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the ultrastructure of the eye of the mosquitofish gambusia affinis.the ultrastructure of the tissue components of the eye of gambusia affinis, excluding the sensory cells, is described. the cornea consists of two different sections of collagenous layers of different density. the choroid includes an argentea composed of alpha- and beta-melanophores, lipopterinophores and a choriocapillaris associated with the rete mirabile of the choroid body, bruch's membrane, underlying the retinal pigment layer, can develop complex associations with fibroblasts delimiting the ...19827066979
acute toxicity of some pesticides & a few inorganic salts to the mosquito fish gambusia affinis (baird & girard). 19807399617
glycogen in the central nervous system of adults and developing anamnia.the distribution of glycogen in the central nervous system of the viviparous teleost gambusia affinis and of the oviparous teleost jordanella floridae during development and in the adults, was examined. it emerged that the glycogen pattern in adults of gambusia and jordanella is very similar, whereas there are considerable differences during development. these differences were related to the different ways in which development takes place in the two species.19807415396
the first record of fish as paratenic hosts of falcaustra spp. (nematoda: kathlaniidae).two types of third-stage nematode larvae (most of which were encapsulated) were collected from the abdominal cavity and liver of the freshwater fishes etheostoma fonticola, etheostoma lepidotum, cichlasoma cyanoguttatum, lepomis auritus, lepomis sp., and gambusia affinis in texas and are referred to the genus falcaustra. this is the first record of falcaustra larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.19957472886
intermediate filaments in the testis of the teleost mosquito fish gambusia affinis holbrooki: a light and electron microscope immunocytochemical study and western blotting analysis.a light and electron microscope immunocytochemical study and western blotting analysis has been performed on intermediate filaments (vimentin, desmin and cytokeratins) in the testis of the teleost fish gambusia affinis holbrooki. an immunoreaction to vimentin was observed in the epithelium of the efferent ducts, testicular canal and their surrounding peritubular cells. positive vimentin immunostaining was also observed in the cells located around seminiferous tubules (boundary cells), leydig cel ...19957635766
detection of proliferating cell nuclear antigen in tissues of three small fish species.an immunohistochemical assay for proliferating cell nuclear antigen (pcna) identifies cells in all active phases of the cell cycle. in this study, pcna methodology, which was developed primarily for mammalian tissues, was adapted to three small fish species, medaka (oryzias latipes), guppy (poecilia reticulata), and western mosquitofish (gambusia affinis) that are used in carcinogenesis bioassays and environmental sentinel studies. our study showed that pcna can be identified in routinely proces ...19947703303
cytoskeleton in sertoli cells of the mosquito fish (gambusia affinis holbrooki).there is little information about the distribution of cytoskeletal components in the testes of teleost fish. the aim of this paper was to know the distribution of some major cytoskeletal proteins (tubulin, actin, vimentin, desmin, and cytokeratins) in the sertoli cells of gambusia affinis holbrooki and in their efferent duct epithelial cells which are possibly originated from the sertoli cells.19957710138
development of the anal fin appendicular support in the western mosquitofish, gambusia affinis affinis (baird and girard, 1854): a reinvestigation and reinterpretation.development of the sexually dimorphic anal fin appendicular support of an internal fertilizing bony fish gambusia affinis affinis was investigated by staining whole-mounted embryos, immature, and adult female and male g. a. affinis with alizarin red s and alcian blue. the tissue was examined histologically to assess development of the amphicelous centrum and to verify specificity of the stains. our data confirm earlier claims about the development of the male and female characteristics in this s ...19947879590
biocontrol efficacy of gerris (a) spinolae, laccotrephes griseus and gambusia affinis on larval mosquitoes.predation experiments using gerris (a) spinolae, laccotrephes griseus and gambusia affinis were conducted against iv stage culicine larvae with varying prey densities. ranking of individual predatory efficiency showed the sequence: large gambusia > medium gambusia > small gambusia > female laccotrephes > male laccotrephes > gerris. predation under coexistence reveals the significance of predatory efficiency of different predator combinations with reference to prey density and exposure period.19938034107
hepatocarcinogenesis in western mosquitofish (gambusia affinis) exposed to methylazoxymethanol acetate.to assess the potential of western mosquitofish (gambusia affinis) for the detection of environmental carcinogens, laboratory-reared specimens were exposed to methylazoxymethanol acetate 10 mg per 1 for 2 h and then examined periodically for the onset of neoplastic lesions. approximately 33 per cent of the exposed fish developed liver neoplasms within 25 weeks of exposure and 52 per cent within 40 weeks. the lesions were mostly hepatocellular carcinomas and cholangiocarcinomas. no neoplastic les ...19948040379
the distribution of corticotropin-releasing factor immunoreactive neurons and nerve fibres in the brain of gambusia affinis and salmo trutta.the study was carried out on the distribution of neurons and fibres which contain the corticotropin releasing factor-like (crf) immunoreactivity in the encephalon of two species of teleosts, gambusia affinis and salmo trutta. the peroxidase-antiperoxidase (pap) immunocytochemical technique was employed. the present study has shown differences between both species. in gambusia affinis, positive neurons were observed in the area ventralis telencephali pars lateralis (vlt), in the nucleus praeoptic ...19948075480
cytonuclear genetics of experimental fish hybrid zones inside biosphere 2.two species of mosquitofish (family poeciliidae) known to hybridize in nature were introduced into freshwater habitats inside biosphere 2, and their population genetics were monitored after 2 years. within four to six generations, nuclear and cytoplasmic markers characteristic of gambusia holbrooki had risen greatly in frequency, although some gambusia affinis alleles and haplotypes were retained primarily in recombinant genotypes, indicative of introgressive hybridization. the temporal cytonucl ...19948197186
control of mosquito breeding through gambusia affinis in rice fields.studies on mosquito breeding and its control through gambusia affinis in nursery and paddy fields after transplantation of seedlings were carried out during june to october 1991 in about 10 ha rice field area. six anopheline species, viz. an. culicifacies, an. annularis, an. subpictus, an. nigerrimus, an. barbirostris and an. aconitus, and four culicine species, viz. cx. tritaeniorhynchus, cx. bitaeniorhynchus, cx. quinquefasciatus, and aedes sp. could be identified. these were found breeding in ...19938405595
variation in heat shock proteins within tropical and desert species of poeciliid fishes.the 70-kilodalton heat shock protein (hsp70) family of molecular chaperones, which contains both stress-inducible and normally abundant constitutive members, is highly conserved across distantly related taxa. analysis of this protein family in individuals from an outbred population of tropical topminnows, poeciliopsis gracilis, showed that while constitutive hsp70 family members showed no variation in protein isoforms, inducibly synthesized hsp70 was polymorphic. several species of poeciliopsis ...19958524039
correlation between biochemical parameters and susceptibility of freshwater fish to malathion.acute toxicity (96-h lc50) of malathion was tested using five species of freshwater fish, namely, topmouth gudgeon (pseudorasbora parva), goldfish (carassius auratus), nile tilapia (tilapia nilotica), mosquitofish (gambusia affinis), and rainbow trout (salmo gairdneri). correlation was found between susceptibility and biochemical parameters such as activity of brain acetylcholinesterase (ache) and in vitro resistance of the enzyme to inhibition (ic50) of malaoxon (a major metabolite of malathion ...19968691510
time course of inhibition of cholinesterase and aliesterase activities, and nonprotein sulfhydryl levels following exposure to organophosphorus insecticides in mosquitofish (gambusia affinis).cholinesterase (che) in brain and muscle was quickly inhibited during a 48-hr in vivo exposure to chlorpyrifos (0.1 ppm), parathion (0.15 ppm), and methyl parathion (8 ppm) in mosquitofish (gambusia affinis). che remained inhibited during a 96-hr nonexposure period. brain che reached peak inhibition by 12 hr after exposure to parathion and chlorpyrifos and by 4 hr after exposure to methyl parathion. all insecticides caused greater than 70% che inhibition by 4 hr in muscle. there was no recovery ...19968742317
adverse assessments of gambusia affinis: an alternate view for mosquito control practitioners.adverse opinions on the introduction of gambusia affinis for the control of larval mosquitoes are reviewed. the sources span a period of some 59 years and come from a variety of sources. the principal opposition to the introduction of g. affinis comes from ichthyologists, although some mosquito researchers have expressed concerns about the environmental impact of placing the fish in habitats to which it is not native. questions concerning the appropriateness of using the fish are presented.19968827587
organizational-activational concept revisited: sexual differentiation in an atherinomorph teleost.because of its numerous sexually dimorphic characters, the western mosquitofish gambusia affinis affinis is an excellent vertebrate system for addressing questions concerning sexual differentiation. in this review, the actions and limits of gonadal sex steroids, specifically testosterone, on the development of the sexually dimorphic anal fin and its axial and appendicular support are described. data from our laboratory show that the critical period in this species for the anterior transposition ...19969047280
sex differences in endogenous retinoid release in the post-embryonic spinal cord of the western mosquitofish, gambusia affinis affinis.in this study we have shown sex differences in endogenous retinoic acid synthesis and retinaldehyde dehydrogenase activity in the post-embryonic spinal cords of immature female and male g. a. affinis. the f9 reporter cell assay and the zymography bioassay showed that the endogenous retinoic acid levels correlated with the levels of the endogenous enzyme(s) responsible for retinoic acid synthesis. these data also showed that both the endogenous retinoic acid levels and the enzyme(s) were higher i ...19979059611
mosquito control with gambusia affinis. 19979152886
activity of esterases from different tissues of freshwater fish and responses of their isoenzymes to inhibitors.activity of nonspecific esterase from different tissues (i.e., liver, gallbladder, heart, intestine, and muscle) of five species of freshwater fish, namely, topmouth gudgeon (pseudorasbora parva), goldfish (carassius auratus), nile tilapia (tilapia nilotica), mosquitofish (gambusia affinis), and rainbow trout (salmo gairdneri) was tested using alpha-naphthyl acetate as substrate. the results indicated that activity of the enzyme was mainly concentrated in the digestive system (i.e., intestine, l ...19979176555
internal lethal concentrations of halobenzenes with fish (gambusia affinis).the internal lethal concentrations is a potential measure of toxicity which could be usefully applied in environmental toxicology and risk assessment. using halobenzenes, which are common environmental contaminants, and represented test compounds, experiments were conducted in aquaria with the mosquitofish (gambusia affinis). the average internal lethal concentration (ilc50) for four representative halohydrocarbons, 1,4-dibb, 1,2,3-tricb, 1,2,4-tribb, and pentacb, were consistent with those prev ...19979212338
opsin sequences of the rod visual pigments in two species of poeciliid fishthe rod opsin sequences from gambusia affinis holbrooki and poecilia reticulata were cloned and sequenced. the opsin sequences were found to be 96·8% identical, reflecting the similarity of the rod visual pigment absorbances in these two poeciliid fish.19979236103
diurnal fluctuations in toxicity in two fish species: gambusia affinis and notropis ludibundis. 19979256395
mosquito control with gambusia affinis. 19979383776
adrenocortical and adrenomedullary homologs in eight species of adult and developing teleosts: morphology, histology, and immunohistochemistry.morphology, histology, and immunohistochemistry of the adrenocortical and adrenomedullary homologs (adrenal glands) of the following developing and adult teleosts were examined: salmoniformes-oncorhynchus mykiss (rainbow trout), salmo trutta fario (brown trout), coregonus lavaretus (white fish); cyprinodontiformes-gambusia affinis (mosquito fish). perciformes-dicentrarchus labrax (sea bass), sparus aurata (sea bream), diplodus sargus (white bream), oblada melanura (saddled bream). the anatomical ...19979405124
effects of halobenzenes on growth rate of fish (gambusia affinis).the growth rate reduction of mosquito fish (gambusia affinis) fry was investigated with a range of sublethal exposure levels of four halobenzenes for 42 days. these compounds were found to produce growth rate reduction in mosquito fish fry at concentrations as low as 0.30, 0.18, 0.025, and 0.010 mumol liter-1 for 1,4-dibromobenzene, 1,2,3-trichlorobenzene, 1,2,4-tribomobenzene, and pentachlorobenzene, respectively. the aqueous exposure concentrations causing growth rate reduction of 50 and 10% ( ...19989515084
a new cacospongionolide inhibitor of human secretory phospholipase a2 from the tyrrhenian sponge fasciospongia cavernosa and absolute configuration of cacospongionolides.a new inhibitor of human secretory phospholipase a2 (pla2), cacospongionolide e (4a), has been isolated from the tyrrhenian sponge fasciospongia cavernosa. the structure was proposed on the basis of spectroscopic data and by chemical transformations. the absolute configuration of cacospongionolides 2a-4a was established using the modified mosher's method. cacospongionolide e was the most potent inhibitor toward human synovial pla2, showing higher potency than the reference compound manoalide and ...19989677277
toxicity and pathogenicity testing of the insect pest control fungus metarhizium anisopliaerenewed interest in the use of metarhizium anisopliae and its toxins for insect control prompted the following safety assessment. a neutral extract (methylene chloride, ph 7.2), derived from m. anisopliae cultures, was evaluated for toxicity and mutagenicity using aquatic animal bioassays and the ames test. the average lc50 of the neutral extract obtained in static, acute 96-h tests conducted with </=24-h-old mysidopsis bahia was 2.41 mg l-1. by partially purifying destruxins from the neutral ex ...19989680524
short-term effects of bolero on the gill apparatus of a small number of mosquitofish (gambusia affinis). 19989702371
internal lethal concentration and internal lethal volume fraction of chlorobenzenes in mosquito fish (gambusia affinis).the internal lethal concentration (ilc) and internal lethal volume fraction (ilvf) of a series of chlorobenzenes with mosquito fish (gambusia affinis) were measured by a semistatic test approach in closed jars. their variation with exposure times were also investigated with different aqueous chemical concentrations and different exposure periods, the measured ilc values on wet weight and lipid weight bases ranged from 3-12 mmol kg-1 and 46-208 mmol kg-1 lipid, respectively. measured ilvf values ...19989717246
parasitological data as monitors of environmental health.when an appropriate fish host is selected, analysis of its parasites offers a useful, reliable, economical, telescoped indication or monitor of environmental health. the value of that information increases when corroborated by another non-parasitological technique. the analysis of parasites is not necessarily simple because not all hosts serve as good models and because the number of species, presence of specific species, intensity of infections, life histories of species, location of species in ...19979802064
a mechanism for anterior transposition of the anal fin and its appendicular support in the western mosquitofish, gambusia affinis affinisthe interosseal and suspensory ligaments of the axial and appendicular skeleton of the western mosquitofish, gambusia affinis affinis were investigated in whole-mounted late embryonic and adult female and male g. a. affinis stained with alcian blue and alizarin red s, cleared, and viewed using differential interference contrast. the interosseal and suspensory ligaments of late embryonic female g. a. affinis are reduced prior to sexual differentiation and continue reduced in adult females. howeve ...19989873137
polymorphic microsatellite markers in the western mosquitofish, gambusia affinis. 19999919704
morphological and reproductive characteristics of male mosquitofish (gambusia affinis holbrooki) inhabiting sewage-contaminated waters in new south wales, australia.the potential effects of exposure of fish to reproductive endocrine disruptors (reds) is of major concern. this study reports on the effects of sewage effluent exposure on morphology of male mosquitofish (gambusia a. holbrooki) in a tributary of the hawksbury-nepean river system in new south wales, australia. the growth and development of the modified anal fin (the gonopodium, gp) is a secondary sexual characteristic in males, forms under the influence of testosterone, and is critical for sperm ...199910047598
use of gambusia affinis in different habitats as a mosquito control agent. 199710085646
comparative efficacy of the threespine stickleback (gasterosteus aculeatus) and the mosquitofish (gambusia affinis) for mosquito control.the effectiveness of the threespine stickleback as a mosquito control agent was compared to that of the mosquitofish in 28-m2 earthen ponds during 26-wk experiments where the 2 fish were stocked alone and together. relative to ponds without fish, the stickleback was not effective for controlling larval mosquito populations; however, sticklebacks reduced the abundance of culex pupae. mosquitofish provided significant levels of control whether stocked alone or concurrently with the stickleback. as ...199910480131
environmental regulation of annual reproductive cycle in the mosquitofish, gambusia affinis.to clarify the environmental factors regulating the annual reproductive cycle of the female mosquitofish, gambusia affinis, a viviparous teleost, histological changes of the ovary in natural population, and laboratory experiments were examined. the results, extending over two years, suggested that ovarian recrudescence is initiated by the rise in temperature during spring and that ovarian regression is caused by the shorter daylength during late summer. the first rearing experiments using four p ...200010617862
scalarane and homoscalarane compounds from the nudibranchs glossodoris sedna and glossodoris dalli: chemical and biological properties.a series of homoscalarane and scalarane compounds (2-7) have been isolated from two distinct species of pacific glossodoris nudibranchs. the structure and elucidation of the relative stereochemistry of the new metabolites 2 and 3 were obtained by spectroscopic methods. compound 2 was ichthyotoxic at 0.1 ppm against gambusia affinis and showed moderate activity (ic(50) 18 microm) to inhibit mammalian phospholipase a(2).200010785432
toxicity of a neem (azadirachta indica) insecticide to certain aquatic organisms.neem based insecticides are likely to show a large increase in use in the near future. in the present work, the toxicity of a neem insecticide, neem-azal-t/s, was tested against the mosquito larvae, as well as against certain non target organisms occurring in a polluted pond and a shallow stream, located in a cultivated area in giza, egypt. samples of water containing the experimental animals were collected from this area, and toxicity tests were conducted in the laboratory by exposing them to a ...200010786033
a model for non-specific toxicity with aquatic organisms over relatively long periods of exposure time.experimental data have shown that the internal lethal concentrations of halobenzenes for aquatic organisms decreased with exposure time. in this paper, a model based on the concept of life expectancy reduction was developed to describe this relationship. the model was verified with experimental data for fish (gambusia affinis) and juvenile crab (porturius pelagicus(l)). it is proposed that long term non-specific toxicity can be measured as the reduction of the life expectancy of the exposed orga ...199910903121
natural control of culex quinquefasciatus larvae in residential ditches by the copepod macrocyclops albidus.natural populations of three larvivorous copepod species live in residential roadside ditches in louisiana: macrocyclops albidus, acanthocyclops vernalis, and megacyclops latipes. macrocyclops is most common and killed an average of 27 first-instar culex quinquefasciatus larvae/copepod/day in the laboratory. although severe pollution from septic tank effluent in some parts of the ditches creates havens for cx. quinquefasciatus production by excluding predatory copepods and fish (gambusia affinis ...200010925792
evaluating mosquito control pesticides for effect on target and nontarget organisms.recent requirements for biomonitoring of urban stormwater runoff have raised the issue of toxic contributions from mosquito control products. a comparison of seven pesticides for their toxicity to target and nontarget organisms was conducted in field and laboratory trials to determine relative impacts in and around craighead county, arkansas. twenty-four and forty-eight-hour acute toxicity tests using ceriodaphnia dubia, daphnia magna, daphnia pulex, and pimephales promelas were employed with u. ...200010948282
toxicity and bioconcentration of chlorpyrifos in aquatic organisms: artemia parthenogenetica(crustacea), gambusia affinis, and aphanius iberus (pisces). 200011014847
experimental evaluation of the usefulness of microsatellite dna for detecting demographic bottlenecks.evolutionary and conservation biologists often use molecular markers to evaluate whether populations have experienced demographic bottlenecks that resulted in a loss of genetic variation. we evaluated the utility of microsatellites for detection of recent, severe bottlenecks and compared the amounts of genetic diversity lost in bottlenecks of different sizes. in experimental mesocosms, we established replicate populations by releasing 1, 2, 4 or 8 pairs of the western mosquitofish, gambusia affi ...200011050547
discrimination between several diterpenoid compounds in feeding by gambusia affinis.the alcyonacean soft coral sinularia flexibilis quoy and gaimard produces a number of bioactive complementary (secondary) metabolites. the ability of three of these diterpenes - flexibilide, sinulariolide and dihydroflexibilide - to elicit differential discriminatory feeding behavior in gambusia affinis was assessed in a feeding deterrence study. terpene-impregnated fish flakes were offered to fish trained to feed on such food, and their responses (acceptance, rejection, avoidance, or no respons ...200111166674
relationship between allozyme genotype and sensitivity to stressors in the western mosquitofish gambusia affinis detected for elevated temperature but not mercury.previous studies with gambusia holbrooki have found associations of allozyme genotype with tolerance to metals, pesticides, heat, and salinity. to examine the generality of these relationships, we looked for similar associations of mercury and heat tolerance with allozyme genotype at the gpi-2, mdh-1 and mdh-2 loci in its sister species gambusia affinis. this was done to assess if the loci themselves or closely linked loci were associated with mercury tolerance, because weaker linkage associatio ...200111239682
mosquitofish (gambusia affinis) vitellogenin: identification, purification, and immunoassay.vitellogenin is a phospholipoglycoprotein precursor of egg yolk. in mature female fish, vitellogenin is synthesized and secreted by the liver in response to circulating estrogens. vitellogenin is normally undetectable in the blood of male fish, but can be induced by exposure to compounds possessing estrogenic activity. thus, the presence of vitellogenin in blood of male fish can serve as a useful biomarker for assessing previous exposure to estrogenic compounds. in the present study, we report i ...200111239836
structure and function of the axillary organ of the gulf toadfish, opsanus beta (goode and bean).the structure of the axillary organ of a batrachoidid species, the gulf toadfish (opsanus beta goode and bean 1879), has been examined and several simple experiments designed to elucidate its function performed. electron microscopy (em) studies revealed cells and structures suggesting secretory and iono regulatory roles (e.g., abundant intracytoplasmic secretory particles, rough endoplasmic reticulum, sparse golgi bodies, indented epithelial cells with microvilli, numerous endocytotic vesicles, ...199811253782
the histopathological effects of thiodan on the liver and gut of mosquitofish, gambusia affinis.thiodan (33.7% endosulfan), a polychlorinated cyclodiene insecticide, was evaluated for its histopathological effects on mosquitofish, gambusia affinis, by light microscopy. fish were exposed to doses of 0.00 (control), 1.00, 2.50, and 5.00 microg/l on days 7, 14, 21, and 30. no histopathological effects were apparent at control group. the histopathological alterations were characterized as oedema, degeneration, accumulation of lymphocytes in the lamina propria, disintegration of villuses, pycno ...200111281257
masculinization of female mosquitofish in kraft mill effluent-contaminated fenholloway river water is associated with androgen receptor agonist activity.female mosquitofish (gambusia affinis holbrooki) downstream from kraft paper mills in florida display masculinization of the anal fin, an androgen-dependent trait. the current investigation was designed to determine if water contaminated with pulp-mill effluent (pme) from the fenholloway river in florida displayed androgenic activity in vitro and to relate this activity to the reproductive status of female mosquitofish taken from this river. we tested water samples for androgenic activity from a ...200111452138
gonopodium development in normal male and 11-ketotestosterone-treated female mosquitofish (gambusia affinis): a quantitative study using computer image analysis.mature male mosquitofish possess a highly modified anal fin called a gonopodium that develops from an unmodified female-like anal fin under the influence of endogenous androgens at sexual maturity. although females do not normally develop gonopodia, their anal fins can be induced to develop into gonopodium-like structures by the administration of androgens. we used computer image analysis techniques to quantify the morphological changes in the anal fins of normal male and female mosquitofish dur ...200111482943
population genetic structure of the western mosquitofish, gambusia affinis, in a highly channelized portion of the san antonio river in san antonio, tx.population genetic assessments were performed on populations of the mosquitofish, gambusia affinis, sampled at seven sites along a 10 km reach of the upper san antonio river in san antonio, tx. mosquitofish populations were sampled from the downtown area, known as the "riverwalk", where the river is concrete lined, deeply pooled, and receives heavy tour boat traffic. populations were also sampled from sites upstream and downstream from the riverwalk. allozyme electrophoresis was performed on app ...200111501432
histopathological changes in the gills of mosquitofish, gambusia affinis exposed to endosulfan. 200211815801
chemicals of predatory mosquitofish (gambusia affinis) influence selection of oviposition site by culex mosquitoes.ovipositing insects may avoid aquatic sites where there is high predation risk to their offspring, but the proximate mechanisms that mediate avoidance behavior are poorly resolved. we conducted an experiment to determine whether mosquitoes would reduce oviposition rates in pools containing chemicals of the mosquitofish (gambusia affinis), a voracious predator that is widely employed to control mosquitoes. experimental treatments consisted of outdoor pools that contained known concentrations of f ...200212035927
toxicological effects of the herbicide oxyfluorfen on acetylcholinesterase in two fish species: oreochromis niloticus and gambusia affinis.the alterations of the ache activity in the brains of two fresh water fishes; oreochromis niloticus and gambusia affinis were measured after exposure to acute, sub-acute and chronic concentrations from the widely used herbicide; oxyfluorfen. bioassays were conducted under controlled laboratory conditions. the used concentrations were acute: lc50 for 6 days, sub-acute 1/3 lc50 for 15 days and chronic 1/10 lc50 for 30 days. the obtained results showed marked inhibitory effects of the herbicide on ...200212046652
reproductive characteristics of male mosquitofish (gambusia affinis) inhabiting a small southeastern u.s. river receiving treated domestic sewage effluent.a population of western mosquitofish (gambusia affinis) living below a wastewater treatment plant in the vicinity of birmingham (al, usa) was studied for evidence of exposure to estrogens. mosquitofish are sexually dimorphic live-bearing fish. males have an elongated and modified anal fin, called a gonopodium, used in mating. it has been hypothesized that exposure to estrogens and/or anti-androgens in treated wastewater might inhibit the androgen-dependent development of the gonopodium. the popu ...200212109740
morphology and life cycle of apatemon hypseleotris species novum from australia including metacercariae viability and excystment.experimental infection of pigeon squabs and rats with encysted metacercariae from the western carp gudgeon (hypseleotris klunzingeri) showed them to be infected with a new strigeid trematode, apatemon hypseleotris. growth and development of a. hypseleotris in pigeons were significantly higher than in rats. eggs appeared in pigeon faeces within 7-14 days; miracidia hatched within 15-21 days and in the snail lymnaea tomentosa released within 21 days. cercariae experimentally encysted in the leeche ...200212161969
potential of origanum compactum as a cercaricide in morocco.at 1 mg/litre, an ethyl-acetate extract of the molluscicidal plant origanum compactum benth. (lamiaceae) immobilized all of the furcocercariae of schistosoma haematobium exposed to it, within 15 min. this apparently cercaricidal activity was attributed to the presence of terpenoids and flavonoids in the extract. encouragingly, several non-target aquatic organisms (larvae of culex pipiens and artemia salina and adult gambusia affinis) and drosophila melanogaster appeared largely unaffected by exp ...200212396321
effects of diflubenzuron on growth and glutathione in mosquito fish (gambusia affinis).although some biological control agents and related biorational approaches are available for mosquito control, insecticides remain the principal control method. in addition, the secondary affects of conventional insecticides in environment has led to the discovery of more target-specific chemical such as insect growth regulators. dimilin (25% wp), the common name of diflubenzuron, prevent molting by interfering with chitin synthesis in several insect orders. this study evaluate toxicity of this ...200112425112
control of the aedes vectors of the dengue viruses and wuchereria bancrofti: the french polynesian experience.in most of the 130 islands of french polynesia, the stenotopic mosquitoes aedes aegypti (the main local vector for the viruses causing dengue) and aedes polynesiensis (the main local vector of wuchereria bancrofti) share many breeding sites in water containers such as discarded cans, coconut shells, buckets and water-storage pots and drums. in addition to selective application of insecticides, non-polluting methods of controlling these mosquitoes have been evaluated during the last decade in two ...200212625924
elements in fish of malibu creek and malibu lagoon near los angeles, california.our aim was to assess whether past discharges from a wastewater treatment plant increased metal pollutant loads in stream mobile species in a one-day baseline sampling study that included a coastal wetland. mosquitofish (gambusia affinis) of two sizes, black bullhead (ameiurus melas), and crayfish (pacifastacus leniusculus) were collected from malibu creek, and california killifish (fundulus parvipinnis) of three sizes, as well as arroyo chub (gila orcutti) were sampled from malibu lagoon near l ...200312705915
in vivo and in vitro assessment of the androgenic potential of a pulp and paper mill effluent.the androgenic potential of a new zealand pulp and paper mill effluent was measured by applying a combination of in vitro and in vivo bioassays with mosquitofish (gambusia affinis) and goldfish (carassius auratus). the in vivo method assessed the rate of gonopodial development (masculinization) and alterations from normal reproductive behavior in adult female mosquitofish exposed for 21 d to untreated or secondary-treated pulp mill effluent. a second in vivo mosquitofish exposure tested the effe ...200312836968
histopathology of gills in mosquitofish, gambusia affinis after long-term exposure to sublethal concentrations of malathion.the histopathological effects of malathion, an organophosphate pesticide, on the gill tissues in mosquitofish, gambusia affinis, were determined by light microscope. the fish were exposed to sublethal concentrations (0.01 and 0.02 mg/l) of malathion for 10, 20 and 30 days. histological examination of the gills treated with malathion showed a variety of histopathological effects. the gill lesions included necrosis and desquamation of secondary lamellar epithelium, lifting up of epithelium, intrae ...200312929717
incidence of coliform bacteria in the intestinal tract of gambusia affinis holbrooki (girard) and in their habitat water. 196313955523
resistance to ddt in the mosquito fish, gambusia affinis.mosquito fish from waters near cotton fields that have had a long history of treatment with chlorinated hydrocarbon pesticides exhibited a marked resistance to ddt compared with fish from areas which had had no past exposure to insecticides.196313997402
sex differentiation and pubertal development of gonads in the viviparous mosquitofish, gambusia affinis.the ontogenetic development of gonads from embryo to adult was observed histologically in the viviparous teleost, gambusia affinis. primordial germ cells (pgcs) appeared in the subendodermal space of the embryo 14 days before birth, and then transferred to the dorsal mesentery to form paired genital ridges 12 days before birth. the pgcs proliferated in the genital ridge, forming gonadal primordia 10 days before birth. all gonadal primordia differentiated to the ovary containing oocytes 2 days be ...200314569146
[experimental study of larval efficiency of gambusia affinis holbrooki (girard, 1859) (fish-poecilidae)].experimental study of efficiency of gambusia affinis holbrooki (girard, 1859) (fish-poecilidae). gambusia affinis is a culiciphage fish which was introduced in tunisia in 1929 to control mosquito larvae. in the present study, we confirm, under laboratory conditions, the good efficacy of gambusia affinis against mosquito larvae. the consumption of larvae decreases with the evolution of larvae instars and increases, for the same instar, in relation with the fish size. in fact, the size of the prey ...200614666756
effects of the agricultural insecticide lambda-cyhalothrin (warrior) on mosquitofish (gambusia affinis).because agricultural insecticides have potential to disrupt biological control of mosquitoes, we quantified whether an insecticide used in rice fields causes mortality of mosquitofish. laboratory studies have shown that lambda-cyhalothrin (warrior) is toxic to fish; however, some studies report low field toxicities of pyrethroids to fish because they degrade rapidly and adsorb to soil. we tested whether warrior kills mosquitofish under field conditions. replicated enclosures in a rice field were ...200314710748
laboratory evaluation of methanolic extract of atlantia monophylla (family: rutaceae) against immature stages of mosquitoes and non-target organisms.methanolic extracts of the leaves of atlantia monophylla (rutaceae) were evaluated for mosquitocidal activity against immature stages of three mosquito species, culex quinquefasciatus, anopheles stephensi, and aedes aegypti in the laboratory. larvae of cx. quinquefasciatus and pupae of an. stephensi were found more susceptible, with lc50 values of 0.14 mg/l and 0.05 mg/l, respectively. insect growth regulating activity of this extract was more pronounced against ae. aegypti, with ei50 value 0.00 ...200415057359
relation of length and sex to selenium concentrations in mosquitofish.analysis of mosquitofish, gambusia affinis, has proven useful for monitoring contaminant levels in aquatic biota; however, the small size of this species often requires the compositing of several fish to provide sufficient biomass for selenium analysis. such composites have usually been obtained without considering the length and sex of the individual fish. the present study found significant differences in mean lengths and sex ratios of mosquitofish sampled with small-mesh dip nets from five si ...198715092705
laboratory evaluation of dimilin on growth and glutathione activity in mosquitofish, a non-target species.recently, dimilin was found to be effective on culex pipiens (diptera: culicidae). although considerable research has evaluated the efficacy of diflubenzuron, a benzoylphenylurea derivative, against target pest populations, impacts of this compound on nontarget organisms are comparatively unknown. therefore, this study evaluate toxicity of dimilin (25% w.p), a trade formulation of diflubenzuron, on a larvivorous non-target species, gambusia affinis (pisces, poeciliidae). the compound, applied fo ...200315149123
interspecies differences in dna single strand breaks caused by benzo(a)pyrene and marine environment.the presence of dna single strand breaks in untreated specimens of selected species, mosquito fish gambusia affinis, painted comber serranus scriba, blue mussel mytilus galloprovincialis, spiny crab maja crispata and sea cucumber holothuria tubulosa as well as in 10 microg/g benzo(a)pyrene (bap) treated mosquito fish, blue mussel and spiny crab was measured, using alkaline filter elution. interspecies differences in alkaline elution profiles were observed and attributed to different lengths of d ...200415288553
complex interactions between native and invasive fish: the simultaneous effects of multiple negative interactions.we suggest that the ultimate outcome of interactions between native species and invasive species (extinction or coexistence) depends on the number of simultaneous negative interactions (competition and predation), which depends on relative body sizes of the species. multiple simultaneous interactions may constrain the ability of native species to trade fitness components (i.e., reduced growth for reduced risk of predation) causing a spiral to extinction. we found evidence for five types of inter ...200415322899
molecular characterization of contaminant-indicative rapd markers.this paper describes genetic markers which can be used to study selection and genetic adaptation of organisms to radionuclide and other types of contaminant stress. previous research using the randomly amplified polymorphic dna (rapd) technique has identified several markers which revealed genetic differences between contaminated and reference western mosquitofish (gambusia affinis) populations. experimental evidence suggested that these markers may be associated with loci involved in determinin ...200415344511
laboratory and field evaluation of teknar hp-d, a biolarvicidal formulation of bacillus thuringiensis ssp. israelensis, against mosquito vectors.larvicidal efficacy of teknar hp-d, an improved biolarvicidal formulation of bacillus thuringiensis ssp. israelensis (bti), against anopheles stephensi, culex quinquefasciatus and aedes aegypti was determined in the laboratory, and in field the efficacy of the formulation was tested against cx. quinquefasciatus breeding in cesspits, unused wells and drains. the toxicity of the formulation to gambusia affinis (larvivorous fish), notonecta sp. and diplonychus indicus (water bugs) was also evaluate ...200415350862
reproductive status of western mosquitofish inhabiting selenium-contaminated waters in the grassland water district, merced county, california.this study was implemented to determine if western mosquitofish (gambusia affinis) populations in the grassland water district suffer from impaired reproduction because of seleniferous inflows of agricultural drainwater from the grassland bypass project. during june to july 2001, laboratory trials with pregnant female fish collected from two seleniferous treatment sites exposed to selenium-laden drainwater and two nonseleniferous reference sites yielded fry that averaged > 96% survival at birth. ...200415386130
androgen dependent development of a modified anal fin, gonopodium, as a model to understand the mechanism of secondary sexual character expression in vertebrates.male external genitalia show structural variations among species. androgenic hormones are essential for the morphological specification of male type copulatory organs, while little is known about the developmental mechanisms of such secondary sexual characters. western mosquitofish gambusia affinis may offer a clue to the sexual differentiation researches, because they show a prominent masculine sexual character for appendage development, anal fin to gonopodium (gp) transition, and its formation ...200415388345
shared and unique features of evolutionary diversification.a fundamental question in evolutionary biology asks whether organisms experiencing similar selective pressures will evolve similar solutions or whether historical contingencies dominate the evolutionary process and yield disparate evolutionary outcomes. it is perhaps most likely that both shared selective forces as well as unique histories play key roles in the course of evolution. consequently, when multiple species face a common environmental gradient, their patterns of divergence might exhibi ...200415478089
toxic response of endosulfan to breeding and non-breeding female mosquitofish.to investigate if toxic effects by endosulfan, a commonly used insecticide, are dependent on the breeding condition of an organism, both breeding and non-breeding female western mosquitofish, gambusia affinis, were exposed to 0.1, 0.5, 1 ppb of endosulfan. after a 5-week exposure period, we examined physical factors such as ovary weight and anal fin length in fish of both reproductive conditions and the size of thyroid follicles in non-breeders. breeding female fish exposed to endosulfan did not ...200415529866
predator-driven phenotypic diversification in gambusia affinis.predation is heterogeneously distributed across space and time, and is presumed to represent a major source of evolutionary diversification. in fishes, fast-starts--sudden, high-energy swimming bursts--are often important in avoiding capture during a predator strike. thus, in the presence of predators, we might expect evolution of morphological features that facilitate increased fast-start speed. we tested this hypothesis using populations of western mosquitofish (gambusia affinis) that differed ...200415562692
multiple vitellogenins (vgs) in mosquitofish (gambusia affinis): identification and characterization of three functional vg genes and their circulating and yolk protein products.the objectives of this study were to characterize multiple forms of vitellogenin (vg) in mosquitofish (gambusia affinis) and to discover the fate of each vg during its processing into product yolk proteins. two vg preparations, with apparent masses of 600 kda (600 vg) and 400 kda (400 vg), were isolated from the plasma of fish treated with estradiol-17beta (e(2)) by various chromatographic procedures. immunological analyses verified the presence of two different vg proteins (600 vga and 600 vgb) ...200515616220
operational use of neem oil as an alternative anopheline larvicide. part b: environmental impact and toxicological potential.this study was conducted to investigate the preliminary environmental and mammalian toxicology of neem oil, temephos and chlorpyriphos-methyl/fenitrothion. culex pipiens, daphnia magna and gambusia affinis were used to study environmental impact. a high level of toxicity was observed, with slight differences between organisms. the emulsifiers individually also displayed toxicity towards the tested organisms. up to 90 days daily oral crude neem oil treatment (5 g/kg body weight) of laboratory mic ...200315748062
effects of maternal and embryo characteristics on post-fertilization provisioning in fishes of the genus gambusia.maternal provisioning of embryos in gambusia (poeciliidae) entails both production of large, yolky eggs and mother-to-embryo transfer of nutrients, the latter of which is readily quantified using injection of radiolabeled nutrients. we assayed patterns of nutrient transfer in broods of 26 gambusia geiseri and 23 gambusia affinis females, using injection of tritiated leucine. we examined maternal and embryo characteristics affecting the instantaneous rate of transfer and characterized the pattern ...200515800747
male genital size reflects a tradeoff between attracting mates and avoiding predators in two live-bearing fish species.male genitalia may experience more rapid, divergent evolution than any other animal character, but why? research during the past several decades has culminated in the view that genital diversification primarily results from postmating sexual selection (e.g., sperm competition or cryptic female choice). however, the potential roles of premating sexual selection (e.g., mate choice) and natural selection have received little attention. we examined the possible importance of these mechanisms by inve ...200515894618
effects of 17alpha-ethynylestradiol on sexual development of male western mosquitofish (gambusia affinis).juvenile male western mosquitofish (gambusia affinis) were exposed to different concentrations of 17alpha-ethynyl estradiol (ee2) in the diet during the period of sexual maturation. a clear inhibiting influence of ee2 on sexual development was apparent. the proportion of males in each treatment group that failed to complete gonopodial development during the 150-day observation period increased significantly with ee2 concentration. there were significant nonlinear trends toward shorter gonopodia ...201315922671
incorporation and utilization of multiple forms of vitellogenin and their derivative yolk proteins during vitellogenesis and embryonic development in the mosquitofish, gambusia affinis.we previously demonstrated the presence of three forms of vitellogenin (vg), two 600 kda vgs (600vg; vga and vgb) and a 400 kda vg (400vg; phosvitinless vg) in plasma from maturing female viviparous mosquitofish, gambusia affinis. for further quantitative elucidation of the accumulation and utilization of the multiple vg-derived yolk proteins, two sandwich enzyme-linked immunosorbent assays (elisa) were developed using antisera against 600vgs and a 400 kda yolk protein (400yp; derived from 400vg ...200515988167
effects of an androgenic growth promoter 17beta-trenbolone on masculinization of mosquitofish (gambusia affinis affinis).endocrine disrupting chemicals can affect normal hormone dependent processes through numerous mechanisms, including ligand mimicky. 17beta-trenbolone (tb), a pharmaceutical, androgenic, anabolic steroid, is a potent agonist of androgen receptors, and has been extensively used as a growth promoter for beef cattle in the us. the effects of tb on adult and newborn mosquitofish (gambusia affinis affinis) were examined. two forms of mosquitofish androgen receptor (ar), aralpha and arbeta, were cloned ...200516061073
sublethal effects of monocrotophos on locomotor behavior and gill architecture of the mosquito fish, gambusia affinis.subacute studies of monocrotophos [dimethyl (e)-1-methyl-2-(methyl-carbamoyl) vinyl phosphate] on mosquito fish, gambusia affinis, were carried out in vivo for 24 days to assess the locomotor behavior, structural integrity of gill, and targeted enzyme acetylcholinesterase (ache, ec: 3.1.1.7) interactions. monocrotophos (mcp) can be rated as moderately toxic to g. affinis, with a median lethal concentration (lc(50)) of 20.49 +/- 2.45 mgl(-1). the fish exposed to sublethal concentration of lc(10) ...200516194919
comparative acute and combinative toxicity of aflatoxin b1 and t-2 toxin in animals and immortalized human cell lines.aflatoxin b1 (afb1) and t-2 toxin (t-2) are important food-borne mycotoxins that have been implicated in human health and as potential biochemical weapons threats. in this study the acute and combinative toxicity of afb1 and t-2 were tested in f-344 rats, mosquitofish (gambusia affinis), immortalized human hepatoma cells (hepg2) and human bronchial epithelial cells (beas-2b). preliminary experiments were conducted in order to assess the acute toxicity and to obtain ld50, lc50 and ic50 values for ...200616229058
quantification of vitellogenin mrna induction in mosquitofish (gambusia affinis) by reverse transcription real-time polymerase chain reaction (rt-pcr).a method to quantify induction of vitellogenin (vtg) mrna in adult male mosquitofish was developed. male mosquitofish were exposed to 0, 1, 20 and 250 ng l(-1) 17beta-oestradiol (e(2)) for 4 and 8 days in static exposures, and liver vtg mrna and 18s rrna expression were quantified in duplex rt-pcr. liver 18s rrna expression was very consistent among individuals, and there was a highly significant increase in vtg mrna expression after exposure of mosquitofish for just 4 days at 250 ng l(-1) e(2). ...201516308267
impact of certain plants and synthetic molluscicides on some fresh water snails and fish.the lc50 (78, 85 ppm) and lc90 (88, 135 ppm) of anagalis arvensis and calendula micrantha respectively against biomphalaria alexandrina were higher than those of the non-target snails, physa acuta, planorbis planorbis, helisoma duryi and melanoides tuberculata. in contrast, the lc50 of niclosamide (0.11 ppm) and copper sulphate (cuso4) (0.42 ppm) against b. alexandrina were lower than those of the non-target snails. the mortalities percentage among non-target snails ranged between 0.0 & 20% when ...200516333905
effects of inorganic nitrogen enrichment on mosquitoes (diptera: culicidae) and the associated aquatic community in constructed treatment wetlands.ammonium nitrogen (nh4-n) is a significant component of municipal and agricultural wastewaters, and nitrogen reduction is an important use of constructed treatment wetlands. the effects of ammonium nitrogen enrichment on resources of larval mosquitoes, larval mosquito abundance, adult mosquito production, and the abundance of related wetland organisms were examined in 0.1-ha replicate treatment wetlands. the hypothesis of a bottom-up effect induced by ammonium addition was not supported by bacte ...200516363159
comparative acute and combinative toxicity of aflatoxin b1 and fumonisin b1 in animals and human cells.aflatoxin b(1) (afb(1)) and fumonisin b(1) (fb(1)) are important food-borne mycotoxins. the co-contamination of food stuffs with these two mycotoxins is well known and has been possibly implicated in the development of human hepatocellular carcinoma in high risk regions around the world. in this study the acute and combinative toxicity of afb(1) and fb(1) were tested in f-344 rats, mosquitofish (gambusia affinis), immortalized human hepatoma cells (hepg2) and human bronchial epithelial cells (be ...200616427177
accumulation of contaminants in fish from wastewater treatment wetlands.increasing demands on water resources in arid environments make reclamation and reuse of municipal wastewater an important component of the water budget. treatment wetlands can be an integral part of the water-reuse cycle providing both water-quality enhancement and habitat functions. when used for habitat, the bioaccumulation potential of contaminants in the wastewater is a critical consideration. water and fish samples collected from the tres rios demonstration constructed wetlands near phoeni ...200616468409
effect of an acute and chronic toxicity of four commercial detergents on the freshwater fish gambusia affinis baird & gerard.the toxic effects of four commercial detergents (two washing powders and two cakes) are reported in this paper on behavior, mortality and rbc counts of a freshwater fish gambusia affinis. during acute toxicity studies (96h), surface movements of fish increased markedly for 24h, only at higher concentrations (>10 ppm) of all the four detergents. thereafter, they were lethargic and bottom dwellers similar to those exposed for a period of 30 days in the longterm ecotoxicological studies made on det ...200516649615
a test of three alternative pathways for consumer regulation of primary productivity.the pathways linking consumer effects to primary productivity (ppr) are likely to vary among taxa because of species-specific trophic and functional differences. thus, it is necessary to understand the dynamics of consumer-ppr interactions so that effects of species loss on ecosystem function can be addressed from a mechanistic approach. in this study, i used three fish taxa (orangethroat darter, etheostoma spectabile; western mosquitofish, gambusia affinis; and bullhead minnow, pimephales vigil ...200616676207
use of biomarkers to investigate toxicological effects of produced water treated with conventional and innovative methods.the aim of this study was to develop and apply a multi-biomarker system to assess the toxicological effects of produced water (pw) from a mediterranean off-shore oil platform. the selected bioindicator organism, mosquitofish (gambusia affinis), was exposed in the laboratory to high concentrations of different pw: pw before treatment (bt), after conventional treatment (act) and after innovative treatment with zeolites in a prototype system (ait). a set of biomarkers (benzo(alpha)pyrene monooxygen ...200616740305
sublethal effects of profenofos on locomotor behavior and gill architecture of the mosquito fish, gambusia affinis.subacute studies of profenofos on mosquito fish, gambusia affinis, were carried out for 20 days to assess the locomotor behavior and structural integrity of gill in relation to bioaccumulation and targeted enzyme acetylcholinesterase (ache; ec 3.1.1.7). the sublethal concentration of 0.13 mg/l (1/5 of lc50) altered locomotor behavior such as distance traveled and swimming speed in exposed fish. this could be due to inhibition in the activity of acetylcholinesterase and deformities in the primary ...200616777704
changes in behavior and brain acetylcholinesterase activity in mosquito fish, gambusia affinis in response to the sub-lethal exposure to chlorpyrifos.sub-lethal studies of chlorpyrifos, o,o-diethyl-o-(3,5,6-trichloro-2-pyridyl) phosphorothioate on mosquito fish, gambusia affinis were carried out in vivo, for 20 days to assess the locomotor behavior in relation to bioaccumulation and interaction with a targeted enzyme, acetylcholinesterase (ache, ec: 3.1.1.7). fish exposed to sub-lethal concentration of 60 microg/l (1/5 of lc 50) were under stress, and reduced their locomotor behavior like distance travelled per unit time (m/min) and swimming ...200516819104
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