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1.
本文对世界范围内的软齿菌属种类进行了研究,并发现无囊软齿菌Dentipellis acystidiatata为一新种,且对该种进行了详细描述。该种的主要特征是子实层体齿状、单系菌丝系统、无囊状体和胶化菌丝、担孢子小(4.1-5.2×2.4-3.2μm)、表面粗糙、具淀粉质反应。对软齿菌属的种类进行了总结,并给出了该属所有种类的检索表。  相似文献   

2.
Feeding dominates copulatory behavior in the few opisthobranchs for which behavioral hierarchies have been established. However, the influence of starvation on the dominant role has not been investigated previously. The present study investigates copulatory activity in the ascoglossan opisthobranch Ercolania nigra (Lemche) subject to varying starvation regimes. Copulatory activity of E. nigra is significantly higher in unstarved animals than in animals starved for 2h, 6h, and 24h. The decrease in copulatory activity is independent of the duration of previous starvation within the range tested (2–24 h). Copulatory behavior dominates feeding behavior in 60–80% of the cases, regardless of the duration of previous starvation. Thus the behavioral hierarchy of E. nigra differs markedly from that of the opisthobranchs previously investigated.  相似文献   

3.
The genitalia of the male holotype of P. towadensis (from Honshu) are illustrated. The distinction from P. ermolenkoi Zhiltzova, 1982 (from Sachalin and the South Kurile Islands) is discussed.  相似文献   

4.
5.
Thomas F. Daniel 《Brittonia》1988,40(3):245-255
Information onC. arizonica, C. hapalocarpa, C. mcvaughii, C. parviflora, andC. pectinata published in a monograph of the genus in 1983 is updated. The generic affinities ofC. myriantha andC. sinaloensis are resolved, with the former placed inCarlowrightia and the latter removed to a separate genus. The new combinationC. neesiana, necessitated by conservation of the generic nameCarlowrightia, is provided for the species previously known asC. glandulosa. Two new species from western Mexico,C. fuertensis andC. huicholiana, are described, mapped, and illustrated.  相似文献   

6.
Phymateus purpurascens Karsch has been studied in the wild and in captivity in Uganda. Its habits, colouration, behaviour and life cycle are described.
All individuals are attracted towards each other by visual stimuli, and a moving individual is more attractive than a stationary one. This behaviour is unchanged by several instars in isolation. The aggregated larvae tend to move in synchronous bursts. and it is suggested that this is due to retinal image stabilization by an optomotor reflex.
In an open field all instars are attracted towards isolated vertical objects in the visual field. This, together with the interindividual visual responses described, produces columns of moving insects. No olfactory communication could be demonstrated.
Adults and larvae behave similarly in experimental situations; this contrasts with the observed dispersion in the wild with increasing age. It is suggested that dispersion results from loss of visual contact, caused by (a) loss of the conspicuous larval colouration, (b) chance isolation, and (c) increased mobility of fledged adults. The possible biological function of the gregariou habit is discussed, and the significance of the various colour patterns of the life history as inter-and intraspecific signals.  相似文献   

7.
The characteristics of the genus Cranosina are discussed and a new species. C. spiralis , which apparently has free-living, lunulitiform colonies with a spiral budding pattern, is introduced. The role of the basal coclom in some free-living species is briefly discussed. The name Copidozoum declinatum nom. n. is introduced for C. transversum. Hayward & Cook, not Silén.  相似文献   

8.
ABSTRACT. Specimens of the rare ciliate Discomorphella pectinata (Levander, 1894) Corliss, 1960 were impregnated with silver nitrate in 1963. The body is discoid, about 60 μ m long, laterally compressed and adorned with long spines. The somatic kineties on the right and left sides are sparse, sometimes disorganized, and locally without cilia. The oral zone has a complex infraciliature that lies above two series of ventral kineties and below a large, visor-like, epistomial fringe. The arrangement of this fringe is similar to that observed in some other heterotichous ciliates, notably members of the Metopidae and Caenomorphidae.  相似文献   

9.
The genus Achlya Billberg, 1820 is reported for the first time from China as A. jezoensis (Matsumura, 1927), which is a species collected from Maorshan, Heilongjiang Province. The adult and genitalia characters of the species are briefly redescribed and illustrated, distribution data is provided.  相似文献   

10.
Studies on Nipponnemertes Friedrich, 1968 (Nemertini, Hoplonemertini)   总被引:2,自引:0,他引:2  
  相似文献   

11.
The Hexanchiformes (Cow Sharks) are regarded as a monophyletic taxon. Cladistic analysis shows that among the various neoselachian taxa proposed so far as the sister group of the Hexanchiformes a sister group relationship between the Hexanchiformes and a (still unnamed) taxon comprising the Squaliformes and Pristiophoriformes appears as the most probable hypothesis. In addition, MAISEY and WOLFRAM'S (1984) concept of hexanchiform interrelationships is critically reviewed. An alternative cladogram of hexanchiform interrelationships is developed which includes Recent as well as fossil hexanchiform taxa. In this cladogram the living genera Hexancbus and Notorynchus are sister groups and both taxa together form the sister group of the Recent Heptranchias. The fossil taxa +Notidanoides, +“Hexanchus” gracilis, +Notidanodon and +Weltonia are arranged in the stem lineage of recent Hexanchiformes.  相似文献   

12.
Sluys  Ronald 《Hydrobiologia》1986,132(1):257-262
The genus Procerodes forms a heterogeneous assemblage of taxa. Although it is premature to attempt phylogenetic weighting of the characters, the genus contains three well delimited subgroups, one with a subantarctic, panaustral distribution, one world-wide in distribution, and one occurring principally in the northern hemisphere. Outside of these subgroups, species in this genus are problematic since a number of their features also occurs in other procerodids. All recognized groups exhibit a wide distributional range. Many of the world-wide taxonomic relations lie on the species level and some at the level of genera. Poor dispersal capacity of extant species of Procerodes suggests that the biogeographic patterns may be very old.  相似文献   

13.
The bending flexibility of six tetramers was studied in an assumption that they were extended in the both directions by regular double helices. The bends of B-DNA in different directions were considered. The stiffness of the B-DNA double helix when bent into the both grooves proved to be less pronounced than in the perpendicular direction by the order of magnitude. Such an anisotropy is a feature of the sugar-phosphate backbone structure. The calculated fluctuations of the DNA bending along the dyad axis, 5-7 degrees, are in agreement with the experimental value of DNA persistence length. Anisotropy of the double helix is sequence-dependent: most easily bent into the minor groove are the tetramers with purine-pyrimidine dimer (RY) in the middle. In contrast, YR dinucleotides prefer bending into the major groove, moreover, they have an equilibrium bend of 6-12 degrees into this groove. The above inequality is caused by the stacking interaction of the bases. The bend in the central dimers is distributed to some extent between the adjacent links, though the main fraction of the bend remains within the central link. Variation of the sugar-phosphate geometry in the bent helix is unessential, so that DNA remains within the limits of the B-family of forms: namely, when the helical axis is bent by 20 degrees the backbone dihedral angles vary by no more than 15 degrees. The obtained results are in accord with the X-ray structure of B-DNA dodecamer; they further substantiate our earlier model of DNA wrapping in the nucleosome by means of "mini-kinks" separated by a half-pitch of the double helix, i.e. by 5-6 b. p. Sequence-dependent anisotropy of DNA presumably dictates the three-dimensional structure of DNA in solution as well. We have found that nonrandom allocation of YR dimers leads to the systematic bends in the equilibrium structure of certain DNA fragments. To the four "Calladine rules" two more can be added: the minor-groove steric clash of purines in the YR sequences are avoided by: (1) bending of the helix into the major groove; (2) increasing the distance between the base pairs (stretching the double helix).  相似文献   

14.
1. Available evidence on butterfly family-level relationships is re-examined according to the principles of phylogenetic (cladistic) systematics. 2. The assumption of a sister-group relationship between the Hesperioidea and Papilionoidea seems a reasonably substantiated working hypothesis. 3. The Papilionoid families Papilionidae, Pieridae and Lycaenidae sensu Ehrlich (1958) are definable as monophyletic entities; of Ehrlich 's two remaining families, Nymphalidae and Libytheidae, the former is paraphyletic in terms of the latter. 4. The interrelationships between the Papilionoid families may be presented as Papilionidae + (Pieridae + [Lycanidae + Nymphalidae]). 5. In a phylogenetic system any given arrangement of taxa is either correct or not: Contrary to the pheneticists' view (Ehrlich and Ehrlich 1967) phylogenetic systematists cannot accept the existence of a multitude of valid classifications.  相似文献   

15.
The new species Rhopalosiphum chusqueae Pérez Hidalgo & Villalobos Muller, is described from apterous viviparous females caught on Chusquea tomentosa in Cerro de la Muerte (Costa Rica). The identity of the species is supported both by the morphological features and by a molecular phylogenetic analysis based on a fragment of the mitochondrial DNA containing the 5' region of the cytochrome c oxidase 1 (COI) and on the nuclear gene coding for the Elongation factor-1 alpha (EF1α). The taxonomic position of the new species is discussed. An identification key to the Aphidinae species living on plants of Bambusoideae (Poaceae) is presented.  相似文献   

16.
The palmyra, or toddy, palm (Borassus flabellifer L., Arecaceae) grows wild from the Persian Gulf to the Cambodian-Vietnamese border; is commonly cultivated in India, Southeast Asia, Malaysia and occasionally in other warm regions including Hawaii and southern Florida, where there are also a number of specimens of the similarB. aethiopum Mart. In addition to the sweet sap from the inflorescence and the many products of the leaves, trunk and underground seedlings, a thin orange pulp coating the fibers of the mature fruit is consumed fresh or dried as a paste. The large seeds, when immature, before the shell hardens, contain jelly-like kernels esteemed for food. These kernels, whole or sliced and canned in thin, clear sirup, are being exported from Thailand and are appearing in Asiatic markets across the United States. Mature kernels are hard as ivory. A number ofBorassus palms have succumbed to lethal-yellowing disease in Florida.  相似文献   

17.
Foraminiferan (Protozoa) epizoites were examined on two deep-water isopods, Neastacilla sp. and Pleuroprion hystrix (Valvifera, Arcturidae), from the north Atlantic Ocean and the Nordic Seas. Most foraminiferans belonged to genus Cibicides and occurred on 27% of Neastacilla and 23% of Pleuroprion hystrix. The pattern of foraminiferan epibiosis was similar in both species, with a concentration on the dorsal body and on the posterior pereopods. The arcturids showed an increase in number of foraminiferans with increased body size, suggesting that available time span for settling on the younger stages (mancas) was relatively short. There was a trend towards larger numbers of foraminiferans occurring on larger arcturid species, suggesting that available space is the factor that determines the total number of foraminiferans for epibenthic arcturid isopod species.  相似文献   

18.
We report the morphology and morphogenesis of Urosoma caudata (Ehrenberg, 1833) Berger, 1999 based on in vivo observation and protargol impregnation and provide an improved diagnosis of Ucaudata based on previous and current work. Urosoma caudata differs from its congeners mainly by the combination of the following features: tail‐like posterior end, colorless cortical granules, and two macronuclear nodules. Urosoma caudata shares most of the ontogenetic features with its congeners: the oral primordium of the opisthe develops apokinetally, and the frontal‐ventral‐transverse cirral anlagen develop in five streaks. However, a unique morphogenetic characteristic is recognizable: the anlagen of three dorsal kineties occur de novo to the left of the parental structures differing from their intrakinetal origin in other Urosoma species. The first record of the 18S rRNA gene sequence for the species is also provided. Phylogenetic analyses based on 18S rRNA gene sequence data suggest that the genus Urosoma is a nonmonophyletic group.  相似文献   

19.
The species composition of anemonefishes (Amphiprioninae) and host sea anemones (Actiniaria: Actiniidae, Stichodactylidae) from the Con Son Islands is given for the first time. The investigations carried out in archipelago waters revealed four species of the anemonefishes associated with four species of the host sea anemones: Amphiprion freanatus in the symbiosis with sea anemone Entacmaea quadricolor (Actiniidae), A. perideraion with sea anemone Heteractis magnifica (Stichodactylidae), A. sandaracinos with sea anemone Stichodactyla mertensii (Stichodactylidae), and A. polymnus with sea anemone S. haddoni. The possibility of larval carrying in one more species of anemonefishes, i.e., A. clarkii, into the water area of the Con Son Islands from the nearby regions of the South China Sea is discussed. The view on the probable revealing of this species in the investigated region in the future is expressed.  相似文献   

20.
The egg, second‐ and third‐instar larvae and puparium of Cleigastra apicalis are described for the first time. All pre‐imaginal stages are found on stems of the common reed affected by flies of the genera Lipara and Platycephala and the butterfly Arenostola phragmitidis. The larvae feed on dead plant and animal tissue and the excreta of other insects that live inside the stems of the common reed. Exceptionally they will scrape living plant tissue. The pupa is the overwintering stage.  相似文献   

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