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Rosenblattichthys nemotoi is described from a single larval specimen, 37 mm SL (standard length) taken from the southern Indian Ocean Subtropical Convergence Zone. This species differs from all otherRosenblattichthys in meristic characters (25 anal-fin rays, 26 or 27 pectoral-fin rays), configuration of accessory pigment areas (two areas present; a dorsal area (DA) and a midlateral peduncular area (PDA), and nonprecocity of pectoral-fin development. All other records ofRosenblattichthys are from tropical or subtropical waters.  相似文献   
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A new type of exterilium larvae referable to Leptobrotula (Ophidiiformes: Ophidiidae) is described on the basis of two specimens (20.7+mm and ca. 35.4mmSL) collected from the tropical Indo-Pacific. They are characterized, in particular, by several elongated anterior dorsal fin rays supported by the large dorsal pterygiophores and the exterilium gut bearing filamentous appendages along the ventral border. It is suggested from larval evidence that Leptobrotula forms a distinct lineage with Brotulotaenia and Lamprogrammus, which may be placed in an expanded Brotulonaeniinae.  相似文献   
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Larvae of the deep-sea lanternfish genus Hygophum (Myctophidae) exhibit a remarkable morphological diversity that is quite unexpected, considering their homogeneous adult morphology. In an attempt to elucidate the evolutionary patterns of such larval morphological diversity, nucleotide sequences of a portion of the mitochondrially encoded 16S ribosomal RNA gene were determined for seven Hygophum species and three outgroup taxa. Secondary structure-based alignment resulted in a character matrix consisting of 1172 bp of unambiguously aligned sequences, which were subjected to phylogenetic analyses using maximum-parsimony, maximum-likelihood, and neighbor-joining methods. The resultant tree topologies from the three methods were congruent, with most nodes, including that of the genus Hygophum, being strongly supported by various tree statistics. The most parsimonious reconstruction of the three previously recognized, distinct larval morphs onto the molecular phylogeny revealed that one of the morphs had originated as the common ancestor of the genus, the other two having diversified separately in two subsequent major clades. The patterns of such diversification are discussed in terms of the unusual larval eye morphology and geographic distribution.  相似文献   
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The surface structures of the cells of Pasteurella pneumotropica from mice and Pasteurella multocida from rabbits were examined by transmission electron microscopy after ruthenium red staining and polycationic ferritin labelling. P. pneumotropica strains ATCC 35149 and K 79114 had slight extracellular fibrous materials associated with cell walls with ruthenium red staining. Ferritin labelling method revealed thick strands or sparsely ferritin-labelled materials on the cell surface of the strains. P. multocida strains Pm-78 and P-2440 had ferritin-labelled capsules surrounded with the cell wall. Strain Pm-78, which was serotyped as A:12, had a thick capsule, whereas serotype -:3 strain P-2440 had a thin and irregular capsule.  相似文献   
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A total of 52 isolates of Pasteurella pneumotropica obtained from rodents were examined for their genetic heterogeneity. On the basis of DNA restriction analysis, including amplified 16S ribosomal DNA restriction analysis (ARDRA) and pulsed-field gel electrophoresis (PFGE), differences were identified among the isolates. ARDRA typing with Hae III revealed 4 different banding patterns of the P. pneumotropica isolates. Eighty-two percent of the 23 isolates identified as a-1 were derived from mice, whereas all the isolates identified as a-3 were derived from rats. Most of the isolates, which showed hemolytic activity on blood agar, obtained from mice and rats, were identified as a-2 and a-4, respectively. By restriction analysis of genomic DNA, Apa I and Not I digestion differentiated 9 variants and an undiscriminating group. However, no close relation with regard to the phenotypic characteristics was observed among the variants. The isolates identified as a-2 and a-4 could not be distinguished by PFGE analysis. DNA restriction analysis revealed that the genetic diversity of the P. pneumotropica isolates was more complex than the phenotypic characteristics among the species, and that at least the P. pneumotropica isolates were clearly differentiated into 4 groups by ARDRA typing with Hae III.  相似文献   
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Spermatocytes of the teleost, Oryzias latipes , at meiotic prophase were cultured without contact with somatic cells. They began to divide, progressing through the meiotic divisions and differentiating into round spermatids within 48 h. The chromosome number in both the primary and secondary spermatocytes at metaphase was n = 24. In spermatids, a single flagellum was formed and the release of residual bodies was observed in vitro . The size and shape of the flagellum were the same as those seen in vivo . The expression of protamine mRNA was detected in round spermatids. This result suggests that gene expression, as well as morphological change, is regulated by the progression of spermatogenesis in cell culture. Furthermore, when the eggs of O. latipes were inseminated with germ cells cultured for 10 days, normal embryos developed and hatched out. These results suggest that the spermatocytes of O. latipes develop into fertile sperm in cell culture.  相似文献   
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Regioselective synthesis of methylated epigallocatechin gallate from epigallocatechin was accomplished using a 2-nitrobenzenesulfonyl (Ns) group as a protecting group for phenols. This methodology provided several methylated catechins, which are naturally scarce catechin derivatives.  相似文献   
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The osteology of the rate Japanese fishPseudotrichonotus altivelis is described based on several specimens collected off the Izu Peninsula. Relationships ofPseudotrichonotus are discussed based on osteological comparisons with other neoteleosts. The placement ofPseudotrichonotus among iniomous fishes has been questioned because of its lower numbers of caudal-fin, pelvic-fin, and branchiostegal rays. Our investigation supports an iniomous affinity forPseudotrichonotus, specifically as a member of the Aulopiformes. Within that group,Pseudotrichonotus belongs in a new suborder diagnosed herein, the Synodontoidei, which also includes the Aulopidae (Aulopus), Synodontidae (Synodus andTrachinocephalus), and Harpadontidae (Harpadon andSaurida). A synodontoid affinity forAulopus has never been suggested, but numerous osteological features support the monophyly of this clade. Synodontoids have a peculiar proximal segmentation of most principal caudal-fin rays, expanded neural and haemal spines on posterior vertebrae, cartilage extending along the ventral margin of the anterior ceratohyal, ventral displacement of the first one to three epineurals, supraneurals with large laminar expansions and six or more branchiostegals on the posterior ceratohyal. They lack median caudal cartilages. Among synodontoids,Pseudotrichonotus is the sister group of the Synodontidae plus Harpadontidae, with which it shares paired peritoneal pigment spots, an abrupt transition between the epipleurals in and beneath the horizontal septum, and absence of the fourth pharyngobranchial toothplate. Our study does not support a previously proposed relationship betweenBathysaurus and synodontids. deceased  相似文献   
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