This study combined several features of acoustic and electromagnetic (EM) waves-based devices including sub-bottom profiler (SBP), side-scan sonar (SSS) and ground penetrating radar (GPR), and in situ sediment data to study responses of bottom sediments after carp removal in Lake Wingra. In 2007, i.e., before carp removal, macrophytes only grew to a water depth of 2 m. Meanwhile, GPR data showed no visible sublayer in vegetated regions, while SBP data revealed a loose and fluffy sediment layer in unvegetated regions, easily affected by wave or current motions. The field data showed that suspended sediment concentrations (SSC) were much greater in unvegetated regions than those in vegetated regions during a one-day wind event, and the resuspended sediments could remain suspended in the water column for two days. In 2009, i.e., after more than half (51%) of carp were removed, the fluffy sediment layer recognized by SBP became thinner or even disappeared, and both SBP and SSS results showed that submerged macrophytes started growing in deeper water. In situ sediment data presented that bulk sediment density and critical shear stress became greater, and bottom sediments consolidated and were harder to be resuspended. Secchi depth collected between 2008 and 2010 was greater than that in the previous 10 years, indicated clearer water state. In short, the fluffy sediment layer because of carp activities may be the main source for suspended sediments to deteriorate water quality. Removal of carp is crucial for stabilizing bottom sediment and improving water clarity in this small lake.

The poem discussed has long been regarded as a “nonsense” poem that was extemporized as part of some kind of poetry game at Court. This article presents evidence to demonstrate that through the use of puns and double entendre the poet in fact ingeniously devised a witty scatological verse. Rather than “nonsense”, the poem is discovered to offer covertly a deeply satirical social commentary on the contemporaneous relationships between men and women, aristocrats and outcastes.

Total RNA was purified from freshly isolated retinas of adult carp and injected into oocytes of Xenopus laevis (stage 5–6). Two to six days after injection, depolarizing voltage-clamp steps evoked a slowly activated outward currents as large as 3 μA. This current inactivated slowly with a single time constant (τ= 3.1 ± 0.24 S.E.M., for Vm= +30 mV). The current was inhibited by tetraethylammonium (3.8 mM for half-maximal inhibition). In the presence of Co2+ (1 mM) or barium methanesulfonate (40 mM), the current-voltage relationship shifted to slightly more depolarized values (5–10 mV); the maximal value of the current that was sensitive to Co2+ or Ba2+ treatments was only a small fraction (about 10%) of the TEA-sensitive current, and its current-voltage relationship was similar to that for uninjected oocytes. The reversal potential of the membrane current was studied with [K+]0 of 1–77 mM. For [K+]0 > 20 mM, the reversal potential changed with a slope of 63 mV (±;2 mV S.E.M.) per 10-fold change in [K+]0. The conductance was induced half-maximally at 17 mV (±;0.9 mV s.e.m.). The depolarization required for an e−fold increase in conductance was 13 mV (±;0.6 mV s.e.m.). From these results, we conclude that the injection of total RNA from carp retinas induces the formation of a membrane K+ channel in Xenopus oocytes. The channel formed has many of properties reported for the maintained outward current of goldfish horizontal and bipolar cells.

Using patch-clamp techniques, properties of cGMP-activated channel were studied at a single-channel level in order to examine (1) whether any differences are recognized between the cGMP-activated channels of rods and cones in the same animal species, and (2) whether the channel properties of the same photoreceptor class differ in different animal species. Experiments were performed on inside-out membrane patches excised from outer segments of rods and morphological subtypes of cones in the carp retina. Single-channel activities could be recorded when the patches were perfused with low concentrations of cGMP (<10 μM). Throughout five morphological subtypes of cones and rod, single-channel currents showed no significant rectification at membrane hyperpolarization in a low divalent cation solution, and single-channel conductances were almost the same: 13.8 ± 0.2 pS (mean ± s.e.m., n = 23) in cones and 12.7 ± 0.8 pS (n = 3) in rods. These values were significantly smaller than that reported in catfish cones (about 50 pS), and that in rods of the toad and the tiger salamander (about 25 pS). In rods and all subtypes of cones of the carp, open durations of cGMP activated channels were brief. In addition, kinetic parameters of channel openings and closings showed no differences throughout all subtypes of cones and rod.

Horizontal cells of the carp retina alter their synaptic connections with cones during dark and light adaptation. At light onset, dendrites of horizontal cells, which are positioned laterally at the ribbon synapse, form “spinules,” little processes with membrane densities. Spinules are retracted again during dark adaptation. Spinule retraction is also elicited upon glutamate application to the retina. In the present study, we address the question whether calcium/calmodulin-dependent pathways are involved in dark- and glutamate-evoked spinule retraction. Light-adapted retinas were isolated and subsequently dark adapted during incubation in media of different calcium concentrations. Spinule retraction was clearly blocked in low-calcium solutions (5 μM and 50 nM CaCl2). Incubation in medium containing cobalt chloride (2 mM) had the same effect. Both treatments blocked the glutamate-induced spinule retraction as well. These results indicate that spinule retraction is induced by a calcium influx into horizontal cells. To investigate whether calmodulin, the primary calcium receptor in eukaryotic cells, is present at the site of spinule formation, light- and dark-adapted retinas, embedded in LR White resin, were labelled with an antibody against calmodulin and gold-conjugated secondary antibodies. Horizontal cell dendrites at the ribbon synapse revealed strong calmodulin immunoreactivity, which was more than twice as high in light- as in dark-adapted retinas. The incubation of isolated retinas with the calmodulin antagonists W5 and W13 inhibited spinule retraction. In summary, these results suggest that spinule retraction may be regulated by calcium influx into horizontal cells and subsequent calcium/calmodulin-dependent pathways.

An in vitro assay was used to determine the effects of Sanguinicola inermis adults and cercariae on the polarization responses of pronephric leucocytes of carp. Leucocytes were isolated and exposed to live adult flukes or cercariae for up to 48 h. Differences in polarization responses were related to the presence of the parasite, the presence or absence of carp serum and the time of incubation. The mean proportions of cells exhibiting polarization in unstimulated controls ranged from 5 to 30% over the experimental period. Within 15 min of exposure to adults or cercariae, significant increases in mean polarization responses were observed of up to 75% and levels remained higher than control values for over 24 h. Overall, the presence of normal carp serum, either untreated or heat inactivated, did not enhance the polarization responses of leucocytes incubated with only cercariae or adults. However, between 0·25 and 3 h, the presence of carp serum with cercariae significantly enhanced polarization responses when compared with cells incubated with cercariae alone.

The objective of the present work was to determine the interaction of cone inputs in the response of horizontal cells using heterochromatic flicker photometry (HFP). Intracellular electrophysiological recordings were made in horizontal cells of isolated retinae of carp maintained in physiological solution, with the receptor side up. Sharp glass microelectrodes filled with 3 M KCl solution with resistances between 100 and 120 MΩ were used. Stimuli comprised six cycles of two 6-Hz sinusoidal light waves in counterphase adjusted for the same number of quanta: a green light (550 nm) from a monochromator with a Xenon lamp and an LED red light (628 nm). The stimulation program consisted of 10 steps with the 550-nm wave at constant amplitude, while the 628-nm wave varied in increments of 10% up to 100%, followed by another 10 steps with the 628-nm wave at constant amplitude while the 550-nm wave varied in increments of 10% up to 100%. We recorded responses from four different horizontal cell classes: H1 (monophasic, broadband, n = 37), H2 (biphasic, red-green color-opponent, n = 13), and H3 (biphasic, blue-yellow color-opponent, n = 2) cone horizontal cells; and RH (monophasic, broadband, n = 3) rod horizontal cells. H1 and RH horizontal cells showed a similar cancellation point at a heterochromatic mixture consistent with mixed inputs from 630- and 550-nm cones. No cancellation point was found for the H2 cell class. Fish H1 cells add cone inputs and signal “luminance” in light levels appropriate for cone stimulation. The same occurs with RH cells, which also signal “luminance,” but in light levels appropriate for rod work. For both cell classes there is an HFP cancellation point occurring at a combination of 628-nm and 550-nm lights in opposing phase that leads to the cancellation of the cell's response. No cancellation was found for H2 and H3 cells, which are the chromatically opponent horizontal cells in lower vertebrates.

Five polymorphic microsatellite DNA loci were identified in Labeo dero (Hamilton Buchanan), through cross-species amplification. Thirty-one primers developed for three cyprinids were tested in the study. The genetic variation detected at each polymorphic microsatellite locus was analysed. Significant genotype heterogeneity indicated that the samples are not drawn from same genepool. The identified microsatellite loci exhibited promise for use in fine scale population structure analysis of L. dero.

The exposure of freshly spawned, immotile carp sperm to hypoosmotic media triggers the initiation of calcium-dependent flagellar motility. Intracellular calcium concentration has been thought to be the critical component in motility initiation, possibly acting through a novel signalling pathway. The sensitivity of sperm cells to changes of osmolality of the environment raises the question whether a mechanoregulated osmosensitive calcium pathway is involved in the activation mechanism of carp sperm motility. The sperm cells are in a depolarized state in the seminal plasma (Ψ = –2.6 ± 3 mV) and they hyperpolarize upon hypoosmosis-induced activation of motility (Ψ = –29 ± 4 mV). The intracellular sodium [Na+]i, potassium [K+]i and calcium [Ca2+]i ion concentrations were determined in quiescent cells, and at 20, 60 and 300 s after activation. The [Na+]i and [K+]i of the quiescent cells were similar to the [Na+]e and [K+]e of the seminal plasma. Following hypoosmotic shock-induced motility, both [Na+]i and [K+]i decreased to one-fourth of the initial concentration. The [Ca2+]i doubled at initiation of the motility of the sperm cells and remained unchanged for 5 min. Bepridil (50–250 μM), a blocker of the Na+/Ca2+ exchanger, blocked carp sperm motility reversibly. Gadolinium, a blocker of stretch-activated channels (10–20 μM), inhibited sperm motility in a dose-dependent manner and its effect was reversible. Hypoosmotic shock fluidized the membrane and gadolinium treatment made it more rigid in both quiescent cells and hypotonic shock treated but immotile sperm cells. Based on these observations, it is suggested that, besides the well-known function of potassium and calcium channels, stretch-induced conformational changes of membrane proteins are also involved in the sperm activation mechanism of common carp.

Experiments were carried out to investigate the effect of five extenders (sucrose, glucose, fructose, KCl and a saline carp sperm extender) and two cryoprotectants (dimethyl-sulfoxide (DMSO) and methanol) on the cryopreservation of common carp sperm. Freezing of sperm using glucose extender and methanol as cryoprotectant resulted in the highest post-thaw motility, fertilization as well as hatching rates (63 ± 9%, 74 ± 15% and 67 ± 17% vs. 87 ± 5%, 84 ± 14% and 69 ± 14% using fresh sperm, respectively). In general, sugar-based extenders combined with methanol as cryoprotectant yielded higher motility, fertilization and hatching rates than ionic extenders in combination with DMSO. The jelly-like agglutination observed after thawing in samples frozen with sugar-based extenders did not reduce fertilization and hatching rates. Frozen–thawed sperm samples were able to successfully fertilize 10 g (8000) eggs.

The expressions of hexokinase IV (glucokinase, GK) and hexokinase (HK)-I genes were analysed during early ontogenesis of common carp (Cyprinus carpio). Unlike HK-I gene, which was expressed during all the stages of the development, GK was only induced by the first feeding with high levels of dextrin as a source of carbohydrate. This study confirms the high capacity of common carp to use glucose even at the very early stages of development.

The technique already adopted by the authors for the cryopreservation of rainbow trout blastomeres was applied to carp. Three stages were utilised for cell freezing: the morula stage, the early blastula stage and the late blastula stage. Survival rates were 89 ± 1.6 % for morula cells, 94 ± 0.6 % for early blastula cells and 96 ± 0.4 % for late blastula cells. Early blastula and late blastula cells reaggregated into morula-like bodies within 2 h in culture medium. Results suggest that the freezing technique adopted for rainbow trout may be successfully applied to carp. The morula stage blastomeres were more sensitive to freezing than blastula stage blastomeres, as already found in rainbow trout.

We propose a simple method to quantify the morphology of 2-3-year-old carps (Cyprinus carpio) which is related to their fillet yield. This method is based on the automated image analysis of the lateral projection of the fish (mask). Seven morphological measurements specifically related to fillet yield of carps were defined. The comparison between this method and the conventional quantification of fish shape, based on measurements of skeletal landmarks, increases the significance of this fitting. From the analysis of the morphometric data, we propose a profitable carp morphotype which is defined by four angles and two distances which quantify the shape of the head and the position of the caudal peduncle, respectively. The main characteristic of this morphotype is the absence of a large dorsal development, and the ventral position of the caudal peduncle.

Four experiments were performed with carp (Cyprinus carpio) in ponds of 200 m2 to test the effects of lysine supplementation of feeds with a low protein content. The initial mean weight of the carp and their daily rations were equal in all the ponds of the same experiment. In experiments 1 (400 fish/pond, 3 replicates) and 2 (200 fish/pond, 4 replicates), three diets were tested: A. 30% crude protein (1.7% total lysine); B. 25% crude protein + 0.5% lysine-HC1(1.7% lysine); C. 25% crude protein (1.3% lysine). In both experiments diet B resulted in weight gains equal to diet A, 20% higher protein retention and 20% less nitrogen discharge per kilogramme gain. Diet C lagged 10% in gain and excreted 10% more nitrogen than B. In experiments 3 and 4 (200 fish/pond, 4 replicates) the feed protein was reduced further and 5 diets were tested: A, B, C, similar to the former experiments, D. 20% crude protein + 1.0% lysine-HC1 (1.8% total lysine), E. 20% crude protein + 0.5% lysine-HC1 (1.4% lysine). In both experiments the results of groups A, B and C were parallel to experiments 1 and 2. Diets D and E resulted in lower growth compared to diet C (significantly in experiment 4) and increased body fat content. In conclusion, 30% protein in carp feeds, of which half the protein was soybean protein, could be decreased to 25%, by replacing soybean meal by grains, and supplementing lysine and methionine to the level of the 30% control. Growth was not impaired and nitrogen discharge into the environment was reduced approximately by 20%. Further feed protein reduction to 20%, with lysine supplementation, impaired growth rate below that of the unsupplemented 25% control diet, although total N-excretion was reduced even more.

Cold shocks and hydrostatic pressure shocks, respectively, were applied for the induction of bothtriploidy and tetraploidy in the common carp. Cold shocks of 0-2 °C, lasting 40 minutes and starting 2–5 minutes after the activation of gametes and hydrostatic pressure shocks with 1-3-5 minute exposures at 49.03–56.88 MPa (i. e. 7 116-8 225 psi – pounds per square inch), starting 5 minutes after the activation of gametes gave the best results. The tetraploidy induction by cold shocks or hydrostatic pressure shocks resulted either in negligible (1.54%), or in zero yields, respectively. The applicability of particular types of ploidy manipulation and the standardization of shock initiation were discussed.

Carps, Cyprinus carpio L., were exposed to a sublethal concentration of ammonia NH3 (0.102±0.059 mg.dm−3) during 3 weeks. The sensitivity of the blood picture and haemopoietic organs were evaluated. Ammonia intoxication resulted in erythroblastosis of circulating blood. Concurrently, a significant decrease in polychromatophilic erythroblasts in kidney and orthochromatic erythroblasts in spleen tissues were observed in exposed fish compared with controls. The relative proportion of erythrocytes in peripheral blood decreased and coincided with a highly significant (p < 0.01) increase of erythrocytes in spleen imprints of intoxicated carps compared with controls. Peripheral leucopenia, mainly lymphopenia as an intoxication response, was observed. In the pronephric cells significant differences in the proportion of young and adult eosinophils and the proportion of plasmocytes with vacuolized cytoplasm were found between those animals exposed to the toxic stress and the controls. Thus, the examination of haemopoietic organs has a great potential in carp health assessment.