The status and causes of alien species invasion in China

Data of classification, origin, pathway and environmental impacts of invasive alien micro-organisms, invertebrates, amphibians and reptiles, fish, birds, mammals, weeds, trees, and marine organisms in terrestrial, aquatic and marine ecosystems of China, were analyzed, based on literature retrieval, field survey and consultation. Some 283 invasive alien species were recorded in China, including 19 invasive alien micro-organisms, 18 aquatic plants, 170 terrestrial plants, 25 aquatic invertebrates, 33 terrestrial invertebrates, 3 amphibians and reptiles, 10 fish, and 5 mammals. Of the invasive alien species, 55.1% originated from North and South America, 21.7% from Europe, 9.9% from Asia, 8.1% from Africa and 0.6% from Oceania. Many institutions and individuals in China lack adequate knowledge of ecological and environmental consequences caused by invasive alien species, with some ignorance of the dangerous invasion in the introduction of alien species. For instance, 50.0% of invasive alien plants were intentionally introduced as pasture, feedingstuff, ornamental plants, textile plants, medicinal plants, vegetables, or lawn plants, 25% of alien invasive animals were intentionally introduced for cultivation, ornament, or biological control, In addition, more efforts are being made in the introduction of alien species, and little attention is paid on the management of introduced alien species, which may cause their escape into natural environment and potential threats to the environment. There were also gaps in quarantine system in China. All microorganisms were unintentionally introduced, through timber, seedling, flowerpot, or soil; 76.3% of alien invasive animals invaded through commodity or transportation facility because of the failure of quarantine. Therefore, quarantine measures should be strictly implemented; and meanwhile the intentional introduction of alien species should be strictly managed and a system of risk assessment should be implemented.

Revised diagnosis of the genus Bangana Hamilton, 1822 (Pisces : Cyprinidae), with taxonomic and nomenclatural notes on the Chinese species

Most morphological characters diagnostic of the 13 Chinese species of the cyprinid genus Sinilabeo Rendahl, 1932, are identical to those of the genus Bangana Hamilton, 1822. Consequently, these 13 species are transferred to Bangana. A revised diagnosis is provided for the now-expanded genus Bangana, and a dichotomous key and taxonomic and nomenclatural notes are included for the following valid Chinese species: B. decora, B. dero, B. devdevi, B. discognathoides, B. lemassoni, B. lippa, B. rendahli, B. tonkinensis, B. tungting, B. wui, B. xanthogenys, B. yunnanensis, and B. zhui. Literature reports, by Chinese authors, of Sinilabeo dero from the upper Irrawady River basin, in Yunnan, are based on misidentifcations of B. devdevi. Sinilabeo cirrhinoides Wu and Lin in Wu, Lin, Chen, Chen and He, 1977, and S. laticeps Wu and Lin in Wu, Lin, Chen, Chen and He, 1977, are junior subjective synonyms of B. devdevi and B. lippa, respectively. Sinilabeo yunnanensis Wu, Lin, Chen, Chen and He, 1977, is an available name, and a lectotype is designated for the species. Bangana zhui ( Zheng and Chen, 1983) is a valid species distinct from B. yunnanensis.

Ex situ conservation status of an endangered Yangtze finless porpoise population (Neophocaena phocaenoides asiaeorientalis) as measured from microsatellites and mtDNA diversity

The Yangtze finless porpoise, Neophocaena phocaenoides asiaeorientalis, is all endangered small cetacean that occurs only in the middle and lower reaches of the Yangtze River of China. The establishment of a breeding population of the porpoise in Tian-e-Zhou Baiji National Natural Reserve represents the first attempt at ex situ conservation efforts for a cetacean species. With the goal of effective protection, management, and monitoring of this preserved population, we examined its genetic diversity using 930 bp of mtDNA control region sequences and 13 polymorphic microsatellite loci. A very low level of genetic variation (h = 0.6010 +/- 0.0029 s.d.; pi = 0.0007 +/- 0.0000002 s.d.) in the mtDNA control region sequences and a moderate genetic diversity (Ho = 0.5740 +/- 0.2575 s.d.) in the microsatellites were detected in the population. It is necessary to introduce more individuals with representative genetic variations into the reserve ill order to foml a larger and healthier group structure for long-term survival of the population. Successful establishment of the Yangtze finless porpoise population in the Reserve also provides a useful model for an ex situ conservation programme for other rare and endangered species. (c) 2005 International Council for the Exploration ofthe Sea. Published by Elsevier Ltd. All rights reserved.

Present status and changes of the phytoplankton community after invasion of Neosalanx taihuensis since 1982 in a deep oligotrophic plateau lake, Lake Fuxian in the subtropical China

Phytoplankton assemblages in the subtrophical oligotrophic Lake Fuxian, the second deepest lake in China, were investigated monthly from September 2002 to August 2003. A total of 113 species belonging to seven phyla were identified, among them, a filamentous green alga, Mougeotia sp., dominated almost throughout the study period and comprised most of the total phytoplankton biomass. Mougeotia sp. has made a substantial development during the past decades: it was absent in 1957, only occasionally present in 1983, increased substantially in 1993, and became predominant in 2002-2003. It is likely that natural invasion of the Taihu Lake noodlefish (Neosalanx taihuensis) has led to a change of dominant herbivorous zooplankton from small to large calanoid, which has increased grazing pressure on small edible algae, and thus has indirectly favored the development of the inedible filamentous Mougeotia sp.

New data on the morphology and systematic status of Spinitectus petrowi and Spinitectus gigi (Nematoda : Cystidicolidae) parasitic in catfishes in central China

Two little-known nematode species of the genus Spinitectus Fourment, 1883, S. petrowi Belous, 1965 (prevalence 25%, intensity 1-8) and S. gigi Fujita, 1927 (prevalence 10%, intensity 2-3), were collected from the gastrointestinal tract of the yellow catfish, Pelteobagrus fulvidraco (Richardson), from Liangzihu Lake, Hubei Province, central China, in September of 2002. The light and scanning electron microscopical examination of this material, supplemented by a few museum specimens of S. gigi collected from the catfish Clarias fuscus (Lacepede) in southern China, made it possible to study in detail the morphology of these parasite species and to redescribe them. The first species, whose correct name is S. petrowi Belous, 1965, exhibits some morphological features (e.g., unusually short vestibule, shape of pseudolabia and of the left spicule) not found in most other congeners; a unique feature is the presence of peculiar pairs of transversely oriented peg-like cuticular spines with rounded ends on the ventral surface of the female tail. Spinitectus gigi was found to have 28-31 cuticular spines in the first ring, relatively long distances between the 2nd-7th rings of spines, and anterior rings divided into 2 sectors; the excretory pore is located at the level of the 4th ring of cuticular spines; males posses 4 pairs of preanal- and 6 pairs of postanal caudal papillae and a pair of small phasmids. Spinitectus bagri Wang, Wu et Yu, 1993 and S. wulingensis Yu et Wang, 1997 are considered junior synonyms of S. petrowi, whereas S. clariasi Ky, 1971, S. ophicephali Ky, 1971 and S. yuanjiangensis Wang, Wit et Yu, 1997 are regarded to be junior synonyms of S. gigi. Spinitectus petrowi was not previously reported from China.

Status of sturgeon aquaculture and sturgeon trade in China: a review based on two recent nationwide surveys

The authors reviewed the aquacultural history of Acipenseriformes in China, related the legal status and examined the current status of the cultured species or hybrids, origins of seedlings, quantities of production, geographic distribution in farming, and the sustainability for both restocking programmes and human consumption. The census shows that since 2000, the production of cultured sturgeons in China appears to have become the largest in the world. As of 2000, the rapid growth of sturgeon farming in China mainly for commercial purposes has shifted harvests in the Amur River from caviar production to the artificial culture of sturgeon seedlings. This dramatic development has also caused a series of extant and potential problems, including insufficient market availability and the impact of exotic sturgeons on indigenous sturgeon species. Annual preservation of sufficient higher-age sturgeons should be a national priority in order to establish a sustainable sturgeon-culture industry and to preserve a gene pool of critically endangered sturgeon species to prevent their extinction.

The picophytoplankton in three Chinese lakes of different trophic status and its relationship to fish populations

A year-round comparison was made of the picophytoplankton populations in three lakes of different trophic status (oligotrophic, mesotrophic, and hypereutrophic), as well as in experimental enclosures stocked with various densities of fish. Picophytoplankton abundance was significantly different between the hypereutrophic lake and the oligotrophic lake (P<0.018) and between the hypereutrophic lake and the mesotrophic lake (P<0.021), whereas the difference between the mesotrophic and oligotrophic lakes was not significant (P<0.745). The effect of total nitrogen:total phosphorus ratio on the abundance of picophytoplankton was demonstrated in the oligotrophic lake, but such effect did not manifest itself in the other lakes or in the experimental enclosures. The average annual picophytoplankton population sizes in the three lakes in 1995-1998 were correlated with estimated fish abundance (r=0.824, n=9, P=0.006). The results of enclosure experiments demonstrated that the abundance of picophytoplankton increased with the stocking density of fish (r=0.619, n=8, P=0.100).

The Yangtze River dolphin or baiji (Lipotes vexillifer): population status and conservation issues in the Yangtze River, China

1. Baiji were sighted 17 times during three recent simultaneous multi-vessel surveys in the Yangtze River, China (November 4-10, 1997; December 4-9, 1998; October 31-November 5, 1999). There were 11 sightings in 1997 (consisting of 17 animals), five in 1998 (seven animals), and two in 1999 (four animals). It was concluded that 13 individuals Could be considered as a minimum number of the baiji currently in the Yangtze River. 2. An annual rate of population decrease was roughly estimated as 10%. From the body sizes observed, the proportions of old, adult and immature individuals were approximately estimated at 57, 26, and 17% respectively. 3. Baiji showed a significant attraction to confluences and sand bars with large eddies. The present distribution range of the baiji is less than 1400 km in length in the Yangtze main river. Distances between the two nearest groups of baiji appear to be increasing. 4. Two typical sightings are described, in which surfacing and movements of baiji were recorded. Baiji were often found swimming together with finless porpoise. In the surveys they occurred in the same group in 63% of occurrences. Interactions between baiji and finless porpoise are described and discussed. 5. Human activities are the main threats to the baiji. Illegal electrical fishing accounted for 40% of known mortalities during the 1990s. Engineering explosions for maintaining navigation channels have become another main cause of baiji deaths. The last hope of saving the species may be to translocate the remaining baiji into a semi-captive reserve. known as the 'Baiji Semi-natural Reserve'. Copyright (C) 2003 John Wiley Sons, Ltd.

Taxonomic revision of water-bloom-forming species of oscillatorioid cyanobacteria

A polyphasic approach was used to clarify the taxonomy of the water-bloom-forming oscillatorioid cyanobacteria. Seventy-five strains of oscillatorioid cyanobacteria were characterized by 16S rDNA sequence analysis, DNA base composition, DNA-DNA hybridization, fatty acid composition, phycobilin pigment composition, complementary chromatic adaptation, morphological characters, growth temperature and salinity tolerance. Phylogenetic analysis based on 165 rDNA sequences divided the strains into six groups, all of which were clearly separated from the type species of the genus Oscillatoria, Oscillatoria princeps Gomont NIVA CYA 150. Therefore, these strains should be classified into genera other than Oscillatoria. Groups I-III were closely related to one another and groups IV-VI were distinct from one another and from groups I to III. Group I was further divided into two subgroups, group I-pc, which includes strains containing only phycocyanin (PC), and group I-pe, which includes strains containing large amounts of phycoerythrin (PE) in addition to PC. This phenotypic distinction was supported by DNA-DNA hybridization studies. Based on the properties examined herein and data from traditional, botanical taxonomic studies, the groups and subgroups were classified into single species and we propose either emended or new taxonomic descriptions for Planktothrix agardhii (type strain NIES 204(T)), Planktothrix rubescens (type strain CCAP 1459/22(T)) Planktothrix pseudagardhii sp. nov. (type strain T1-8-4(T)), Planktothrix mougeotii (type strain TR1-5(T)), Planktothricoides raciborskii gen. nov., comb. nov. (type strain NIES 207(T)), Tychonema bourrellyi (type strain CCAP 1459/11B(T)) and Limnothrix redekei (type strain NIVA CYA 277/1(T)).

Common evolutionary origin of aquareoviruses and orthoreoviruses revealed by genome characterization of Golden shiner reovirus, Grass carp reovirus, Striped bass reovirus and golden ide reovirus (genus Aquareovirus, family Reoviridae)

Full-length and partial genome sequences of four members of the genus Aquareovirus, family Reoviridae (Golden shiner reovirus, Grass carp reovirus, Striped bass reovirus and golden ide reovirus) were characterized. Based on sequence comparison, the unclassified Grass carp reovirus was shown to be a member of the species Aquareovirus C The status of golden ide reovirus, another unclassified aquareovirus, was also examined. Sequence analysis showed that it did not belong to the species Aquareovirus A or C, but assessment of its relationship to the species Aquareovirus B, D, E and F was hampered by the absence of genetic data from these species. In agreement with previous reports of ultrastructural resemblance between aquareoviruses and orthoreoviruses, genetic analysis revealed homology in the genes of the two groups. This homology concerned eight of the 11 segments of the aquareovirus genome (amino acid identity 17-42%), and similar genetic organization was observed in two other segments. The conserved terminal sequences in the genomes of members of the two groups were also similar. These data are undoubtedly an indication of the common evolutionary origin of these viruses. This clear genetic relatedness between members of distinct genera is unique within the family Reoviridae. Such a genetic relationship is usually observed between members of a single genus. However, the current taxonomic classification of aquareoviruses and orthoreoviruses in two different genera is supported by a number of characteristics, including their distinct G+C contents, unequal numbers of genome segments, absence of an antigenic relationship, different cytopathic effects and specific econiches.

Taxonomic studies of parasitic nyctotherans from chinese Anura amphibians III. Wichtermania

Wu-Han Xiao, Jian-Guo Wang and Lian-Xiang Li (2002) Taxonomic studies of parasitic nyctotherans from Chinese Anura amphibians III. Wichtermania. Zoological Studies 41(1): 69-76. This paper describes 6 new species belonging to the genus Wichtermania from Anura amphibians distributed in southern China. The 6 species are Wichtermania multigranularis sp. nov., W. oviformis sp. nov., W vesiformis sp. nov., W. reticulatis sp. nov., W granuliformis sp. nov., and W obliquoides sp. nov. The characteristics for diagnosis of the 6 new species are described in this paper.

Taxonomic studies of parasitic nyctotherans from chinese Anura amphibians IV. Spirocytopharynxa gen. nov and Macrocytopharynxa gen. nov.

Lian-Xiang U, Jian-Guo Wang and Wu-Han Xiao (2002) Taxonomic studies of parasitic nyctotherans from Chinese Anura amphibians IV. Spirocytopharynxa gen. nov. and Macrocytopharynxa gen. nov. Zoological Studies 41(1): 77-84. This paper describes 2 new genera and 5 new species of nyctotherans from Anura amphibians distributed in southern China. Based on the composition of the upper and bottom flaps, the number and position of sutural lines, the length of the oral groove, and the morphology and position of the end of the cytopharynx, the adoral zone of the membranelle (AZM), and the macronucleus, two new genera were established. The 3 new species, Spirocytopharynxa sinensis, S. guangxiensis, and S. quadranus, belong to the new genus Spirocytopharynxa, Another 2 species, Macrocytopharynxa (Nyctotheroidae Nie, 1932) pyriformis n. comb. and M. lingchuanensis n. sp., belong to the new genus Macrocytopharynxa. The characteristics for diagnosis of the 2 new genera and 5 new species are described in this paper.

Taxonomic re-evaluation of Aphanizomenon flos-aquae NH-5 based on morphology and 16S rRNA gene sequences

The taxonomy of Aphanizomenon flos-aquae strain NH-5, a producer of cyanotoxins, was re-evaluated by comparison with six other Aphanizomenon strains using morphological characteristics and 16S rRNA gene sequences. Strain NH-5 was concluded to be improperly identified as Aph. flos-aquae based upon (1) lack of bundle formation in the trichomes, (2) location of akinetes next to heterocytes, (3) lower similarities (less than 97.5%) in the 16S rRNA gene sequences relative to Aph. flos-aquae strains, and (4) comparison within a phylogenetic tree constructed from 16S rRNA gene sequences. The Aphanizomenon strains investigated in this study are classified to four morphological groups as described by the classical taxonomy of Komarek & Kovacik (1989). This classification was supported from the phylogenetic results of 16S rRNA gene sequences. This study also discusses the generic boundaries between Aphanizomenon and Anabaena.

Inland free-living nematodes in China: A historical review of taxonomic studies with descriptions of Aphanonchus orientalis sp nov (Chromadorida : Leptolaimidae) and Daptonema limnobia sp nov (Monhysterida : Xyalidae)

The study of inland free-living nematodes is relatively imperfect in China, only seventeen papers were previously published. Since the early researches in 20-30s, few works have been accomplished until 80s. Altogether 171 taxa were formerly recorded, among which, over eighty species have been re-combined. A checklist of the former records with notes on their distribution is presented in this paper. Recently, the function of free-living nematodes has received much attention from Chinese zoologists. Hence, the present authors carried out their studies with emphasis on taxonomy of inland nematodes. During the survey of freshwater lakes, two species are found to be nem to science. Aphanonchus orientalis sp. nov. is characterized by having sclerotized vagina, the presence of 10-11 tubular supplements and 42-62 alveoli supplements in males, but no alveoli in females. Daptonema limnobia sp, nov. is distinguished from other species of the genus in the presence of larger and more anteriorly located amphids, shorter bifurcated spicules, smaller apophysis of gubernaculum, shorter terminal setae, and postvulval uterine sac in females.