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一、公鱼属鱼类的分类地位和分布 公鱼属(Hypomesus)是鲑形目胡瓜鱼科的一群小型经济鱼类。公鱼属鱼类分类各家意见不一，但主要包括两个种是一致的意见。这两个种一是池沼公鱼(Hypomesus olidus)，淡水里产卵，有溯河产卵和陆封两种类型，另一种是海公鱼(Hypomesus pretiosus)，海里产卵。 相似文献
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研究了圆斑星鲽卵巢年周期发育的组织学规律及其数量形态特征变化.结果表明,圆斑星鲽产卵属1年1次成熟分批产卵类型,卵巢发育属非同步分批成熟类型.性成熟亲鱼在年周期发育中经历5个发育时期,同时可见5个发育时相的卵母细胞,不同发育时期的卵巢中卵母细胞类型和组成比例不同.性腺指数(GSD、肝脏指数(HSI)和肥满度(CF)在亲鱼的年周期发育中呈现规律性的变化,与卵巢发育呈现密切的关联.亲鱼卵巢发育的有效积温为1050日度. 相似文献
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我们对(歺又鱼)属Hemiculter鱼类进行了核查,确认在苏联境内有两种:1)H.Leucisculus (Bas.),别尔格(1949)和尼科里斯基(1947、1956)认为,H.Leucisculus的同物异名之一是H.eigenmanni. 2)H.Lucidus (Dyb),别尔格和尼科里斯基认定H.Lucidus的同物异名之一是H.Leucisculus.依据这些种的同物异名,分布和主要特征方面的资料进行了性状鉴别,推测H.Leucisculus 相似文献
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《天津水产》2015,(1)
<正>海马:Hippocampus sp.属脊索动物门(Phylum Chordata)、辐鳍鱼纲(Actinopterygii)、棘背鱼目(Gasterosteiformes)、海龙亚目(Syngnathoidei)、海龙科(Syngnathidao)、海马属(Hippocampus Rafinseque),因其体型高度特化,头似马状,故被称为"海马",为近陆浅海中的小型鱼类,种类较多,分布较广,主要分布在我国海区的有冠海马(H.coronatus)、棘海马(H.histrix)、大海马(H.kuda)、斑海马(H.trimaeutatus)、克氏海马(H.kelloggi)及日本海马(H.japonicus)6种,其中大海马、斑海马体型大、生长速度快、经济价值高,为养殖所选品种。 相似文献
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黑尻鲹(Caranx melampygus Cuvier)能很好地适应蓄养,夏威夷海洋所蓄养的雌性黑尻鲹(均重3,389±425g、叉长52.1±2.8cm)于第二年开始自然产卵。产卵大部分发生在夏天(5-8月),少数可延伸至冬天,黑尻鲹属多次产卵,雌鱼在繁殖期以短至5天的间隙产卵8次。产卵在晚间进行,产卵的主要形式为几天内以连续或间隔数天的方式进行。雌鱼每克体重能产卵1545粒,年产卵量接近6,062,200粒。虽然记录到的产卵行为大部分发生在第三、第四月相(新月期),但产卵似乎与月周期无关。产出卵子的平均直径范围0.721-0.787mm。这两组试验结果显示黑尻鲹是适宜蓄养的品种。 相似文献
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太平湖水库翘嘴红Bo的产卵场及种群控制 总被引：1，自引：0，他引：1
太平湖水库翘嘴红Ｂｏ产卵场位于入库河流中，产卵期的流速０．１－０．５ｍ／ｓ，水温２１－３０℃，时间约为６月中旬－７月中旬。雨后流速增加是刺激产卵的主要因素。因过度捕捞，翘嘴红Ｂｏ资源量近年呈下降趋势，有必要在繁殖期对其产卵群体进行适当保护。文章将库内家鱼种的放养规格定为１３．３ｃｍ以上，将翘嘴红Ｂｏ的起捕规格定为５０ｃｍ以上。 相似文献
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Abstract. Overexploitation and pollution has led to the decline of Scotland's traditional smelt fisheries. The one remaining commercial fishery is on the River Cree in south-west Scotland and the characteristics of the spawning runs of the smelt, Osmerus eperlanus (L.), on which this fishery is based have been studied with a view to conservation and re-establishment of the species elsewhere in Scotland. The spawning-runs which started in early March when water temperatures were greater than 5°C were characterized by marked temporal changes in size, age and sex ratio. The fish enter the spawning stock at 1+ years of age and, in common with other estuarine smelt populations, are highly fecund. The spawning stock was composed mainly of two age-classes (1+ and 2+ years) and fish of the 1978 year-class dominated the spawning stock in 1980 and 1981. Spawning, which was interrupted during periods of high flow, lasted about 1 week. Male fish tended to remain on the spawning grounds after females had vacated the area. Recommendations for management and re-establishing smelt stocks are discussed. 相似文献
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Abstract – Lake Höytiäinen in eastern Finland has suffered from a prolonged vendace Coregonus albula (L.) recession during the last two decades. The present study examined the capacity of smelt Osmerus eperlanus (L.) to prey on vendace larvae as well as the diet of smelt in Lake Höytiäinen to reveal its possible predation on vendace larvae. The larvae were observed to be most vulnerable to smelt >100 mm (TL) predation at a total length of 13 mm. In Lake Höytiäinen, the diet of smelt was clearly dominated by zooplankton and no vendace larvae were found in the stomachs, probably due to small size of the smelt and low abundance of the larvae. Spawning time of smelt and larval period of coregonids overlap in spring and an observed decrease in feeding activity of smelt during spawning time may provide a temporal refuge against predation. Although smelt has been found to intensively predate on coregonid larvae in other lakes, it does not play an important role in maintaining the present low-density state of vendace in Lake Höytiäinen. 相似文献
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Use of GIS to predict effects of water level on the spawning area for smelt, Retropinna retropinna, in Lake Taupo, New Zealand 总被引：1，自引：0，他引：1
A GIS model of the littoral bathymetry and substrate composition of Lake Taupo was created using ArcInfo. Littoral substrates were mapped by aerial photography and confirmed by ground-truthing. Water depths were determined by echosounding linked to a differential GPS. These data were imported into ArcInfo where a 3D GIS model was used to calculate the total area of smelt, Retropinna retropinna Richardson, spawning habitat (i.e. clean sand between depths of 0.5–2.5 m) at each of five lake levels. There was little change in area over the first 50 cm below the natural maximum lake level, but spawning habitat decreased rapidly over the next 1.4 m such that a 30% reduction occurred at the natural minimum level. Anecdotal information on inter-annual variations in lake level and smelt abundance supported the notion that high lake levels in spring result in high recruitment of smelt. The GIS model also predicted effects of lake level change on areas of macrophyte cover and on other littoral substrates, and could be used to assess effects of lake level changes on the habitats of other biota. 相似文献
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M. Vetemaa R. Eschbaum A. Verliin A. Albert M. Eero R. Lillemägi M. Pihlak T. Saat 《Ecology of Freshwater Fish》2006,15(2):211-220
Abstract – Matsalu Bay in the Väinameri (West-Estonian Archipelago Sea) is a relatively shallow but large bay. It is the only real delta estuary in the northern Baltic Sea. The fish fauna is strongly dominated by freshwater species such as perch Perca fluviatilis , roach Rutilus rutilus , white bream Blicca bjoerkna and rudd Scardinius erythrophthalmus . The study presents CPUE data describing annual and seasonal variations in the species composition, abundance and spatial distribution, based on 1 year of monthly samplings from August 2001 to August 2002 and routine coastal monitoring (in late July–early August) between 1994 and 2003. The bay can be divided into three rather distinct parts. The fish fauna of the inner part (salinity 0–2 p.p.t.) is different from two open parts and resembles that of freshwater lakes. In the openmost part (salinity usually 4–6 p.p.t.) some marine species, such as herring Clupea harengus membras , flounder Platichthys flesus and eelpout Zoarces viviparus may seasonally be abundant. Species composition and abundance of most species varies seasonally and interannually. Only the abundance of few species such as pike Esox lucius and pikeperch Stizostedion lucioperca was not impacted by seasonality. The most dynamic period in the bay is spring, when several species (some of them very rare in summer, such as herring and smelt Osmerus eperlanus ) enter the bay for spawning. 相似文献
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W.R. Driedzic J.L. West D.H. Sephton J.A. Raymond 《Fish physiology and biochemistry》1998,18(2):125-134
Rainbow smelt (Osmerus mordax) tolerate temperatures close to the freezing point of sea water, in part, through the use of glycerol as an antifreeze. Potential mechanisms for glycerol production by liver were assessed by comparing activities of key enzym es of carbohydrate and amino acid metabolism in rainbow smelt to those in Atlantic tomcod (Microgadus tomcod) and smooth flounder (Liopsetta putmani). The latter two species inhabit the same environment but do not maintain high levels of blood glycerol. The enzyme profile of liver from rainbow smelt is substantially different from those of the other species and is poised for glycerol production. With respect to carbohydrate metabolism, glycerol-3-phosphate dehydrogenase activity in rainbow smelt liver was 156 µmoles min-1 g-1, a level which was 28 and 12-fold higher than activities in tomcod and flounder liver, respectively. Glycerol-3-phosphatase activity in smelt liver was 1.95 µmol min-1 g-1. This activity was 2.7 and 5.4-fold higher than those in tomcod and flounder liver, respectively. As such, the production of glycerol appears to be dependent upon the concerted action of glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase. The enzyme profile also suggests that amino acids are a potential source of carbon for glycerol. Aspartate aminotransferase activity in rainbow smelt was 7 to 14-fold higher in comparison to tomcod and flounder liver, respectively. Activities of alanine aminotransferase and glutamate dehydrogenase in liver were between 2 and 3-fold higher in rainbow smelt than in the other two species. Finally, it is shown that in vitro preparations of smelt liver sections produce glycerol at 0°C lending support to the concept that liver is a site of glycerol synthesis in vivo. 相似文献
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Understanding imperfect detection in a San Francisco Estuary long‐term larval and juvenile fish monitoring programme 
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下载免费PDF全文 Imperfect detection can present a significant challenge when monitoring for a rare and imperilled species. Here, a long‐term larval and early‐juvenile fish monitoring programme in the upper San Francisco Estuary was examined to evaluate its overall reliability in detecting various fish species, including the imperilled delta smelt, Hypomesus transpacificus McAllister, for which the programme was designed. Using occupancy modelling, detection probability of species with pelagic larval or juvenile life stages was found to be generally high (≥.95) based on the current sampling effort of three larval net tows per site. However, detection probability can vary considerably from year to year depending on the species’ level of larval production. Water temperature and turbidity were identified as important predictors of occurrence for young‐of‐year delta smelt, longfin smelt Spirinchus thaleichthys (Ayres) and striped bass Morone saxatilis (Walbaum), and there was evidence for fish size selectivity by the sampling gear in all three species. These results highlight the need to consider adaptively managing detection probability by increasing sampling effort in years when young‐of‐year delta smelt abundance is expected to be low, especially when information on the species’ occurrence at a particular region is critical. 相似文献
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Md Rakeb‐Ul Islam Daniel J. Schmidt David A. Crook Jane M. Hughes 《Ecology of Freshwater Fish》2019,28(2):229-240
A comprehensive knowledge of migratory behaviour is paramount for the effective management and conservation of fishes in coastal drainages. The Australian smelt (Retropinna semoni) is a common fish distributed throughout coastal and inland drainages in south‐eastern Australia. Multiple life history patterns (potamodromy, facultative diadromy, estuarine residence) in the southern regions of its geographic distribution have been reported, and it is possible that some of these differences reflect characteristic behaviours of cryptic species within the group. To elucidate the life history patterns of smelt at the northern extent of their range and to identify any differences in migratory behaviour between two genetically distinct lineages (“SEQ‐N”, “SEQ‐S”) in this region, the movement patterns of Australian smelt were assessed using otolith chemistry. No evidence of marine residence was found based on otolith Sr:Ca and Ba:Ca transects for either group, suggesting that both are non‐diadromous. Significant differences in multi‐elemental otolith chemistry signatures were found among rivers and between paired sites within some rivers, suggesting no connectivity among drainages and limited dispersal of individuals over large spatial scales within rivers. These findings provide key insights into the migratory patterns of northern Australian smelt populations and, in combination with previous research, suggest that life history variation in the Australian smelt complex may occur primarily at the intra‐population level rather than among genetically distinct lineages. Conservation and management strategies for Australian smelt should take limited dispersal and individual life history variation into consideration in order to protect the components of this important species complex. 相似文献
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Rainbow smelt (Osmerus mordax) synthesize high amounts of glycerol in winter as a cryoprotectant through the direct dephosphorylation of glycerol-3-phosphate by a phosphatase, glycerol-3-phosphatase (G3Pase). Such a protein is well described in a few species including fungi, bacteria and plants but never studied beyond tissue homogenates in any animal species. Purification, identification and characterization of this enzyme is thus crucial for a better comprehension of the biochemical adaptation in rainbow smelt in response to low temperature and more generally of the biochemical mechanisms involved in glycerol synthesis in animals. This work presents the first attempt to purify G3Pase from smelt liver, the main site of glycerol synthesis for the whole animal. A partial purification was performed, and some characteristics of the protein determined, including optimal pH, Km and cation requirements. Smelt G3Pase is most likely a low molecular weight, Mg2+-dependent and cytosolic phosphatase. 相似文献
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Satoshi Katayama 《Fisheries Science》2001,67(3):401-407
SUMMARY: The objective of this study was to reveal the spawning grounds and reproductive characteristics of anadromous and resident pond smelt, Hypomesus nipponensis , coexisting in Lake Ogawara. Life history styles of females shedding in spawning grounds in the lake and its inflowing rivers were differentiated by otolith increment analysis. Size, dry weight, and water content of mature oocytes and fecundity of fish were compared between resident and anadromous fish. Both anadromous and resident fish spawned in the lake. In contrast, no resident fish were found in any of the inflowing rivers, where only anadromous fish spawned. Regression of fecundity against standard length was discontinuous with an inflection point at 63.8 mm, which is the body size that differentiates large anadromous spawning groups from small resident spawning groups. Mean oocyte diameters were not significantly different between resident and anadromous fish. The eggs of resident fish had significantly more water content and a significantly lower dry weight than those of anadromous fish. These differences might influence the growth and developmental processes of progeny. 相似文献
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Wild‐caught blacklip (Haliotis rubra, Leach 1814) and greenlip (H. laevigata, Donovan 1808) abalone fed a formulated feed were held at 16 or 18°C for different conditioning intervals ranging from 114 to 235 days and induced to spawn using ultraviolet‐irradiated seawater. They were conditioned again for a second identical period before another induction. For H. rubra, mean spawning rate of both sexes was higher in groups held at 18°C than at 16°C, as was the repeat spawning rate. Conversely, animals held at 16°C produced significantly more gametes than those at 18°C. Egg production peaked in groups held at 16°C for ≥165 days. While both mean and total sperm production of H. rubra varied significantly, both figures were always high. Unlike H. rubra, the spawning rate, repeat spawning rate and gamete production of both sexes of H. laevigata were higher when cultured at 16°C than at 18°C. Egg production peaked in groups conditioned at 16°C for ≥212 days. Both mean and total sperm production by H. laevigata were much lower than for H. rubra. This study demonstrates that year‐round hatchery production of seedstock of both species is possible providing broodstock are held under favourable environmental conditions, preferably 16°C. 相似文献