Rotifer community structure and assessment of water quality in Yangcheng Lake

Rotifer community structure was investigated in Yangcheng Lake in 2008. Dominant species and species diversity indices were determined and QB/T was used to assess water quality. The annual average density and biomass of the rotifers in Yangcheng Lake was 2 894 ± 1 006 ind./L and 12.47 ± 10.28 mg/L, respectively. The highest densities were observed in the western portion of the lake in March, but the highest biomass occurred in inflowing creeks in September. Within a year of monitoring in Yangcheng Lake, 93 species were identified and the dominant species were found to be Polyarthra trigla, Brachionus angularis, Keratella cochlearis, Keratella valga, Brachionus calyciflorus, and Filinia major. Of the species recorded, 75 were pollution indicator species. Density and biomass exhibited significant positive correlations with water temperature (R = 0.209, P = 0.003; R = 0.446, P = 0.000), but the peak density showed two lags in response to chl a. According to the Jaccard similarity index (SJ), the greatest similarity among dominant species occurred between creeks and the eastern part of the lake. The annual average Shannon-Wiener diversity index H’, Margalef richness index D and Pielou evenness index J were 1.96 ± 0.34, 1.61 ± 0.50 and 0.77 ± 0.10, respectively. In all four areas of Yangcheng Lake, β- mesosaprobic species comprised the largest share of pollution indicator species. These data suggest that Yangcheng Lake is mesosaprobic.     

Phytoplankton Assemblage of Yangtze River Estuary and the Adjacent East China Sea in Summer, 2004

A cruise was conducted from late August to early September 2004 with the intention of obtaining an interdisciplinary understanding of the Yangtze River Estuary including the biological, chemical and physical subjects. Water sample analysis indicated that total phytoplankton species richness was 137. Of them 81 were found in Bacillariophyta and 48 in Pyrrophyta, accounting for 59.1% and 35.0% respectively. The average cell abundance of surface water samples was 8.8×104 cells L-1, with the maximum, 102.9×104 cells L-1, encountered in the area (31.75°N, 122.33°E) and the minimum, 0.2×104 cells L-1, in (30.75°N, 122.17°E). The dominant species at most stations were Skeletonema costatum and Proboscia alata f. gracillima with the dominance of 0.35 and 0.27. Vertical distribution analysis indicated that obvious stratification of cell abundance and dominant species was found in the representative stations of 5, 18 and 33. Shannon-Wiener index and evenness of phytoplankton assemblage presented negative correlation with the cell abundance, with the optimum appearing in (30.75°N, 122.67°E). According to the PCA analysis of the environmental variables, elevated nutrients of nitrate, silicate and phosphate through river discharge were mainly responsible for the phytoplankton bloom in this area.     

Winter Phytoplankton Assemblages of Coastal Yellow Sea Connected to Jiaozhou Bay,China

I Introduction Phytoplankton play an important role in the primary production of ocean (Ning et al., 1995). They are impor-tant biological mediators of carbon turnover in seawater ecosystems (Zhu et al., 1993). Phytoplankton in Jiaozhou Bay have been preliminarily studied on the subjects of community structure, primary productivity and carbon budget (Qian et al., 1983; Guo et al., 1992; Jiao et al., 1994). It has been found that seasonal variation of phytoplankton cell abundance presents w…     

中街山水域虾类组成及其群落多样性

根据2010~2011年中街山列岛水域4个季节的渔业资源调查资料,分析了该水域虾类资源密度和群落多样性,并探讨了底层温度、底层盐度和水深对虾类数量分布和多样性的影响.结果表明:共有虾类20种,隶属于9科18属;广温广盐种无论在种类数还是尾数密度与生物量均占主导地位;虾类生物量和尾数密度在季节分布上,以冬季最高,冬季均与春、夏和秋三季呈显著差异(p值<0.05);平面分布上,生物量与密度指数总体上呈南北高、中间低,东部高西部低的特征;生物量与平均底温显著相关(P<0.05),与平均底盐和水深相关性较差(p值>0.05);葛氏长臂虾、细巧仿对虾、中国毛虾、日本鼓虾和中华管鞭虾为四季的优势种,且均属广温广盐种;虾类群落Margalef丰富度指数为0.61~1.09,Shannon-Wiener多样性指数为0.76~1.31,Pielou均匀度指数为0.50~0.70,其中丰富度指数和多样性指数春季与冬季均存在显著差异(P<0.05),均匀度指数秋季与冬季存在显著差异(p值<0.05).     

Spatio-temporal variability of small fishes related with environmental factors in a typical domestic tap water lake,Eastern China

The knowledge of prey small fish stock, distribution and abundance is necessary to guide stocking of piscivorous fish for the biomanipulation in domestic tap water lakes. This study describes the current status of small fish community in Lake Kuilei (China), and examines the spatial and seasonal variations of the community in relation to key environmental factors. Based on submerged macrophyte cover and water depth, the lake was divided into five major habitats: (1) macrophyte covered shallow habitat of water depth < 2.00 m, (2) uncovered or less-covered shallow habitat (2.00 m–3.50 m), (3) uncovered medium shallow habitat (3.50 m–5.00 m), (4) uncovered medium deep habitat (5.00 m–6.50 m) and (5) uncovered deep habitat (6.50 m–8.50 m). The abundance and composition of small fish were monitored by benthic fykenet sampling from April 2013 to January 2014. A total of 2881 individuals belonging to 5 families and 21 species were collected. Based on their abundance (accounted for 88.96% of the total) and occurrence (more than 33.33%), Acheilognathus chankaensis, Acheilognathus macropterus, Microphysogobio microstomus, Pseudorasbora parva and Rhinogobius giurinus were recognized as dominant small fish species. The results of correlation analysis identified that species richness ( Sr ), Shannon-Wiener diversity index ( H′ ) and Margalef′s richness index ( D ) were significantly negatively correlated with water depth, but positively correlated with biomass of submerged macrophytes.Redundancy analysis (RDA) revealed that the spatial distributions of most small fishes were negatively associated with water depth. The details of these findings are beneficial to understanding the adaptation of the small fishes in degraded environments, and to developing suitable biomanipulation strategies for the management of fish resources and water quality in the lakes along the lower reach of the Changjiang (Yangtze) River basin.

     

Optimal salinity for dominant copepods in the East China Sea, determined using a yield density model

From 1997 to 2000, four field surveys were conducted in the East China Sea (ECS) (23°30′–33°00′N, 118°30′–128°00′E). A field data yield density model was used to determine the optimal salinities for 19 dominant copepod species to establish the relationship between surface salinities and abundance of those species. In addition, ecological groups of the copepods were classified based on optimal salinity and geographical distribution. The results indicate that the yield density model is suitable for determining the relationship between salinity and abundance. Cosmocalanus darwini, Euchaeta rimana, Pleuromamma gracilis, Rhincalanus cornutus, Scolecithrix danae and Pareucalanus attenuatus were determined as oceanic species, with optimal salinities of >34.0. They were stenohaline and mainly distributed in waters influenced by the Kuroshio or Taiwan warm current. Temora discaudata, T. stylifera and Canthocalanus pauper were nearshore species with optimal salinities of <33.0 and most abundant in coastal waters. The remaining 10 species, including Undinula vulgaris and Subeucalanus subcrassus, were offshore species, with optimal salinity ranging from 33.0–34.0. They were widely distributed in nearshore, offshore and oceanic waters but mainly in the mixed water of the ECS.     

Amino acid composition and functional properties of giant red sea cucumber (Parastichopus californicus) collagen hydrolysates

Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species.The degree of hydrolysis (DH),amino acid composition,SDS-PAGE,emulsion activity index (EAI),emulsion stability index (ESI),foam expansion (FE),and foam stability (FS) of hydrolysates were investigated.The effects of pH on the EAI,ESI FE and FS of hydrolysates were also inves-tigated.The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 50℃ with an En-zyme/Substrate (E/S) ration of 1:20 (w:w).The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin.The hydrolysates had a molecular weight distribution of 1.1 17 kDa,and were abundant in glycine (Gly),proline (Pro),glutamic acid (Glu),alanine (Ala) and hydroxyproline (Hyp) residues.The hydrolysates were fractionated into three fractions (< 3 kDa,3 10 kDa,and > 10 kDa),and the fraction of 3 10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05).The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05).The pH had an important effect on the EAI,ESI,FE and FS.All the fractions showed undesirable emulsion and forming properties at pH 4.0.Under pH 7.0 and pH 10.0,the 3 10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value,respectively.They are hoped to be utilized as functional ingredients in food and nutraceutical industries.     

Current Vegetation Pattern along Glacial Landscape in Central （Garhwal） Himalaya, India

Introduction High mountain ecosystems are comparatively thrilling and sensitive at least at the upper elevation levels, and are determined by abiotic climate related ecological factors. Therefore, the ecosystems at the low temperature limits of plant life are generally considered to be particularly sensitive to climate changes (Koerner 1999). As temperature is a key factor for high mountain plants (Koerner and Larcher 1988, Gottfried et al. 1998), an upward migration of species must be conse…     

Effects of rearing temperature and density on growth, survival and development of sea cucumber larvae, Apostichopus japonicus (Selenka)

In laboratory conditions, effects of rearing temperature and stocking density were examined on hatching of fertilized egg and growth of auricularia larvae of Apostichopus japonicus respectively. Data series like larval length and density, metamorphic time, and survival rate of the larvae were recorded. Statistics showed that for A. japonicus, survival rate (from fertilized egg to late auricularia) decreased significantly with the increasing rearing temperature (P<0.05). At different temperatures SGR was statistically significant as well (P<0.05) from day 1, and maximal SGR was found on day 9 at 24°C (159.26±3.28). This study clearly indicated that at low temperature (<24°C), metamorphic rate was remarkably higher than at higher temperature (>26°C). Hatching rate was significantly different between 0.2–5 ind./ml groups and 20–50 ind./ml groups. Rearing larvae at the higher density had the smaller maximal-length, whereas needed longer time to complete metamorphosis. This study suggested that 21°C and 0.4 ind./ml can be used as the most suitable rearing temperature and stocking density for large -scale artificial breeding of A. japonicus’s larvae.     

Study on the dominant species of Pteropoda in East China Sea

1 INTRODUCTION Pteropoda is a group of marine pelagic mol- lusks, which belongs to Opisthobranchia of Gastro- poda. Although Pteropoda is not a major group in pelagic zooplankton in terms of abundance and number of species, their ecological characters are…     

Comparative study on the protease inhibitors from fish eggs

The protease inhibitor was purified from five different fish eggs. The molecular weights of Pacific herring, chum salmon, pond smelt, glassfish, and Alaska pollock egg protease inhibitors were 120, 89, 84.5, 17, and 16.8kDa, respectively. The specific inhibitory activity of glassfish egg protease inhibitor was the highest followed by those of Pacific herring and Alaska pollock in order. The specific inhibitory activity and purity of glassfish egg protease inhibitor were 19.70 U mg^- 1 protein and 164.70 folds of purification, respectively. Glassfish egg protease inhibitor was reasonably stable at 50 - 65℃ and pH 8, which was more stable at high temperature and pH than protease inhibitors from the other fish species. Glassfish egg protease inhibitor was noncompetitive with inhibitor constant （Ki） of 4.44 nmol L^-1     

RELATION OF BODY WEIGHT AND FOOD CONSUMPTION TO METABOLIC RATE OF JUVENILE JAPANESE SEA BASS, LATEOLABRAX JAPONICUS

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＪａｐａｎｅｓｅｓｅａｂａｓｓ (ＬａｔｅｏｌａｂｒａｘｊａｐｏｎｉｃｕｓＣ＆Ｖ)ｄｉｓｔｒｉｂｕｔｅｓｗｉｄｅｌｙｉｎｔｈｅｃｏａｓｔａｌｗａｔｅｒｓａｌｏｎｇｔｈｅＢｏｈａｉＳｅａ ,ＹｅｌｌｏｗＳｅａ ,ＥａｓｔＣｈｉｎａＳｅａ,ａｎｄＳｏｕｔｈＣｈｉｎａＳｅａ .Ａｓａｃａｒｎｉｖｏｒｏｕｓｆｉｓｈ ,ｉｔｏｃｃｕｐｉｅｓｔｈｅｈｉｇｈｔｒｏｐｈｉｃｌｅｖｅｌｉｎｔｈｅｍａｒｉｎｅｅｃｏｓｙｓｔｅｍａｎｄｈａｓａｄａｐｔｅｄｔｏｖａｒｉｏｕｓｅｎｖｉｒｏｎｍｅｎｔａｌｒ…     

Population parameters and dynamic pool models of commercial fishes in the Beibu Gulf, northern South China Sea

Length-frequency data of eight commercial fish species in the Beibu Gulf (Golf of Tonkin), northern South China Sea, were collected during 2006-2007. Length-weight relationships and growth and mortality parameters were analyzed using FiSAT II software. Five species had isometric growth, two species had negative allometric growth, and one species had positive allometric growth. Overall, the exploitation rates of the eight species were lower in 2006-2007 than in 1997-1999: for four species (Saurida tumbil, Saurida undosquamis, Argyrosomus macrocephalus, and Nemipterus virgatus) it was lower in 2006-2007 than in 1997-1999, for two species (Parargyrops edita and Trichiurus haumela) it remained the same, and for the other two species (Trachurus japonicus and Decapterus maruadsi) it was higher in 2006-2007 than in 1997-1999. The exploitation rates might have declined because of the decline in fishing intensity caused by high crude oil prices. The optimum exploitation rate, estimated using Beverton-Holt dynamic pool models, indicated that although fishes in the Beibu Gulf could sustain high exploitation rates, the under-size fishes at first capture resulted in low yields. To increase the yield per recruitment, it is more effective to increase the size at first capture than to control fishing effort.     

东海中部夏季鱼类群落结构及其多样性分析

根据2008年8月东海区主要渔场重要渔业资源调查资料,分析东海中部鱼类的种类组成、区系特征、多样性等群落结构特征。结果表明:共调查捕获鱼类88种,其中暖水种59种,占67.0%;暖温种29种,占33.0%。相对重要性指数(IRI)值大于500的优势种鱼类共有5种,分别为带鱼、刺鲳、小黄鱼、六斑刺鲀和鳄齿鱼;种类丰富度指数变动范围为0.10～2.31,平均为0.88;Shannon-Wiener多样度指数变动范围为0.01～1.86,平均为0.87;种类均匀度指数变动范围为0.01～0.92,平均为0.41;东海中部夏季鱼类多样性指数与往年相比有下降的趋势。     

PROFESSOR ZHU KEZHEN OPENING UP A PATH FOR RESEARCH ON CLIMATIC CHANGE IN CHINA

ＰＲＯＦＥＳＳＯＲ ＺＨＵ ＫＥＺＨＥＮ ＯＰＥＮＩＮＧ ＵＰ Ａ ＰＡＴＨ ＦＯＲ ＲＥＳＥＡＲＣＨ ＯＮ ＣＬＩＭＡＴＩＣ ＣＨＡＮＧＥ ＩＮ ＣＨＩＮＡ ＳｈｉＹａｆｅｎｇ（施雅风）（ＬａｎｚｈｏｕＩｎｓｔｉｔｕｔｅｏｆＧｌａｃｉｏｌｏｇｙａｎ...     

ORGANIC GEOCHEMISTRY MARKERSOF CLIMATIC EVOLUTION IN LOESSREGION OF CHINA

Two hundred and thirty-five samples collected from Weinan loess section (L₂ – S₀) have been analyzed by TOC (total organic carbon) and pyrolysis hydrocarbons. The curve of TOC with depth has been set up and compared well with other climatic markers. The main periods of TOC variation of the last 0.14 Ma are 67.08 ka and 18.29 ka, which is near with the periods of the variation of sunshine, showing that the TOC variation may be controlled by the variation of 65°N sun-shine. The distribution of pyrolysis hydrocarbon and its parameters shows that there are two kinds of hydrocarbon associated with climatic change. One is called hydrocarbon pyrolysted directly from organism (pHC_2–1) which is in the range of T _max350°C – 500°C, and associated with atmospheric water. The other is called carbonate inclusion hydrocarbon (pHC_2–2) which is in the range of T _max 500°C – 600°C and formed by evaporation and associated with dry climate. The formula calculating humidity has been deduced Og=pHC_2–1/(pHC_2–1 + pHC_2–2). The range of humidity of the section is 47% – 77% and the reducing order is S_1–3, S_1–2, S₀, S_1–1, S_1–4, S_1–1, L_1–1, L_1–3, and L_1–5. And the trend of the humidity is still increasing today.     

Oxygen consumption and ammonia-N excretion of Meretrix meretrix in different temperature and salinity

Effects of temperatures and salinities on oxygen consumption and ammonia-N excretion rate of clamMeretrix meretrix were studied in laboratory from Oct. 2003 to Jan. 2004. Two schemes were designed in incremented temperature at 10, 15, 20, 25°C at 31.5 salinity and in incremented salinity at 16.0, 21.0, 26.0, 31.5, 36.0, and 41.0 at 20°C, all for 8–10 days. From 10 to 25°C, both respiration and excretion rate were increased. One-way ANOVA analysis demonstrated significant difference (P<0.01) in physiological parameters in this temperature range except between 15 and 20°C. The highestQ ₁₀ thermal coefficient value (12.27) was acquired between 10 and 15°C, and about 1 between 15 and 20°C, indicatingM. meretrix could well acclimate to temperature changes in this range. Salinity also had significant effects on respiration and excretion rate (P<0.05). The highest values of respiration and excretion rate ofM. meretrix were recorded at 16.0 salinity (20°C). These two physiological parameters decreased as salinity increased until reached the minimumQ ₁₀ value at 31.5 (20°C), then again, these parameters increased with increasing salinity from 31.5 to 41.0.M. meretrix can catabolize body protein to cope with osmotic pressure stress when environmental salinity is away from its optimal range. No significant difference was observed between 26.0 and 36.0 in salinity (P>0.05), suggesting that a best metabolic salinity range for this species is between 26.0 and 36.0. This work is supported by National High-Tech R & D Program of China. (863 Program) (2002AA603014).     

Studies on the eggs and larvae,ofSardinella aurita (Cuv. & Val.) in the fishing grounds of Southern Fujian and the Taiwan Bank

In this paper, the morphological characters of eggs and larvae ofSardinella aurita (Cuvier & Valenciennes), its spawning ground, spawning seasons and spawning conditions have been studied. Sardinella aurita likes to breed in the upwelling area and selects the Waixie fishing ground as its main spawning ground. The months from February to September are its spawning seasons, reaching its peak in April. In the main spawning ground, the temperature of the surface layer was found to be 24.4–25.2°C, the salinity 33.87–34.07%. and the depth of water between 34–60m. The distribution of the larvae is closely related to the distribution of plankton, the path of migration of adult fish, and the current direction of the water system. In order to protect fishery resources, it is necessary to prohibit catching the spawning fish in the Waixie fishing ground in April, and the catching of immatures from March to June. This paper was published in Chinese inOcean. Limn. Sinica 14(3): 240–248, 1983.     

Physiological responses of Chinese longsnout catfish to water temperature

We evaluated the effect of water temperature on the growth and physiology of the Chinese longsnout catfish (Leiocassis longirostris Günther). The fish were reared at four temperatures (20, 25, 30, and 35°C) and sampled on days 7, 20, and 30. We measured plasma levels of insulin, free thyroxine (FT4), free 3,5,3′-triiodothyronine (FT3), lysozyme and leukocyte phagocytic activity. The optimum water temperature for growth was 27.7°C. The plasma levels of insulin and FT4 declined significantly (P<0.05) on day 30 at temperatures above 20°C. Lysozyme activity was significantly (P<0.05) lower at 25°C than at other temperatures. We conclude that final weight, insulin, FT4, and lysozyme were significantly affected by water temperature.     

A study on the meat and bone meal and poultry by-product meal as protein substitutes of fish meal in practical diets for Litopenaeus vannamei juveniles

A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients (ADC) of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences (Pτ;0.05) in growth performance and ADC among the treatments fed with the diets in which 0–60% fish meal had been replaced with MBM, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences (Pτ;0.05) in growth performance and ADC among all the treatments fed with the diets in which 0–80% fish meal had been replaced with PBM.