鳜鱼人工繁殖的生态生理学特性

在鱖鱼(Siniperca chuatsi)苗种培育过程中,适时投喂适口饵料鱼是成功的关键。要掌握好鳜鱼人工养殖期中的不同水温,催情剂组合与效应时间、胚胎发育时间、胚后內源性营养期之间的关系,才能有效地制订鳜鱼和饵料鱼催产的计划,使鳜鱼苗适时地获得适口饵料。       

仿刺参在海南地区的苗种培育与养成

为了解海南地区进行仿刺参养殖的可行性,在海南琼海进行了仿刺参苗种中间培育、养成和度夏研究。苗种中间培育时,不同规格仿刺参的生长速度均较快,绝对生长率呈逐渐增加趋势,规格越大绝对生长率越高,但是苗种规格越大个体增重率越小,最小增重率为(317.88±73.2)%;苗种规格越大成活率越高,成活率变动范围为(39.3±4.8)%~(53.7±8.7)%。经过105 d养成后,投喂天然饵料的仿刺参大约是投喂人工饵料刺参的3倍体重,而投喂两种饵料的仿刺参成活率约为60%、彼此间没有显著差异;投喂人工饵料仿刺参的绝对生长率基本恒定,而投喂天然饵料的仿刺参绝对生长率呈现迅速增加的趋势,而且后者至少是前者的2.32倍。度夏结束时仿刺参平均体重均显著下降,至少减少了56.23%;仿刺参度夏时成活率最高仅为(46.4±3.4)%,而且仿刺参室内度夏的成活率明显高于室外度夏仿刺参,大规格仿刺参的成活率略高于小规格仿刺参。因此,在海南地区适宜的季节可以进行南北接力养殖仿刺参。     

稻虾田黄鳝的食物组成及其对克氏原螯虾捕食强度研究

文章研究了稻田黄鳝(Monopterus albus)天然饵料生物资源、稻田黄鳝对克氏原螯虾(Procambarus clarkii)捕食选择及不同投喂策略下黄鳝对克氏原螯虾的捕食强度,旨在为构建与优化稻-虾-鳝综合种养模式提供依据。结果表明,稻田中黄鳝天然饵料生物种类丰富,达16种(属);克氏原螯虾是黄鳝最喜猎物,其次为米虾,再次为蚯蚓和水生寡毛类;稻田黄鳝自然生长期间,其胃和肠前端食物团中,克氏原螯虾重量百分比均显著高于其他猎物,其中8月份占比最大,达93.90%, 4月份占比最小,为76.85%;当克氏原螯虾为唯一食物时,每尾大规格成鳝(≥200 g)日均捕食量为(1.63±0.065) g;当克氏原螯虾、米虾和蚯蚓作为食物时,黄鳝主要捕食克氏原螯虾且不捕食蚯蚓,对三者的选择指数分别为0.066、–0.266和–1;若以克氏原螯虾、鱼糜-饲料为食物时,黄鳝主要摄食鱼糜-饲料,极少捕食克氏原螯虾,对两者的选择指数分别为–0.846和0.591。     

不同饵料对大口黑鲈生长性能和肠道微生物的影响

以冰鲜鱼、配合饲料和混合投喂3种饵料, 研究其对大口黑鲈(Micropterus salmoides)生长性能和肠道微生物的影响。结果表明, 在生长性能方面, 配合饲料组试验鱼的末均重、体长、增重率和特定生长率均显著低于冰鲜鱼组和混合投喂组(P<0.05), 混合投喂组最后养成规格最大, 生长速度也最快, 但与冰鲜鱼组差异不显著(P>0.05)。在肠道微生物群落的丰富度与多样性方面, 配合饲料投喂组丰富度最高, 冰鲜鱼组最低, 但冰鲜鱼组多样性最高, 配合饲料投喂组次之, 混合投喂组最低。在门级水平上, 厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)、蓝藻门(Cyanobacteria)、拟杆菌门(Bacteroidota)、浮霉菌门(Planctomycetota)、绿弯菌门(Chloroflexi)和酸杆菌门(Acidobacteriota)是大口黑鲈肠道优势菌群。属级水平上, 冰鲜鱼组的优势菌属主要为支原体属(Mycoplasma)、克雷伯氏菌属(Klebsiella)及聚球菌属(Synechococcus_CC9902); 配合饲料组优势菌属为克雷伯氏菌属(Klebsiella)、罗姆布茨菌(Romboutsia)及分枝杆菌属(Mycobacterium); 混合投喂组优势菌属则是支原体属(Mycoplasma)、厌氧氨氧化菌(Candidatus_Brocadia)及罗姆布茨菌(Romboutsia)。功能预测表明, 配合饲料投喂组大口黑鲈肠道菌群在“能量生产与转化”“碳水化合物运输和代谢”“氨基酸转运与代谢”和“脂质转运与代谢”等功能类群的相对丰度最高, 而冰鲜鱼组肠道菌群在“核苷酸的转运和代谢”“辅酶运输和代谢和翻译”“核糖体结构和生物发生”等功能类群的相对丰度占优。饵料对大口黑鲈的生长、肠道菌群组成和功能都具有显著的影响。研究为大口黑鲈的配合饲料开发和健康养殖提供了理论依据。     

养殖水环境对中华绒螯蟹不同营养供给模式的响应

以初始体重为（9.67&#177;0.47）g/只的二龄中华绒螯蟹为实验对象,采用正交设计法L9（34）将水体水草覆盖率、活螺蛳投放量、饵料中动物性饵料比例、投饵方式等4个因子设计成9种营养供给模式,每个模式设3个重复,在东太湖围养区27个独立网围（6m&#215;5m&#215;2.5m,20只蟹/格）中进行为期240d的养殖实验,对各网围养殖水体的水化学指标、浮游生物动态变化进行比较研究。结果表明,在中华绒螯蟹放养密度相同的条件下,不同的营养供给模式显著影响养殖水体水质和浮游生物多样性,其中模式4（水草覆盖率为70%,螺蛳投放量为4500kg/ha,动物性饵料比例为50%,投饵方式为全程投喂,其中5月底前为7.5%,6月开始为5%）的养殖水体中的DO、CODC r、TP、TN、NH4＋-N、NO2--N等水质指标值均优于国家地表水环境质量标准（GB3838-2002）的Ⅲ类水水质标准,也显著优于网围外非养殖区（航道）的水质。浮游生物“指示群落”和“马加利夫多样性指数”分析结果也显示,模式4的水体生物多样性显著高于非养殖区,水质属于寡污型。方差分析结果显示,4个因子对水质影响作用的顺序为：水草覆盖率〉投饵方式〉螺蛳投放量〉动物性饵料比例;将4个因子与主要水质指标CODC r、TP、TN、Chla、浮游生物多样性指数等参数进行回归分析,表明水体水草覆盖率、投饵方式等因子与这些参数关系密切,筛选出有益于湖泊生态保护的中华绒螯蟹养殖的适宜营养供给模式：水草覆盖率为66%—76%、投饵方式为全程投喂7.5%—5.0%、螺蛳投放量为9000kg/ha、动物性饵料比例为50%。     

基于生物能量学模型的尖吻鲈精准投喂管理辅助决策系统构建

为提高养殖管理的信息化、智能化水平, 研究基于生物能量学原理和生产养殖数据构建了精养条件下尖吻鲈(Lates calcarifer)精准投喂管理模型, 并通过软件开发, 构建了方便使用的精准投喂管理辅助决策系统。该系统主要功能为可预测尖吻鲈生长周期中任一时间点的生长、任一生长点的饲料需求量及养殖周期对水体排放的氮磷次生污染。结果显示, 通过建模和分析, 发现尖吻鲈在其生长过程中含有1个异速生长点, 由此将尖吻鲈的生长周期分为2个生长期: <296 g(第一生长期)和>296 g(第二生长期); 在尖吻鲈的两个生长期中, 相比于特定增长率、日均增重和日增长系数等生长模型, 优化后的热积温系数模型对尖吻鲈的生长预测效果更佳; 采用实际蛋白含量分别为44.4%和42.6%的商业饲料投喂不同生长时期的尖吻鲈, 每生产1000 kg尖吻鲈(体重为1—1000 g), 所需要的消化能约为2.33×107 kJ, 所排放的总固态污染物约为543 kg; 验证实验中尖吻鲈体重的模型预测值与实际观测值之间显著相关, 饲料系数(FCR)模型观测值大于实际预测值。以上结果表明, 实验中构建的精准投喂管理模型可以有效地估计养殖中鱼体生长情况和饲料需求, 但由于实际养殖中饲料投喂多为过量投喂, 可能导致实际投喂量大于养殖需求量, 进而导致污染排放量的增加。研究中开发的精准投喂管理辅助决策系统软件, 为养殖投喂管理精准化和信息化奠定了一定的理论和技术基础。     

不同饵料养殖黄喉拟水龟效果的研究

用5种不同的饵料(中华鳖配合饲料、蚯蚓、鲢鱼肉、福寿螺肉和河蚌肉)分别投喂黄喉拟水龟幼龟,结果表明,①投喂中华鳖配合饲料的黄喉拟水龟,其增重速度最快,平均日增重和蛋白质效率都最高,且耗料增重比最低,其后依次是: 蚯蚓＞鲢鱼肉＞福寿螺肉＞河蚌肉.②投喂福寿螺肉的黄喉拟水龟,其饵料成本最低,其后依次是: 中华鳖配合饲料＞蚯蚓＞河蚌肉＞鲢鱼肉.③中华鳖配合饲料是养殖黄喉拟水龟较好的饵料,但福寿螺、蚯蚓来源方便,也不失为养殖黄喉拟水龟的好饵料.     

蚯蚓对瓦氏黄颡鱼摄食达氏鳇卵的干扰实验

自然水域中中华鲟(Acipenser sinensis)卵常受到敌害鱼类捕食的威胁,瓦氏黄颡鱼Pelteobagrus vachelli(Richerdson)是中华鲟卵的重要敌害鱼类。以中华鲟卵的敌害鱼类瓦氏黄颡鱼为研究对象,选择环毛蚓(Pheretima tschiliensis)为瓦氏黄颡鱼的饵料,以达氏鳇卵(Kalugasturgeon)替代中华鲟卵进行室内实验,通过研究适合瓦氏黄颡鱼摄食的环毛蚓规格,以及环毛蚓干扰瓦氏黄颡鱼摄食达氏鳇卵投放比例,探讨中华鲟卵的保护方法。在水温为(20.0±1.5)℃的条件下,研究了3种不同体长规格[体长(15.3±1.4)cm、(12.0±2.1)cm、(7.7±0.5)cm]实验鱼个体分别摄食3种不同体长规格环毛蚓(体高为0.3cm,体长分别为8、4、2cm)和达氏鳇卵的摄食率;研究了体长为4cm的环毛蚓对3种不同体长实验鱼摄食达氏鳇卵的干扰效果。实验结果表明:3种体长规格瓦氏黄颡鱼均摄食达氏鳇卵;3种体长规格瓦氏黄颡鱼共同摄食的替代饵料规格为体长4cm及以下的环毛蚓;适宜干扰实验所选体长实验鱼摄食达氏鳇卵的饵料为体长4 cm的环毛蚓;当环毛蚓与达氏鳇卵数量比例为1∶1时,可实现达氏鳇卵的保护。研究证明在实验条件下可实现环毛蚓对中华鲟卵敌害鱼类——瓦氏黄颡鱼实施摄食干扰,提示下一步可以尝试选择环毛蚓作为替代中华鲟卵的饵料,进行干扰食卵鱼类摄食中华鲟卵的野外验证试验。     

几种氨基酸及香味物质对黄鳝诱食活性的初步研究

目前黄鳝(Monopterus albus)养殖在我国发展较快,但取得成功的养殖者主要靠投喂动物饵料,而动物饵料的资源有限,限制了黄鳝养殖的发展。黄鳝的规模化养殖生产必须走投喂配合饲料的道路。从配合饲料养殖黄鳝的试验看,存在着黄鳝对配合饲料喜食性差、利用率低等问题,还不能应用于大规模的生产。如何解决黄鳝对配合饲料喜食性差的问题成为攻克其配合饲料难关的关键。为此,开展了用氨基酸和香味物质对黄鳝诱食的研究,并取得了一定的效果,现将试验结果报道如下.       

蛋白质限制后恢复投喂对牙鲆幼鱼生长的影响

2004年4月4日~5月22日,在(23.0±0.5)℃条件下研究了牙鲆(平均体重,(8.80±0.18)g)继蛋白质限制后恢复投喂对其生长的影响。整个实验期间对照组(C组)连续48d饱食投喂含能17.29kJ/g,含粗蛋白50.00%的饵料。蛋白质限制阶段(1~18d)处理组T30和T40的饵料蛋白含量分别为27.95%和40.47%,但饵料含能与对照组相同,在恢复投喂阶段(19~48d)各处理组均投喂与对照组相同的饵料。实验结果表明,在蛋白质限制阶段,饵料蛋白质水平下降显著降低了处理组鱼的体重、特定生长率、饵料湿重、干重以及能量转化率(p<0.05),而摄食率、蛋白质效率和饵料蛋白质转化率随饵料蛋白水平降低而显著升高(p<0.05)。恢复投喂结束后,处理组上述各指标均恢复至对照组水平(p>0.05)。此外,除实验结束时T30组鱼体脂肪含量显著低于对照组(p<0.05)外,整个实验期间各处理组的表观消化率及鱼体成分与对照组相比均无显著差异(p>0.05)。实验结果表明,牙鲆幼鱼继蛋白质限制后的恢复投喂阶段出现了完全补偿生长效应。     

Gape-limitation,foraging tactics and prey size selectivity of two microcarnivorous species of fish

Summary Patterns of prey size selectivity were quantified in the field for two species of marine microcarnivorous fish, Embiotoca jacksoni and Embiotoca lateralis (Embiotocidae) to test Scott and Murdoch's (1983) size spectrum hypothesis. Two mechanisms accounted for observed selectivity: the relative size of a fish in relation to its prey, and the type of foraging behavior used. Juvenile E. jacksoni were gape limited and newborn individuals achieved highest selectivity for the smallest prey size by using a visual picking foraging strategy. As young E. jacksoni grew, highest preference shifted to the next larger prey sizes. When E. jacksoni reached adulthood, the principal mode of foraging changed from visual picking to relatively indiscriminant winnowing behavior. The shift in foraging behavior by adults was accompanied by a decline in overall preference for prey size; sizes were taken nearly in proportion to their relative abundance. Adult E. lateralis retained a visual picking strategy and achieved highest selectivity for the largest class of prey. These differences in selectivity patterns by adult fish were not explained by gape-limination since adults of both species could ingest the largest prey items available to them. These results support Scott and Murdoch's (1983) hypothesis that the qualitative pattern of size selectivity depends largely on the range of available prey sizes relative to that a predator can effectively harvest.     

Morphological limitations, prey size selectivity, and growth response of juvenile atlantic salmon, Salmo salar

The head and jaw movements involved in capture, buccal manipulation, ingestion and rejection of prey were investigated using sequential photography of juvenile Atlantic salmon feeding in a simulated stream environment. The results are described and discussed and mouth breadth and gill raker spacing are proposed as morphometric limitations to the range of prey sizes available which remains constant at 0·06 · fish fork length ( PFR ).
A recirculatory flume tank was used to study prey size selectivity behavior. Simplified downstream-drifting prey items elicited a variety of responses depending on their physical size. One hundred percent of offered prey of PFR 0·025 were ingested, while 90 % of prey at PFR 0·051 and 100% of prey at PFR 0·105 were rejected. It is demonstrated that fish show negative selection for prey sizes smaller than PFR 0·025 and that prey of this size elicits maximum growth response.
The validity of the proposed morphometric limitations on the available prey sizes is demonstrated by reference to selectivity behaviour and prey size related differential growth.     

Size-related changes in cranial morphology affect diet in the catfish Clariallabes longicauda

Within the catfish family Clariidae, species exist with different degrees of jaw adductor hypertrophy. This jaw adductor hypertrophy has been related to bite performance, in turn suggesting a link to dietary specialization. Thus, an increase in the degree of hypertrophy will likely be reflected in an increase in the amount of hard prey in the diet. In the present study, we examine the ontogenetic scaling of cranial structure and diet in a species of catfish with a moderate degree of jaw adductor hypertrophy, Clariallabes longicauda . Additionally, we investigate whether the observed changes in the morphology of the feeding system during growth are linked to changes in diet. The fish examined demonstrate a strong positively allometric growth of the jaw adductors, of head height and of maximal head width, suggesting that larger fish can feed on larger and harder prey. Dietary data confirm these hypotheses and reveal an increase in maximal prey size consumed, the proportion of large prey in the diet, and average prey hardness during ontogeny. Moreover, the observed changes in the proportion of large prey consumed and prey hardness are correlated with an increase in lower jaw width and maximal head width, respectively. An increase in the amount of evasive prey in the diet with fish size is correlated with an increase in hyoid length. In summary, not only size dependent, but also size-independent variation of the feeding system was associated with ontogenetic changes in diet in C. longicauda .  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 323–334.     

Feeding selectivity of four species of sympatric stickleback in brackish-water habitats in eastern Canada

Although sympatric populations of sticklebacks occur commonly along the north-eastern coast of North America, very few studies have considered the interspecific relationships within such populations. This paper investigates prey selectivity, feeding behaviour and potential prey availability within sympatric populations from five brackish-water sites in New Brunswick. Differences between the diets of species from different sites were related to differences in the range of prey available. Fish collected from sites with abundant aquatic vegetation consumed greater numbers of prey than those from vegetation-poor sites. The proportions of prey types eaten by both adults and juveniles reflected prey species abundance at the different sites; thus shifts in diet over time were found to be related to changes in the abundance of potential prey and not to shifts in prey preference on the part of the fish. The size of prey consumed was related to mouth size; adult and juvenile Gasterosteus wheatlandi , having the smallest mouths, consumed the smallest prey. Differences in prey size detected in the four species studied were due to differences in the types of prey consumed. Laboratory experiments on feeding behaviour showed that adult Apeltes quadracus and Pungitius pungitius were more efficient at capturing benthic prey than were Gasterosteus aculeatus and G. wheatlandi. Competition for food is thought not to occur in these populations, because of the abundance of potential prey and the morphological constraints on feeding behaviour.     

Ontogenetic variations in the type and size of prey consumed by juvenile coho,Oncorhynchus kisutch,and chinook,O. tshawytscha,salmon

Synopsis Stomach contents of juvenile coho,Oncorhynchus kisutch, and chinook,O. tshawytscha, salmon collected in purse seines off the coast of Washington and Oregon were examined for variations related to predator size. There was a general trend toward increasing consumption of fish with increasing body size, due mainly to the increase in northern anchovy biomass consumed by the larger salmon. Most of the major prey taxa showed significant differences among the size classes examined for both salmon species. There was a direct relationship between predator and prey size for both coho and chinook, but considerable variation was found in prey length consumed within each size class. Prey width did not provide as good a fit as prey length for either species. In general, coho consumed larger fish prey in relation to their body length than chinook but there were substantial differences by month or year of collection.     

Prosobranch mollusc species- and size-preferences of Sargochromis codringtonii (Cichlidae) in Lake Kariba,Zimbabwe

From the stomach contents of 28 wild-caught Sargochromis codringtonii from Lake Kariba the size and species of snails consumed were estimated from opercula found. An energetic cost/benefit ratio of the various sizes of the most frequent prey, Bellamya capillata, was calculated. The size of snails consumed increased significantly with fish size, with large fish showing individual size preferences. Ingested snails were of sizes with relatively low energetic cost/benefit ratios.     

Feeding ecology of a vertebrate assemblage inhabiting a stream of NW Spain (Riobo; Ulla basin)

The food resource use of a stream in NW Spain by fish (Salmo trutta L. and Anguilla anguilla L.), birds (Cinclus cinclus L. and Motacilla cinerea L.) and mammals (Galemys pyrenaicus G. and Neomys anomalus C.) was studied. Data on seasonal diets and stream benthos prey were used to determine prey selection patterns.Caddisfly larvae are the main resource for Cinclus and Galemys, but these predators also consumed other benthic prey. Salmo fed on a wide range of benthic invertebrates, emergent pupae and terrestrial prey, whereas Anguilla consumed primarily benthic invertebrates, especially Lumbricids. Neomys fed mainly on terrestrial prey (Gasteropods and Lumbricids), but also consumed aquatic prey. Motacilla captured aquatic insects both in larval and aerial stages, as well as terrestrial prey.Both prey availability and selection led to seasonal differences in the use of food resources. All species showed a marked prey selection of aquatic taxa. Prey size plays an important role in this selection, most species consuming the largest of available prey sizes. In spite of the fact that all species feed upon freshwater invertebrates, substantial resource partitioning was observed in all seasons. This partitioning may be attributable to morpholological and physiological differences. Nevertheless, Anguilla and Galemys, two quite different animals, did feed on the same prey much of the time.     

Diet, food resource partitioning and feeding periodicity of two riffle-dwelling fish species in a New Zealand river

The diets and feeding periodicities of two small, riffle-dwelling fish, the torrentfish, Cheimarrichthys fosteri , and the bluegilled bully, Gobiomorphus hubbsi , were investigated in an unstable, braided New Zealand river from May 1985 to April 1986. Aquatic insect larvae dominated diets of all fish and dietary overlap between species was high in 10 of 12 months. Nevertheless, the relative importance of prey items, as assessed by the index of relative importance (IRI), differed between species. Gobiomorphus hubbsi fed almost exclusively on larval Deleatidium (Ephemeroptera), whereas C. fosteri consumed a greater variety of prey items, with Deleatidium and trichopteran, elmid and chironomid larvae numerically dominant. A dietary switch from Deleatidium to chironomid larvae occurred in both species during December 1985, when total and relative abundances of mayfly and other benthic macroinvertebrate larvae were severely reduced by two consecutive floods. A diel sampling programme indicated that the feeding periodicity of the two species differed: C. fosteri was a nocturnal feeder, whereas G. hubbsi exhibited a strong crepuscular peak in feeding activity. Overall, the two fish partition their food resource weakly by consuming prey items in different proportions and sizes and more strongly by utilizing the food resource at different times.     

An experimental study of body size and food size relations in crucian carp,Carassius carassius

Synopsis In dense, single-species assemblages of crucian carp, competition is intense and results in populations of stunted fish. To explore mechanisms underlying this competition, we measured handling times, return rates, and prey choice for five sizes of crucian carp feeding on six sizes of a standardized food. Handling times increased with prey size and decreased with fish size. Return rates (dry mass ingested per unit handling time) increased dramatically with fish size, and generally decreased with increasing prey size, especially for small fish. Patterns of return rates among size-classes suggested that one or more size-related shifts in feeding efficiency exist for crucian carp; combined with physiological stresses related to winter anoxia, the inability of fish to make these shifts may contribute to size structures observed in high-density populations. Comparisons of relations among fish size, prey size, and return rates for crucian carp and bluegill, Lepomis macrochirus, suggest that similar intraspecific competitive relations exist between generalist species with size-structured populations. Despite differences in return rates among prey sizes, the extent of food selectivity based on prey size exhibited by crucian carp in two types of choice trials was less than predicted. Crucian carp commonly take in several items before mechanically processing food with their pharyngeal apparatus; this multiple prey processing may contribute to disparities between observed choice patterns and those predicted based on return rates for single prey.     

The foraging ecology of two pairs of congeneric demersal fish species: importance of morphological characteristics in prey selection

The feeding habits of two sympatric species pairs of demersal fish ( Mullus barbatus-Mullus surmuletus, Serranus cabrilla-Serranus hepatus ) which occupy the shallow coastal area (25–30 m) in Iraklion Bay were investigated from samples collected on a monthly basis (August 1990 to August 1992). Stomach content analyses revealed that all of them were carnivores, feeding mainly on benthic invertebrates, and that each species consumed a narrow range of prey species with no significant dietary overlap. The morphology of their feeding apparatus was compared to examine the effect of any morphological differences on food selection and resource partitioning between the fish species. The species could be distinguished on the basis of the size of their mouth gape, the number of gill rakers and the length of their intestine. This study shows that each species pair follows a different strategy segregating along food niche dimensions. In particular, M. barbatus and M. surmuletus segregate their feeding niche consuming different prey taxa with similar sizes whereas S. cabrilla and S. hepatus differ considerably with respect to the degree to which prey species contribute to their diets coupled with differences in mean prey sizes.