White Amur Research Articles

Isolation and characterization of polymorphic microsatellite loci in Wuchang bream (Megalobrama amblycephala)

AbstractWuchang bream (Megalobrama amblycephala) is an economically important fish in China. From a (GT)13‐enriched genomic library, 20 microsatellites were developed. Nine of these 20 loci were polymorphic in a test population with allele numbers ranging from two to four, and the observed and expected heterozygosities ranging from 0.2609 to 0.7826 and from 0.3739 to 0.7546, respectively. In the cross‐species amplifications, six of these nine loci were also polymorphic in white amur bream (Parabramis pekinensis). These polymorphic microsatellite loci are potentially useful for population genetics of Wuchang bream and its closely related species.

Genetic manipulations in aquaculture: a review of stock improvement by classical and modern technologies.

The aim of this review was to highlight the extent to which the genetic technologies are implemented by the aquaculture industry. The review shows that some of the modern genetic technologies are already extensively applied by the diverse aquaculture industries, though not to the same extent for all important aquacultured species (according to FAO 1998 figures). Some species (common carp, Atlantic salmon, rainbow trout, channel catfish, Nile tilapia, and the Pacific oyster) received concentrated breeding efforts, while other major cultured species (Chinese and Indian carps and the giant tiger shrimp) received, so far, relatively limited attention, and a few species (Yesso scallop, blue mussel, white Amur bream, and milkfish) have, apparently, not been genetically improved at all. Most of the genetically improved strains reaching the aquaculture industry were developed through traditional selective breeding (selection, crossbreeding, and hybridization). Emerging, more modern technologies for genetic manipulation seem to take 10-20 years from being established experimentally until applications affect the industry. Thus, chromosome-set and sex manipulations started to affect the industry during the 1980's and 1990's. DNA marker technology and gene manipulations have yet hardly affected the industry. The former have not matured yet, but hold much promise. The latter could have affected the industry already had it not been restricted by public concern.

Effects, constraints and the future of weed biocontrol

Many pest control approaches are presently promoted as biocontrol, however, in this paper the definition is restricted to ‘the utilization of parasites, predators and pathogens to regulate pest populations’. This covers two approaches against weeds: inundative and classical biocontrol. Inundative control applies an organism (usually a fungal disease) in the manner of a herbicide, and like a herbicide, it is usually marketed by industry. Classical biocontrol establishes an organism (usually an insect) from another region, to give continuing control of the pest and is largely done by governments in the public interest. Both types of biocontrol are regulated by legislation originally designed for other purposes, which is, at best, awkward. Both biocontrol approaches, in the right circumstances, are effective means of weed control with few harmful environmental impacts, but their use is limited by ecological, economic and regulatory constraints. These are illustrated by Canadian examples of a fungal disease for inundative control of round-leaved mallow and the white Amur fish for aquatic weeds. The classical biocontrol examples discussed are St. John's-wort, nodding thistle, leafy spurge and knapweed, as well as some new applications. The steps in classical weed biocontrol are outlined as well as the public involvement needed to develop a biocontrol solution for a weed.

Bacteriological Profile and Shelflife of White Amur (Ctenopharyngodon idella)

ABSTRACTOur objective was to compile a bacteriological profile and determine the effect of several storage conditions on the shelflife of white amur (Ctenopharyngodon idella). The profile showed the presence of Acinetobacter, Citrobacter, Enterobacter, Escherichia, Micrococcus, Moraxella, Pseudomonas, Staphylococcus, and Streptococcus. Storage studies on white amur flesh indicated 4°C and 200 μg/mL sodium hypochlorite dip were most effective against coliforms. Packaging in 100% CO2 significantly reduced aerobic bacterial growth (APC) compared to air. Freezing the flesh for 8 wk at ‐ 18°C reduced viable APC, psychrotrophs, and coliforms. Shelflife of white amur should be increased using storage conditions evaluated.

Environmental Impact of Weed-Control Insects

local and temporary. Such use of the organism is regulated under the legislation for chemical pesticides, and registration can be withdrawn if there are unwanted side effects. In contrast, classical biological control establishes an organism from another part of the world. With this approach the weed is continually controlled, but the introduction is generally irreversible. Once an organism is established, it is usually impossible to eradicate it. Most classical biological control organisms have been insects, although some micro-organisms, nematodes, and mites have been used. With a few exceptions, such as the White Amur fish, Ctenopharydon idella (Val.), vertebrates have not been used for weed control. Unless confined, their ecological impact tends to be devastating, such as the deforestation of the Mediterranean basin by goats. Worldwide, there are more than 300 examples in which an insect species has been introduced for the pur-

Significance of Preburial Taphonomic Processes to Visual Organic Analyses of Recent Lacustrine Sediments of Reelfoot Lake, Tennessee: ABSTRACT

Visual microscopic analyses of the recent lacustrine sediments of Reelfoot Lake in northwestern Tennessee revealed a possible paradox between the organic matter (OM) types expected versus those presently accumulating within this small lacustrine-palustrine environment. Based on the present wetland habitats, the dispersed OM actively being accumulated should predominantly consist of herbaceous (Type II) and woody (Type III) debris. However, preliminary observations revealed abundant Type I, amorphous/sapropel-like dispersed OM in bottom sediments. Two biologic conditions may account for some taphonomic loss. The lake is located within the northern end of the Mississippi Embayment and, therefore, is situated directly in a major migrational route for waterfowl. The Environmental Protection Agency reported that 16.1% of the total phosphorous loading into the lake results from feeding activities of wild ducks and geese, suggesting that a considerable part of OM being deposited in the lake has been affected by avian activities. Also, in 1983, 30,000 White Amur (grass carp) fish were introduced into the lake to control the aquatic vegetation encroachment. These fish can consume and digest mass quantities of aquatic vegetation during their lifetime (average 5-7 years). Thus, such aquatic herbivores also should account for a significant amount of the erosional activity within thismore » environment. These observations of biological activities indicate that OM may be degraded considerably, penecontemporaneously with deposition. Therefore, these factors should be considered when evaluating visual kerogen analyses of organic-rich lacustrine sequences.« less

Grass Carp as a Potential Control Agent for Cattails

Grass Carp as a Potential Control Agent for Cattails

Effects of white amur ( Ctenopharyngodon idella) on a Florida lake: a model

The Lake Conway model predicts that stocking white amur will decrease lake productivity and respiration, increase epipelic algae biomass for two years, and increase biomass of benthic invertebrates and biomass and number of secondary predator fish for at least nine years. Water quality, as defined by submersed macrophyte abundance, phytoplankton biomass, orthophosphate in the epilimnion, and amount of dead particulate matter in the water column, increases during to 10-y simulation. Because of the nature of white amur growth and assimilation rates, simulated grazing impact is heaviest three years after stocking. Carbon flow through both grazing and detritus food chains increases in the simulation, in spite of decreased photosynthesis.

Integration of duck and fish farming: Experimental results

In 1977 and 1978, two fish ponds at the Dor Aquaculture Experiment Station were integrated with duck production. Each pond's area was 400 m 2 and they were stocked with a polyculture of common carp, Tilapia, silver carp and grass carp (White Amur). The ducks were fed with prepared, nutritionally balanced feed, while the fish had to get by with the ducks' droppings plus the feed dropped directly from the ducks' beaks into the ponds. The ducks' performance on the ponds was superior to their ‘land’ control in growth rate, feed efficiency, viability and cleanness of feathers and skin. The average daily gain of the fish was 38.5 kg ha −1, not significantly different from ponds receiving similar mixtures of dry poultry manure plus supplementary feeds. Our experimental results provide necessary empirical support to the conclusion that the system is very efficient and its use should be expanded in warm water aquaculture.

Rotenone as a causative agent in the mass mortality of white Amur in an orange county, Florida pond

Abstract Water taken some two days after a mass mortality of white amur in an Orange County, Florida, holding pond was extracted with chloroform. The concentrated extracts were analyzed by high pressure liquid chromatrography (HPLC) and were found to contain rotenone, a known fish toxicant, upon comparison with an authentic sample. The water contained, by estimation, 1.8 ppm rotenone. Additional studies were made of the degradation of rotenone and associated materials of commercial samples in lake water in contact with sediment. The carrier materials degrade rapidly, i.e., within two days, though rotenone should persist for purposes of HPLC analysis for two days under ambient environmental conditions. The origin of rotenone in this water is unknown.

The White Amur as a Biological Control Agent of Aquatic Weeds in the Panama Canal

Abstract The Panama Canal has been plagued with both floating and submerged aquatic weeds since its opening. Although more and more money has been spent on herbicides over the years, the weed problem has become more intense. In February 1978 the Panama Canal Company introduced the white amur fish as a biological tool to control the submerged macrophyte hydrilla to Gatun Lake, the large freshwater reservoir through which the majority of the length of the Canal passes. The first shipment of fish (125,000) did not successfully withstand the rapid change from cold Arkansas water temperatures to the warm tropical waters, with a resultant loss of about 50 percent. A series of tests was conducted to determine tempering rates of the fish with temperature, dissolved oxygen level, and time as the variables. Various experiments with chemical additives in the tempering water such as salt and quinaldine were also conducted. Based upon the tests, a tempering facility to acclimate a second fish shipment was constructed ...

Intensive polyculture of fish in freshwater ponds. I. Substitution of expensive feeds by liquid cow manure

In 1974 and 1975 nine experimental treatments of fish polyculture in stagnant water ponds without aeration were conducted at Dor. The polyculture was composed of common carp, silver carp, white amur (grass carp) and Tilapia. The treatments differed in stocking densities, feeding and manuring levels. The most productive treatment of the experiment, in which the fish were fed with protein-rich pellets, produced 50 kg/ha per day, probably a record for unaerated ponds of stagnant water. Two treatments (low and high stocking densities) fed exclusively with liquid cow manure produced an average yield of around 32 kg/ha per day. The yields of the treatments receiving high-protein pellets exceeded those of the treatments receiving grain pellets by 20 and 9.6 kg/day per ha, at high and low stocking densities, respectively, and in both cases the yield increments justified the extra cost of high-protein feed. The responses of the four fish species to the different levels of feeding and stocking densities were widely different. The common carp and white amur showed the greatest responses to increased feeding inputs while the silver carp and Tilapia, even at high densities, have done equally well at low feeding levels. Total body fat contents of the common carp were 20%, 15% and 6.2% when fed with high-protein pellets, grains pellets and liquid cow manure, respectively. Intermittent harvesting did not result in increased yields.

Isozymes in androgenetic and gynogenetic white amur, gynogenetic carp, and carp-amur hybrids.

Gynogentic and androgenetic progeny appeared in crosses between white amur, Ctenopharyngodon idella, and carp, Cyprinus carpio. Hemoglobin, plasma general proteins, and plasma isoenzymes were studied by electrophoresis to determine inheritance patterns. Electrophoretic bands indicated that gynogenetic white amur had no paternal inheritance from carp and that adrogenetic white amur also were pure white amur. Gynogeneiss in carp was confirmed by the absence of paternal inheritance. Hemoglobins, general proteins, and esterases distinguished the two species. Within a species there were no differences in proteins between gynogenetic, adrogenetic and normal fish. Lactate dehydrogenase (LDH) differed between carp and white amur and was a good marker for detecting heterologous inheritance in adrogenesis or gynogenesis because expression of LDH alleles from white amur was inhibited by the carp genome. Alkaline phosphatase and malate dehydrogenase had similar electrophoretic mobility in the two species.

Pros and Cons: the Value of Aquatic Weeds in Reservoirs

Some people feel that aquatic weeds should be eliminated from reservoirs and some of the weapons used are the domesticated water buffalo, the manatee or sea cow (but not successfully), the water hyacinth weevil, the white amur fish and a virus which attacks three kinds of blue‐green algae. Some states have banned the use of the white amur because of fears that it could reproduce and produce an imbalance in more desirable game fish and that the destruction of vegetation could eliminate potential food sources for other life forms. There are also some people who feel aquatic weeds should be left alone. Recently it was found that water hyacinths and bullrushes could be useful in controlling pollutants and even in producing energy.

Various Fish Species as Biological Control Agents for the Dark Rice Field Mosquito 1 in Arkansas Rice Fields 2

During the summers of 1972–73, 10 fish species were evaluated as predators against larvae of the dark rice field mosquito, Psorophora confinnis (Lynch-Arribalzaga), near Stuttgart, Ark. Stocking rates were 0.02, 0.03, and 0.06 fish/ft2. At the lowest stocking rate green sunfish, Lepomis cyanellus Rafinesque, reduced larval numbers by 89.7% and were significantly more effective than adult mosquitofish, Gambusia affinis (Baird and Girard). The white amur, Ctenopharynogodon idella Valenciennes, was intermediate in effectiveness when compared with the above. At 0.03 fish/ft2, green sunfish reduced larvae by 99.2% and were significantly more efficient than juvenile mosquitofish, which had little effect on the larval population. At the 0.06 fish/ft2 rate mosquitofish; white amur; Israeli carp, Cyprinus carpio L.; and hybrids (Israeli carp × goldfish) were significantly more effective than bigmouth buffalo, Ictiobus cyprinellus (Valenciennes); black buffalo, Ictiobus niger (Rafinesque); goldfish, Carassius auratus (L.); or juvenile mosquitofish. Recovery counts of fish indicated that fish survived under natural conditions in Arkansas rice fields.

Observations on the Jumping and Escapement of White Amur

Observations on the Jumping and Escapement of White Amur

The White Amur for Aquatic Weed Control

The use of herbivorous fish for the biological control of aquatic weeds has great potential. The susceptibility of most herbivorous fish to low temperature is the principal factor limiting their use in the United States. The white amur (Ctenopharyngodon idella Val.) can tolerate low temperature and other water quality extremes. This fish has a voracious appetite for many aquatic plants, and after attaining a length of 30 mm, it is almost exclusively phytophagous. Factors affecting the feeding habits of the white amur include the species of plants and water temperature. The white amur has been introduced for aquatic weed control in various countries. This fish might ameliorate some of the aquatic weed problems in the United States, and also provide a new source of protein.

Sensitivity of the White Amur to Fish Toxicants

Sensitivity of the White Amur to Fish Toxicants

Food Habits of the White Amur Stocked in Ponds Alone and in Combination with other Species

that biological methods be used for controlling undesirable aquatic plants in both artificial impoundments and natural waters, since many of our existing chemical nntrol methods are potentially hazardous to the ecological balance of a pond, lake, or river, as well as to man himself. A number of organisms exist which will effectively control or eliminate certain aquatic plants. Several fish species have shown promise fs weed control agents, one of these being the white amur (Ctenopharjngodonidellua Va, lenciennes) also known as grass carp (Avault, Smitherman, and Shell, 1968). This fish has been in the United States for a decade, but is an exotic species indigenous to large rivers in China. One of the major reasons that white amur are not being widely used in this country is the fear that they may become established in our natural waters, as did the common carp, and compete with native fish for food organisms. Hora and Pillky (1962) reported that white amur do not spawn in ponds--they spawn in large rivers. If this is so, and it seems to be, it is possible that they can be used in ponds which are not connected to natural waters. Hora and Pillay (1962) classified white amur as an omnivore, and stated that it has a

IV.—On the Biology of a herbivorous Fish, the White Amur or Grass Carp,Ctenopharyngodon idellaVal

SynopsisThe important macrophyte-feeding cyprinid fishCtenopharyngodon idellaVal., the White Amur or Grass Carp, is native to temperate climates. The present paper is concerned with its biology when transplanted to Malacca, a tropical research station in latitude 2° 17′ N.At this station, the fish has a faster growth-rate, and may mature at an earlier age and smaller size, than in its native habitat. There are no marked seasonal changes at Malacca, and in these conditions the Grass Carp shows no spawning cycle, but some fish are ripe at any time of the year. While the testes of the males appear to develop normal milt, the ovaries in the fish examined seldom produced as many eggs as in their native habitat, and the eggs themselves have been shown to be mostly defective and to undergo early atresion.Consequently, though the ovulation of eggs of normal size was induced by pituitary injection in nineteen out of forty-eight trials, no success was got in the artificial fertilization of the eggs, though elsewhere success has been got in 25 per cent and more of trials. It is suggested that this fish may need the external stimuli which are associated with its natural spawning season to develope normal fertile eggs.