洱海鲢、鳙的食物组成及与太湖新银鱼的食性重叠研究

为了研究鲢（Hypophthalmichthys molitrix）、鳙（Aristichthys nobilis）两种鱼食物组成的空间变化,分析了2010年7月至2011年10月在洱海古生和北部两采样点逐月采集或收集的共93尾鲢和71尾鳙的肠道内含物,对其食物组成的季节变化、空间变化及与太湖新银鱼（Neosalanx taihuensis）的食物重叠进行了研究。结果表明,鲢、鳙全年摄食的饵料生物数分别为75 属和 64属。根据相对重要性指数（IRI%）,微囊藻（Microcystis）和象鼻溞（Bosmina）为两种鱼的主要饵料类群。鲢、鳙的食物组成呈明显的季节变化,这与饵料生物的季节变化密切相关。在空间上,两种鱼在古生摄食的浮游植物比例大于北部,这是由不同区域饵料生物组成差异导致的结果。Schoener重叠指数显示鲢、鳙与太湖新银鱼之间的食性重叠不显著（E0.6）。       

Biochemical genetic comparison of bighead (Hypophthalmichthys molitrix), silver carp (Aristichthys nobilis), and their hybrids reared in Czechoslovakia

Incidental and/or uncontrolled hybridization between silver carp ( Hypophthalmichthys molitrix ) and bighead ( Aristichthys nobilis ) represents a serious problem in Czechoslovak aquaculture. This fact affects fitness traits very negatively in successive generations of hybrids. To solve this problem, 1076 individuals in a total of both H. molitrix. A. nobilis , and their hybrids in 12 groups from six rearing facilities were analysed. Twelve protein systems representing 21 presumptive loci were studied to analyse the electrophoretic patterns of their products using horizontal starch gel electrophoresis of blood and tissue extracts. Both species displayed identical electrophoretic patterns in MYO-I* , LDH-A *, LDH-B *, sMDH-1 *, sIDHP-3*, GPI-1*, and CK-I * loci. For a reliable differentiation of both species products of the following nine loci are applicable ALB *, PA *, TF, sMDH-2 *, SOD *, NDH *, MYO-IF , MYO-III *, and CK-2 *. In addition, some polymorphic variants in slDHP-1 *, sIDHP-2 *, LDH-C *, EST-II *, and GPI-2 * loci are of use as auxillary markers while the other variants are common to both species. A high level of gene introgression was evident through hybridization between both species. All groups declared previously as ' H. molifrix ' were actually confirmed biochemically to be H. molitrix . However, all groups declared as ' A. nobilis ' were proved to be a mixture of A. nobilis and its hybrids of different level with H. molitrix . This suggests it is impossible to distinguish between A. nobilis and hybrids using their external morphology only.     

Nucleolar variations during the ontogenesis of diploid and tetraploid cyprinid species

Studying the quantitative characteristics of nucleoli in cells of several cyprinid species ( Cyprinus carpio, Carassius auratus gibelio, Carassius auratus auratus, Aristichthys nobilis, Ctenopharyngodon idella, Hypophthalmichthys molitrix ) has shown a definite programme that controls genetically changes in the nucleolar characteristics during fish ontogenesis. In embryogenesis, the nucleolar activity, which has been estimated from the number and size of nucleoli, decreased; this process was realized dissimilarly in diploid and tetraploid cells. A correlation between the nucleolar characteristics and the body mass of juvenile fish was found. Parameters of the nucleolar activity were closely related to the physiological state of mature organisms and featured tissue specificity, rhythmicity, and high level of heritability.     

Erythrocyte measurements of diploid and triploid Ctenopharyngodon idella×Hypophthalmichthys nobilis hybrids

Diploid and triploid hybrids resulted when grass carp, Ctenopharyngodon idella , and big-head carp, Hypophthalmichthys nobilis , were experimentally hybridized. Erythrocyte size can be used to distinguish C. idella × H. nobilis hybrids of different ploidies.     

Iron(III) binding proteins of echidna (Tachyglossus aculeatus) and platypus (Ornithorhynchus anatinus)

Iron (III) binding proteins are isolated from echidna (Tachyglossus aculeatus multiaculeatus) and platypus (Ornithorhynchus anatinus) milk and blood. On the basis of several criteria it is shown that the milk proteins are not lactoferrins, but are transferrins similar to the corresponding transferrins from the blood. The heterogeneity of the proteins, particularly the echidna milk transferrin, is, at least in part, due to different levels of sialic acid. Their N-terminal sequences (30 residues) are determined and compared with those of other transferrins and lactoferrins. The role of the proteins is discussed.     

鲢鱼、鳙鱼、草鱼谷胱甘肽过氧化物酶cDNA的克隆及肝组织表达

利用RT-PCR技术分别从淡水食毒藻鱼类鲢鱼(Hypophthalmichthys molitrix)、鳙鱼(Aristichthys nobilis)及草食性鱼类草鱼(Ctenopharyngodon idella)肝组织扩增出谷胱甘肽过氧化物酶(GPX)cDNA核心序列。序列分析表明鲢鱼、鳙鱼、草鱼GPX的cDNA序列均为263bp,编码87个氨基酸。鲢鱼、鳙鱼、草鱼与斑马鱼(Danio rerio)(同属鲤科)、条石鲷(Oplegnathus fasciatus)、虹鳟(Oncorhynchus mykiss)(鲈形目)等鱼类GPX氨基酸序列同源性很高,为75%～93%;与人(Homo sapiens)、小鼠(Mus musculus)、大鼠(Rattus norvegicus)、猪(Sus scrofa)、牛(Bos taurus)等哺乳动物GPX氨基酸序列的同源性也较高,为76%～79%。以β-肌动蛋白为内参照,比较鲢鱼、鳙鱼、草鱼肝组织GPX cDNA的表达水平,鲢鱼、鳙鱼肝组织GPX的表达量远高于草鱼肝的GPX表达量,这与鲢鱼、鳙鱼大量摄入微囊藻毒素在鱼体内引发产生过量的脂过氧化物相适应。     

Study of the haemoglobin content of a single erythrocyte (M index) in various cultured fish species

Investigations of the erythrocyte count, haemoglobin content and M index of 7 fish species were performed under equivalent environmental conditions in the same period of the year. The species were: bighead Hypophthalmichthys nobilis (Richardson), carp Cyprinus carpio L., silver carp Hypophthalmichthys molitrix (Val.), grass carp Ctenopharyngodon idella (Val.), sheat-fish Silurus glanis L. , pike Esox Indus L., pike-perch Lucioperca lucioperca (L.). Bighead and carp are carnivorous and omnivorous, silver carp and grass carp are herbivorous and sheat-fish, pike and pike-perch are predatory. Significant differences were demonstrable between M values of fish living on different type of food, where the M index is: It is concluded that M index values are useful as one parameter differentiating between fish with distinctly different food habits.     

Polymorphism and heterogeneity of transferrins in some species of the fish family Cyprinidae

In fish of the family Cyprinidae extensive polymorphism and heterogeneity of serum transferrins were found. Ten variants of transferrins were detected in barbel, 9 in dace and bleak, 7 in chub and bream, 6 in rudd, 5 in roach, white bream, silver carp, big head and crucian carp, 3 in tench, and 2 variants in nase, ide and goldfish. All the variants observed bound radioactive iron. The phenotype patterns indicated a simple genetic determination, by a set of codominant alleles at one locus, and this even in tetraploid species. Transferrins of some species were partly isolated. The transferrins of all 22 species analysed were heterogeneous and homozygous pheno-types had 1 to 6 zones of various intensities, binding ⁵⁹Fe. In barbel both single-zone and two-zone variants were present and transferrins of roach had variable heterogeneity. Sialic acid was found only in transferrins of silver carp, big head and in the two-zone variants of barbel. The occurrence of phenotypes with single and double zones of transferrins in barbel indicates the possibility of genetic determination of the inability of single-zone variants to bind sialic acid.     

The hearing abilities of the silver carp (Hypopthalmichthys molitrix) and bighead carp (Aristichthys nobilis)

Concern regarding the spread of silver carp (Hypopthalmichthys molitrix) and bighead carp (Aristichthys nobilis) through the Illinois River has prompted the development of a Bio-acoustic Fish Fence (BAFF) to act as an acoustic fish deterrent. The application of this technology has resulted in a need to understand the auditory physiology of the target species, in order to maximise the effect of the barrier in preventing the migration of the non-indigenous carp species into Lake Michigan, whilst minimising the effect on indigenous fish populations. Therefore, the hearing thresholds of 12 H. molitrix and 12 A. nobilis were defined using the Auditory Brainstem Response (ABR) technique, in a pressure-dominated sound field generated by submerged transducers of the type used in the construction of the BAFF system. The results clearly show that these fish are most sensitive to sounds in a frequency bandwidth of between 750 Hz and 1500 Hz, with higher thresholds below 300 Hz and above 2000 Hz.     

A comparison of complete mitochondrial genomes of silver carp Hypophthalmichthys molitrix and bighead carp Hypophthalmichthys nobilis: implications for their taxonomic relationship and phylogeny

Based upon morphological characters, Silver carp Hypophthalmichthys molitrix and bighead carp Hypophthalmichthys nobilis (or Aristichthys nobilis ) have been classified into either the same genus or two distinct genera. Consequently, the taxonomic relationship of the two species at the generic level remains equivocal. This issue is addressed by sequencing complete mitochondrial genomes of H. molitrix and H. nobilis , comparing their mitogenome organization, structure and sequence similarity, and conducting a comprehensive phylogenetic analysis of cyprinid species. As with other cyprinid fishes, the mitogenomes of the two species were structurally conserved, containing 37 genes including 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA (tRNAs) genes and a putative control region (D-loop). Sequence similarity between the two mitogenomes varied in different genes or regions, being highest in the tRNA genes (98·8%), lowest in the control region (89·4%) and intermediate in the protein-coding genes (94·2%). Analyses of the sequence comparison and phylogeny using concatenated protein sequences support the view that the two species belong to the genus Hypophthalmichthys . Further studies using nuclear markers and involving more closely related species, and the systematic combination of traditional biology and molecular biology are needed in order to confirm this conclusion.     

The inner ear morphology and hearing abilities of the Paddlefish (Polyodon spathula) and the Lake Sturgeon (Acipenser fulvescens)

Concern regarding the spread of silver carp (Hypopthalmichthys molitrix) and bighead carp (Aristichthysc nobilis) through the Illinois River has prompted the development of an Acoustic Fish Deterrent (AFD) system. The application of this technology has resulted in a need to understand the auditory physiology of fish other than the target species, in order to minimise the effect of the AFD barrier on the ecology of indigenous fish populations. To this end, both the structures involved in sound reception and the hearing abilities of the paddlefish (Polyodon spathula) and the lake sturgeon (Acipenser fulvescens) are studied here using a combination of morphological and physiological approaches, revealing that both fish are responsive to sounds ranging in frequency from 100 to 500 Hz. The lowest hearing thresholds from both species were acquired from frequencies in a bandwidth of between 200 and 300 Hz, with higher thresholds at 100 and 500 Hz. The rationale for studying hearing in P. spathula and A. fulvescens in particular, is the value placed on them by both the commercial caviar producing industry and by the recreational fisheries sector. The hearing abilities of twelve P. spathula and twelve A. fulvescens were tested in sound fields dominated by either sound pressure or particle motion, with the results showing that acipenseriform fish are responsive to the motion of water particles in a sound field, rather than the sound pressure component. In this study, we measure the intensity of the sound field required to evoke threshold responses using a pressure sensitive hydrophone, as pressure dominated sound fields are the most audible acoustic condition for specialists like H. molitrix and A. nobilis (the target species). The results of the auditory examination clearly show that P. spathula and A. fulvescens are not sensitive to sound pressure, and will therefore have a significantly higher deterrent threshold than H. molitrix and A. nobilis in a pressure dominated sound field.     

Zooplankton community dynamics along the bigheaded carp invasion front in the Upper Mississippi River

Hydrobiologia - Invasive Silver Hypophthalmichthys molitrix and Bighead Carp H. nobilis (collectively bigheaded carp) regularly alter zooplankton communities in lentic systems but dynamics in lotic...     

Comparative study on the gut microbiotas of four economically important Asian carp species

Gut microbiota of four economically important Asian carp species(silver carp, Hypophthalmichthys molitrix; bighead carp,Hypophthalmichthys nobilis; grass carp, Ctenopharyngodon idella; common carp, Cyprinus carpio) were compared using 16 S rRNA gene pyrosequencing. Analysis of more than 590,000 quality-filtered sequences obtained from the foregut, midgut and hindgut of these four carp species revealed high microbial diversity among the samples. The foregut samples of grass carp exhibited more than 1,600 operational taxonomy units(OTUs) and the highest alpha-diversity index, followed by the silver carp foregut and midgut. Proteobacteria, Firmicutes, Bacteroidetes and Fusobacteria were the predominant phyla regardless of fish species or gut type. Pairwise(weighted) UniFrac distance-based permutational multivariate analysis of variance with fish species as a factor produced significant association(P0.01). The gut microbiotas of all four carp species harbored saccharolytic or proteolytic microbes, likely in response to the differences in their feeding habits. In addition, extensive variations were also observed even within the same fish species. Our results indicate that the gut microbiotas of Asian carp depend on the exact species, even when the different species were cohabiting in the same environment. This study provides some new insights into developing commercial fish feeds and improving existing aquaculture strategies.     

Does aquatic invasive species removal benefit native fish? The response of gizzard shad (Dorosoma cepedianum) to commercial harvest of bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix)

Hydrobiologia - Bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix), collectively known as Asian carp, are planktivorous fishes that have invaded aquatic ecosystems throughout...     

微型生态系统中浮游动物正磷酸盐排泄率的估算

在考查罗非鱼或鲢、鳙下行影响的微型生态系统实验后期,对其唯一的浮游动物──大型的特定正磷酸盐(PO4-P)排泄率按不同大小级别和培育时间进行了测定,同时估算了该浮游动物种群的PO4-P排泄率。结果表明,大型的特定PO4-P排泄率依其体重的增长呈指数式下降,并且随着培育时间的增加而大大降低。有鱼系统中大型种群的PO4-P排泄率及其与浮游植物PO4-P摄取率的比值都显著地小于无鱼系统,而放养罗非鱼或鳙的系统之二项估算值又明显地比鲢单养系统低。看来,大型种群的磷排泄在鲢单养系统的PO4-P再生中起有一定的作用,而在放养罗非鱼或鳙的系统中所起的作用很小。       

Partial characterization of transferrins of catfish (Silurus glanis L.) and pike (Esox lucius L.)

Basic composition and properties of isolated transferrins of Silurus glanis and Esox lucius have been compared. In transferrin of S. glanis carbohydrate is absent, but it is present in transferrin of E. lucius (2.5%). The N-terminal amino acid is alanine in both species. Mol. wts are 68,400 (S. glanis) and 86,800 (E. lucius). Transferrins of the two species are heterogeneous, but genetic polymorphism was not observed.     

Richness and diversity of helminth parasite communities in the common carp and in three more recently introduced carp species

It can be predicted that common carp Cyprinus carpio , as an introduced species, would harbour poor helminth infra-communities but that these would nevertheless be richer than those in three other species of carps introduced into Europe in recent decades. These predictions were tested by comparing the helminth infra-communities of common carp, Ctenopharyngodon idella, Hypophthalmichthys molitrix and Aristichthys nobilis reared under similar conditions in a fish farm. Data were presented on species richness of total helminth infra-communities, and on richness and diversity of gill, eye and intestinal infra-communities separately. These confirmed that common carp helminth infra-communities were poor and that they were no richer than those of the three other species of carp. This situation in the farm was considered to be representative of the situation in natural habitats in Europe. It is suggested that the poor infra-communities in common carp reflect the facts that their helminth communities are composed mainly of specialists, that they are not readily susceptible to invasion by specialists of other fish hosts and that, as introduced species, they have not had sufficient time to acquire many generalist helminths from native species of fish. The difference in time between the introduction of common carp into Europe centuries ago and the introduction of the other three species of carps decades ago is not sufficient to produce any significant differences in the richness and diversity of their helminth infra-communities.     

Primate (Macaca fascicularis) transferrin: isolation and partial characterization

The serum transferrin from the primate, Macaca fascicularis is isolated by a purification protocol consisting of ammonium sulphate precipitation and column chromatography. The hexose (galactose + mannose) content of Macaca transferrin is 4.7 mole per mole of protein. Quantitative determination of the sialic acid content shows that there are two sialic acid residues per molecule of Macaca transferrin. This conclusion is supported by the neuraminidase treatment of Macaca transferrin, in which there is a 2-step decrease in electrophoretic mobility. Monoferric Macaca transferrins with Fe3+ selectively labelled at the C- and N-terminal sites (TfFec and FeNTf) are prepared at pH 5.5 and 8.5 using ferric dinitrilotriacetate [Fe(NTA)2] chelate and ferrous ammonium sulphate, respectively.     

Cloning and expression of a putative transferrin cDNA of the spruce budworm, Choristoneura fumiferana

A spruce budworm (Choristoneura fumiferana) transferrin cDNA (CfTf) was isolated and cloned from a cDNA library that was constructed using mRNA from fifth to sixth instar larvae. CfTf cDNA encoded a predicted protein of 681 amino acids with a molecular mass of approximately 76 kDa. CfTf shared 72% and 74% identities at the amino acid level with transferrins of Manduca sexta and Bombyx mori, respectively. Like other transferrins, CfTf retains most of the N-terminal, iron-binding amino acid residues. Northern blot analyses indicated that CfTf mRNA was present at high levels after ecdysis, but that the expression level was low prior to ecdysis at the fourth-sixth instar stages. The highest level of CfTf expression was detected in the fat body. Relatively low levels of expression were detected in the epidermis and no expression was found in the midgut. Expression of CfTf mRNA could be induced by bacteria but not fungi. Expression of CfTf mRNA was suppressed by iron load.