饲养条件下月鳢仔鱼摄食习性的研究

对人工饲养条件下月鳢仔鱼的摄食习性进行了研究。仔鱼孵出２ｄ后即开口摄食外界食物,仔鱼开口饵料为轮虫。随着鱼体的生长,摄食枝角类、桡足类和摇蚊幼虫的比例迅速增加。仔鱼昼夜摄食强度有一定的节律,夜间１８～２２时摄食强度最大。     

泥鳅早期发育阶段食性的研究

对池养泥鳅(Misgurnus anguillicaudatus)早期发育阶段的食物组成和食物选择性进行了研究.结果表明,泥鳅早期发育阶段主要摄食浮游动物.7日龄和9日龄泥鳅主要摄食轮虫,其数量比例和重量比例分别达到98.73％、79.59％和97.59％、66.67％.13日龄枝角类的数量和重量比例高达41.15％和98.04％,17日龄桡足类的数量比例和重量比例为30.00％和62.03％.24日龄和31日龄,枝角类和桡足类的数量比例虽然都小于20.00％,但是其重量比例共占到95.00％;13 ～31日龄,枝角类和桡足类为泥鳅的主要食物.7日龄和9日龄,泥鳅对臂尾轮虫属(Brachionus)、龟甲轮虫属(Keratella)和异尾轮虫属(Trichocerca)表现出较强的摄食喜好性,对微型裸腹溞(Moina micrura)也表现出一定的摄食喜好性,对桡足类回避.13日龄和17日龄泥鳅对臂尾轮虫属和龟甲轮虫属仍有较强的摄食偏好性,同时对裸腹溞属(Moina)、秀体溞属(Diaphanosoma)、剑水蚤属(Cyclops)和华哲水蚤属(Sinocalanus)也表现出了较强的摄食喜好性.24日龄和31日龄泥鳅不再主动选食轮虫,喜好摄食裸腹潘属、低额溞属(Simocephalus)、剑水蚤属和华哲水蚤属.     

丰溪河花（鱼骨）仔鱼的食性初步探索

本文以采自江西省广丰县境内丰溪河流域的花（鱼骨）（Hemibarbus maculatus Bleeker）亲本孵化后的鱼苗为研究对象，从食物组成、摄食强度和摄食形态学等方面研究了花（鱼骨）的食性特点。结果表明：鱼苗阶段花（鱼骨）仔鱼有一定的趋弱光性，2—3cm夏花阶段表现为中上层，5cm以上仔鱼一般白天潜伏于水底和石砾中，晚上到岸边或池边觅食，以后营底栖生活，起捕率不高，这种摄食行为与水体中浮游生物的分布规律相一致。鱼苗阶段主要摄食轮虫、枝角类和桡足类及其它小型浮游动物，稍大时能摄食摇蚊幼虫、水蚯蚓、幼虫等，主食水生昆虫，也摄食黄蚬、螺蛳等软体动物和小鱼、小虾，可以认为花鲔的食物由摇蚊幼虫等16类饵料生物组成，并以摇蚊幼虫在全年的出现率为最高。     

长江宜昌江段和东洞庭湖鲢、鳙饵料生物组成及季节性变化

为了研究鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)饵料生物组成及季节变化,分析了2016年7月-2017年3月在长江宜昌江段及东洞庭湖不同季度采集的84尾鲢和65尾鳙的肠道内含物。结果显示:鲢、鳙在长江宜昌江段摄食的饵料生物种类分别是55种和48种,在东洞庭湖分别是55种和43种。根据相对重要性指数(IRI),鲢、鳙的主要饵料生物均为枝角类。鲢、鳙食物组成呈现季节变化,鲢在长江宜昌江段春季、夏季、秋季和冬季的主要饵料生物分别是硅藻门、枝角类、枝角类和硅藻门,在东洞庭湖分别为枝角类、蓝藻门、枝角类和桡足类;鳙在长江宜昌江段春季、夏季、秋季和冬季的主要饵料分别是枝角类、枝角类、枝角类和硅藻门,在东洞庭湖分别为枝角类、枝角类、枝角类和桡足类。     

黄颡鱼人繁及无公害养殖技术（三）

3．饲料及投喂 投放3厘米的苗种时池塘中浮游动物量可以基本上满足几天的需求量，在鱼种2～3厘米之间最好是轮虫、桡足类、枝角类、摇蚊幼虫、水蚯蚓等活饵料，随着个体的增大，池塘中天然饵料减少，必须要投喂人工混合饲料才能满足苗种的摄食需求。     

池养条件下大银鱼食性的初步研究

初孵的大银鱼仔鱼全长为4.90～5.10mm。孵化后第3天口裂形成,消化道与外界相通,肠管开始蠕动。第10天开食,在池塘中,仔鱼卵黄存留时间为26～31天,前期以轮虫为食,后期兼食枝角炎和桡足类。幼鱼期主食枝角类和桡足类,兼食摇蚊幼虫。成鱼期直至性成熟,部分以小型鱼虾为食,多数仍大量摄食枝角类和桡足类。     

山东半岛南部癆鱼产卵场癆鱼仔、稚鱼摄食的研究

研究了山东半岛南部Ti鱼产卵场体长2．5－17．9mm的Ti鱼仔、稚鱼的摄食。Ti鱼仔、稚鱼主要饵料为原生动物的鼎形虫、单角铠甲虫、三角铠甲虫。小型桡足类的卵、桡足类的无节幼体和桡足幼体。桡足类种类为墨氏胸刺水蚤、小拟哲水蚤、克氏纺锤水蚤、双刺纺锤水蚤和拟长腹剑蚤等小型类桡足类。各种饵料所占的个数的百分比为：鼎形虫2．2％，单角铠甲虫7．6％，三角铠甲虫3．3％，桡足类的卵42．2％，无节幼体30．4％，桡足幼体14．1％，Ti鱼仔、稚鱼的摄食率为16．2％，摄食活动主要在白天，在水的中下层进行。由于摄食率低，肠道饱满度差，饥锇可能是引起Ti鱼仔、稚鱼死亡的主要原因。     

太阳鱼人工繁殖及养殖技术研究

蓝绿鳞鳃太阳鱼（Ｌｅｐｏｍｉｓｍａｃｒｏｃｈｉｒｕｓ）为鲈形目、太阳鱼科的淡水鱼类 ,又名蓝鳃太阳鱼 ,原产于北美洲淡水水域。蓝绿鳞鳃太阳鱼属温水性小体型鱼类。生长适温范围大 ,可在１～３８℃水温状态下生活。在水温８℃以下或３８℃以上时才停止摄食 ,水温２℃仍能在自然环境下安全越冬。蓝绿鳞鳃太阳鱼是一种攻击性摄食鱼类 ,以动物性饵料为主要食物 ,幼鱼以枝角类、桡足类、摇蚊幼虫等水生生物为食物。小鱼摄食植物茎叶、鞘藻、小杂鱼、小虾、软体动物和轮虫等。人工养殖可大量投喂冰鲜鱼等动物饲料和人工配合饲料。我国于１９…     

池养条件下革胡子鲶仔幼鱼摄食习性与生长的初步研究

本文报道了在人工饲养条件下革胡子鲶仔幼鱼的摄食习性和生长的研究结果。仔鱼孵出2或3日,尚残存卵黄囊时即行开口摄食。仔鱼适口的开食饵料是轮虫,随着鱼体的生长,摄食枝角类、桡足类和摇蚊幼虫的比例迅速增加。幼鱼昼夜摄食强度有一定的节律,夜间18:00～22:00时摄食强度最大。经测量和数理统计分析,确定革胡子鲶仔幼鱼的全长与日龄呈直线关系,体重与日龄和全长对体重的关系均为幂函数关系,并计算出它们相应的回归方程式。     

池养线纹尖塘鳢仔、稚、幼鱼的食性与生长

对池养仔、稚、幼鱼的摄食与生长作了较深入研究.仔鱼的混合营养期短,仅2～3 d,并处在开食期内,开口摄食率低.5日龄仔鱼全长4.31 mm,开口饵料主要为100～150 μm轮虫:稚鱼饵料为350～800 μm裸腹溞、枝角类幼体和桡足类无节幼体,并逐渐转为枝角类为主:后期稚鱼可驯化摄食人工混合饲料.仔、稚、幼鱼具明显的昼夜摄食节率,属晚间摄食为主的昏晨摄食型鱼类.体长与日龄呈直线关系,体重与日龄呈指数函数关系,体长与体重呈幂函数关系,其曲线回归方程为W=0.0112L3.1827,b=3.1827,接近于3,属等速生长型.     

剑湖摇蚊幼虫的空间分布与水质评价

通过研究云南剑湖摇蚊幼虫的种类组成和空间分布,结合水质生物学评价指数,分析其群落结构特征并评价水质现状,旨在为该湖泊水生态系统健康评价和发展渔业生产提供基础数据。于2011年1月、4月、6月和10月分冬、春、夏、秋4个季节在剑湖设定11个采样点,进行摇蚊幼虫群落调查。结果表明,摇蚊幼虫共检出13种,隶属3亚科、6属,优势种为中华摇蚊(Chironomus sinicus)、溪流摇蚊(Chironomus riparius)、花纹前突摇蚊(Procladius choreus)和多足摇蚊(Polypedilum spp.);其中中华摇蚊为全湖性分布,其分布平均水深为162 cm,前突摇蚊属种类分布的平均水深最大,其它种类为局部性分布。摇蚊幼虫的平均密度冬季最高,为858.091个/m~2,夏季最低,为154.182个/m~2;冬季生物量最高,为15.741 g/m~2,其它3季均处在较低水平,其中秋季最低,仅1.245 g/m~2。根据水质生物学评价指数,目前剑湖的水质等级为中-重污染,已达富营养化水平;同时给出了剑湖水环境治理和控制建议。     

A production season of turbot larvae Scophthalmus maximus (Linnaeus, 1758) reared on copepods in a Danish (56°N) semi‐intensive outdoor system

Turbot were reared from yolk sack larvae to juvenile in an outdoor semi‐intensive system. Three production cycles were monitored from May to September. A pelagic food chain was established with phytoplankton, copepods and turbot larvae. Abiotic and biotic parameters of lower trophic levels together with turbot larval survival, development, prey electivity and growth were monitored. A decreasing larval survival from 18.4% in May to 13.6% in July and just 7.0% in September was observed. The overall phytoplankton and copepod abundance decreased during the productive season. The turbot larval growth showed significant differences between larvae below (isometric) and above (allometric) 7 mm. Larval fish gut content showed no differences with available prey between production cycles. Therefore, it appears that the available prey concentration is governing their growth in this outdoor system. First‐feeding turbot larvae exhibited active selection for nauplii whereas developed larvae switched to copepodites and adult copepods. Although developing turbot larva exhibited active selection towards copepod size classes, there was no evidence of selective feeding on either of the two dominant copepod species. The turbot larvae's prey ingestion was modelled together with the standing stock of copepod biomass. The model results indicated that the estimated need for daily ingestion exceeded the standing stock of copepods. Hence, the initially established food web was unable to sustain the added turbot larvae with starvation as a consequence. We therefore suggest several solutions to circumvent starvation in the semi‐intensive system.     

Food habits of fishes in a freshwater reed belt in Lake Kitaura,eastern Japan,in summer

The diets and feeding guild structure of a freshwater reed belt fish assemblage (30 species) were examined in Lake Kitaura, part of the Lake Kasumigaura system, eastern Japan, from June to September in 2009 and 2010. Ontogenetic dietary shifts were recognized in 14 species, including several species (e.g., Cyprinus carpio, Tridentiger brevispinis and Hyporhamphus intermedius) targeted by local fisheries. Juveniles of these species generally fed on zooplankton, later switching to other prey items (e.g., benthic chironomid larvae, gammaridean amphipods, shrimps, juvenile fishes, diatoms and decomposing reeds) with growth. A cluster analysis based on dietary overlaps showed that the reed belt fish assemblage comprised five feeding guilds (plant, zooplankton, benthic invertebrate, terrestrial insect and fish feeders). Of these, zooplankton feeders were the most abundantly represented in terms of species numbers, suggesting that the main food items for the fish assemblage were zooplankton (e.g., cladocerans, and calanoid and cyclopoid copepods). Fish feeders included five species, of which one was an alien species introduced from another region in Japan (Opsariichthys uncirostris) and three were from foreign countries (Micropterus salmoides, Lepomis macrochirus macrochirus and Ictalurus punctatus).     

黄颡鱼早期发育阶段摄食的研究

本实验采用实验生态学的方法，分别对池养9、13、17、23日龄黄颡鱼的食物组成，选食行为和昼夜摄食节律进行了研究。结果表明，黄颡鱼早期发育阶段主要摄食浮游动物，其食物组成随仔稚鱼的生长而变化。摄食初期（黄颡鱼9日龄时）主要食物为枝角类和轮虫，其中枝角类数量和重量百分比分别为86.71%和89.65%，占绝对优势。之后，黄颡鱼的摄食范围进一步扩大，从23日龄开始，由主要选食枝角类转为主要选食桡足类，桡足类所占数量百分比也从初期的3.29%上升到23日龄时的26.68%；而且，从13日龄开始，摇蚊幼虫等底栖动物所占比重呈上升趋势，从初期的54.84%到23日龄的69.52%，始终在食物组成中占主要优势。黄颡鱼摄食具有明显的昼夜节律性，9日龄时摄食高峰值出现在20:00（897.7），低峰值出现在19:00（161.8）；13、17、23日龄仔稚鱼胃平均饱满指数均于4:00达最高峰（914.1、1113.1和199.7），于19:00、19:00和16:00达最低值，分别为50.9、60.9和76.6，夜间时段摄食水平显著高于白天时段，黄颡鱼仔稚鱼明显表现为晚上摄食类型。     

汉阳地区湖泊摇蚊幼虫群落结构及其与环境因子的关系

为了解武汉市汉阳地区湖泊摇蚊幼虫群落结构和多样性及其与湖泊富营养化的关系,2011-2012年对后官湖、三角湖、南太子湖、墨水湖和龙阳湖等5个湖泊的摇蚊幼虫群落及环境因子进行了季节性调查。在汉阳5个湖泊共采集摇蚊科幼虫6属6种。中国长足摇蚊是这些湖泊摇蚊幼虫群落的共同优势种,优势度变化范围为26.8%~86.4%。摇蚊幼虫年平均密度为(748±162)ind./m~2,年平均生物量为(2.77±0.98)g/m~2,后官湖摇蚊幼虫密度和生物量最低[(171±32)ind./m~2,(0.32±0.12)g/m~2],龙阳湖最高[(1 066±468)ind./m~2,(5.37±2.48)g/m~2])。摇蚊幼虫密度和生物量最高值出现在1月份。摇蚊幼虫Margalef指数(dM)和Shannon-Wiener指数(H')平均值分别为0.38±0.05和0.72±0.12,后官湖摇蚊幼虫多样性指数最高(dM=0.58±0.12,H'=1.03±0.19),南太子湖最低(dM=0.28±0.14,H'=0.38±0.13)。相关分析表明,汉阳地区湖泊摇蚊幼虫密度和生物量与水体总氮、氨氮、总磷和叶绿素a呈显著正相关。冗余分析(RDA)表明,透明度和总氮是影响摇蚊幼虫群落组成的关键因子。研究结果表明汉阳湖泊摇蚊幼虫优势种、密度、生物量和多样性指数对湖泊水质有较好的指示作用。     

Natural foods utilized by Nile tilapia, <Emphasis Type="Italic">Oreochromis niloticus</Emphasis>, in fertilizer-based fish ponds in Lao PDR identified through stable isotope analysis

Nile tilapia, Oreochromis niloticus, is one of the most popular freshwater aquaculture species in developing countries. Although formulated feed provides higher fish yield, it is expensive. Therefore, fertilizer-based fish culture using natural food sources is generally implemented in developing countries. The aim of this study was to identify the major natural foods contributing to tilapia growth in fertilizer-based fish ponds. The stomach contents of tilapia in a fertilizer-based fish pond in Lao PDR were analyzed to estimate their feeding behaviors; stable isotope ratios of carbon and nitrogen in the potential food organisms and suspended solids were measured and compared with the ratios in the fish muscle tissues. Further, the feed efficiency of chironomid larvae was compared with that of chlorella and formulated feed in a laboratory feeding experiment. Consequently, chironomid larvae were identified as the main contributors to tilapia growth in the fertilizer-based fish pond. In conclusion, benthic larvae of insects belonging to the family Chironomidae are confirmed to be a natural food source for tilapia in the fertilizer-based fish pond.     

Feeding ecology and habitat of the threespine stickleback, Gasterosteus aculeatus microcephalus, in a remnant population of northwestern Baja California, México

Abstract – The feeding ecology and habitat of the threespine stickleback ( Gasterosteus aculeatus microcephalus Girard, 1854) was studied from November 1996 to May 1997 in a remnant population of northwestern Baja California, México. The analysis of the stomach content of 179 individuals (25 to 56 mm standard length [SL]) showed a diet dominated by cyclopoid copepods (43.8%) and chironomid larvae (39.1%). Diet in relation to size and sex of the fish was dominated by copepods in autumn and winter and by chironomid larvae during spring. Diet overlap (Schoener's index) was significant (≥60%) between fish size-classes in January, March and April and between sexes for most sampling months. The average size of prey consumed was independent of fish mouth size. The feeding strategy of the threespine stickleback shifted from opportunist in winter to specialist in spring.     

The use of artificial temporary streams with and without shelters by Japanese dace Tribolodon hakonensis

SUMMARY: In order to know how fish use temporary streams, we set up artificial temporary streams with and without shelters and investigated the fish that colonized there from connected permanent streams. A total of 220 fish belonging to six species were captured over four sampling periods from May to September, with Japanese dace Tribolodon hakonensis being the most abundant (75%). More Japanese dace colonized the stream with shelters than without shelters. The standard length and condition of Japanese dace tended to be greater in the stream with shelters than without shelters. Foraging behavior and area of Japanese dace differed significantly between the two streams; more Japanese dace employing drift feeding near the entrance of the shelterless stream. Japanese dace predominantly fed upon chironomid larvae, which became abundant in stream mud in July. However, in August and September, Japanese dace rarely preyed upon chironomid larvae and their digestive canal fullness was low, probably because most chironomid larvae had been consumed. This tendency was more prominent in the stream with shelters. The use of temporary waters by Japanese dace changed dynamically in response to the abundance of chironomid larvae and the presence or absence of shelters.     

Feeding success and survivorship of Arctic cod larvae,Boreogadus saida,in the Northeast Water polynya (Greenland Sea)*

We tested the hypothesis that enhanced feeding success and survivorship of Arctic cod larvae in the Northeast Water polynya (Greenland Sea) are associated with high densities of their zooplankton prey in areas of low sea ice concentration. From late May to early August 1993, first-feeding yolk-sac larvae (6.5–8.5 mm long) were collected primarily along the coast and over shallow banks in the polynya, whereas post yolk-sac larvae (8.5–14 mm) were more uniformly dispersed over the sampling area. Arctic cod larvae < 14 mm fed almost exclusively on copepod nauplii (74% of total prey number) and copepod eggs (16%). Feeding success was defined as the residuals of the regression of the number of prey ingested against larval length. Nauplii density varied from 9600 to 731300 nauplii m^-2(equivalent to 0.16 to 12.2 nauplii 1^-1) but, contrary to our hypothesis, seldom limited the feeding success of Arctic cod larvae. Water temperature was the best predictor of feeding success in larvae of all sizes. First-feeding success and survivorship were low for larvae hatched before mid-July, and improved thereafter as surface temperatures increased in the open waters of the polynya. There was no relationship between feeding success and irradiance or wind. Assuming a fixed spawning season, it is concluded that a larger fraction of the newly hatched larvae would experience adequate temperatures in years when the polynya opens early. Based on this conclusion, we propose that the timing of the opening of polynyas is a critical determinant of year- class strength in Arctic cod, a key species in the Arctic food web.     

Food resource partitioning of Arctic charr, Salvelinus alpinus (L.) and three-spined stickleback, Gasterosteus aculeatus L., in the littoral zone of lake Takvatn in northern Norway

The food resource partitioning of Arctic charr (Salvelinus alpinus L.) and three-spined stickleback (Gasterosteus aculeatus L.) were investigated in the littoral zone of lake Takvatn in northern Norway in the ice-free period June–November. Charr and sticklebacks had different feeding habits. Sticklebacks ate several small benthic prey items that were never eaten by charr, and the sticklebacks' diet were dominated by the benthic microcrustaceans Chydoridae and Ostracoda, chironomid larvae and stickleback eggs. Small charr (<17 cm) consumed a wide spectrum of chironomid pupae, terrestrial insects and zooplankton. Intermediate (17–20 cm) and small charr had quite similar feeding habits, while large charr (>20 cm) frequently ate both benthos, pelagic and terrestrial food. The diet overlap between small charr and sticklebacks was never larger than 0.6 (Schoener's index). The segregation in feeding habits indicates that small charr and sticklebacks are segregated in microhabitat when they are both in the littoral zone.