共查询到20条相似文献，搜索用时 218 毫秒
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Andrew E. Goodwin John M. Grizzle Douglas Tave Mike D. Gibson Jimmy Barnett Don H. Fiegel Berry F. Beavers 《Journal of the World Aquaculture Society》1994,25(2):230-235
Hybrid fish were produced in ponds by crossing golden shiners × rudd ( Notemigonus crysoleucas × Scardinius erythrophthalmus ) and rudd × golden shiners. Histologically, testes from the hybrids contained spermatocytes that resembled those of the parental species, but no sperm were observed. Lack of sperm in hybrids could have been a seasonal effect. The ovaries of both types of hybrids contained variable numbers of morphologically normal, vitellogenic oocytes and numerous abnormal oocytes in the chromatin nucleolar stage. Abnormal oocytes were necrotic or had irregularly shaped nuclei and clumped chromatin. Many oocyte nests contained infiltrating macrophnges. Spawning trials with F1 hybrids did not result in spawning behavior or production of F2 generation fish. Colden shiner × rudd hybrids are of reduced fecundity, but sterility was not conclusively demonstrated. 相似文献
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Abstract – The complexity of substrate covering spawning grounds of Coregonus lavaretus is assumed to have a role in the protection of incubating ova from predation. It is believed that the Loch Lomond population of C. lavaretus is adversely affected by invasive ruffe (Gymnocephalus cernuus) predation on eggs. To discover the protective ability of substrate commonly found on whitefish spawning grounds, predation experiments of ruffe on artificial eggs were conducted. These were presented to ruffe over different substrates: sand, gravel, pebbles and cobbles. It was found that the greatest protection was provided by pebbles and gravel. Eggs are exposed on sand, but are protected by small gaps between pebbles and gravel, while in cobbles the gaps between substrate particles are large enough to sometimes allow ruffe to foraging within the substrate. Using these results, a comparison between the potential protective ability of substrates of spawning grounds in four Scottish whitefish sites was attempted. 相似文献
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We studied daily spawning periodicity of a nest-building species, bluehead chub (Nocomis leptocephalus), and a nest associate, yellowfin shiner (Notropis lutipinnis), in three streams in the upper Piedmont region of South Carolina, USA. Field observations were conducted for 89 consecutive days in 2016 by recording the number of active nests and environmental variables. A total of 71 nests were located across study streams; bluhead chub and yellowfin shiner spawned between April and June. Spawning was observed periodically at intervals of 4–6 days within the same stream and across different streams, indicating broad-scale influences of the same environmental factors leading to synchrony. A generalized linear auto-regressive and moving average model showed that the periodic spawning pattern was likely caused by changes in water temperature, with effects of water level varying by stream. Specifically, spawning was triggered by a short-term (2-day) increase in water temperature and was observed under stable flow conditions (i.e. a lack of precipitation). This study showed that spawning periodicity of bluehead chub and yellowfin shiner tracked daily variation in in-stream conditions, indicating that their reproduction might be affected by anthropogenic disturbances that affect the rate of change in thermal and flow regimes at the fine temporal scale (e.g. hydroelectric dams and impervious cover). 相似文献
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Nicholas T. Simpson Alexander P. Bybel Michael J. Weber Clay L. Pierce Kevin J. Roe 《水产资源保护:海洋与淡水生态系统》2021,31(7):1831-1846
- Many fish species of greatest conservation need (SGCN) in Iowa and Minnesota, USA, have been in decline for decades. A key reason for the decline is the alteration and degradation of naturally flowing streams owing to land use changes resulting from agricultural practices. Populations of several fishes have been adversely affected by widespread stream channelization that has resulted in more homogeneous stream habitats throughout Iowa and Minnesota.
- The goal of this study was to determine the abiotic and fish assemblage characteristics associated with the presence of these rare fishes. Electrofishing and seining were used to sample fish assemblages and 43 abiotic characteristics were measured at 111 sites in the North Raccoon and Boone River basins in central Iowa and the Rock River and Beaver Creek basins in north-west Iowa and south-west Minnesota during 2016 and 2017.
- Six SGCN, including the federally endangered Topeka shiner (Notropis topeka), were included in statistical modelling to determine habitat and fish assemblage characteristics associated with their presence.
- Species-specific nonmetric multidimensional scaling ordinations indicated that abiotic characteristics and fish assemblages often differed between sites where SGCN were present and absent. Random forest and logistic regression models suggested that the presence of four of six SGCN were positively associated with species richness, whereas all other 10 important abiotic and fish assemblage variables were unique to only one or two of the six SGCN.
- Topeka shiners were present at 36% of sites and were positively associated with orangespotted sunfish (Lepomis humilis) catch per unit effort while being negatively associated with canopy cover and fantail darter (Etheostoma flabellare) catch per unit effort.
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C. E.Johnston 《Ecology of Freshwater Fish》2000,9(3):170-176
Abstract – The blue shiner ( Cyprinella caerulea ) is a federally threatened cyprinid that inhabits discrete habitat patches, but whether the fish in these patches represent distinct subpopulations or a continuous population is not known. Movement patterns of adult blue shiners among habitat patches in the Conasauga River (Tennessee and Georgia, USA) were investigated to determine if movement among patches was unrestricted, or if each patch represented a relatively discrete subpopulation. Movement was restricted to a small proportion of individuals at any given time, and most fish that moved did so between adjacent habitat patches. The average distance moved by blue shiners over the two study periods (1997 and 1998) was just 130.7 m. Riffle and glide mesohabitats were not barriers to the dispersal of blue shiners, and fish moved both upstream and downstream in approximately equal numbers. It is suggested that the fish that are mobile at a given time are responsible for recolonization of habitat patches via cumulative, stepwise movements between adjacent patches, and that intervening patches must be present to maintain connectivity of the entire population. Blue shiners exist as relatively discrete subpopulations in the Conasauga River. This finding emphasizes the importance of protecting habitat integrity throughout the entire course of the river to prevent isolation of subpopulations. This species may be used as a model for the conservation of other patch-restricted aquatic species. Note 相似文献
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Abstract – Bluegill ( Lepomis macrochirus ) primarily reproduce in spawning colonies. We assessed habitat characteristics at 15 bluegill spawning colonies in a South Dakota glacial lake. Nesting sites were visually identified and angling was used to verify the species of nesting fish. Habitat characteristics were measured at each nesting site and compared with those measured at 75 randomly selected sites. In Lake Cochrane, mean water depth of spawning colonies was 1.0 m. Of the 13 habitat characteristics measured, four (substrate type, substrate firmness, vegetation density and dissolved oxygen levels) were significantly different ( P ≤ 0.05) between nesting and random sites. Every bluegill nest site contained gravel substrate, despite the availability of muck, sand and rock. Substrate firmness was indexed at 0-cm penetration and vegetation density was low at all nesting sites. Additionally, bluegills selected nesting locations with relatively moderate dissolved oxygen levels. Lake Cochrane bluegill nest sites consisted of shallow, gravel areas with short, low-density, live submergent Chara vegetation. 相似文献
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Growth and mortality of prairie stream fishes: relations with fish community and instream habitat characteristics 总被引：2，自引：1，他引：2
Abstract – Few studies have been conducted to describe the age structure, growth rates and mortality of fishes in small stream ecosystems. The purpose of this study was therefore to determine age structure, growth rates and mortality (i.e., total annual mortality and, age-specific mortality) of central stonerollers Campostoma anomalum , creek chubs Semotilus atromaculatus , red shiners Cyprinella lutrensis and green sunfish Lepomis cyanellus from 13 streams on Fort Riley Military Reservation, Kansas, using incremental growth analysis. Further, we were interested in determining the influence of fish community and instream habitat characteristics on growth rates. The age structure of central stonerollers, creek chubs, and red shiners was dominated by young individuals (i.e., less than age 2); however, over 60% of the green sunfish were age 2 to age 4. Mean total annual mortality was >60% for cyprinids and averaged approximately 44% for green sunfish. The age-specific mortality of central stonerollers and red shiners was generally less than 45% between age 0 and 1 and increased to over 85% for fishes greater than age 1. Fish community characteristics (e.g., catch per unit effort of trophic guilds) and chemical habitat (e.g., total phosphorous) were not related to growth rates ( P >0.05). Growth of central stonerollers was not significantly correlated with physical habitat ( P >0.05). However, the growth increments of creek chubs, red shiners, and green sunfish were related to the amount of woody debris (e.g., total woody debris, log complex habitat; r >0.60; P ≤0.05). The results of this study provide important information on the population dynamic rate functions of cyprinid and green sunfish populations in small prairie streams. Furthermore, these data suggest that woody debris is important habitat influencing growth of stream fishes. Note 相似文献
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The role of flow dependency and water availability in fish assemblage homogenization in tributaries of the Chattahoochee River,Alabama, USA 
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下载免费PDF全文 The availability of water is becoming more variable as flow regime alterations intensify both locally and on a global scale. This pattern has been observed in the tributaries of the central Chattahoochee River System as water withdrawal and natural drought have caused flows to diminish. Stream discharge has steadily decreased in the study area by 31% over the last 50 years, and during this time, fish assemblage homogenization has occurred throughout the system. Our primary objective was to assess whether spawning mode and water availability are catalysts for fish assemblage change in tributaries of the Chattahoochee River System. We found that species which prefer or have adapted to low flow conditions (e.g. blacktail shiner Cyprinella venusta, redbreast sunfish Lepomis auritus and blackbanded darter Percina nigrofasciata) are becoming dominant and replacing historically dominant fluvial specialists. When examining short‐term changes between a dry year (2009) and a wet year (2010), some species preferring higher flows such as the highscale shiner Notropis hypsilepis were detected during the wet year, suggesting that the amount of water is important for the presence of these species in upstream reaches where they were historically abundant. Species that can reproduce successfully in low flow conditions are thriving and expanding their native ranges as more habitat becomes suitable. Species that require higher flows for part of their life cycle, however, appear to be declining from upstream areas as water availability continues to decrease, despite temporary recovery from downstream refugia during wet years. 相似文献
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Kaori Mizuno Sonoko Shimizu-Yamaguchi Chiemi Miura Takeshi Miura 《Fisheries Science》2012,78(5):1059-1064
To develop an efficient and stable method for enhancing spawning of black scrapers in captivity, we examined the following three factors: (1) different kinds of spawning substrate, (2) the area of the spawning substrate, (3) the grain size of the spawning substrate. The results demonstrated that sand is the optimum spawning substrate when compared to a hard polyvinyl chloride sheet, a piece of shading net, or artificial spawning grass. No difference was observed in the spawning frequency between a small sand bed of area 400?cm2 and sand spread over the bottom of the tank to an area of 7085?cm2, since the egg masses were spawned on the sand in a small area approximately 15?cm in diameter. In addition to the spawned eggs, the small movable sand bed is useful for subsequent harvest. No differences were observed in either the spawning frequency or the hatching rate when using sand beds with different grain sizes. In large-scale egg collection trials, an average of 33 egg masses from which an average of 403,000 larval fish were obtained. We can therefore conclude that the procedure developed in the present study is applicable to the commercial-scale seed production of black scraper. 相似文献
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Abstract – We used a combination of methods to study the reproductive ecology of the imperiled smalleye shiner Notropis buccula Cross in the Brazos River, Texas between April 2003 and March 2005. Patterns in oocyte development, gonadosomatic index and oocyte size distribution indicate that reproduction occurs over a 6‐month period between April and September and that the population spawns asynchronously with individual fish spawning small batches of ova throughout the reproductive season except during periods of elevated streamflow when spawning becomes more intense and is synchronised within the population. This combination of asynchronous spawning and episodic synchronous spawning in the same species challenges the current paradigm of an exclusive association between spawning and periods of elevated streamflow for pelagic, broadcast‐spawning cyprinids in North American Great Plains Rivers. The combination of asynchronous and synchronous spawning that we observed for the smalleye shiner is likely widespread among pelagic, broadcast‐spawning cyprinids and limitations of the methods commonly used to assess reproductive ecology likely contributed to an incomplete understanding of the relationship between spawning and streamflow. An accurate understanding of this relationship is necessary to design and implement appropriate conservation and management strategies for the smalleye shiner and other imperiled broadcast‐spawning cyprinid fishes. 相似文献
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Abstract– The southern cavefish ( Typhlichthys subterraneus Girard) is a small troglobitic fish found in a few disjunct populations in the central United States. Protecting and managing these populations requires a knowledge of southern cavefish microhabitat requirements, including their preference for substrate. We conducted tests of their preferences for cobble, gravel, pea gravel, and sand substrates in two-way and multiple choice experiments for extended periods using time-lapse video photography. Cobble proved to be the substrate these fish preferred to occur within. In nature, this preference may provide cavefish increased foraging opportunities and/or refuge from high flows associated with flooding. Our results indicate the need to (1) maintain coarse substrate as an integral part of cavefish habitats, and (2) direct cavefish censusing attempts towards such key areas. 相似文献
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Gregory Scott W. Guthrie Perry James W. Avault 《Journal of the World Aquaculture Society》1988,19(3):118-126
Juvenile prawns (Macrobrachium rosenbergii) were stocked at 37,050/ha and golden shiner (Noremigonus crysoleucas) fry at 321,100/ha into 16 earthen ponds at Rockefeller Wildlife Refuge, Grand Chenier, Louisiana. Four replicated treatments were tested: fed prawn monoculture, fed shiner monoculture, fed prawn and fed shiner polyculture, and unfed prawn fed shiner polyculture. The study lasted 149 days. There were no significant differences in growth between prawns fed in monoculture and prawns fed in polyculture (P > 0.05). However, fed prawns grew significantly larger (P < 0.05) than unfed prawns. Prawn survival in all treatments combined averaged 63%. Survival was significantly higher (P < 0.05) for fed prawns than for unfed prawns. Prawn yields averaged 533 kg/ha, when all treatments were combined. Yield was significantly higher (P < 0.05) for prawns grown with shiners and for prawns that received supplemental feed. Growth was significantly higher (P < 0.05) for shiners grown with fed prawns than for shiners grown with unfed prawns. Shiner survival averaged 33% and was significantly higher (P < 0.05) in monoculture than in polyculture. Yield for all ponds averaged 392 kg/ha, with no significant differences between treatments (P > 0.05). 相似文献
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Abstract Low-head dams in arid regions restrict fish movement and create novel habitats that have complex effects on fish assemblages. The influence of low-head dams and artificial wetlands on fishes in Muddy Creek, a tributary of the Colorado River system in the USA was examined. Upstream, fish assemblages were dominated by native species including two species of conservation concern, bluehead sucker, Catostomus discobolus Cope, and roundtail chub, Gila robusta Baird and Girard. The artificial wetlands contained almost exclusively non-native fathead minnow, Pimephales promelas Rafinesque, and white sucker, Catostomus commersonii (Lacepède). Downstream, fish assemblages were dominated by non-native species. Upstream spawning migrations by non-native white suckers were blocked by dams associated with the wetlands. However, the wetlands do not provide habitat for native fishes and likely inhibit fish movement. The wetlands appear to be a source habitat for non-native fishes and a sink habitat for native fishes. Two non-native species, sand shiner, Notropis stramineus (Cope), and redside shiner, Richardsonius balteatus (Richardson), were present only downstream of the wetlands, suggesting a beneficial role of the wetlands in preventing upstream colonisation by non-native fishes. 相似文献
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The golden shiner, Notemigonus crysoleucas, is a major bait and forage fish species in the USA. Farmers produce millions of golden shiners annually that are distributed live, many across state boundaries. Native over much of the eastern and central USA, this species is often present but rarely abundant in natural systems, as fish density is apparently controlled by predation rather than by food resources. Aquaculture of the golden shiner is a century‐old practice and culture methods have evolved over time, resulting in today's farm‐raised, certified specific pathogen– and aquatic nuisance species–free baitfish. Federal and state agencies and universities have a long history of developing culture methods and promoting baitfish culture to replace the indiscriminate and wasteful harvest of fish from natural waters. Despite advances in culture methods and the advantages of a farm‐raised species produced under controlled and biosecure conditions, golden shiner farming is only marginally profitable and remaining farmers survive on farm equity and increased market share from others exiting the business. Ironically, increasing regulations and restrictions leading to a reduction in the supply of farm‐raised baitfish could drive anglers back to harvesting bait from natural waters, the very concern that initiated government support for baitfish culture a century ago. 相似文献
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Abstract – Lake Michigan has experienced many ecological changes as a result of introductions of non‐native species. Arguably the most significant was that of alewife (Alosa pseudoharengus), yet studies on diet overlap with native species are lacking. We analysed diet trends of alewife, spottail shiner (Notropis hudsonius) and yellow perch (Perca flavescens) collected in summer and fall 2000–2007 near Waukegan, IL, in 3–10 m depths. Mean percentage composition by dry weight for 23 prey taxa was used in multivariate analysis to test whether diet differed across species and size classes. We also tested whether zooplankton and benthic invertebrate community composition changed over time. Fish diets were similar over all years but differed seasonally. In summer, diets of large alewife were similar to both small alewife and small yellow perch, with Bosminidae, chironomid larvae and copepods as primary common prey. During fall, alewife and yellow perch size classes exhibited strong intraspecific diet overlap, while there was low diet overlap between species. Primary distinctions between species’ diets in fall were higher consumption of amphipods by yellow perch and dreissenids by spottail shiners compared to alewife, which consumed higher proportions of zooplankton. Overall, high yellow perch diet overlap with alewife during summer and with their larger conspecifics during fall could lead to negative implications for yellow perch growth before the critical overwintering period. Detailed insights into diet overlap and prey availability are critical first steps in understanding competitive interactions between native and non‐native fish that dominate the nearshore community in southwestern Lake Michigan. 相似文献
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Long‐term fish assemblages respond to habitat and niche breadth in the West Fork White River,Indiana
Identification of patterns in community structure is a central theme in freshwater ecology. Our objectives were to identify temporal patterns in fish assemblages from 1980 to 2010 in the West Fork White River in east‐central Indiana using the Malthusian growth model and determine whether changes in the population growth rate parameter were related to Grinnellian niche breadth. We studied local‐scale fish assemblages in a Midwestern United States river at 16 sites for a period of 30 years. We used a hierarchical model to estimate population abundance parameters of the Malthusian growth model. Niche breadth was incorporated as a model parameter to explain variation in the population growth rate. Parameters of the model were fit using Bayesian inference. We identified notable changes in the fish assemblages; however, the patterns for temporal trends in individual species abundances were not conserved across sites. Decreasing trends were observed in longear sunfish, striped shiner, white sucker, central stoneroller, common carp and creek chub while bluegill and mimic shiner increased in abundance. Longear sunfish was the only species that exhibited the same trend in abundance for all sites. Niche breadth was inversely related to the population growth rate at sites adjacent to low‐head dam impoundments. We suggest that the presence of multiple impoundments has resulted in a fragmented series of fish assemblages. 相似文献