic analysis of RNL shows that it has maximum catalytic efficiency at state “B” which is
15-fold higher than state “N.” The CD and tryptophanyl fluorescence studies of RNL on GuHCl and temperature-induced unfolding reveal that the “MG” state
is more stable than the other states. The DSC endotherms of RNL obtained at pH 9.0, 7.4, and 2.2 were with two transitions,
while at pH 1.8 it showed only a single transition. 相似文献
8.
Relationships among three Japanese Laetiporus taxa (“L. sulphureus var. sulphureus” auct. jap., L. sulphureus var. miniatus, and L. versisporus) were assessed with phylogenetic analysis and incompatibility tests. Gene phylogenies inferred from the internal transcribed
spacer region of nuclear ribosomal DNA, elongation factor 1α, and β-tubulin gene regions suggested that Japanese Laetiporus was divided into four groups: the yellow pore form of L. sulphureus var. miniatus, the white pore form of L. sulphureus var. miniatus, and two “L. sulphureus var. sulphureus”/ L. versisporus groups. A morphologically distinct species, Laetiporus versisporus, sharing a clade with “L. sulphureus var. sulphureus” auct. jap., was proved to be an anamorphic form of “L. sulphureus var. sulphureus” auct. jap. The “sulphureus/versisporus” isolates showed two divergent sequence types in each region. Some isolates had intraindividual polymorphism assigned to
both sequence types. This finding suggests that speciation via hybridization is ongoing in the “sulphureus/versisporus” group. Single spore isolates from the “sulphureus/versisporus” group, white pore group, and yellow pore group were incompatible with each other. Our results provided strong support for
the new recognition of three Laetiporus taxa in Japan. 相似文献
9.
B. M. Kataev 《Entomological Review》2011,91(1):90-95
Harpalus apache sp. n. is described from the eastern part of New Mexico, USA (type locality: Hwy I 40, near Santa Rosa, Guadalupe Co). The
new species is very similar in appearance to H. cordatus (Le-Conte, 1853) but readily distinguished from it by the male genitalia structure. These two species constitute a natural
taxon which is included as the “cordatus” group (= Opadius Casey, 1914) in the subgenus Glanodes Casey, 1914. Distinctive characters, distribution and composition of the subgenus Glanodes and two its species groups (“obliquus” and “cordatus”) are provided. Two names, H. cordatus (LeConte, 1853) (= H. tadorcus Ball, 1972) and H. puncticeps (Casey, 1914) (= H. cunctipeps Ball, 1973), rejected because of the secondary homonymy, are reinstated as valid since they are not homonyms of Ophonus cordatus (Duftschmid, 1812) and Ophonus puncticeps Stephens, 1828, respectively. 相似文献
10.
Paula J. Rudall 《The Botanical review》2002,68(4):488-509
A morphological cladistic analysis is presented of the lilioid order Asparagales, with emphasis on relationships within the
“lower” asparagoids, in the context of recent new data on both floral and vegetative structures. The analysis retrieved a
monophyletic “lower” asparagoid clade, in contrast to molecular analyses, in which lower asparagoids invariably form a grade.
However, limited outgroup sampling in the current analysis is a significant factor in this “inside-out” topology; if the morphological
tree is rerooted with Orchidaceae as the outgroup, the result is a topology broadly similar to the molecular one. The relatively
low resolution of the “lower” asparagoid clade identified here is a result of high homoplasy in several characters, which
could be regarded as iterative evolutionary themes within Asparagales, notably (among floral characters) epigyny and zygomorphy.
Close relationships between some family pairs were inferred, including Orchidaceae and Hypoxidaceae, Boryaceae and Blandfordiaceae,
Asphodelaceae and Hemerocallidaceae, and Iridaceae and Doryanthaceae. The small South African genusPauridia, which differs from other Hypoxidaceae in that it lacks the outer stamen whorl, was placed as sister to Orchidaceae rather
than being embedded in Hypoxidaceae as in molecular analyses, because despite some significant similarities with other Hypoxidaceae
(e.g., mucilage canals), it shares some characters with Orchidaceae, notably the presence of a gynostemium and pontoperculate
pollen.Xanthorrhoea andLanaria were wild-card taxa in the context of this analysis, with characters in common with more than one different group. 相似文献
11.
Pre-dispersal seed predators of quickly maturing inflorescences of Asteraceae are constrained by shortage of development time.
At seed dispersal, they should pupate or, if still immature, relocate into another inflorescence. To investigate how dominant
coleopteran predators of dandelion seed, Glocianus punctiger (Curculionidae) and Olibrus bicolor (Phalacridae), cope with time limitation we combined observation (development and temperature of dandelion capitulum, thermal
constants of predator development, age structure of larval populations at seed dispersal) and analogy (“rate isomorphy” in
predator development, comparing “model” coleopteran species with similar temperature requirements). Development of a dandelion
capitulum takes 21 days. The time available to G. punctiger (140–190 day degrees, development threshold 6.3°C) is sufficient to complete development and pupate after seed dispersal.
By contrast, only 30–50 day degrees are available to O. bicolor (threshold 13.5°C) and this is not enough to complete development and consequently immature larvae should move to other capitula
to continue feeding until pupation. These contrast strategies which are determined by this thermal adaptation, are accompanied
by differences in larval morphology. The “cold adapted” G. punctiger has an apodous larva not capable of migrating between capitula while the “warm adapted” O. bicolor has a mobile campodeiform larva capable of migration. 相似文献
12.
Morphological and anatomical characters of four ectomycorrhizae with affinities to the genera Humaria, Geopora, and Trichophaea of Pyronemataceae (Pezizomycetes, Ascomycota) on Chinese Pine (Pinus tabulaeformis) are described. The ectomycorrhizae are yellowish brown to brown, and have pseudoparenchymatous outer mantle layers and partially
warty emanating hyphae with thick walls and without clamps. Intrahyphal hyphae are present, and no rhizomorphs are formed.
The four ectomycorrhizae are distinguishable by differences in cell shape of outer mantle layers and the presence of cystidia.
Ectomycorrhizae of a possible Humaria species (Pinirhiza humarioides) lack cystidia and have irregularly inflated cells on the outer mantle layer that are connected with thin septa. The two
ectomycorrhizae showing probable affinities to Geopora species (“P. daqingensis” and “P. geoporoides”) possess row-like arranged cells in the outer mantle layer and cell heaps, and differ by the presence or absence of cystidia
as well as by the structure of the inner mantle layers. Ectomycorrhizae likely having been formed by a Trichophaea species (“P. trichophaeoides”) have oval to polygonal cells and no cystidia. The possible taxa affiliations were assessed by molecular-phylogenetic analyses
of the internal transcribed spacer (ITS) and partial large subunit (LSU) nrDNA. Morphological and anatomical characters are
discussed against the background of the LSU phylogeny. 相似文献
13.
Two associated partial skeletons, one from the McCarty ranch (MOTTU site 0690) near Kalgary, Texas, Tecovas Formation, and
the other from the Petrified Forest Member of the Chinle Formation, outside the Petrified Forest, Arizona, represent the most
complete specimens ofPoposaurus gracilis found to date, and increase our understanding of the osteology of this rare pseudosuchian archosaur. The cervical centrum
of TTUP-10419 possesses an accessory dorsal parapophyseal rib facet, as in “Lythrosuchus”. The ilia of these new fossils are the first ofPoposaurus to preserve the complete preacetabular blade, which is long and “blade-like” rather than “paddle-shaped” as previously thought.
These specimens also confirm that isolated elements previously referred toPoposaurus (fused sacral vertebrae, the pubes and the ischia), but not present in the holotype indeed belong to that taxon. The morphology
of the cervical centrum and the preacetabular blade of the ilium are identical to the much larger type of“Lythrosuchus” langstoni, suggesting that “Lythrosuchus” is a junior synonym ofPoposaurus. However, we retain the speciesPoposaurus langstoni nov. comb. on the basis of larger size, absence of a distinct ridge on the lateral surface of the ilium, and the lack of
a pit on the proximal end of the ischium. A phylogenetic analysis suggests a monophyletic Poposauroidea and a paraphyletic
“Rauisuchia”. 相似文献
14.
Sevcikova L Pechova A Pavlata L Antos D Mala E Palenik T Panev A Dvorak R 《Biological trace element research》2011,143(2):882-892
The aim of this trial was to compare the effect of long-term supplementation of goats with different forms of selenium on
body reserves of selenium in their kids at the time of weaning. Thirty-three pregnant goats were divided into five groups.
Group C was control while the other four groups were supplemented with selenium (Se) for 6 weeks before parturition (0.3 mg/goat/day)
and after parturition (0.9 mg/goat/day). Group “Se-I” received sodium selenite and three other groups received organic forms:
“Se-L,” lactate–protein complex; “Se-P,” Se-proteinate; and “Se-Y,” Se-yeast. The kids were weaned at 3 months of age and
samples of tissues (liver, pancreas, myocardium, lungs, kidneys, spleen, thigh, tongue, and diaphragm) were taken after slaughtering.
The long-term supplementation of goats with Se influenced Se concentration in all examined tissues of kids. Significant differences
(p ≤ 0.01) were found between the control and all experimental groups, except for the renal cortex and pancreas (Se-I). The
average increase of Se concentration in overall examined tissues in comparison with the control (100%) was as follows: Se-Y,
192%; Se-P, 167%; Se-L, 161%; Se-I, 144%. The highest efficiency was found in the group supplemented with Se-yeast with a
high content of selenomethionine, also the other two organic forms of Se were more efficient than the inorganic form. 相似文献
15.
Residential form of white-spotted char Salvelinus leucomaenis appears in volcanic stream characterized by stable water and temperature regime. The maximal body length of fish is 285 mm
and body mass is 245 g; the oldest specimen is 7 years old. The somatic growth does not relax, and the annual growth rate
is 30–40 mm. The maturation begins at the age of 4 years after the fish reaches 175 mm length and 60 g in weight. The spawning
takes place in autumn. Sex dimorphism and nuptial coloration are not observed, and the “spotted” coloration remains through
the year. Vomer is toothless, or only one tooth is presented (in 15% of sampled specimens). Sagittal otoliths are characterized
by deformation granular texture of ventral area, the layering is broken. The food spectra of a mature specimen comprises gammarids,
large-size larvae, and imagoes of amphibiotic insects during the summer period. 相似文献
16.
A. Yu. Ivantsov 《Paleontological Journal》2009,43(6):601-611
Six groups of fossil remains of Kimberella quadrata are described. They represent the imprints of the body in different types of preservation (including the group of specimens
that are elongated more than twice in comparison with the common ones) and also the feeding traces and mucus secretions. The
imprint is considered to be created only by the upper side of the body. The fossil material shows that Kimberella had hard sclerites, probably of aragonite, and several teeth in its mouth. Kimberella is suggested to have “the mantle” with sclerites, wider foot, which was spread over the outer surface of the mantle, and
the strong transverse and longitudinal musculature. 相似文献
17.
Elaphoglossum amygdalifolium holds a critical phylogenetic position as sister to the remaining ca. 600 extant species of Elaphoglossum and may provide important insight into the evolution of epiphytism in this clade of ferns. Here, we present the first examination
of growth habit and gametophyte morphology for this species. We show that the cordate to elongate-cordate gametophytes occur
up to 0.5 m above the ground on the base of tree trunks. Unlike the gametophytes of all other studied species of Elaphoglossum, rhizoids are absent along the thallus margin and the hairs present on the margin lack whitish waxy caps; both differences
are pleisiomorphic for the genus. Sporelings of E. amygdalifolium produce a single long root that grows straight into the soil where it branches profusely. Mature sporophytes have long-creeping
rhizomes that climb to heights of at least 3 m and produce two types of roots: “feeding roots” that reach the ground and “clasping
roots” that anchor the sporophyte to its host plant. Our observations reveal that E. amygdalifolium is a primary hemiepiphyte, the first example of this growth habit to be documented in Elaphoglossum. Results of an ancestral state reconstruction of growth habit in bolbitidoid ferns show that both primary hemiepiphytism
and holoepiphytism are equally likely to be the ancestral character state for Elaphoglossum. 相似文献
18.
Over two consecutive years in the North Bank Plain Zone of Assam, India, during the spring growing season (February–June)
of- 2006 and 2007 we examined effects of morpho-physiological characteristics of rice (Oryza sativa L.) plants in relation to methane (CH4) emission from paddy fields. Traditional cultivar “Agni” and modern improved cultivar “Ranjit” were grown in light textured
loamy soil under irrigation. A higher seasonal integrated methane flux (E
sif) was recorded from “Agni” compared to “Ranjit”. Both cultivars exhibited an emission peak during active vegetative growth
and a second peak at panicle initiation. Leaf and tiller number, leaf area, length, and volume of root were greater in “Agni”,
but grain yield and yield-related parameters such as increased photosynthate partitioning to panicles at the expense of roots
were greater in “Ranjit”. “Ranjit” also photosynthesed faster than “Agni” during panicle development but slower than “Agni”
at tillering. In both the years, a higher soil organic carbon content was recorded in plots of “Agni”. Our results suggest
that in “Agni” enhanced diversion of photosynthate to roots resulted in more substrate being available to methanogenic bacteria
in the rhizosphere. Additionally, the more extensive vegetative growth of this cultivar may enhance methane transport from
the soil to the above-ground atmosphere. 相似文献
19.
Rimoldi S Papis E Bernardini G Prati M Gornati R 《Molecular and cellular biochemistry》2007,301(1-2):143-153
GD3, a minor ganglioside in most normal tissues, is involved in important biological events and its expression could increase
in pathological conditions. Organism integrity requires a tight balance between the anabolic and catabolic processes, thus
it is important to control the intracellular expression of those “key” enzymes, which act at the “branching point” of ganglioside
metabolism; one of these is the GD3-synthase (ST8Sia I). In this paper, we report the sequences of two ST8Sia I mRNAs found
in Xenopus laevis and their genomic organization; the canonical form resulted constituted of 5 exons and 4 introns, while the “short” mRNA
lacks of the exon 2. The expression of the two ST8Sia I mRNAs during embryo development and their tissue distribution in adult
animals showed the single or simultaneous presence of the two forms. Experiments of in vitro expression and evaluation of
enzymatic activity of the two hypothetical proteins turned out to be ST8Sia I. In the end, considering the growing interest
toward the specie Xenopus tropicalis, due to its diploid genome that render it more suitable for genetic studies, we also cloned X. tropicalis ST8Sia I.
Accession numbers: AY272057, AY272056 相似文献
20.
Akio Mori 《Primates; journal of primatology》1995,36(1):11-26
The feeding process of Japanese monkeys on soy beans which were scattered over a sandy beach on Koshima islet was studied.
Younger monkeys were able to pick up more beans when 8 kg of beans were divided and given two times (“two times feeding”)
than when the whole amount (8 kg) of beans was given at one time (“one time feeding”). The effect of saturation of the food
intake capacity in younger monkeys at the first feeding in “two times feeding” did not appear at the second feeding one hour
later. The minutely intake of soy beans (feeding speed) for each age class was analyzed. The decline of feeding speed in adult
females after the peak in “one time feeding” was not related to the decline in density of beans on the ground, and this decline
was caused by saturation of their food intake capacity.
Adult females were divided into four classes according to their dominance rank order: high, lower-high, higher-low, and low
classes. The total amount of intake in “one time feeding” was far larger in the high class than in any of the other classes.
The total amount of feeding in the first feeding of “two times feeding” increased in accordance with rise in the dominance
rank class, and there was no relation to rank and total feeding amount in the second feeding of “two times feeding.” Differences
existed in the process of feeding between the rank classes. The feeding speed of the low class was as high as that of the
high class on the curve of minutely intake, while the low class stopped feeding much earlier than the high class. The lower-high
class displayed a low feeding speed, and stopped feeding the latest. The order of the duration to stay and to feed in the
feeding area was lower-high > high > higher-low > low, and this order did not change under the three different feeding conditions,
“one time feeding,” and the first and second feedings of “two times feeding.” Adolescent females tended to stay the longest
duration in the feeding area among all age classes. Both the lower-high class females and adolescent females had an unstable
social status in the Koshima group, and their social status affected their feeding behaviors. The feeding behaviors were similar
in attitude depending on social status, and are considered to be maintained for a fairly long time.
The feeding strategy of the lower-high class, in staying a longer duration in the artificial feeding area, and departing later,
may be effective under the artificial feeding conditions, but it may be a bad strategy in a natural habitat where the food
is not so clumped as in artificial feeding, and where choice of other food patches is possible. The above results agree well
with previous reports for the Koshima group, indicating that the rank of the lower-high class females was unstable (Mori et al., 1989), and that their reproductive success was low (Watanabe et al., 1992). 相似文献