51 resultados para CRABS CRUSTACEA

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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A new species of the previously monotypic xanthid genus Crosnierius Serene & Vadon, 1981 is described from the South China Sea. The species differs from Crosnierius carinatus Serene & Vadon, 1981 in the structure of the anterolateral teeth, ambulatory leg proportions and form of the male first pleopod. Paramedaeus planifrons (Sakai, 1965) is also reported from the South China Sea, the first record of the species outside its type locality of Japan.

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A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.

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Given the commercial and ecological importance of the Asian paddle crab, Charybdis japonica, there is a clearly need for genetic and molecular research on this species. Here, we present the complete mitochondrial genome sequence of C. japonica, determined by the long-polymerase chain reaction and primer walking sequencing method. The entire genome is 15,738 bp in length, encoding a standard set of 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes, plus the putative control region, which is typical for metazoans. The total A+T content of the genome is 69.2%, lower than the other brachyuran crabs except for Callinectes sapidus. The gene order is identical to the published marine brachyurans and differs from the ancestral pancrustacean order by only the position of the tRNA (His) gene. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of 13 protein-coding genes strongly support the monophyly of Dendrobranchiata and Pleocyemata, which is consistent with the previous taxonomic classification. However, the systematic status of Charybdis within subfamily Thalamitinae of family Portunidae is not supported. C. japonica, as the first species of Charybdis with complete mitochondrial genome available, will provide important information on both genomics and molecular ecology of the group.

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The phylogenetic relationships within the family Penaeidae are examined based on mitochondrial 16S rRNA gene sequence analysis of 30 species from 20 genera. The analysis generally supports the three- tribe scheme proposed by Burkenroad ( 1983) but it is not consistent with the five- group classification of Kubo ( 1949). Three clades are resolved: ( Penaeus sensu stricto + Fenneropenaeus + Litopenaeus + Farfantepenaeus + Marsupenaeus + Melicertus + Funchalia + Heteropenaeus), ( Metapenaeus + Parapenaeopsis + Xiphopenaeus + Rimapenaeus + Megokris + Trachysalambria) and ( Metapenaeopsis + Penaeopsis + Parapenaeus), corresponding to the Penaeini, Trachypenaeini and Parapenaeini respectively, while the affinities of Atypopenaeus and Trachypenaeopsis are obscure. The molecular data support that Miyadiella represents the juvenile stage of Atypopenaeus. Within the Trachypenaeini, Trachypenaeus sensu lato is clearly paraphyletic, while the monophyly of Penaeus sensu lato in the Penaeini is questionable.

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Stocking experiments with Eriocheir sinensis were conducted in two small, shallow lakes to study its growth pattern in 1994-1997. For the initially immature crabs, carapace width (CW) increases from 21.2 +/- 0.4 mm (mean +/- s.e.) for females and 22.3 +/- 0.5 mm for males in January, to 65.4 +/- 0.5 mm for females and 66.9 +/- 0.6 mm for males in October. There is no significant difference in CW and carapace length (CL), although there is a large difference in body weight (BW) between sexes in every month from January to August when crabs are juvenile, however, there are significant differences in CW, CL. and BW between sexes after September when the crabs become sexually mature. The growth curve from January to October fits a logistic equation and may be expressed as CW = 75.7 (1 + exp (0.914 - 0.011t))(-1) for females, and CW = 77.5 (1 + exp (0.889 - 0.011t))-1 for males, where CW is in mm, t in days. For precocious crabs (reaching maturity by the first autumn, CW does not change much from January to July, which indicates that precocious crabs stop growing. Like juveniles, the precocious crabs show no differences in CW and CL, but do show a statistically significant difference in BW between sexes.

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Isolation and characterization of androgenic hormone in decapod crustaceans depend on an effective bioassay of its action. In the present study, the effect of androgenic gland on ovarian development in the mud crab Scylla paramamosain was investigated with a view to develop a bioassay for androgenic hormone. Ovarian regression with degeneration of oocytes occurred in some female crabs implanted with androgenic gland in vivo. In vitro incubation of ovarian tissues at secondary vitellogenesis in extract of androgenic gland resulted in a significant decrease in amino acid uptake by the tissues. We propose that this inhibitory effect could be established as an effective bioassay for the isolation of androgenic hormone in the mud crab. (c) 2005 Published by Elsevier Inc.

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A molecular phylogeny is presented for the subfamily Dorippinae (including 9 individuals, representing 5 species and 4 genera), based on the sequence data from 16S rRNA gene. Two-cluster test between lineages in these phylogenetic trees has been performed. On the basis of rate constancy, the rate of nucleotide substitutions of 16S rDNA sequence data is estimated as 0.27% per million years. The analysis strongly supports the recognition of the Dorippinae as a monophyletic subfamily. Phylogenetic tree indicates that the subfamily Dorippinae is divided into two main clades, and genus Dorippe appears basal in the subfamily, diverging from other species 36.6 Ma ago. It is also clear that the Heikea is closely related to the genus Neodorippe. The divergence time between them is 15.8 Ma.

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The complete mitochondrial (mt) genome sequence of Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda) was determined; a circular molecule of 15,783 bp in length. The gene content and arrangement are consistent with the pancrustacean ground pattern. The mt control region of O. oratoria is characterized by no GA-block near the 3' end and different position of [TA(A)]n-blocks compared with other reported Stomatopoda species. The sequence of the second hairpin structure is relative conserved which suggests this region may be a synapomorphic character for the Stomatopoda. In addition, a relative large intergenic spacer (101 bp) with higher A + T content than that in control region was identified between the tRNA(Glu) and tRNA(Phe) genes. Phylogenetic analyses based on the current dataset of complete mt genomes strongly support the Stomatopoda is closely related to Euphausiacea. They in turn cluster with Penaeoidea and Caridea clades while other decapods form a separate group, which rejects the monophyly of Decapoda. This challenges the suitability of Stomatopoda as an outgroup of Decapoda in phylogenetic analyses. The basal position of Stomatopoda within Eumalacostraca according to the morphological characters is also questioned. (C) 2010 Elsevier Inc. All rights reserved.

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The vertical distribution and stage-specific abundance of Calanus sinicus were investigated on three key transects in the southern Yellow Sea and the northern East China Sea in August 1999. The results showed that in summer C. sinicus shrank its distribution area to the central cold (less than or equal to10degreesC) bottom water in the Yellow Sea, i.e. the Yellow Sea Cold Bottom Water, remaining in high abundance (345.7 ind m(-3)). In the northern East China Sea on a transect from the mouth of the Yangtze River to the Okinawa trench, only a few individuals appeared in the inner side and none had been found either in the upper layer or in the deep layer of the outer shelf area. The population of C. sinicus in YSCBW consisted of mainly adults (46.83%) and C5 (37.41%). C1-C4 only accounted for 15.76%. The low proportion of the earlier copepodite stages and the high female:male ratio (11.39) indicated that the reproduction of C. sinicus in YSCBW was at a very low level due to the low temperature and low food concentration. It is concluded that the dramatic decrease of C. sinicus population in the shelf area of China seas in summer is caused by the shrinkage of its distribution area and the YSCBW served as an oversummering site.

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Pigment ingestion rate (PIR) and egg production rate (EPR) of the dominant copepod Calanus sinicus, as well as chlorophyll-a concentration and phytoplankton assemblages were measured in the Bohai Sea, North China in June 1997, October 1998 and May 1999. A herbivore index (H) was also calculated as the carbon specific ratio of PIR and EPR, in order to investigate its feeding habits in the spring and autumn phytoplankton bloom respectively. On average, chlorophyll-a concentration was relatively similar (1-1.34 mg m(-3)) in the three cruises, but PIR was quite different. It was 3.24 mu g C female(-1) d(-1) in October, equivalent to one half of the PIR for June and one third of the PIR for May. Average EPR was highest in May, and quite similar during the other two months. According to H values, herbivorous feeding contributed 100% of the egg production of C. sinicus in June, 82.5% in May, but only 47.8% in October. It is possible that omnivorous feeding of C. sinicus in October was induced by a prevalence of large-sized diatoms and sufficient non-phytoplankton food resources during the autumn bloom period.

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Eight species among six genera of bopyrid isopods (representing the subfamilies Pseudionmae and loninae) infesting thalassinideans from China are reported. Of these, four species are new to science: Gyge.fujianensis n. sp., Progebiophilits elongatus n. sp., Upogebione bidigitatus n. sp., and Procepon liuruiyui n. sp., infesting Upogebia major (de Haan), Nihonotrypaea japonica Ortmann, Upogebia carinicauda (Stimpson), and Austinogebia wuhsienweni (Yu). One species, lone cornuta Bate, 1864, is recorded for the first time from Chinese waters and from a new host. Pseudione longicauda Shiino, 1937, Gyge ovalis (Shiino, 1939), and Progebiophilus sinicus Markham, 1982, previously known from Hong Kong or Taiwan, are recorded for the first time from mainland China, extending their range north.

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This paper reports the occurrence of a marine brachyuran crab species Eucrate alcocki SerSne, in SerSne et al., 1973, of the family Euryplacidae Stimpson, 1871, for first time from India, based on a male specimen from Parangipettai fish landing centre in Bay of Bengal, Southeast Coast of India. Although morphologically corresponding with what is currently defined as E. alcocki, the color pattern of the carapace of the present specimen is rather different from that of the Chinese material-only the anterior fifth of the carapace is marked with scattered red spots, the rest of the surface is yellowish, with four unusually shaped red blotches which almost look like Sanskrit characters.

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Thirty-four palaemonid species from the northern area of South China Sea are reported in the present paper, including two new species, Paranchistus lini, new species, and Periclimenes chacei, new species, and eight other species are reported for the first time from South China Sea: Leander tenuicornis (Say, 1818), Leandrites stenopus Holthuis, 1950, Palaemon debilis Dana, 1852, Urocaridella antonbrurnii (Bruce, 1967), Kemponia platycheles (Holthuis, 1952), Paraclimenes franklini (Bruce, 1990b), Paranchistus spondylis Suzuki, 1971, Periclimenes hirsutus Bruce, 1971.

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The present paper reports 8 pontoniine shrimp species, from Anambas and Natuna, Indonesia, i. e., Anchistus miersi (De Man, 1888), Conchodytes meleagrinae Peters, 1852, Hamodacotylus boschmai Holthuis, 1952, Jocaste japonica (Ortmann, 1890), Palaemonella pottsi (Borradaile, 1915), Periclimenes andamanensis Kemp, 1922, Periclimenes attenuatus Bruce, 1971, and Periclimenes grandis (Stimpson, 1860).