2013 Vol. 34, No. 4
2013, 34(4): 251-266. doi: 10.11813/j.issn.0254-5853.2013.4.0251
We reviewed the taxonomy and systematics research history of freshwater fish in China based on 1 236 taxonomic literature records on Chinese freshwater fish. The research was divided into five research periods according to specific historical events: (1) period by foreign scholars, (2) period with Chinese scholars, (3) period during World War II and Civil War, (4) recovery period and (5) period of rapid development. There were representative studies and innovations in all periods. We also discuss here the characteristics of each period on the basis of literature analysis.
Due to declining fishery resources and the growing development of conservation aquaculture, artificial freshwater fish enhancement and releasing have begun to replace traditional means of recovering endemic and rare fish populations. Artificial proliferation can be beneficial both to endemic fish conservation and technical bottleneck breakthroughs. This overview presents a review of the latest research and the underlying principles behind the conservation implementation processes, as well as the research status of artificial enhancement and release of endangered freshwater fish species in China, such as Mylopharyngodon piceus, Ctenopharyngodon idellus, Hypophthalmichthys molitrix, H. nobilis, Acipenser sinensis, Myxocyprinus asiaticus, and Sinocyclocheilus grahami. The overview also presents evolutionarily significant units, sperm and egg quality, and cryopreservation technologies and cell cultures used in artificial enhancement and release, which help standardize genetic management and minimize the genetic differences between hatched and wild populations. Monitoring fish from cultivation to release is essential to evaluating wild population recovery and adjusting recovery plans. Moreover, the remaining problems of artificial releases are discussed in-depth, touching on issues such as the limitations of domestic hatching, the base number of wild populations necessary to the environment, the proper size at which to release juveniles’ into the environment, the geographic confusion of populations, the contradictions in commercial fish selection and fish conservation, and “exotic species” invasion.
Based on extant literatures and taking into accounts updated results of taxonomy and phylogeny, we have updated this checklist of fishes present in Yunnan, including the number of taxa and drainage areas. As of 2013, there were 13 orders, 43 families, 199 genera and 629 valid species recorded in Yunnan Province, of which 594 were native species, 35 alien species, 255 species endemic to Yunnan, and 152 species only occuring in Yunnan within China. The number of species in Yunnan accounts for 39.93% of China’s total fish species (of which there are 1 583 recorded freshwater fish species according to data present in Fishbase), and of these 6 families and 66 genera only occur in Yunnan. The number of fish species of the six major drainages in Yunnan were as follows: 202 in Pearl River, 183 in Lancangjiang River (upper Mekong), 151 in Jinshajiang River (upper Yangtze), 120 in Red River, 84 in Irrawaddy Drainage, 77 in Nujiang-Salween Drainage. There are also 99 endangered species of fish occurring in Yunnan, among them 23 species protected by the national and/or the provincial government, including 2 species of national key protected animal class one, 4 species of national key protected animal class two, 17 species of Yunnan provincial protected animal. Totally, 43 species were listed in China Red Data Book of Endangered Animals, Pisces; 73 species were listed in China Species Red List Vol. 1; 50 species were listed in endangered categories of IUCN Red List; and 2 species were listed in the Appendix 2 of CITES. The Chinese name, Latin name, synomyns, distribution and literatures of the 620 species of fishes in Yunnan are listed.
As of 2013, some 178 fish type species and 2131 type specimens belonging to 4 orders and 11 families were currently being preserved at the Kunming Natural History Museum of Zoology, located as art of the Kunming Institute of Zoology, Chinese Academy of Sciences. These specimens were collected from across western China, includingYunnan, Sicuan, Guizhou, Guangxi, Hunan, Chongqi, Gansu and Xinjiang. In general, most species are Cyprinidae (71 species and 1103 specimens), followed by Nemacheilidae (52 species and 556 specimens). For the convenience of research and communication, the present paper presents a detailed list of fish type species preserved in the Kunming Natural History Museum of Zoology.
The Irrawaddy River crosses international borders throughout South-Eastern Asia, though several heads of different streams connected to the river are found in China. In the present study, two species never previously described were identified during taxonomic works on Schizothorax species distributed in the Irrawaddy drainage area in China, and were named Schizothorax leukus sp. nov. and Schizothorax heteri sp. nov. Schizothorax leukus can be distinguished from its congeners by a combination of the following characters: surface of lower lip covered with papilla, posterior edge of lower lip straight; low jaw developed, almost full the oral cavity, anterior edge of low jaw covered with horny sheath; breast and belly before pectoral-fin tip scaleless; barbels equal to eye diameter; last un-branched dorsal fin ray soft, lower third of the ray enlarged with posterior edge serrated; lateral line scales 94-105, scales between dorsal-fin origin to lateral line 26-34, scales between pelvic-fin origin to lateral line 21-27; outer side of the first gill arch with 16-20 gill rakers; body dark brown, without dark spots. Schizothorax heteri can be distinguished from its congeners by a combination of the following characters: rostral fold equal to upper lip; lower lip developed, trilobed, the median lobe minute, its width equal to diameter of the rostral barbel base; postlabial groove continuous; low jaw without horny sheath; breast and belly before pectoral-fin tip scaleless; barbels equal to eye diameter; last un-branched dorsal fin ray strong, posterior edge serrated; dorsal-fin origin posterior to pelvic-fin origin; lateral line scales 89-104, scales between dorsal-fin origin to lateral line 24-33, scales between pelvic-fin origin to lateral line 19-29; body light brown, without any spots. Likewise, we discuss the validation of S. rotundimaxillaris and the questionable records of S. molesworthi, S. griseus and S. paoshanensis. In total, eight valid species of Schizothorax were found and recorded from the Chinese Irrawaddy drainage area, with a key for identification is provided.
In the present study, a new species of the genus Sinocyclocheilus Fang 1936, Sinocyclocheilus xichouensis, was described from the Ganhaizi tributary of Chouyang River, Red River drainage, located in southeast Yunnan, China. This species has normal eyes and a strong dorsal spine with serrations on the lower 3/5 part. In general, this species is similar in morphology to S. macrophthalmus, S. guishanensis, S. angustiporus, S. lateristritus, S. qiubeiensis, S. grahami, S. qujingensis, S. maculatus and S. purpureus distributed in the Nanpanjiang River, and S. qiubeiensis distributed in the Red River. It is distinguished from S. macrophthalmus by possessing fewer than 9 gill rakers. However, S. xichouensis can be distinguished from S. guishanensis by its interorbital width/SL of 8.1~9.9%, rostral barbels extended to posterior margin of eye and maxillary barbels extended to posterior preopercular. It is distinct from S. lateristritus by dorsal-fin origin opposite of pelvic fin origin, with no a black stripe along the lateral line. It is distinguished from S. grahami by 74~88 lateral-line scales, 20 scale rows above the lateral line, and 16 scale rows below the lateral line. It is distinguished from S. qujingensis by a curved lateral line, 74-88 lateral-line scales, 48 circumpeduncular scales. It can be distinguished from S. yimenensis by the ratio of predorsal length, dorsal-fin base length, preanal length, anal fin length, prepectoral length, caudal-peduncle length and lower jaw length to SL, 47.1%-53.7%, 12.8%-15.8%, 66.0%-71.0%, 13.7%-17.1%, 26.0%-29.5%, 19.3%-24.7%, 4.7%-7.0%, respectively. It is distinguished from S. maculatus and S. purpureus by possession of lateral line and scaled body and distinguished from S. angustiporus and S. qiubeiensis by 35~39 predorsal scales, 6 gill rakers, and interorbital width/SL of 8.1%-9.9%.
Sinocyclocheilus aluensis was previously synonymized with S. angustiporus, but through the comparison of the specimens collected from Luxi County (type locality of S. aluensis) and type specimens of S. angustiporus, we identified several clear and stable characteristics to distinguish them. These findings suggest that S. aluensis should be considered as a valid species, as it can be distinguished from S. angustiporus by the position of the dorsal-fin insertion (posterior to vs. opposite to the pelvic-fin insertion), eye (22.4%-29.7% vs. 26.4%-38.9%, percentage of head length), eye-ball diameter (16.0%-23.6% vs. 21.3%-29.0%), and interorbital width (21.0%-32.3% vs. 19.7%-22.6%).
The phylogenetic position of Gobiocypris rarus, a small cyprinid fish of interest in many biological areas due to its unique characteristics, is still under debate. At the morphological view, it belongs to the Danioninae subfamily of Cyprinidae; however, recent molecular research recognizes it as a member of the Gobioninae subfamily. To investigate the phylogenetic position of Gobiocypris rarus, we prepared transparent skeleton specimens, selected 47 characteristics and reconstructed the phylogenetic tree using PAUP. The results indicated that Gobiocypris rarus was clustered with Gobioninae, which was in agreement with recent molecular phylogenetic conclusions.
Gill morphologies of two subspecies of Gymnocypris przewalskii (Gymnocypris przewalskii przewalskii and Gymnocypris przewalskii ganzihonensis) in different habitats were analyzed under scanning electron microscope. Results indicated that G. p. przewalskii had numerous long and dense-lined gill rakers while G. p. ganzihonensis had few short and scatter-lined gill rakers. There were no significant differences in distance between gill filaments (DBF) and distance gill lamella (DBL) between the two subspecies, but gill filaments of G. p. przewalskii were longer than in G. p. ganzihonensis. The electron microscopic study indicated that the pavement epithelium cells of G. p. przewalskii were well defined as irregular ovals, but were hexagonal in G. p. ganzihonensis. Moreover, G. p. przewalskii had more chloride cells than G. p. ganzihonensis, and mucous cells were only found on the surface of gill filaments of G. p. przewalskii. The morphological differences between the two subspecies of G. przewalskii are adaptations to their corresponding diets and habitats.
This study examined the age structure of the Loach, Homatula pycnolepis through the otolith growth rings in 204 individual specimens collected from the Xiaomengtong River of the Nujiang River (Salween River) basin in April, 2008. There were only two different age classes, 1 and 2 years of age—no 3 year olds were detected. The age structure of H. pycnolepis was simple. The complete mitochondrial DNA cytochrome b gene sequences (1140) of 80 individuals from 4 populations collected in the Nujiang River drainage were sequenced and a total of 44 variable sites were found among 4 different haplotypes. The global haplotype diversity (Hd) and nucleotide diversity (Pi) were calculated at 0.7595, 0.0151 respectively, and 0, 0 in each population, indicating a consistent lack of genetic diversity in each small population. There was obvious geographic structure in both the Nujiang River basin (NJB) group, and the Nanding River (NDR) group. The genetic distance between NJB and NDR was calculated at 0.0356, suggesting that genetic divergence resulted from long-term isolation of individual population. Such a simple age structure and a lack of genetic diversity in H. pycnolepis may potentially be due to small populations and locale fishing pressures. Accordingly, the results of this study prompt us to recommend that the NJB, NDR and Lancang River populations should be protected as three different evolutionary significant units or separated management units.
The NFκB inhibitor (IκBα) is an integral part of NFκB/IκB signaling pathways, which plays roles in a variety of immune responses, such as bacterial infection resistance. By interacting with nuclear transcription factor NFκB, IκBα controls a variety of biological immune gene expressions. In this study, full-length cDNA (1341 bp) of the NFκB inhibitor IκBα (PaIκBα, GenBank Accession No. JN801027) of Plecoglossus altivelis was obtained by RACE and PCR, and included a 5' untranslated region (UTR) (64 bp), a 3' untranslated region (UTR) (341 bp) and an open reading frame (ORF) (936 bp) encoding a polypeptide of 311 amino acids. PaIκBα had high homology with other IκBαs, containing a conserved ankyrin repeat domain, which was required for interacting with NFκB, a PEST sequence in the C-terminus and a signal responsive domain in the N-terminus. The deduced amino acid sequence of PaIκBα shared 95% homology with Osmerus mordax, and 76%, 75%, 70%, and 68% homology with Salmo salar, Oncorhynchus mykiss, Nile tilapia, and Siniperca chuatsi, respectively. Phylogenetic analysis revealed that IκBα of ayu and Osmerus mordax, Salmo salar, Oncorhynchus mykiss, Nile tilapia, and Siniperca chuatsi were in the same phylogenetic tree. RT-PCR analysis showed that PaIκBα mRNA expression was highest in the liver, kidney, intestine, and gills, then followed by the spleen, brain and muscle, and was lowly expressed in the heart. Likewise, after Aeromonas hydrophila infection, the mRNA level of ayu PaIκBα in the liver was also up-regulated.
In this study, 149 polymorphic markers were screened from 200 microsatellite markers. From a family of mirror carp, which included 107 individuals. All samples were analyzed for body correlation, and intermuscular bone number was tested using the General Linear Model (GLM) single marker regression. Determination of the threshold values by 10,000 permutation tests showed that eight markers had significant correlation (P<0.05), in which HLJ3086, HLJ3642 and HLJ3515 had very significant correlation with intermuscular bone number (P<0.01). In addition, the genotypes of the captured correlative loci were determined by Duncan’s test using SPSS17.0 software. Markers were used to screen the protein and nucleotide database in the National Center for Biotechnology Information (NCBI). Blasting results showed that HLJ2891 was highly correlated (92%) with latrophilin-2-like and HLJ3515 was highly correlated (81%) with serine/threonine-protein kinase 32B-like of zebrafish. These functional markers and genotypes may provide an efficient basis for marker-assisted selection of intermuscular bone number in mirror carp.
Distribution and ultrastructural changes in the mitochondrion-rich cells in gills of artificial selected Trachinotus ovatus under different salinities (5, 20, and 30) were examined by light and transmission electron micrograph. Results indicated that the mitochondrion-rich cells were mainly present on the base of the gill filaments and branchial leaflets, and the volume and quantity of mitochondrion-rich cells increased with salinity. All three salinity groups had apical crypts, which were constituted by the mitochondrion-rich cells, pavement cells and accessory cells. Mitochondrion-rich cells in the salinity 5 group had large apical membranes with developed microridges and shallow apical crypts. Apical crypts in the salinity 20 and 30 groups had small apical membranes and undeveloped microridges, and were embolic obviously. Cytoplasm of mitochondrion-rich cells in the salinity 5 and 30 groups developed tubular systems and abundant cristae mitochondria. The tubular system of the salinity 20 group was non-spatially constant and had loose structure. Part of the tubular system contracted into a pearl bubble structure and shared rough endoplasmic reticulum. Mitochondrion-rich cells in Trachinotus ovatus under salinities 5 and 20 appeared both seawater-type’s and freshwater-type’s features, and those in salinity 30 had typical characteristics as seawater-type MR cells. Structural changes of mitochondrion-rich cells were suited to different osmotic pressure.
Identifying and clarifying how stream fish assemblage patterns vary spatially and temporally are basic measures for the conservation and management of fish species. Based on data collected from 24 wadeable reaches within the Qiupu Headwaters National Wetland Park between May and October 2012, we examined the spatial and temporal patterns of the assemblage structures and diversities, collecting a total of 29 fish species belonging to four orders and ten families. The results of our survey showed influences of local habitat and tributary spatial position variables on fish assemblages. Fish diversity showed significant variations across stream-orders and seasons, which were higher in the second-order streams than in first-order streams and higher in October than in May. Habitat factors such as substrate coarseness and heterogeneity, water temperature and water depth, as well as tributary position factor-link, showed significant effects on fish diversity. Fish assemblages fitted the nested pattern that upstream assemblages presented as a nested subset of downstream assemblages. Fish assemblage structures did not vary significantly across seasons but did across stream-orders; fish assemblages between first- and second-order streams showed significant differences despite some overlap. These spatial differences mainly resulted from spatial variations of the relative abundance of Cobitis rarus, Ctenogobius sp., Zacco platypus, Phoxinus oxycephalus, Rhodeus ocellatus and Vanmanenia stenosoma, among which P. oxycephalus had higher abundance in first-order than in second-order streams but the other five species were more abundant in second-order streams. Fish assemblage structures were significantly related to substrate heterogeneity, water depth, stream order, link and C-link.
To investigate the swimming behavior of juvenile Megalobrama amblycephala, a tracking analysis device was designed to monitor behavior indicators including velocity (V), swimming distance (SD), turn angle (TA), distance to center-point (DC) and swimming track (ST) at different flow rates (0, 0.1, 0.2, 0.3 and 0.4 m/s) at 25℃. Results showed that indicator values all increased with increasing flow rate. Values of V, SD and TA showed no significant differences among the flow rates of 0, 0.1 and 0.2 m/s, respectively (P>0.05). However, they increased obviously at flow rates of 0.3 and 0.4 m/s (P<0.05), with no significant differences found between these two flow rates (P>0.05). The SD value did not change markedly according to flow rates (P>0.05), while ST showed complex patterns corresponding to increasing flow rate. A significant linear positive correlation occurred in free-swimming fish between V and SD, while a negative relationship was found between V and TA. No regular relationship was deduced between swimming speed and DC.