黄河河南段非漂流性卵鱼类产卵场现状调查

为了掌握黄河河南段鱼类产卵场的分布现状,2013-2015年的每年3-7月,采用卫星GPS定位,实地走访渔民,采集鱼卵和仔稚鱼,捕获并解剖分析繁殖亲鱼,同步进行理化因子测定和环境指标监测。结果表明,黄河河南段鱼类规模产卵场共有30处,主要分布在河边浅滩、河流消落区和河心岛等水生生物资源丰富、适合非漂流性卵鱼类产卵孵化的水域。监测调查270d,采集主要鱼类标本1 156尾,各产卵场的鱼类优势种组成差异明显。产卵经济鱼类有鲤(Cyprinus carpio)、鲫(Carassius auratus)、鲶(Silurus asotus)、鳊(Parabramis pekinensis)、泥鳅(Misgurnus anguillicaudatus)、黄颡鱼(Pelteobagrus fulvidraco)、赤眼鳟(Squaliobarbus curriculus)共计7种。黄河南段主要经济鱼类产卵场的分布位置及范围规模存在明显的地域差异。为保护黄河南段经济鱼类及其产卵场,提出了具体的保护措施。     

Variation in growth rate,liver weight and body composition at first sexual maturity in rainbow trout

Rainbow trout around 743 g were fed four different diets over an 8-month period. Maturing males grew faster in the period before spawning (Sept.–Dec.) than maturing females, and significantly faster than immature fish. Mature fish stagnated in growth while the immature fish surpassed the growth of mature fish during the spawning season. The condition factor was moderately influenced by the maturation process. In the period before spawning (Sept.–Jan.) maturing females had a significantly higher hepatosomatic index than males and immature fish. An increase in dry matter and fat and a decrease of protein were observed in the muscle of maturing males and immature fish towards the spawning season, while maturing females had a slight fall in dry matter and fat and a small increase in protein in the same period. Dry matter and fat in muscle of rainbow trout were positively correlated.     

Conservation of spawning time between years in lumpfish Cyclopterus lumpus and potential impacts from the temporal distribution of fishing effort

Lumpfish, Cyclopterus lumpus L., has an extended ovary development period and a relatively long spawning season. It therefore seems unlikely that individuals spawning later in the season would be able to recover from spawning and develop their gonads in time to spawn during the early part of the season the following year. The hypothesis that individuals spawning early or late in a spawning season would spawn early or late the following year was tested using fish tagged in Iceland between 2008 and 2017. The tagging date and recapture date the following year were positively correlated with an average of 356 days at large (DAL). Fish sampled from the fishery indicate that tagging/recapture date gives an indication of spawning time. From this, it was concluded that spawning time in the current year can be used to predict spawning time the following year. As fishing effort was greatest at the end of April/beginning of May, it seems likely that fish that come to spawn at this time will be subject to a higher fishing mortality. Therefore, they will be less likely to spawn successfully than fish spawning earlier or later in the year. If spawning time is under genetic control, then this could have consequences for the spawning phenology of lumpfish.     

Spawning grounds and reproductive traits of anadromous and resident pond smelt, Hypomesus nipponensis, in Lake Ogawara, Japan

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.     

Observations and Techniques for Maturation, Spawning, and Larval Rearing of the Yellowtail Snapper Ocyurus chrysurus

Abstract.— This paper describes current techniques used at our laboratory for the controlled spawning, maturation and larval rearing of the yellowtail snapper. Juvenile yellowtail snapper were obtained from Florida and transferred to the Fisheries and Mariculture Laboratory in July 1990. Temperature and photoperiod manipulation resulted in precocial spawning in 1991, with sustained successive spawning beginning in February 1992. Average weekly spawning from 1992–1994 was 308,000 and 247,000 eggs/tank, with fertilization rates of 46.1 % and 32.5% for fish maintained in two separate spawning tanks. Observations on spawning activity from 1995 to 1996, during which a decreasing trend in egg and larval quality was observed, imply a possible problem with broodstock nutrition. Evaluation of feeding regimes during this period indicated a shift to a high (almost exclusively) usage of fresh squid and a reduction in fish and shrimp. Returning to a feeding regime of alternating feedings of fresh fish, squid. and shrimp have yielded improved spawning and egg quality. Larval rearing techniques using live and prepared feeds has resulted in an overall survival of 3% from egg to advanced juvenile. Growout of first generation (F1) juveniles yielded a marketable size (1 1b) fish in 25 mo. Spawning of F1 fish hegan in 1998. larval rearing and grow out of F2 fish are currently underway. Results demonstrate that yellowtail snapper culture is technically feasible; however. further research to develop species specific culture techniques will be required before the culture potential of this species can be accurately evaluated.     

DNA barcoding of fish eggs collected off northwestern Cuba and across the Florida Straits demonstrates egg transport by mesoscale eddies

Identifying spawning sites for broadcast spawning fish species is a key element of delineating critical habitat for managing and regulating marine fisheries. Genetic barcoding has enabled accurate taxonomic identification of individual fish eggs, overcoming limitations of morphological classification techniques. In this study, planktonic fish eggs were collected at 23 stations along the northwestern coast of Cuba and across the Florida Straits to United States waters. A total of 564 fish eggs were successfully identified to 89 taxa within 30 families, with the majority of taxa resolved to species. We provide new spawning information for Luvarus imperialis (Louvar), Bothus lunatus (Plate Fish), Eumegistus illustris (Brilliant Pomfret), and many economically important species. Data from most sites supported previously established patterns of eggs from neritic fish species being found on continental shelves and oceanic species spawning over deeper waters. However, some sites deviated from this pattern, with eggs from reef‐associated fish species detected in the deep waters of the Florida Straits and pelagic species detected in the shallow, continental shelf waters off the coast of northwestern Cuba. Further investigation using satellite imagery revealed the presence of a mesoscale cyclonic eddy that likely entrained neritic fish eggs and transported them into the Florida Straits. The technique of combining DNA‐based fish egg identification with remotely‐sensed hydrodynamics provides an important new tool for assessing the interplay of regional oceanography with fish spawning strategies.     

Dynamic in-lake spawning migrations by female sockeye salmon

Abstract –  Precise homing by salmon to natal habitats is considered the primary mechanism in the evolution of population-specific traits, yet few studies have focused on this final phase of their spawning migration. We radio tagged 157 female sockeye salmon ( Oncorhynchus nerka ) as they entered Lake Clark, Alaska, and tracked them every 1–10 days to their spawning locations. Contrary to past research, no specific shoreline migration pattern was observed (e.g., clockwise) nor did fish enter a tributary unless they spawned in that tributary. Tributary spawning fish migrated faster (mean = 4.7 km·day⁻¹, SD = 2.7, vs. 1.6 km·day⁻¹, SD = 2.1) and more directly (mean linearity = 0.8, SD = 0.2, vs. 0.4, SD = 0.2) than Lake Clark beach spawning fish. Although radio-tagged salmon migrated to within 5 km of their final spawning location in an average of 21.2 days (SD = 13.2), some fish migrated five times the distance necessary and over 50 days to reach their spawning destination. These results demonstrate the dynamic nature of this final phase of migration and support studies indicating a higher degree of homing precision by tributary spawning fish.     

Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary

Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.     

辽东湾安氏短吻银鱼的生物学

安氏短吻银鱼Neosalanx andersoni(Randahl)曾为辽东湾早春的重要捕捞对象。本文对该鱼的形态特征、繁殖、食性、洄游等进行了调查，并对其分布、精巢数目、资源下降的原因以及繁殖保护的措施作了分析和讨论．     

Effect of squid meal in dry pellets on the spawning performance of striped jack Pseudocaranx dentex

SUMMARY: This study was carried out to investigate the effects of dietary squid meal or a combination of squid meal and krill meal as part of the protein source in dry pellets on the spawning of striped jack Pseudocaranx dentex . Five months prior to spawning, 7-year-old fish were divided into three groups of 10 fish each (male : female ratio, 5 : 5). The control group was fed a raw fish mix (RF) and the other two groups were fed either steam-dry pellets with squid meal replacing 50% of their fish meal (fs-DP) or steam-dry pellets containing equal proportions of fish, squid and krill meals (fsk-DP). Feeding was carried out once every other day in 5 × 5 × 5 m floating net cages and the fish were transferred to 65 m³ indoor tanks for spawning. Eggs and yolksac larvae produced were evaluated for their quality and those obtained during the first 2 weeks of spawning were sampled for chemical analysis. The fish had an average bodyweight of 3.5 ± 0.4 kg at spawning. Although egg production of the RF group was significantly higher ( P < 0.05) than that of the dry pellet groups, the fs-DP group produced the best quality eggs with higher fertilization and hatching rates. The fsk-DP group had the lowest egg production and quality. Lipid classes and fatty acid compositions of eggs and yolksac larvae were dependent on the broodstock diets. These results show that the combination of fish meal and squid meal in dry pellets for striped jack improved egg quality but not production whereas the combination of fish meal, squid meal and krill meal was not effective.     

基于DNA条形码技术的永暑礁泻湖鱼卵鉴定研究

为了解南海珊瑚礁鱼类的产卵时间、产卵地点和种类分布,本研究以南海永暑礁泻湖鱼卵为研究对象,根据形态学特征和DNA条形码序列信息对其进行种属鉴定分析。71个鱼卵样品根据形态学特征分为圆形和椭圆形2种类型,圆形鱼卵44个,椭圆形鱼卵27个。利用DNA条形码技术扩增测序获得了30个鱼卵样品的线粒体COI条形码序列,经BOLD数据库比对分析显示30个鱼卵样品均可鉴定到种,分属于1个目,7个科,13个种。双斑栉齿刺尾鱼有10个鱼卵,白尾栉齿刺尾鱼有4个鱼卵,为该海域的优势种类,其余各种类均为1~2个鱼卵。根据线粒体COI序列计算种内的K2P(Kimura-2-parameter)遗传距离为0.002,同一个属种间的遗传距离为0.004~0.132,而同一个科不同属间的遗传距离为0.117~0.185。该研究结果表明DNA条形码技术可以作为鉴定南沙群岛珊瑚礁海域鱼卵的有效方法,能被广泛应用于南沙群岛珊瑚海区域鱼卵和仔稚鱼的鉴定工作。     

生态调度专刊—鱼类产卵行为与生态水文指标响应关系研究-以长江四大家鱼为例

四大家鱼作为我国重要淡水经济鱼类，近年来产卵规模大幅衰减，水文条件作为影响家鱼自然繁殖的重要因素，确定四大家鱼产卵行为与生态水文指标响应关系对保护四大家鱼早期资源具有重要意义。本文采用ROC曲线、分类回归树、Logistic回归等方法以长江中游宜昌段为研究区域，将生态水文指标对家鱼产卵刺激划分为“无效、低效、高效”多分类问题，应用不同数据挖掘方法，分析家鱼产卵行为与生态水文指标响应关系，并对比研究了不同方法间的性能与优缺点。结果显示，ROC曲线判别准确率、预测准确率、模型鲁棒性均最优，认为ROC曲线是本次研究中判定生态水文指标对四大家鱼产卵规模影响的最优方法。当流量日增量大于1370m3/s且两次洪峰间隔时间大于7.5d时可以引起四大家鱼高效产卵响应。辨识出高效刺激家鱼产卵的生态水文指标及其阈值，将对生态调度的优化改进具有重要的现实意义。     

赣江下游丰城江段鱼类早期资源现状调查

对赣江鱼类早期资源的调查,可为赣江鱼类资源保护以及水利工程生态调度提供科学依据.2017年5-7月,在赣江丰城段使用圆锥网采集鱼卵和弶网采集仔鱼,对鱼类早期资源种类组成、产卵规模和产卵场进行分析.结果显示,调查期间共采集鱼卵11215粒,仔鱼12645尾,隶属于4目、8科、36种,其中产漂流性卵鱼类24种.估算调查期间通过丰城段卵苗径流量为66.66×１０^８粒(尾),其中鱼卵径流量63.84×10^8 粒,鱼苗径流量2.82×10^8 尾;“四大家鱼”卵苗径流量为0.11×10^8 粒(尾),其中鱼卵径流量0.07×10^8 粒,鱼苗径流量0.04×10^8 尾.调查期间出现3次产卵高峰,集中在6 月上、中旬.各类群鱼卵数量呈现出不同的时间动态,银鮈(Squalidusargentatus)产卵高峰期主要出现在5月,银鲴(Xenocyprisargentea)、鳊(Parabramispekinensis)、赤眼鳟(Squaliobarbuscurriculus)以及“四大家鱼”则主要出现在6月.研究表明,峡江水利枢纽运行后,邻近峡江水利枢纽的巴邱“四大家鱼”产卵场消失,但其下游的仁和、新干产卵场保存较完整,在离坝较远的大洋洲镇江段新调查到一处“四大家鱼”产卵场.建议开展生态调度及增殖放流活动,以保护赣江鱼类资源.     

水电站影响下太湖西苕溪鱼类产卵生境及其早期资源与环境因子的关系

水利设施运行影响下的鱼类早期资源发生规律被逐渐关注,坝下区域也成为鱼类产卵生境的关注热点。西苕溪作为太湖上游的重要补充支流,是太湖流域鱼类完成生活史过程的重要载体。为解析电站影响下的坝下河流生境变量与鱼类早期资源的内在联系,本研究于2022年4—7月在西苕溪江东电站坝下的东山段开展了持续90 d的鱼类早期资源调查以及时空格局研究。结果显示,该区域鱼卵日平均密度为(0.5±0.7)ind/m3,仔鱼日平均密度为(0.5±0.6) ind/m3。运用形态学结合分子生物学方法进行种类鉴定,共鉴定鱼类35种,隶属4目14科22属,其中产沉性卵鱼类9种,产浮性卵5种,产黏性卵9种,产漂流性卵12种。5月下旬、6月上旬和6月下旬为产卵高峰期。左右岸样线以沉性卵和以水生植物为黏附基质的产黏性卵鱼类为主,河心样线则以产漂流性卵、产黏性卵和浮性卵鱼类为主。该区域鱼类卵苗数量受水温、流速、水位影响较大,水位、流速是影响鱼类繁殖的主要因子,电站调度对卵苗量有显著影响。基于卵苗收获量、卵苗发育时期等结果,判定该采样区域——西苕溪江东电站坝下东山段为适宜多种鱼类繁殖的复合型产卵场,对太湖流域鱼类多样性和渔业资源...     

Multiple spawning and related variations in female reproductive parameters of amphidromous type ayu

Adult ayu Plecoglossus altivelis were sampled from the Nezugaseki River, Yamagata Prefecture to investigate the reproductive parameters and analyze their variations related to multiple spawning. Ovarian histology (mainly based on the occurrence of postovulatory follicles) indicated that female ayu can be divided into four groups, which are considered to correspond with unspawned, once spawned, twice spawned, and three (or more) times spawned individuals. Comprehensive analysis of the ovarian state with field surveys revealed that most of the female ayu achieve second spawning and that third spawning is very common in this river. Mean relative batch fecundity (RBF) for the second, third, and fourth spawning indicated 69, 42, and 22%, respectively, of the value for the first spawning, showing a decline with the number of spawning batches. Mean gonadosomatic index (GSI) values of non-ovulating fish showed a similar decline during the main spawning period (October). Condition factor (without gonads) during autumn also decreased with the number of batches spawned, suggesting that multiple spawning is achieved partly by transfer of body mass nutrients to the ovary. Size dependency in reproductive parameters such as occurrence of the multiple spawning, RBF values, and GSI values of the unspawned fish, was not evident except for GSI values in early September (generally during the early phases of ovarian development), when larger fish had larger GSI.     

A follow‐up study of selected biomarkers of health in cod Gadus morhua L. collected from the southern Baltic off the Polish coast

Selected biomarkers of health were examined in 50 post‐spawning cod Gadus morhua collected in November 2015 from the southern Baltic. The biomarkers included condition factor (CF), macroscopic lesions, histopathology of spleen, liver and gonads, and morphometry of follicular atresia and hepatic and splenic melanomacrophage cells (MMC). All fish appeared in good body condition. One fish had a dermal ulcer, and in seven, macroscopic nematodes were noted within body cavity. Microscopic lesions in the liver included biliary myxozoanosis, microsporidial and necrocentric granulomas, parasitic hepatitis, multifocal necrosis, foci of cellular alterations, spongiosis, peliosis and cytoplasmic fibrillar inclusions. The spleen and gonads had microsporidial and/or necrocentric granulomas. Some of the biomarkers showed differences as compared to spawning cod collected in May from the same location in 2012, most importantly values an order of magnitude lower for splenic MMC in post‐spawning fish. In post‐spawning fish, there were statistically significant correlations between MMC, CF, follicular atresia, parasitic hepatitis and microsporidiosis. This is the first comparison of biomarkers of health in post‐spawning and spawning Baltic cod. Future studies need to examine the relationships of biomarkers to levels of pollutants in the environment and in tissues of cod.     

Reproduction related immunoglobulin changes in rainbow trout

Annual changes in plasma immunoglobulin (IgM) levels were investigated in three strains of rainbow trout Oncorhynchus mykiss which have different spawning periods, i.e., September–October, November–December, and January, reared under constant water temperature and natural day length. Plasma IgM levels decreased during the spawning season in all strains tested. The IgM changes became reversed in response to significant increases in plasma testosterone (T) and estradiol-17 in females and T and 11-ketotestosterone in males. Though the IgM decline showed a connection with suppressed immunocompetence, since many mature fish caught fungal diseases, no clear differences were observed in the plasma IgM levels between infected and noninfected fish during the spawning season. Incidentally, plasma IgM levels in infection prone fish were higher than in noninfection prone fish prior to the spawning season, whereas coincident differences in the plasma steroid levels were observed. Immature fish reared under lower water temperatures showed lower IgM levels. The effect of water temperature may have to be considered when analyzing the defense mechanism during the spawning season in rainbow trout.     

Tank spawning of grass carp

Induced spawning of grass carp in indoor tanks without hand stripping of gametes is described. Circular tanks (1.83 m diameter) with biofiltration units were utilized for conditioning and spawning. This method was found to be successful and has several advantages over the dry-fertilization method: (1) preliminary ripening and spawning is conducted in small systems where the environment is controlled; (2) manpower requirements are reduced; (3) handling of brood fish is reduced, thereby minimizing mortalities; and (4) spawning occurs when the fish is physiologically ready, insuring good egg quality.     

Using coupled fish behavior–hydrodynamic model to investigate spawning migration of Japanese anchovy,Engraulis japonicus,from the East China Sea to Taiwan

Adult Japanese anchovies (Engraulis japonicus) migrate from the East China Sea to the coastal region of Taiwan to spawn around late winter and early spring and, later, their larvae constitute important fisheries in Taiwan. However, their migration route and its mechanism remain unclear. To investigate their spawning migration, we used a coupled fish behavior–hydrodynamic modeling approach. The physical field is simulated by the Pacific Ocean adaptation of the TaIwan Multi‐scale Community Ocean Model (TIMCOM) and the fish migration by Lagrangian tracer tracking with the aid of approximation of fish swimming behavior. We investigated three fish behavioral scenarios: (i) passive tracking of the current, (ii) swimming along with the current, and (iii) swimming along with the current and then changing to swimming toward the optimal spawning temperature. The comparison with and without Changjiang discharge is used to investigate the impacts of discharge reduction due to the Three Gorges Dam. Our results suggest that spawning migration of Japanese anchovy from the East China Sea to Taiwan may be aided by the China Coastal Current and that adult anchovies cannot reach the spawning site by passive advection alone. Thus, the swimming behavior of anchovies is crucial during the spawning migration, as it provides extra velocity and the orientation to the favorable spawning grounds. In addition, the adult anchovy is unlikely to reach the coastal area of Taiwan without Changjiang discharge. Our findings indicate that a coupled fish behavior–hydrodynamic model can help understand the influences of physical environment on the migration of Japanese anchovies.     

Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA

Howell PJ, Dunham JB, Sankovich PM. Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA.
Ecology of Freshwater Fish 2010: 19: 96–106. This article is a US Government work and is in the public domain in the USA Abstract – Understanding thermal habitat use by migratory fish has been limited by difficulties in matching fish locations with water temperatures. To describe spatial and temporal patterns of thermal habitat use by migratory adult bull trout, Salvelinus confluentus, that spawn in the Lostine River, Oregon, we employed a combination of archival temperature tags, radio tags, and thermographs. We also compared temperatures of the tagged fish to ambient water temperatures to determine if the fish were using thermal refuges. The timing and temperatures at which fish moved upstream from overwintering areas to spawning locations varied considerably among individuals. The annual maximum 7‐day average daily maximum (7DADM) temperatures of tagged fish were 16–18 °C and potentially as high as 21 °C. Maximum 7DADM ambient water temperatures within the range of tagged fish during summer were 18–25 °C. However, there was no evidence of the tagged fish using localized cold water refuges. Tagged fish appeared to spawn at 7DADM temperatures of 7–14 °C. Maximum 7DADM temperatures of tagged fish and ambient temperatures at the onset of the spawning period in late August were 11–18 °C. Water temperatures in most of the upper Lostine River used for spawning and rearing appear to be largely natural since there has been little development, whereas downstream reaches used by migratory bull trout are heavily diverted for irrigation. Although the population effects of these temperatures are unknown, summer temperatures and the higher temperatures observed for spawning fish appear to be at or above the upper range of suitability reported for the species.