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1.
Morphogenesis during cell division was investigated in oligotrichous ciliate,Halteria grandinella utilizing protargol impregnated specimens. The cortical morphogenetical pattern of Hdteria grandinella is generally similar to that given by Faure-Fremiet. The prater inherits the parental adoral zone of membranelles (AZM) appar ently unchanged; in the opisthe the oral primordium develops de novo from a single AZM-anlage; somatic cirri for both the proter and opisthe are separately differentiated from 10 (seldom 9) cirral primordia that originate de novo from 10 latitudinal developmental anlagen. The anlage of paroral membrane of opisthe forms just to the right of the posterior end of the oral primordium. Each streak of cirral primordia develops 4 groups of basal body pairs: both of the anterior two consist of only one pair of basal bodies, on the contrary, each of the last two groups has 2 basal body pairs.  相似文献   

2.
Morphogenesis of a population of the marine euplotid ciliate, Uronychia binucleata, which was found in Yellow Sea coastal waters next to a sewage outfall at a beach near Zhanqiao Pier, Qingdao, China, was investigated using protargol staining. The main pattern of morphogenesis is typical for the genus and can be summarized as follows: 1) the oral primordium in both proter and opisthe develops de novo in a subcortical pouch. In each daughter cell, the developing adoral zone of membranelles divides into two parts. The new membranelles formed in the proter's oral primordium will replace the leftmost five parental ones; six parental membranelles are retained by the proter; 2) the undulating membranes anlage is formed and develops independently from the oral primordium within the same subcortical pouch; 3) five primary front oventral-transverse cirral anlagen appear de novo on the cell surface; 4) the marginal cirral anlagen are formed de novo; 5) the leftmost frontal cirrus develops de novo on the cell surface; 6) two caudal cirri are formed at the posterior end of the rightmost anlage while the second primordium from the right gives rise to the third caudal cirrus. In contrast to its congeners, the anlage of the leftmost frontal cirrus is formed to the right of the undulating membranes anlage and before the formation of the latter.  相似文献   

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We documented the pattern of cell development in Euplotes charon. The ontogenesis of this species was similar to many of its congeners, except for the formation of the caudal cirri. In E. Charon, a caudal cirrus is formed posterior to each of the rightmost two or three dorsal kinety anlage in the proter, and the second rightmost dorsal kinety in the opisthe. In addition, two caudal cirri are formed posterior to the rightmost dorsal kinety in the opisthe. This pattern of development represents a completely new type. Based on our evaluation, and in comparison with previous studies, we also conclude that the pattern of cell development is variable among species in the Euplotes genera. The variation is particularly evident during the formation of frontoventral and caudal cirri. Based on the segmentation pattern of frontal-midventral transverse cirral anlagen, cirri reduction, and migration of frontoventral cirri, we identified five types: the affinis-type, the eurystomus-type, the charon-type, the raikovi-type and orientalis-type. Euplotes (s. l.) can also be divided into three types based on the formation of caudal cirri: focardii-type, vannus-type and charon-type. Indeed, we conclude that the number (one or two) of marginal cirri should be given as much consideration as the genetic separation. Given this, we reassessed the validity of using genetic separation to classify the group. Generally, the morphogenetic data disagreed with the molecular data (SSrRNA gene sequences). Given these discrepancies, it is too early to draw conclusions on the systematic arrangement of this species-rich taxon.  相似文献   

6.
We estimated the reproductive success of adult brood fish and the heritability of growth-related traits for large yellow croaker (Larimichthys crocea). We created two independent full-factorial cross groups (1 and 2) by crossing 4 males×4 females and 4 males×3 females, respectively. We measured the body weight (BW), body length (BL), and body height (BH) of 281 individuals from group 1 and 318 individuals from group 2 at 20 months post hatch (harvest age). We also collected a tissue sample from each individual. The parents and offspring were genotyped using six polymorphic microsatellites. Of the 599 offspring, 99.2% were assigned to a single pair of parents. In both groups, some parent pairs produced a large number of offsprings while other pairs did not produce any offspring. The genetic diversity and putative Ne were lower in the offsprings than in the parents in both groups. The heritability estimates at 20-month age were 0.13±0.10 for BW, 0.19±0.13 for BL, and 0.09±0.06 for BH. The genetic and phenotype correlation between BW, BL, and BH was close to 1. The results provide basic information for selective breeding and further genetic characterization of large yellow croaker.  相似文献   

7.
The characteristics and infraciliature of a new euplotid ciliate,Euplotes qingdaoensis n.sp.,discovered from the coastal waters of Jiaozhou Bay,northern China,were studied using live observation and silver impregnation.The new marine species is characterized by a slightly fl attened body(90–110 μm×70–80 μm,in vivo),an adoral zone of 26–29 membranelles,10 strong frontoventral and fi ve transverse cirri,two caudal cirri,a single left marginal cirrus,seven dorsal kineties,a middle kinety with about 15 pairs of basal bodies,a silverline system of the double-eurystomus type,and a C-shaped macronucleus.  相似文献   

8.
Male and female adult midges ofPseudosmittia aizaiensis sp.n. are described and illustrated with figures of morphological characters. The inferior volsella of gonocoxite with large lobes, the long but equal width gonostylus, and the small projection in basal part of outer margin are the characters that may separate this species from others. One larva of this genus is purely aquatic in habitat and is associated with Cricotopus bicinctus,Cardiocladius capucinus andPolypedilum sp. in the same algae debris (Spirogyra sp.) of the Dunghe River. Further, the larva's very short SI and SII bifids, its 5 pairs of lateral teeth on mentum and its absence of premandible brush are the characters that may also separate this species from any known species of this genus.  相似文献   

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1 INTRODUCTION Red algae C. ocellatus lives in temperate zone of coastal area, and inhabits at substrates from high tide to low tide regions. Its life history is composed of three phases: tetrasporophyte, gametophyte and carposporophyte. Chondrus is one o…  相似文献   

11.
Two nemerteans of the Zhoushan Islands,Paranemertes sinensis sp. nov. andP. peregrina, are reported in this paper.P. sinensis sp. nov. has the body wall longitudinal musculature anteriorly divided, numerous eyes grouped into four clusters, two pairs of cephalic furrows, rhynchocoel 1/3 to 1/2 of full body length, cephalic glands well developed and posteriorly extending beyond the cerebral ganglia, precerebral septum absent, cerebral sense organs situated in front of brain, three pairs of nephridiopores, and 17–18 proboscis nerves. The project supported by National Natural Science Foundation of China  相似文献   

12.
Brown alga ( Undaria pinnatifida) was treated with alginate lyase and hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for the angiotensin-I-converting enzyme (ACE) was measured. Four hydrolysates with potent ACE-inhibitory activity were administered singly and orally to spontaneously hypertensive rats (SHRs). The systolic blood pressure of SHRs decreases significantly after single oral administration of the brown alga hydrolysates by pro- tease S ' Amano' (from Bacillus stearothermophilus) at the concentration of 10 (mg protein) (kg body weight)^ - 1. In the 17 weeks of feeding experiment, 7-week-old SHRs were fed standard diet supplemented with the brown alga hydrolysates for 10 weeks. In SHRs fed 1.0 and 0.1% brown alga hydrolysates, elevating of systolic bloodpressure was significantly suppressed for 7 weeks. To elucidate the active components, the brown alga hydrolysates were fractionated by 1-butanol extraction and HPLC on a reverse-phase column. Seven kinds of ACE-inhibitory peptides were isolated and identified by amino acid composition analysis, sequence analysis, and LC-MS with the results Val-Tyr, Ile-Tyr, Ala-Trp, Phe-Tyr, Val-Trp, Ile-Trp, and Leu-Trp. Each peptide was determined to have an antihypertensive effect after a single oral administration in SHRs. The brown alga hydrolysates were also confirmed to decrease the blood pressure in humans.  相似文献   

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1 INTRODUCTION The red alga Gracilaria belongs to Gracilari- aceae, Gigartinales, Florideophyceae, and includes over 100 recorded species, wildly distributing in tropical and temperate regions (Oliveira and Plastino, 1994), and is useful for producing val…  相似文献   

14.
Prostomates and haptorians are two basal groups of ciliates with limited morphological characteristics available for taxonomy. Morphologically, the structures used to identify prostomates and haptorians are similar or even identical, which generate heavy taxonomic and phylogenetic confusion. In present work, phylogenetic positions lineage of two rare genera, Plagiopogon and Askenasia, were investigated. Three genes including small subunit ribosomal RNA gene(hereafter SSU r DNA), internal transcribed spacer region(ITS region), and large subunit ribosomal RNA gene(LSU r DNA) were analyzed, 10 new sequences five species each. Our findings included 1) class Prostomatea and order Haptorida are multiphyletic; 2) it may not be appropriate to place order Cyclotrichiida in subclass Haptoria, and the systematic lineage of order Cyclotrichiida needs to be verified further; 3) genus Plagiopogon branches consistently within a clade covering most prostomes and is basal of clade Colepidae, implying its close lineage to Prostomatea; and 4) Askenasia is phylogenetically distant from the subclass Haptoria but close to classes Prostomatea, Plagiopylea and Oligohymenophorea. We supposed that the toxicyst of Askenasia may be close to taxa of prostomes instead of haptorians, and the dorsal brush is a more typical morphological characteristics of haptorians than toxicysts.  相似文献   

15.
A diplomonad flagellateHexamita capsularis sp. nov. from the posterior intestine of the fish (Xenocypris dividi) from Liangzi Lake, Hubei Province, is described. The flagellate was oval, with smooth surface and homogenous cytoplasm, 6.21±0.28 μm in length, 3.43±0.48 μm in width and with an elliptical capsule. Two recurrent flagellae arranged between two nuclei ran longitudinally to the posterior end. Fibrillar bands connected the accessory organelles of two cytostomal tubes, the body depressed at the posterior end of the body. This work is a part of the M. S. thesis of Xiao Wu-han and was supported by the National Natural Science Foundation of China (Grant No. 3870489).  相似文献   

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Two nematode species of the genusDorylaimopsis (Family Comesometidae) from the Bohai Sea are described.Dorylaimopsis rabalaisi n. sp. similar toD. punctata Ditlevsen, 1918 from which it can be separated by the small size, short and simple spicules without ventral apophyses or joint line.Dorylaimopsis turneri n. sp. differs from the closest speciesDorylaimopsis angelae (Inglis, 1967) by its higher values of de Man ratio ‘a’, much shorter spicules and higher ratio of gubernacular to spicules length. A key to species of the genus based on the key by Jensen (1979) is given. This project was supported by the National Science Foundation, No: 3860804  相似文献   

18.
We collected five specimens of threadfin bream from Beihai, Guangxi, China in March 2010. These were subsequently identified as red filament threadfin bream Nemipterus marginatus (Valenciennes, 1830), being the first record of this species from Chinese waters. N. marginatus is distinguished by the following characteristics: lower border of eye lies above a line from tip of snout to upper base of pectoral fin; mouth oblique, maxillary extending to lower anterior border of pupil; teeth in jaws in several rows, pointed; upper jaw with 3 to 5 pairs of small recurved canines; suborbital with straight lower edge and rounded posterior edge; pectoral fins extending to between level of anus and origin of anal fin; pelvic fins reaching to the first or second anal rays; caudal fin forked, upper lobe tails into a short reddish filament; dorsal fin bluish with a yellow margin distally and a broad yellow median band which subdivides posteriorly into 3 small bands.  相似文献   

19.
Nephroselmis gaoae sp. nov. is described on the basis of light and electron microscope observations of cultured material originally collected and isolated from seawater of Jiaozhou Bay, Qingdao, China. The periplasts on the cell body and flagella are covered by five types of scales, two types on the flagella and three on the body. Among these, the morphology and the number of spines of large stellate body scales differ remarkably from those of previously described species ofNephroselmis. Apart from these, the unusual fine structure of the eyespot (stigma) is very characteristic. As in the other species ofNephroselmis, the eyespot lies immediately under the two-membraned chloroplast envelope; unlike the others, however, it is not composed of a number of osmiophilic globules, but consists of about 14 curved rod-shaped osmiophilic bodies arranged loosely and randomly. This feature distinguishes the present new species not only from the other species ofNephroselmis but also from the other motile algal species, the eyespots structure of which had been previously described. Contribution No. 2316 from the Institute of Oceanology, Chinese Academy of Sciences. This paper was presented at the XIVth International Seaweed Symposium held in Brittany, France, 1992.  相似文献   

20.
A new species of ciliatesHemiophrys polymicronuclei sp. nov. from Donghu Lake is described. It is characterized by its colorless to yellowish, soft, flat and spindle-shaped body with four micronuclei. The right side of the body is a little more convex than the left side, and more transparent at both anterior and posterior ends. Its slit-like cytostome accounts for 1/4 of the body length on the left side without any trichocyst. There are two rows of trichites near the right anterior end, 6–8 straight bristles on the pellicle opposite the cytostome, 23–25 rows of kinetides on the right side of the body, two ellipsoid macronuclei and many contractile vacuoles in the cytoplasm.  相似文献   

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