海南森林溪流淡水鱼类区系及动物地理初步研究

从海南岛森林溪流中采集到40种淡水鱼，分别隶属于5目15科34属。分布区系属东洋区、华南亚区的海南岛分区，分属5个区系复合体，其中热带平原鱼类复合体有23种，占57．5％，中印山区鱼类区系复合体10种，占25％。按鱼类分布水系进行了比较，提出了保护和利用该地区鱼类资源的建议。     

沁阳市鱼类资源调查

2016年4月鱼类资源调查队在沁阳市开展鱼类资源调查。根据沁阳市的水系分布特征,共设置18个样点。涵盖沁阳市主要河流,如沁河、潴龙河、蚰蜒河等河流,八一水库等水库。同时前往当地的农贸市场收集鱼类的样本。本次鱼类资源调查共得到鱼类标本30种,隶属于4目9科29属。其中种类最多的是鲤形目,占总数的76.67%;其次是鲈形目,占总数的13.33%;鲇形目有两种,占总数的6.67%;合鳃目一种,占总数的3.33%。根据整理的调查结果表明,沁阳市的鱼类资源丰富,鱼类在食性、生活栖息场所等方面表现出多种多样的特点。根据鱼类区系复合体学说,沁阳市的鱼类资源可以划分为:江河平原区系复合体、北方平原区系复合体、晚第三纪早期区系复合体、北方山地区系复合体、南方平原区系复合体,但江河平原区系复合体存在最多。     

海南森林溪流淡水鱼类区系及动物地理初报

从 1998年 5目至 2 0 0 1年 10月 ,在海南岛森林溪流中实际采集到 4 0种淡水鱼 ,分别隶属于 5目 15科34属 ,分属五个区系复合体 ,其中热带平原鱼类复合体有 2 3种 ,占 5 7 5 % ,中印山区鱼类区系复合体 10种 ,占 2 5 % ,分布于昌化江水系 2 3种 ,万泉河水系 2 9种 ,南渡江水系 2 0种 ,分别占总数的 5 7 5 %、 72 5 %、 5 0 %。     

唐河县鱼类资源调查

2016年11月,河南鱼类资源调查队开展了对唐河县主要的河流水库的调查工作。根据唐河县的水系分布特征,共设置24个采样点。涵盖唐河、泌阳河、桐河等河流及其支流,并且结合当地的农贸市场收集鱼类标本。本次共采集鱼类标本47种,隶属于6目12科40属。其中鲤形目最多,占总数的74.47%;其次是鲈形目,占总数的10.64%;鲇形目占总数的6.38%;合鳃目占总数的4.25%;鳉形目和鹤鱵目仅一种,占总数的2.13%。调查结果显示:唐河县的鱼类在摄食、繁殖、栖息等生活习性等诸多方面表现出多种多样的特点。根据鱼类区系复合体系学说,禹州市鱼类资源可划分为:江河平原区复合体系、北方平原区系复合体系、晚第三纪早期区系复合体系、南方平原区系复合体系。唐河县鱼类资源主要以江河平原区系复合体种类为主。     

黄河兰州市区段秋季鱼类资源现状调查

于2014年秋季在黄河兰州市区段设置7个采样断面对鱼类资源进行了调查。结果显示:调查的鱼类有13种,隶属于4目5科。其中鲤科鱼类占优势,有9种,占总种类数的69.23%。鲤科鱼类中鲦数量最多,占总渔获物数量的28.41%,鲤鱼的体重最大,平均为312g/尾,占总渔获物重量的83.78%。黄河兰州市区段鱼类区系具有5种区系复合体特征。本次调查结果表明黄河兰州市区段鱼类种类明显减少,渔获物中小型鱼类数量占很大优势。建议加大流域生态环境保护力度,适时进行经济鱼类的增殖放流。     

广东星湖鱼类区系及其特点

为了给星湖国家城市湿地公园水域科学管理提供依据，2006~2008年对星湖鱼类区系现状进行了系统调查。本调查在星湖5个湖区共设15个监测点，j进行了12次调查。结果：采集到鱼类45种，隶属于8目21科37属；其中鲤形目2科8亚科18属，19种，占星湖鱼种类的42%；其次是鲈形目7科7属，11种，占星湖鱼类种数的24%；土著鱼类32种，占星湖鱼类种数71%，外来物种13种，占星湖鱼类种数29%；星湖鱼类可分3种生态类型：洄游型鱼类3种、半洄游型13种、定居性型29种；地理区划为3个区系复合体：热带平原鱼类区系复合体、中国江河平原鱼类区系复合体、古代第3世纪鱼类区系复合体。星湖鱼类种群变化受制于人类的各项活动，主要经济鱼类为人工放养的奥利亚罗非鱼、尼罗罗非鱼、鳙、鲢，其中奥利亚罗非鱼、尼罗罗非鱼经过近10年自然繁殖，已发展为绝对优势种。     

广东星湖鱼类区系及其特点

为了给星湖国家城市湿地公园科学管理提供依据,2006～2008年对星湖鱼类区系现状进行了系统调查。在星湖5个湖区共设15个监测点,进行了12次调查。结果表明,有鱼类45种,隶属于8目、21科、37属;其中,鲤形目2科、8亚科、18属、19种,占星湖鱼种类的42%;其次是鲈形目7科、7属、11种,占星湖鱼类种数的24%;土著鱼类32种,占星湖鱼类种数的71%;外来物种13种,占星湖鱼类种数的29%。星湖鱼类可分3种生态类型,即洄游型鱼类3种、半洄游型13种、定居性型29种;地理区划为3个区系复合体,即热带平原鱼类区系复合体、中国江河平原鱼类区系复合体、古代第3世纪鱼类区系复合体。星湖鱼类种群变化受制于人类的各项活动,主要经济鱼类为人工放养的奥利亚罗非鱼、尼罗罗非鱼、鳙、鲢;其中奥利亚罗非鱼、尼罗罗非鱼经过近10年自然繁殖,已发展为绝对优势种。     

桐柏县鱼类资源调查

2016年11月,鱼类资源调查队对桐柏县主要的河流以及水库展开调查工作。根据桐柏县的水系分布特征,共设置了32个采样点。涵盖陈留店河、月河、淮河、三夹河、鸿雁河、鸿仪河等河流,以及二郎山水库、赵庄水库等,并且结合当地的农贸市场收集相关的鱼类标本。本次调查共采集鱼类样本41种,隶属于6目12科35属。其中鲤形目最多,占总数的70.73%;其次是鲈形目,占总数的9.75%;鲇形目占总数的7.32%;合鳃目和鳉形目各两种,各占总数的4.88%;鲑形目一种,占总数的2.44%。根据调查结果显示:桐柏县的鱼类在栖息、繁殖、生长习性等诸多方面,表现出了各种各样的特点。根据鱼类区系复合体系学说,桐柏县鱼类资源可以划分为:江河平原区系复合体、北方平原区系复合体、晚第三纪早期区系复合体、南方平原区系复合体。桐柏县鱼类资源主要以江河平原区系复合体为主。     

贵州都柳江的鱼类区系及动物地理区划

为了全面深入研究都柳江的鱼类区系并为开展其鱼类资源的保护与利用提供基础资料,通过2002年10月—2010年6月的野外调查,并结合文献资料整理出都柳江共分布有鱼类4目13科56属88种(亚种)。其中,四须盘鮈、粗唇鮠和月鳢等28种鱼类为本次调查都柳江鱼类的新记录,而横纹南鳅、短鳔盘鮈、云南盘鮈、棒花鱼、长脂拟鲿和黄等6种鱼类为柳江水系鱼类新记录。多鳞盘口鲮、中间爬岩鳅和麻鳜为都柳江鱼类特有种。都柳江鱼类区系以鲤形目鲤科为主。都柳江鱼类区系具有物种多样性丰富、富于特有种和受威胁种、缺乏裂腹鱼亚科和高原鳅属等高原鱼类、无洄游鱼类和洞穴鱼类等特点。都柳江鱼类区系起源于第三纪早期,并分别来源于老第三纪鱼类、中印山区鱼类、南方热带鱼类和中国江河平原鱼类等4种区系成分,都柳江鱼类区系属东洋区南东亚亚区华南小区。     

禹州市鱼类资源调查

2017年8月到9月在禹州市全境开展鱼类资源调查。根据禹州市的水系分布特征,共设置25个采样点。涵盖颍河、兰河、北汝河等淮河的一级及二级支流,纸坊水库等水库,并且结合当地的农贸市场收集鱼类样本。此次鱼类资源调查共得到鱼类样本32种,隶属于6目11科28属。其中种类最多的是鲤形目,占总数的68.75%;其次是鲈形目,占总数的12.5%;鲇形目和合鳃目各两种,各占总数的6.25%;鹤鱵目和鳉形目各一种,各占总数的3.125%。根据调查的结果显示,禹州市的鱼类资源较为丰富,鱼类在繁殖、摄食等方面呈现出多样化的特点。根据鱼类区系复合体学说,禹州市鱼类资源可以划分为:江河平原区系复合体;北方平原区系复合体;晚第三纪早期区系复合体;南方平原区系复合体。但北方平原区系复合体存在较少。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.     

Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845)

Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.     

Effects of cadmium on the kinetics of calcium uptake in developing tilapia larvae, Oreochromis mossambicus

The toxic effects of Cd²⁺ on Ca²⁺ influx kinetics in developing tilapia (Oreochromis mossambicus) larvae were evaluated. Addition of 20 µg l^-1 of Cd²⁺ to the environment of 0 and 3 day-old larvae competitively inhibited the Ca²⁺ uptake within 4h resulting in a great increase in K_m values for Ca²⁺ influx (19.3 and 17.4 fold, respectively) as compared with their respective controls. Consequently, the actual Ca²⁺ influx of larvae in solutions of 0.2 mM Ca²⁺ are suppressed by 32–45%. Also, 3 day-old larvae were more sensitive to internally accumulated Cd²⁺ than 0 day-old larvae. Although the Ca²⁺ influx in 0 and 3 day-old larvae may be restored to the levels of their respective controls with 24h of being transferred to a 20 µg l^-1 Cd²⁺ solution, total body Ca²⁺ content was significantly reduced in 3 day-old larvae. Increased Ca²⁺ uptake efficiency ensures sufficient Ca²⁺ for normal growth. However, rapid increase in Ca²⁺ influx after hatching also leads to higher Cd²⁺ uptake. Exposure to Cd²⁺ will lead to a drop in body Ca²⁺ content resulting in retardation of larval growth. Therefore, we conclude that if Ca²⁺ uptake is interfered with at this critical stage of development, larvae will not be able to maintain normal levels of body Ca²⁺ and will show signs of Cd²⁺ poisoning.     

Migratory dynamics of stream-spawning longnose gar (Lepisosteus osseus)

Abstract– Literature evidence suggests that lake-dwelling longnose gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose gar disperse from the spawning stream great distances, with gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.     

Nutritional regulation of hepatocyte fatty acid desaturation and polyunsaturated fatty acid composition in zebrafish (Danio rerio) and tilapia (Oreochromis niloticus)

The desaturation and elongation of [1-¹⁴C]18:3n-3 was investigated in hepatocytes of the tropical warm freshwater species, zebrafish (Danio rerio) and Nile tilapia (Oreochromis niloticus). The hepatocyte fatty acid desaturation/elongation pathway was assayed before and after the fish were fed two experimental diets, a control diet containing fish oil (FO) and a diet containing vegetable oil (VO; a blend of olive, linseed and high oleic acid sunflower oils) for 10 weeks. The VO diet was formulated to provide 1% each of 18:2n-6 and 18:3n-3, and so satisfy the possible EFA requirements of zebrafish and tilapia. At the end of the dietary trial, the lipid and fatty acid composition was determined in whole zebrafish, and liver, white muscle and brain of tilapia. Both zebrafish and tilapia expressed a hepatocyte fatty acid desaturation/elongation pattern consistent with them being freshwater and planktonivorous fish. The data also showed that hepatic fatty acid desaturation/elongation was nutritionally regulated with the activities being higher in fish fed the VO diet compared to fish fed the FO diet. In zebrafish, the main effect of the VO diet was increased fatty acid Δ6 desaturase activity resulting in the production of significantly more 18:4n-3 compared to fish fed the FO diet. In tilapia, all activities in the pathway were greater in fish fed the VO diet resulting in increased amounts of all fatty acids in the pathway, but primarily eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). However, the fatty acid compositional data indicated that despite increased activity, desaturation of 18:3n-3 was insufficient to maintain tissue proportions of EPA and DHA in fish fed the VO diet at the same level as in fish fed the FO diet. Practically, these results indicate that manipulation of tilapia diets in commercial culture in response to the declining global fish oil market would have important consequences for fish fatty acid composition and the health of consumers. Scientifically, zebrafish and tilapia, both the subject of active genome mapping projects, could be useful models for studies of lipid and fatty acid metabolism at a molecular biological and genetic level. This revised version was published online in August 2006 with corrections to the Cover Date.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.