RESUMEN

China harbors a high species diversity of freshwater fishes not shared with any of its neighboring nations. Freshwater fish diversity in the country has been under severe threat from human activities over the past decades, thus conservation freshwater fishes and ecosystems is urgently needed. To accumulate baseline data for guiding protection actions, the third red list assessment of Chinese freshwater fishes was carried out. Among Chinese freshwater fishes assessed, there are 355 at-risk species (22.3% of the total), including 69 ranked as Critically Endangered, 97 as Endangered, and 189 as Vulnerable. Two species are classified as Extinct and one as Regionally Extinct. China's threat level seems to be lower than the known average level found in the IUCN's global assessment of freshwater fishes, but this is an artifact of a high rate of species classified as Data Deficient. Conservation of freshwater fishes is presently facing a grim situation in China. Imperilment of Chinese freshwater fishes is primarily attributed to habitat loss and degradation arising from human perturbations, particularly river damming. Despite the adoption of protected areas setting up, captive breeding and release, and a fishing moratorium, conservation efforts for freshwater fishes are compromised by disproportional attention in China's biodiversity conservation, baseline data deficiency, insufficiently designed protection networks, and inefficient or inadequate implementation of conservation strategies. To achieve the objectives of Chinese freshwater fish conservation, it is proposed to conduct a national-scale survey of fish diversity and reassess their at-risk status, develop systematic conservation planning of freshwater fish diversity and ecosystems, prioritize strategies for protected areas development, perform genetic-based captive breeding for releasing in concert with other protection actions, and implement flexible fishing moratorium strategies in different water bodies.

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There is increasing evidence that species diversity is underestimated in the current taxonomy of widespread freshwater fishes. The bagrid species T. albomarginatus s.l. is mainly distributed in the lowlands of South China, as currently identified. A total of 40 localities (including the type locality), which covers most of its known range, were sampled. Molecular phylogenetic analyses based on concatenated mtDNA and nuclear genes recover nine highly supported lineages clustering into eight geographic populations. The integration of molecular evidence, morphological data, and geographic distribution demonstrates the delineation of T. albomarginatus s.l. as eight putative species. Four species, namely, T. albomarginatus, T. lani, T. analis, and T. zhangfei sp. nov. and the T. similis complex are taxonomically recognized herein. Moreover, T. zhangfei sp. nov. comprises two genetically distinct lineages with no morphological and geographical difference. This study also reveals aspects of estimation of divergence time, distribution, and ecological adaption within the T. albomarginatus group. The unraveling of the hidden species diversity of this lowland bagrid fish highlights the need for not only the molecular scrutiny of widely distributed species of South China but also the adjustment of current biodiversity conservation strategies to protect the largely overlooked diversity of fishes from low-elevation rapids.

RESUMEN

Eighteen compounds were isolated from the EtOAc soluble fraction of Bletilla striata by various chromatographic techniques, such as silica gel, ODS, Sephadex LH-20, RP-HPLC. Their structures were identified by spectroscopic methods and physicochemical properties, as 5-hydroxy-2-(p-hydroxybenzyl)- 3- methoxybibenzyl(1), shancigusins B(2), shanciguol(3),arundinan(4), 3',5-dihydroxy-2,4-di(p-hydroxybenzyl)-3-methoxybibenzyl(5), arundin(6), 3,3'-dihydroxy-2-(p-hydroxybenzyl)-5-methoxybibenzyl(7), 3, 3'-dihydroxy-2', 6'-bis(p-hydroxybenzyl)-5-methoxybibenzyl(8), 7-hydroxy-2,4-dimethoxyphenanthrene(9), bleformin B(10),nudol(11), 3,7-dihydroxy-2, 4-dimethoxyphenanthrene(12), 2, 7-dihydroxy-4-methoxy-9,10-dihydrophenathrene(13), bleformin D(14), 4,4'-dimethoxy-9,10-dyhydro-[6,1'-biphenanthrene]-2,2',7,7'-tetraol(15),gymconopin C(16),(2,3-trans)-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-10-methoxy-2,3,4,5-tetrahydro-phenanthro[2,1-b]furan-7-ol(17),shanciol(18). Among them, compound 1 was a new compound, Compounds 2-6,9,15-18 were isolated from this genus for the first time.

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The digestive physiology of Chinese loach (Paramisgurnus dabryanus) was studied by assessing the specific and total activities of different pancreatic (trypsin, chymotrypsin, amylase and lipase), gastric (pepsin) and intestinal (alkaline phosphatase and leucine-aminopeptidase) enzymes from hatching to 40 days after hatching (DAH). Larvae were reared at 24.4 ± 0.4 °C and fed with rotifers from mouth opening (4 DAH) to 15 DAH, from 10 to 35 DAH with Cladocera and from 30 to 40 DAH with compound diet. Enzyme activities for trypsin, chymotrypsin, amylase and lipase were detected before the onset of exogenous feeding, indicating that these enzymes were genetically pre-programmed. Most of the pancreatic enzyme specific activities increased until 20 DAH and decreased thereafter. The pepsin activity of Chinese loach was firstly detected at 30 DAH, indicating the appearance of functional gastric gland. Alkaline phosphatase specific activity was detected from hatching onward, showed marked increase and reached the second peak at 20 DAH, while a gradual increase in specific leucine-aminopeptidase activity was observed until the end of the experiment. Accordingly, the larvae of Chinese loach possess a functional digestive system before the onset of exogenous feeding and the digestive capacity gradually increases as development progresses. The abrupt increase in intestinal enzyme activities between 10 and 20 DAH demonstrates onset of juvenile-like digestive mode in Chinese loach larvae. The increase in pepsin activity after 30 DAH indicates the shift from alkaline to acidic digestion in Chinese loach larvae, which may be considered as the onset of weaning.

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Ten glucosyloxybenzyl 2-isobutylmalates and one benzyl alcohol glycoside were isolated from the dry tuber of Pleione bulbocodioides, which is a specie of Orchidaceae family and its dry tuber is one of the main sources of traditional Chinese medicine "shanci-gu", by a combination of various column chromatographic methods, including ODS, macroporous adsorbent resin, Sepheadex LH-20, and preparative HPLC. Their structures were identified on the basis of chemical evidences and spectroscopic analysis asloroglossin (1), grammatophylloside A (2), cronupapine (3), (-)-(2R, 3S)-1-(4-β-D-glucopyranosyloxybenzyl)-4-methyl-2-isobutyltartrate (4), vandateroside II (5), grammatophylloside B (6), bis [4-(β-D-glucopyranosyloxy) -benzyl] (S) -2-isopropylmalate (7), gymnoside I (8), militarine (9), dactylorhin A (10), gastrodin (11). Compounds 1-7 were isolated from this genus for the firt time.

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Fourteen compoumds were isolated from the ethyl acetate portion of the 95% ethanolic extract of Pleione bulbocodioides by a combination of various chromatographic techniques including silica gel, ODS, macroporous adsorbent resin, Sephadex LH-20, and preparative HPLC, of which ten compoumds were phenanthrenes and dihydrophenanthrenes, two compoumds were bibenzyls, one was lignan and a sterol. Their structures were identified on the basis of spectroscopic data as monbarbatain A(1), 2, 7, 2'-trihy-droxy-4, 4', 7'-trimethoxy-1, 1'- biphenanthrene(2), blestriarene A(3), pleionesin B(4), shanciol H(5), 17-hydroxy-7'-(4'-hy-droxy-3 '-methoxyphenyl)- 4-methoxy-9, 10, 7', 8'-tetrahydrophenanthro[2, 3-b]furan-8'-yl methyl acetate(6), 1-p-hydroxybenzyl-4-methoxy phenanthrene-2, 7-diol(7), 1-p-hydroxybenzyl-4-met-hoxy-9, 10-dihydrophenanthrene-2, 7-diol(8), hircinol(9), coelonin( 10), gigantol(11), batatasin 11 (12), syringaresinol(13) and ergosta4, 6, 8 ( 14) , 22-tetraen-3-one (14). Compounds 1-3, 9, 13 and 14 were isolated from this genus for the first time.

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