Publications

fish responses to flow velocity and turbulence in relation to size, sex and parasite load.	riverine fish are subjected to heterogeneous flow velocities and turbulence and may use this to their advantage by selecting regions that balance energy expenditure for station holding while maximizing energy gain through feeding opportunities. this study investigated microhabitat selection by guppies poecilia reticulata in terms of flow characteristics generated by hemisphere boulders in an open channel flume. velocity and turbulence influenced the variation in swimming behaviour with respect t ...	2014	24284893
male gonadal differentiation and the paedomorphic evolution of the testis in teleostei.	testis differentiation from representatives of the otophysi (cyprinus carpio), percomorpha (amatitlania nigrofasciata), and atherinomorpha (poecilia reticulata) was comparatively described. in the undifferentiated gonad of c. carpio, the primordial germ cells (pgcs) are scattered throughout the gonads while in a. nigrofasciata and p. reticulata the pgcs are restricted to the ventral periphery. in the dorsal region of the developing gonads, with the exception of c. carpio, somatic cell rearrangem ...	2014	24740886
studies of in vitro embryo culture of guppy (poecilia reticulata).	different with other fishes, the guppies (poecilia reticulata) is ovoviviparity, which retain their fertilized eggs within the follicle throughout gestation. the synchronously growing diplotene oocytes store nutrients in droplets and yolk, before their maturation and fertilization. the lecithotrophic strategy of development entails the provisioning of embryos with resources from the maternal yolk deposit rather than from a placenta, it allows the extracorporeal culture of guppy embryo. studies o ...	2014	25949182
comparative study of infection with tetrahymena of different ornamental fish species.	tetrahymena is a ciliated protozoan that can infect a wide range of fish species, although it is most commonly reported in guppies (poecilia reticulata). the aim of this study was to compare the susceptibility to infection with tetrahymena of five different ornamental fish species from two different super orders. the species examined were platy (xiphophorus), molly (poecilia sphenops) and angelfish (pterophyllum scalare) of the acanthopterygii super order (which also includes guppies) and goldfi ...	2014	24650892
identification of quantitative trait locus (qtl) linked to dorsal fin length from preliminary linkage map of molly fish, poecilia sp.	a preliminary linkage map was constructed by applying backcross and testcross strategy using microsatellite (ssr) markers developed for xiphophorus and poecilia reticulata in ornamental fish, molly poecilia sp. the linkage map having 18 ssr loci consisted of four linkage groups that spanned a map size of 516.1cm. association between genotypes and phenotypes was tested in a random fashion and qtl for dorsal fin length was found to be linked to locus msb069 on linkage group 2. coincidentally, locu ...	2014	24333858
efficacy of commercially available products against gyrodactylus turnbulli infections on guppies poecilia reticulata.	the demand for ornamental fish has led to a steep rise in aquaculture for the hobbyist trade, promoting the emergence, persistence and spread of various infectious diseases. complete control of disease outbreaks with antibiotics and chemical-based medicines is rare, but plant compounds may herald potential alternatives effective against a range of pathogens. melafix® and pimafix® are formulated with the essential oils cajuput (melaleuca cajuputi) and west indian bay (pimenta racemosa) and are ma ...	2015	26203884
efficacy of ginger-based treatments against infection with gyrodactylus turnbulli in the guppy (poecilia reticulata (peters)).	monogenean infections of commercially farmed fishes are responsible for significant economic losses and existing chemical therapeutants, often stressful to the fish, pose associated risks. as part of a recent trend to move towards the use of alternative, plant-based remedies for commonly occurring aquaculture-related diseases, the efficiency of ginger (zingiber officinale) was investigated against the monogenean parasite gyrodactylus turnbulli in the guppy. in vitro trials revealed the clear ant ...	2015	25819871
intraspecific variation in aerobic and anaerobic locomotion: gilthead sea bream (sparus aurata) and trinidadian guppy (poecilia reticulata) do not exhibit a trade-off between maximum sustained swimming speed and minimum cost of transport.	intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. using gilthead sea bream (sparus aurata) and trinidadian guppy (poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (epoc); (2) variation in swimming performance (critical swimming speed; ...	2015	25741285
demasculinization of male guppies increases resistance to a common and harmful ectoparasite.	parasites are detrimental to host fitness and therefore should strongly select for host defence mechanisms. yet, hosts vary considerably in their observed parasite loads. one notable source of inter-individual variation in parasitism is host sex. such variation could be caused by the immunomodulatory effects of gonadal steroids. here we assess the influence of gonadal steroids on the ability of guppies (poecilia reticulata) to defend themselves against a common and deleterious parasite (gyrodact ...	2015	26399637
experimental and molecular study of cercariae of clinostomum sp. (trematoda: clinostomidae) from biomphalaria spp. (mollusca: planorbidae) in brazil.	despite the large number of reports of species of clinostomum from vertebrate hosts in south america, studies evaluating the molluscan transmitters of these parasites are scarce. in the present study, clinostomatoid cercariae shed from 0.02% (4/17,485) specimens of biomphalaria spp., collected at the pampulha reservoir, belo horizonte, minas gerais, brazil, were used for experimental infection of poecilia reticulata . samples of cercariae from molluscs and metacercariae experimentally obtained f ...	2015	25090192
cell phone-generated radio frequency electromagnetic field effects on the locomotor behaviors of the fishes poecilia reticulata and danio rerio.	the locomotor behavior of small fish was characterized under a cell phone-generated radio frequency electromagnetic field (rf emf).	2015	26073525
expression change in angiopoietin-1 underlies change in relative brain size in fish.	brain size varies substantially across the animal kingdom and is often associated with cognitive ability; however, the genetic architecture underpinning natural variation in these key traits is virtually unknown. in order to identify the genetic architecture and loci underlying variation in brain size, we analysed both coding sequence and expression for all the loci expressed in the telencephalon in replicate populations of guppies (poecilia reticulata) artificially selected for large and small ...	2015	26108626
short-term exposure to low doses of rotenone induces developmental, biochemical, behavioral, and histological changes in fish.	rotenone, a natural compound derived from plants of the genera derris and lonchocarpus, is used worldwide as a pesticide and piscicide. this study aims to assess short-term toxicity of rotenone to early-life stages of the fish danio rerio and poecilia reticulata using a wide and integrative range of biomarkers (developmental, biochemical, behavioral, and histopathological). moreover, the species sensitivity distribution (ssd) approach was used to compare rotenone acute toxicity to fish species. ...	2015	25948382
cryptosporidium huwi n. sp. (apicomplexa: eimeriidae) from the guppy (poecilia reticulata).	the morphological, biological, and molecular characteristics of cryptosporidium piscine genotype 1 from the guppy (poecilia reticulata) are described, and the species name cryptosporidium huwi n. sp. is proposed to reflect its genetic and biological differences from gastric and intestinal cryptosporidium species. oocysts of c.huwi n. sp. over-lap in size with cryptosporidium molnari, measuring approximately 4.4-4.9 µm (mean 4.6) by 4.0-4.8 µm (mean 4.4 µm) with a length to width ratio of 1.04 (0 ...	2015	25637783
biosynthesis, mosquitocidal and antibacterial properties of toddalia asiatica-synthesized silver nanoparticles: do they impact predation of guppy poecilia reticulata against the filariasis mosquito culex quinquefasciatus?	mosquito-borne diseases represent a deadly threat for millions of people worldwide. furthermore, pathogens and parasites polluting water also constitute a severe plague for populations of developing countries. in this study, silver nanoparticles (agn) were biosynthesized a cheap aqueous extract of t. asiatica leaves as reducing and stabilizing agent. the formation of nanoparticle was confirmed by surface plasmon resonance band illustrated in uv-vis spectrophotometer. agn were characterized by ft ...	2015	26122577
towards green oviposition deterrents? effectiveness of syzygium lanceolatum (myrtaceae) essential oil against six mosquito vectors and impact on four aquatic biological control agents.	essential oils (eos) from plants may be alternative sources of molecules toxic against mosquito vectors of public health relevance. most of researches in this field focused on eos as larvicides or ovicides, while limited efforts focused on the exploitation of eos as oviposition deterrents. in the present study, the larvicidal and oviposition deterrent activity of syzygium lanceolatum leaf eo was evaluated against six mosquito species, anopheles stephensi, an. subpictus, aedes aegypti, ae. albopi ...	2016	27921244
a further cost for the sicker sex? evidence for male-biased parasite-induced vulnerability to predation.	males are typically the sicker sex. data from multiple taxa indicate that they are more likely to be infected with parasites, and are less "tolerant," or less able to mitigate the fitness costs of a given infection, than females. one cost of infection for many animals is an increased probability of being captured by a predator. a clear, hitherto untested, prediction is therefore that this parasite-induced vulnerability to predation is more pronounced among males than females. we tested this pred ...	2016	27066240
toxicological assessment of spinosad: implications for integrated control of aedes aegypti using larvicides and larvivorous fish.	integration of larvivorous fish and biolarvicides at low concentrations to control of mosquito larvae in field situations may result in a safer and more effective tool. however, the usefulness of integrated approach depends upon survival and ecological fitness of fish employed. thus, the aim of this study was to examine the genotoxic effects of combining different sublethal concentrations of spinosad, a naturally occurring neurotoxic insecticide, with male adult poecilid larvivorous guppy (poeci ...	2016	27294296
[hypophysectomy and spermatogenesis in poecilia reticulata (cyprinodontidae fish)].		2016	4977302
an assessment of the physicochemical properties and toxicity potential of carwash effluents from professional carwash outlets in gauteng province, south africa.	the assessment of the quality of carwash effluents has received scant attention as a potential source of public and environmental health hazard in south africa as demonstrated by the lack of literature in this subject. the physicochemical quality and potential ramifications of carwash effluents on receiving waterbodies were investigated in this study. grab effluent samples were collected from six carwash outlets in gauteng province of south africa and analysed for selected physicochemical qualit ...	2016	26957430
imprinting can cause a maladaptive preference for infectious conspecifics.	recognizing and associating with specific individuals, such as conspecifics or kin, brings many benefits. one mechanism underlying such recognition is imprinting: the long-term memory of cues encountered during development. typically, juveniles imprint on cues of nearby individuals and may later associate with phenotypes matching their 'recognition template'. however, phenotype matching could lead to maladaptive social decisions if, for instance, individuals imprint on the cues of conspecifics i ...	2016	27072405
chronic nitrate enrichment decreases severity and induces protection against an infectious disease.	excessive fertilisation is one of the most pernicious forms of global change resulting in eutrophication. it has major implications for disease control and the conservation of biodiversity. yet, the direct link between nutrient enrichment and disease remains largely unexplored. here, we present the first experimental evidence that chronic nitrate enrichment decreases severity and induces protection against an infectious disease. specifically, this study shows that nitrate concentrations ranging ...	2016	26995268
getting into hot water: sick guppies frequent warmer thermal conditions.	ectotherms depend on the environmental temperature for thermoregulation and exploit thermal regimes that optimise physiological functioning. they may also frequent warmer conditions to up-regulate their immune response against parasite infection and/or impede parasite development. this adaptive response, known as 'behavioural fever', has been documented in various taxa including insects, reptiles and fish, but only in response to endoparasite infections. here, a choice chamber experiment was use ...	2016	26965895
parting ways: parasite release in nature leads to sex-specific evolution of defence.	we evaluated the extent to which males and females evolve along similar or different trajectories in response to the same environmental shift. specifically, we used replicate experimental introductions in nature to consider how release from a key parasite (gyrodactylus) generates similar or different defence evolution in male vs. female guppies (poecilia reticulata). after 4-8 generations of evolution, guppies were collected from the ancestral (parasite still present) and derived (parasite now a ...	2016	26356531
the effects of inbreeding on disease susceptibility: gyrodactylus turnbulli infection of guppies, poecilia reticulata.	inbreeding can threaten population persistence by reducing disease resistance through the accelerated loss of gene diversity (i.e. heterozygosity). such inbreeding depression can affect many different fitness-related traits, including survival, reproductive success, and parasite susceptibility. empirically quantifying the effects of inbreeding on parasite resistance is therefore important for ex-situ conservation of vertebrates. the present study evaluates the disease susceptibility of individua ...	2016	27130704
density-dependent prey mortality is determined by the spatial scale of predator foraging.	foraging theory predicts which prey patches predators should target. however, in most habitats, what constitutes a 'patch' and how prey density is calculated are subjective concepts and depend on the spatial scale at which the predator (or scientist) is observing. moreover, the predator's 'foraging scale' affects prey population dynamics: predators should produce directly density-dependent (ddd) prey mortality at the foraging scale, but inversely density-dependent (idd) mortality (safety-in-numb ...	2016	26116266
partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (ocltt) hypothesis.	ongoing climate change is predicted to affect the distribution and abundance of aquatic ectotherms owing to increasing constraints on organismal physiology, in particular involving the metabolic scope (ms) available for performance and fitness. the oxygen- and capacity-limited thermal tolerance (ocltt) hypothesis prescribes ms as an overarching benchmark for fitness-related performance and assumes that any anaerobic contribution within the ms is insignificant. the ms is typically derived from re ...	2016	27293766
exposure to an agricultural contaminant, 17β-trenbolone, impairs female mate choice in a freshwater fish.	despite the pivotal role sexual selection plays in population dynamics and broader evolutionary processes, the impact of chemical pollution on female mate choice is poorly understood. one group of chemical contaminants with the potential to disrupt the mechanisms of female mate choice is endocrine disrupting chemicals (edcs); a broad class of environmental pollutants that can interfere with the endocrinology of organisms at extremely low concentrations. recent research has revealed that estrogen ...	2016	26466515
biomphalaria straminea (mollusca: planorbidae) as an intermediate host of drepanocephalus spp. (trematoda: echinostomatidae) in brazil: a morphological and molecular study.	species of trematodes belonging to the genus drepanocephalus are intestinal parasites of piscivorous birds, primarily cormorants (phalachrocorax spp.), and are widely reported in the americas. during a 4-year malacological study conducted on an urban lake in brazil, 27-collar-spined echinostome cercariae were found in 1665/15,459 (10.7 %) specimens of biomphalaria straminea collected. the cercariae were identified as drepanocephalus spp. by sequencing the 18s (ssu) rdna, its1/5.8s rdna/its2 (its ...	2016	25982569
crypt cell markers in the olfactory organ of poecilia reticulata: analysis and comparison with the fish model danio rerio.	olfactory crypt neurons have been observed in several bony fishes and chondrichtyans. although their morphology is uniform in all fish, very few is known about their antigenic properties, usually studied in zebrafish, but quite overlooked in other species. we tested in poecilia reticulata (guppy) the two antibodies recognized to mark zebrafish crypt cells: while anti-s100 showed an immunohistochemical pattern comparable to what reported in zebrafish, anti-trka gave no signal. western blot analys ...	2017	28280935
host heterogeneity affects both parasite transmission to and fitness on subsequent hosts.	infectious disease dynamics depend on the speed, number and fitness of parasites transmitting from infected hosts ('donors') to parasite-naive 'recipients'. donor heterogeneity likely affects these three parameters, and may arise from variation between donors in traits including: (i) infection load, (ii) resistance, (iii) stage of infection, and (iv) previous experience of transmission. we used the trinidadian guppy, poecilia reticulata, and a directly transmitted monogenean ectoparasite, gyroda ...	2017	28289260
toxicity of ar-curcumene and epi-β-bisabolol from hedychium larsenii (zingiberaceae) essential oil on malaria, chikungunya and st. louis encephalitis mosquito vectors.	mosquitoes act as vectors of key pathogens and parasites. plant essential oils have been recognized as important sources of biopesticides, which do not induce resistance and have limited toxic effects on human health and non-target organisms. in this research, we evaluated the larvicidal and oviposition deterrence activity of hedychium larsenii essential oil (eo) and its major compounds ar-curcumene and epi-β-bisabolol. both molecules showed high toxicity against early third instars of anopheles ...	2017	27918946
ivermectin efficacy against biomphalaria, intermediate host snail vectors of schistosomiasis.	the impact of ivermectin on adult snails of the genus biomphalaria (b. glabrata, b. tenagophila and b. straminea), b. glabrata infected with schistosoma mansoni, snail egg-masses cercariae and miracidia, as well as on guppy fish (poecilia reticulata) was examined and evaluated. biomphalaria snails, egg-masses, parasite stages and guppies were all exposed to different concentrations of ivermectin for 24 h, followed by regular observations of mortality. the calculated lethal doses of ivermectin we ...	2017	28293033