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1.
We investigated the genetic structure of populations of the brackish-water crab Deiratonotus cristatus (de Man, 1895) (family Camptandriidae) on the Japanese coast, together with morphological and the ecological variations. Genetic characteristics of the local populations based on mitochondrial DNA COI sequence data have revealed genetic differentiation between many populations, with the haplotype networks forming three geographical clades: a clade occurring on the Pacific coast, one occurring predominantly in northern Hokkaido, Kyushu and the Seto Inland Sea, and a third occurring in the Ryukyu Islands. Male pleopod morphology, carapace length relative to carapace width, and carapace width of adult crabs varied inconsistently among the geographic groups corresponding to the three clades. Life history traits were similar throughout, although differences in the breeding season were apparent between populations on the Pacific coast, and in the Seto Inland Sea and the Ryukyu Islands.  相似文献   

2.
The activity of and consumption of organic material by the sand-bubbler crab Dotilla fenestrata was studied over neap and spring tides on a sheltered sand bank close to the mouth of the warm, temperate Kowie Estuary, South Africa. Crabs emerged from their burrows only after the tide receded, and it was light. Time to emergence therefore varied from about 30 minutes to three hours after exposure, depending on the time of low water in the early morning vs at midday. General activity of the crab population was longer on a spring tide (about five hours) than on a neap tide (about three hours). Maximum densities of active crabs were 140 m–2 and 41 m–2 on spring and neap tides, respectively. After emergence, crabs spent 60% to 80% of their time feeding. In the Kowie Estuary, D. fenestrata produced between 7 and 12 pseudofaecal pellets, average weight 0.0358 g per pellet, per minute. These pellets had a significantly lower organic and chlorophyll a content than the substratum, and it was estimated that crabs removed about 25% of the organic content from the sediment.  相似文献   

3.
Two new Stenhelia (Stenhelia) species are described: 5. (S.) diegensis from 1200 m depth in San Diego Trough, California and 5. (S.) asetosa from the intertidal of Nanaimo Estuary, British Columbia. S. (S.) diegensis differs from previously known species in having but one seta on the terminal segment of the P, endopod. 5. (S.) asetosa lacks inner setae on the first segments of the P2–P, exopods. A table listing the salient morphological features of the species of Stenhelia (Stenhelia) is given as is a new key to the subgenus.  相似文献   

4.
5.
记述了寄生于北京猛禽体内的2种合饰带属线虫,其中一种为新种,一种为中国新纪录种.标本保存于北京师范大学生命科学学院.红角鸮合饰带线虫Synhimantus(Dispharynx)oti sp.nov.(图1~7)新种与Synhimantus(Dispharynx)capitata(Molin,1860)和S.(D.)buccalis(Gogoi and Sarmah,1988)较相似,但新种在第5对肛后乳突内侧有1对无柄乳突,左交合刺末端分叉,饰带长而与S.(D.)capitata有明显区别.新种与S.(D.)buccalis的主要区别为肛后乳突5对,左交合刺短,颈乳突三叉状位于饰带之后,阴门位于体中之前.正模♂,副模♀,采自红角鸮Otus scops(Linnaeus,1758)的食道.词源:新种的种名来自宿主名.纵纹腹小鸮合饰带线虫乌兹别克斯坦亚种Synhimantus(Dispharynx)noctuae uzbehistanica(Sultanov,1950)中国新纪录(图8~10)从纵纹腹小鸮Athene noctua(Scopoli,1769)的食道和口腔中采到3条雄虫.作者所采标本与Sultanov(1950)的原始描述基本相同,但前者饰带稍有波浪状的弯曲而原始描述为直的.  相似文献   

6.
Gastropod shells: A potentially limiting resource for hermit crabs   总被引:1,自引:0,他引:1  
The availability of gastropod shells to hermit crabs in the Newport River Estuary, Beaufort, N.C. has been assessed by determining the numbers of usuable shells occurring in characteristic subtidal habitats and by measuring shell size adequacy. The proportion of useable shells occupied by hermit crabs ranged from 58–99 % and many of the shells not used by hermit crabs were judged unavailable because they were occupied by sipunculids or only uncovered by the dredge. The shell adequacy index (shell size occupied/shell size preferred) was significantly below 1.0 for the largest species (Pagurus pollicaris Say) in the one location where sufficient numbers were collected and for the next largest species (P. longicarpus Say) in three of the four locations where it was collected. The shell size adequacy index for the smallest species (P. annulipes Stimpson) did not differ significantly from 1.0 in either of the two locations in which it was found. These observations suggest that the availability of gastropod shells plays a significant rôle in limiting the abundance of at least the larger hermit crabs.  相似文献   

7.
The mitten crab Eriocheir japonica (de Haan, 1835) is used as an indicator species for the biochemical monitoring of different estuarine zones in Peter the Great Bay (Sea of Japan). The following molecular biomarkers are determined in the gills and hepatopancreas of the crabs: the activity of biotransformation of enzyme glutathione-S-transferase; antioxidative enzymes, superoxide dismutase, and catalase; and reduced glutathione concentration and lipid peroxidation level measured as malondialdehyde. The state of biochemical indicators testify to the good physiological condition of crabs from estuaries of Shkotovka and Sukhodol rivers and to a depressed physiological condition for crans from the Tesnya River. The latter crabs have lower activity of catalase but higher glutathione-S-transferase activity and lipid peroxidation level. Using the data of molecular-biomarker determination, the integral biochemical index was calculated, which made it possible to rank the estuaries by the extent of adverse effects on the biota. Researching the functional condition of the indicator species allows one to estimate and predict the biota state under anthropogenic impact.  相似文献   

8.
9.
《Mycoscience》2014,55(5):390-399
Based on morphological characteristics and molecular phylogeny, a rust fungus on Salix hsinganica, S. sinica, S. starkeana, S. wallichiana and S. xerophila in China is described as a new species, Melampsora salicis-sinicae. This new species morphologically resembles M. capraearum and M. epiphylla in having subcuticular teliospores with a thickened apical wall, but it differs from these two species in its amphigenous telia. In addition, this new species differs from M. capraearum in its slender teliospores and thinner apical thickness of teliospores, and it also differs from M. epiphylla in the dimension of urediniospores, the position of teliospores and the apical thickness of teliospores. Phylogenetic analyses using partial sequences of the D1/D2 region of nuclear large subunit and the internal transcribed spacer (ITS1 and ITS2) regions including 5.8S of ribosomal RNA gene and the translation elongation factor 1 alpha (EF-1α) gene revealed that this rust fungus was distinct from its morphologically similar species, M. capraearum and M. epiphylla.  相似文献   

10.
Leeches exhibit a marked scope of diversity, including different kinds of symbiosis. The aim of the present study was to demonstrate through biochemical and histological analysis that a species of piscicolid leech, Myzobdella platensis, is a true parasite of blue crabs, feeding on their hemolymph and using them as a site for cocoon deposition. In a total of 48 blue crabs collected on October 2007 at 3 sites of the S?o Vicente Estuary, 12 specimens were infested with leeches. Callinectes bocourti (n = 7) was the most infested species with leeches and cocoons; it was chosen for biochemical and histological assays. The immunoblotting assays showed a positive reaction of the proteins in the intestinal samples of leeches collected from crabs using antihemocyanin polyclonal antibody of Ampullaria canaliculata. In addition, leech intestinal samples were recognized by antihemolymph polyclonal antibody of nonparasitized blue crabs. Histological sections of leech gut showed hemocytes and a granular matrix similar to those found in crab blood vessels. Collectively, this evidence strongly suggests a parasitic interaction between the leech M. platensis and the blue crab C. bocourti, in which the former utilizes the latter as a site for cocoon deposition and possibly for dispersal similar to that proposed for Myzobdella lugubris in Callinectes sapidus in North America.  相似文献   

11.
Sinocyclocheilus zhenfengensis sp. nov. is a new species from an underground water environment in a karst cave located in Beipanjiang River of the Pearl River Basin in Shuangrufeng (Double Breasts Hill) Scenic, Etian Village, Zhexiang Township, Zhenfeng County, Guizhou Province, Southwest China. The new species has eyes, its body is completely scaled, an anteriorly directed bulge has formed on the back of its head, and a long pectoral fin exceeds the pelvic fin insertion. The body of the new species is apparently similar to that of S. bicornutus, but differs in scale rows above the lateral line, scale rows below the lateral line, snout length, and eye diameter. Phylogenetic reconstruction of the cytochrome b gene using the maximum parsimony (MP) and Bayesian inference (BI) methods indicates that S. zhenfengensis is closely related to S. bicornutus, S. tianeensis, S. jiuxuensis, and S. altishoulderus; however, it differs in terms of eye size, lateral line scales, scale rows above and below the lateral line.  相似文献   

12.
额尔齐斯河白斑狗鱼假尾复口吸虫的分子鉴定   总被引:1,自引:0,他引:1  
利用分子生物学方法对采自额尔齐斯河(中国段)的白斑狗鱼(Esox lucius Linnaeus)晶状体内寄生的复口吸虫(Diplostomum)进行了种类鉴定,结果显示其种类为假尾复口吸虫(D.paracaudum),为中国新记录种。通过PCR扩增待鉴定种的部分18S-ITS1-5.8S序列,测序后与GenBank中假尾复口吸虫的序列进行比对,发现其相似度达到99.6%。将该序列与7种复口吸虫的ITS1序列进行比对后构建系统进化树,进化树以单殖吸虫Gyrodactylus parvae为外类群,结果显示:待鉴定种与假尾复口吸虫(D.paracaudum)聚为一支,其支持率达到了50%以上,支持它们为同一虫种。  相似文献   

13.
A new species of Acantholochus Cressey, 1984 (Copepoda: Bomolochidae) parasitic on the gills of common snook, Centropomus undecimalis, from the coastal zone of the State of Rio de Janeiro, Brazil, is described and illustrated. The new species differs from all other species of Acantholochus by the presence of only one inner seta on middle segment of the second and third endopods.  相似文献   

14.
Two new yeast strains of the genus Candida were isolated from insect frass collected in Khao-Yai National Park, Nakhonrachasima, Thailand. Based on the morphological, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 domain of 26S rRNA gene, these two strains were found to represent two distinct undescribed species and were named Candida thailandica sp. nov. (ST-17 = BCC 7717(T) = NBRC 102562(T)=CBS 10 610) and Candida lignicola sp. nov. (ST-33 = BCC 7733(T) = NBRC 102564(T) = CBS 10612). In the D1/D2 domain of 26S rRNA gene, C. thailandica (GeneBank accession no. AY228491) differs from Candida tsuchiyae, the nearest species, in 66 nucleotide substitutions (10%) and C. lignicola (GeneBank accession no. AY845350) differs from Candida coipomoensis, the nearest species, in nine nucleotides (1.6%). These two new species are clearly distinguished from their closest species by the assimilation of several carbon compounds.  相似文献   

15.
To help resolve phylogenetic relationships among the mitten crabs, complete sequences of the nuclear DNA internal transcribed spacer (ITS) and portions of the mitochondrial genome corresponding to the cytochrome oxidase I (COI), were sequenced for all Asian mitten crabs of the genus Eriocheir and seven species of the Grapsoidea. The resulting phylogeny supports the establishment of a separate genus Neoeriocheir, but does not provide justification for the recognition of Platyeriocheir. A female mitten crab specimen from the Zhujiang River, China, was considered to be Eriocheir recta (), a species previously synonymized with Eriocheir japonica (de Haan, 1835). In the ITS analysis, a sequence from Eriocheir formosa (from Taiwan) falls within a well-supported E. recta group, which indicates that E. formosa may have to be synonymized with E. recta. Three previously recognized members of the genus, E. japonica, Eriocheir sinensis, and Eriocheir hepuensis constitute a monophyletic sister group to E. recta in all phylogenetic trees. We provide evidence for the conspecific status of these taxa. Phylogenetic trees based on COI and combined COI and ITS sequences indicate that E. japonica consists of three subgroups. Since the name E. japonica (de Haan, 1835) takes precedence over E. sinensis (H. Milne Edwards, 1853) and E. hepuensis, we suggest that these three subgroups correspond to three subspecies of E. japonica: E. j. japonica, E. j. sinensis, and E. j. hepuensis.  相似文献   

16.
The Central American River Turtle (Dermatemys mawii) is an endangered species that has been poorly studied. There are no reports on their population status, habitat condition, and the species distribution area is still unknown. This study analyzes the seasonal and spatial variations of their habitat and the presence/absence of D. mawii in three rivers within the Pantanos de Centla Biosphere Reserve (Tabasco, Mexico). For habitat characterization, natural segmentation of rivers was used and three sites per segment were identified, 9 in each rivers (Grijalva and Usumacinta) and 6 in Tabasquillo. Additionally, the evaluation of 11 environmental variables such as water hydrological, physicochemical characteristics and riparian and hydrophytic vegetation were carried out during two different seasons (dry and rainy). The presence/absence of species was assessed with eight fike nets that were set per segment, with a capture effort of 384 hours per trap. The capture per unit effort (CPUE) was used as an indicator of relative abundance. The results indicated spatio-temporal variations in habitat characteristics and the presence of environmental gradients. The principal components analysis (PCA) applied allowed us to determine that the first three components explained 67.8% of the environmental variability. The species presence was confirmed in all rivers, however significant differences exists in their relative abundance: the highest was registered in the Tabasquillo River where the species was present in both seasons and in all segments. Of the 11 environmental variables analyzed, the gradient, shelter and depth were the most indicative of species presence. The obtained results evidenced the importance of riparian vegetation as habitat for Dermatemys. This represents the first approach towards an action plan for a species and its habitat protection within the Pantanos de Centla Biosphere Reserve.  相似文献   

17.
Samples collected in “restinga” areas of two conservation units in Rio de Janeiro state revealed the presence of two new species of Neanuridae family. The first, Pseudachorutes solaris sp. nov., from Parque Estadual da Costa do Sol and from Parque Nacional da Restinga de Jurubatiba, differs from other species for having 34–50 vesicles in the postantennal organ, and the second, Friesea jurubatiba sp. nov. from Parque Nacional da Restinga de Jurubatiba, differs from other species for having 8 clavate chaetae in the abdominal segment VI.  相似文献   

18.
Selaginella bifida D. Delmail, a new species of the Selaginellaceae from Rodrigues Island, (Mascarene archipelago, Mauritius) is described and illustrated. The new species is related to S. rodrigueziana Baker in phenotypic appearance, but differs by having ciliate lateral leaf margins and bifid microsporophyll apices.  相似文献   

19.
Marine subsurface sediments represent a novel archaeal biosphere with unknown physiology. To get to know the composition and ecological roles of the archaeal communities within the sediments of the Pearl River Estuary, Southern China, the diversity and vertical distribution of active archaea in a sediment core were characterized by 16S rRNA phylogenetic analysis of clone libraries derived from RNA. In this study, the archaeal diversity above, within, and beneath the sulfate-methane transition zone (SMTZ) in the Pearl River Estuary sediment core was described. The majority of the clones obtained from the metabolically active fraction of the archaeal community were most closely related to miscellaneous crenarchaeotal group and terrestrial miscellaneous euryarchaeotal group. Notably, although the Pearl River Estuary sediment belong to high methane and high organic carbon environment, sequences affiliated with methanotrophic and methanogenic archaea were detected as minor group in 16S rRNA clone libraries. No obvious evidence suggested that these unknown archaeal phylotypes related directly to anaerobic oxidation of methane in SMTZ. This is the first phylogenetic analysis of the metabolically active fraction of the archaeal community in the coastal sediment environments.  相似文献   

20.
Taxonomic studies of the genus Astyanax from the Iguaçu River (Brazil) indicate that they may be differentiated into 11 distinct species, some of which have not been formally described and named so for. This study focuses on three of these species, Astyanax sp. B, Astyanax sp. C and Astyanax sp. D from the Upper Iguaçu River Basin. Comparative cytogenetic analyses of C‐banding, Ag‐NORs (silver nitrate stained nucleolar organizer region) and 18S and 5S rDNA corroborate that they are distinct species. A diploid number of 50 chromosomes and similar karyotypic formulae were observed in the three taxa, with the exception of Astyanax sp. D that differs in the number of submetacentric and subtelocentric chromosomes. However, the NOR silver‐staining pattern, the heterochromatic bands (C‐bands) and the mapping of the 18S and 5S rDNA sites in the chromosomes showed divergences between all three species under study, supporting the occurrence of distinct evolutionary units.  相似文献   

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