Poecilia Reticulata Research Articles

Partial Purification and Characterization of the Acetylcholinesterase from Poecilia reticulata (Peters, 1859)

Poecilia reticulata (P. reticulata) is a species of tropical fish in the family Poeciliidae that is found all over the world and is a favorite in freshwater aquariums. The Malay name for this fish is "Ikan Gapi," although the English term "Guppy" has become more common. The Million Fish, or Rainbow Fish, as it's known in other parts of the world. The goals of this research were to char-acterize the acetylcholinesterase that will be partially purified from P. reticulata brain extract using ammonium sulphate fractionation followed by an affinity chromatography method. The result shows that ammonium sulphate fractionation gave better purification fold over the procainamide affinity chromatographic method with fold of purification of 3.38 compared to 0.64 for the latter. Polyacrylamide gel electrophoresis (SDS-PAGE) shows a dramatic reduction of protein bands compared to crude extract. A pH of 9 in a Tris-HCl buffer system and a temperature of 15 °C were found to be ideal for the activity of the enzyme. Based on its high Vmax and low Km with acetylthiocholine iodide (ATC) as a substrate compared to butyryl thiocholine iodide (BTC) and propionyl thiocholine iodide (PTC), the substrate specificity profile identified acetylcholinesterase (AChE) as the major enzyme present in the purified enzyme. The molecular weights of the en-zyme following affinity chromatographic purification are about 92 kDa.

Inhibitive Assay of Insecticides using the Acetylcholinesterase from Poe-cilia reticulata (Peters, 1859)

Poecilia reticulata (P. reticulata) is a species of tropical fish in the family Poeciliidae that is found all over the world and is a favorite in freshwater aquariums. The Malay name for this fish is "Ikan Gapi," although the English term "Guppy" has become more common. The Million Fish, or Rainbow Fish, as it's known in other parts of the world. The goals of this research were to char-acterize the acetylcholinesterase that will be partially purified from P. reticulata brain extract using ammonium sulphate fractionation The screening results show that at 1 mg/L insecticide, acephate, dimethoate, trichlorfon and bendiocarb leads to 100% inhibition, whilst parathion, methomyl and malathion cause >90% inhibition. The AChE from P. reticulata is less sensitive to other species as far as the insecticides carbofuran, carbaryl, methomyl, bendiocarb, parathion, diazinon, chlorpyrifos with the exception of malathion, where the sensitivity of malathion to the AChE from was within the range of the AChE from other species such a E. electricus , Pangasius sp., Chan-na micropeltes, Clarias batrachus, H. nemurus, Tor tambroides, and Osteochilus hasselti.

Mate Discrimination Using Chemical Cues by Male Guppies.

Males often perform mate choice with the aim of maximizing reproductive success. To identify profitable mates, the males of some animals are known to use visual and chemical cues derived from females. In this study, we aimed to examine mate discrimination by male guppies (Poecilia reticulata) using chemical cues received from females under different reproductive statuses, i.e., virgin females, pregnant females, females after copulation with another male, and post-partum females. We conducted a dichotomous choice experiment for each combination of chemical stimuli from females under different reproductive statuses. In experiment 1, in which females were removed from water that was subsequently used as a chemical stimulus, male preferences did not differ significantly in all combinations of chemical stimuli from females under different reproductive statuses. However, in experiment 2, in which females remained within bottles containing the water used as a chemical stimulus, with the exception of one combination of chemical stimuli, significant differences in male preferences were detected for chemical stimuli derived from females under different reproductive statuses. Overall, males generally showed a preference for chemical stimulus received from females after copulation with other males. The findings of this study indicate that male guppies can discriminate the reproductive status of females based solely on chemical cues that may disappear or degenerate within a short period of time, thereby facilitating profitable mate choice.

Validation of machine learning approach for direct mutation rate estimation.

Mutations are the primary source of all genetic variation. Knowledge about their rates is critical for any evolutionary genetic analyses, but for a long time, that knowledge has remained elusive and indirectly inferred. In recent years, parent-offspring comparisons have yielded the first direct mutation rate estimates. The analyses are, however, challenging due to high rate of false positives and no consensus regarding standardized filtering of candidate de novo mutations. Here, we validate the application of a machine learning approach for such a task and estimate the mutation rate for the guppy (Poecilia reticulata), a model species in eco-evolutionary studies. We sequenced 4 parents and 20 offspring, followed by screening their genomes for de novo mutations. The initial large number of candidate de novo mutations was hard-filtered to remove false-positive results. These results were compared with mutation rate estimated with a supervised machine learning approach. Both approaches were followed by molecular validation of all candidate de novo mutations and yielded similar results. The ML method uniquely identified three mutations, but overall required more hands-on curation and had higher rates of false positives and false negatives. Both methods concordantly showed no difference in mutation rates between families. Estimated here the guppy mutation rate is among the lowest directly estimated mutation rates in vertebrates; however, previous research has also found low estimated rates in other teleost fishes. We discuss potential explanations for such a pattern, as well as future utility and limitations of machine learning approaches.

Extensive variation in germline de novo mutations in Poecilia reticulata.

The rate of germline mutation is fundamental to evolutionary processes, as it generates the variation upon which selection acts. The guppy, Poecilia reticulata, is a model of rapid adaptation, however the relative contribution of standing genetic variation versus de novo mutation (DNM) to evolution in this species remains unclear. Here, we use pedigree-based approaches to quantify and characterize germline DNMs in three large guppy families. Our results suggest germline mutation rate in the guppy varies substantially across individuals and families. Most DNMs are shared across multiple siblings, suggesting they arose during early embryonic development. DNMs are randomly distributed throughout the genome, and male-biased mutation rate is low, as would be expected from the short guppy generation time. Overall, our study shows remarkable variation in germline mutation rate and provides insights into rapid evolution of guppies.

Temperature and turbidity interact synergistically to alter anti-predator behaviour in the Trinidadian guppy.

Due to climate change, freshwater habitats are facing increasing temperatures and more extreme weather that disrupts water flow. Together with eutrophication and sedimentation from farming, quarrying and urbanization, freshwaters are becoming more turbid as well as warmer. Predators and prey need to be able to respond to one another adaptively, yet how changes in temperature and turbidity interact to affect predator-prey behaviour remains unexplored. Using a fully factorial design, we tested the combined effects of increased temperature and turbidity on the behaviour of guppy shoals (Poecilia reticulata) in the presence of one of their natural cichlid predators, the blue acara (Andinoacara pulcher). Our results demonstrate that the prey and predator were in closest proximity in warmer, turbid water, with an interaction between these stressors showing a greater than additive effect. There was also an interaction between the stressors in the inter-individual distances between the prey, where shoal cohesion increased with temperature in clear water, but decreased when temperature increased in turbid water. The closer proximity to predators and reduction in shoaling in turbid, warmer water may increase the risk of predation for the guppy, suggesting that the combined effects of elevated temperature and turbidity may favour predators rather than prey.

Conversion of sugarcane vinasse into biomass of Aspergillus sp. V1 and its potential application as a fish feed ingredient

Vinasse generated by bioethanol industry is the acid liquid waste with high content of organic matter that causes undesirable impacts when it is poured into the ecosystem, indiscriminately. Therefore, the development of new technologies to improve the vinasse management is relevant worldwide. As a possible alternative, in this study, conversion of sugarcane vinasse into biomass of Aspergillus sp. V1 for use as a cheap fish feed ingredient was evaluated. Vinasse toxicity was also monitored, before and after biomass production, using growth parameters in Lactuca sativa as endpoints. Biomass of Aspergillus sp. V1 produced from vinasse supplemented with 2 g/L urea revealed a nutritional composition within recommended levels for fish diets, and an aflatoxins concentration of 12.9 µg/kg, which was within permissible levels for animal feeds. Fish feeding assays with 50 % and 100 % fungus biomass did not demonstrate any adverse effects for Poecilia reticulata, used as a model organism. Finally, inhibitory concentration (IC50) on L. sativa root elongation was 11.7 % for initially received vinasse and 23.8 % for vinasse resulting from biomass production. These findings demonstrate that it is feasible to minimize the transfer of distilleries pollution to the environment through biological conversion of vinasse into fungal biomass with nutritional value.

Insights from the judgment bias paradigm: Social group and tank size does not affect mental state in female guppies.

Optimal holding conditions are key to animal welfare. How stressful husbandry is perceived by the animal can be determined via assessment of an animal's mental state - where it is positioned on the continuum between optimistic and pessimistic state - and can be measured using the judgment bias paradigm. In this test, individuals are trained to distinguish a rewarded from an unrewarded cue before being presented an ambiguous, intermediate cue. The response time to the ambiguous cue is then indicative of mental state. A shorter latency suggests a more positive (optimistic) mental state, a longer latency a more negative (pessimistic) mental state. Here, we used the judgment bias paradigm to assess the impact of standard laboratory housing conditions on the mental states of female guppies (Poecilia reticulata). As it is debated which holding conditions confer optimal welfare, we tested the impact of husbandry on mental state by keeping animals for three weeks in small or large social groups in either small or large tanks. We found that the different standard housing conditions we used did not lead to differences in mental state. As an unexpected side result, we found that female guppies seem lateral. Our findings of comparable mental state across housing conditions suggest that guppies either perceive the tested conditions as equally stressful or alternatively, that guppies are relatively resilient to the combination of group and tank sizes tested in this study. We conclude that the judgment bias paradigm can be a useful tool to assess fish welfare. This article is protected by copyright. All rights reserved.

Adaptive phenotypic plasticity induces individual variability along a cognitive trade-off

Animal species, including humans, display patterns of individual variability in cognition that are difficult to explain. For instance, some individuals perform well in certain cognitive tasks but show difficulties in others. We experimentally analysed the contribution of cognitive plasticity to such variability. Theory suggests that diametrically opposed cognitive phenotypes increase individuals' fitness in environments with different conditions such as resource predictability. Therefore, if selection has generated plasticity that matches individuals’ cognitive phenotypes to the environment, this might produce remarkable cognitive variability. We found that guppies, Poecilia reticulata , exposed to an environment with high resource predictability (i.e. food available at the same time and in the same location) developed enhanced learning abilities. Conversely, guppies exposed to an environment with low resource predictability (i.e. food available at a random time and location) developed enhanced cognitive flexibility and inhibitory control. These cognitive differences align along a trade-off between functions that favour the acquisition of regularities such as learning and functions that adjust behaviour to changing conditions (cognitive flexibility and inhibitory control). Therefore, adaptive cognitive plasticity in response to resource predictability (and potentially similar factors) is a key determinant of cognitive individual differences.

The Composition and Diversity of Fresh Water Fish in The Upstream of the Bedadung River, Jember District

The river is an irrational body of water from upstream to downstream. The upstream part of the river generally has a narrow width of the river flow, heavy air currents, the right and left banks of the river have vegetation trees, sandy rocky substrate types, and are located in the highlands or mountains. This character is also found in the Upper Bedadung River in the Argopuro Mountains. Characteristics in the upper reaches of the river are thought to affect the existence of creatures that live in it, such as fish. The purpose of this study was to determine the composition, dominance, and types of freshwater fish in the upper reaches of the Bedadung River, Jember Regency. The research method used is roaming method. The exploration was carried out at four research stations. The results showed that in the Upper S. Bedadung five species of fish were found including Channa gachua, Poecilia reticulata, Barbodes binotatus, Glyptothorax platypogon, and Nemacheilus fasciatus. The diversity of freshwater fish species in the upper reaches of the Bedadung River is moderate.

Sex-specific transgenerational plasticity: developmental temperatures of mothers and fathers have different effects on sons and daughters.

Each parent can influence offspring phenotype via provisioning of the zygote or sex-specific DNA methylation. Transgenerational plasticity may therefore depend on the environmental conditions experienced by each parent. We tested this hypothesis by conducting a fully factorial experiment across three generations of guppies (Poecilia reticulata), determining the effects of warm (28°C) and cold (21°C) thermal backgrounds of mothers and fathers on mass and length, and thermal performance (sustained and sprint swimming speeds, citrate synthase and lactate dehydrogenase activities; 18, 24, 28, 32 and 36°C test temperatures) of sons and daughters. Offspring sex was significant for all traits except for sprint speed. Warmer mothers produced sons and daughters with reduced mass and length, and warmer fathers produced shorter sons. Sustained swimming speed (Ucrit) of male offspring was greatest when both parents were raised at 28°C, and warmer fathers produced daughters with greater Ucrit. Similarly, warmer fathers produced sons and daughters with greater metabolic capacity. We show that the thermal variation experienced by parents can modify offspring phenotype, and that predicting the impacts of environmental change on populations would require knowledge of the thermal background of each mother and father, particularly where sexes are spatially segregated.

Discovery of two novel tilapia lake virus-like virus isolates in the transcriptomic data of guppy fish (Poecilia reticulata).

The author declares no conflict of interest. All raw datasets (SRR6377113–SRR6377114) reanalysed in this study are accessible via the SRA database. The assembled genome sequences (BK063200–BK063219) are available in Supplementary material and also in the Third Party Annotation (TPA) section of the GenBank database. Appendix S1. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Sex chromosome heteromorphism and the Fast-X effect in poeciliids.

Fast-X evolution has been observed in a range of heteromorphic sex chromosomes. However, it remains unclear how early in the process of sex chromosome differentiation the Fast-X effect becomes detectible. Recently, we uncovered an extreme variation in sex chromosome heteromorphism across poeciliid fish species. The common guppy, Poecilia reticulata, Endler's guppy, P. wingei, swamp guppy, P. picta and para guppy, P. parae, appear to share the same XY system and exhibit a remarkable range of heteromorphism. Species outside this group lack this sex chromosome system. We combined analyses of sequence divergence and polymorphism data across poeciliids to investigate X chromosome evolution as a function of hemizygosity and reveal the causes for Fast-X effects. Consistent with the extent of Y degeneration in each species, we detect higher rates of divergence on the X relative to autosomes, a signal of Fast-X evolution, in P. picta and P. parae, species with high levels of X hemizygosity in males. In P. reticulata, which exhibits largely homomorphic sex chromosomes and little evidence of hemizygosity, we observe no change in the rate of evolution of X-linked relative to autosomal genes. In P. wingei, the species with intermediate sex chromosome differentiation, we see an increase in the rate of nonsynonymous substitutions on the older stratum of divergence only. We also use our comparative approach to test for the time of origin of the sex chromosomes in this clade. Taken together, our study reveals an important role of hemizygosity in Fast-X evolution.

Experimental expansion of relative telencephalon size improves the main executive function abilities in guppy.

Executive functions are a set of cognitive control processes required for optimizing goal-directed behavior. Despite more than two centuries of research on executive functions, mostly in humans and nonhuman primates, there is still a knowledge gap in what constitutes the mechanistic basis of evolutionary variation in executive function abilities. Here, we show experimentally that size changes in a forebrain structure (i.e. telencephalon) underlie individual variation in executive function capacities in a fish. For this, we used male guppies (Poecilia reticulata) issued from artificial selection lines with substantial differences in telencephalon size relative to the rest of the brain. We tested fish from the up- and down-selected lines not only in three tasks for the main core executive functions: cognitive flexibility, inhibitory control, and working memory, but also in a basic conditioning test that does not require executive functions. Individuals with relatively larger telencephalons outperformed individuals with smaller telencephalons in all three executive function assays but not in the conditioning assay. Based on our findings, we propose that the telencephalon is the executive brain in teleost fish. Together, it suggests that selective enlargement of key brain structures with distinct functions, like the fish telencephalon, is a potent evolutionary pathway toward evolutionary enhancement of advanced cognitive abilities in vertebrates.

Effects of salinity stress on anxiety behavior and antioxidant capability of guppy (Poecilia reticulata).

The objective of this study was to determine the effect of salinity on anxiety behavior and liver antioxidant capacity in the guppy (Poecilia reticulata). Guppies were exposed to salinities of 0‰, 5‰, 10‰, 15‰ and 20‰ for acute stress tests, and then we analyzed the activity of antioxidant enzymes at 3, 6, 12, 24, 48, 72 and 96 h. During the experiment, the anxiety behavior of guppy was enhanced at salinities of 10‰, 15‰, and 20‰, as evidenced by a significantly higher latency time for the first passage through the upper part than that of the control group (P < 0.05). CAT activity was highest at 24 h in the treatment with the salinity of 10‰, and SOD and GPX activities were highest at 12 h into the treatment with the salinity of 10‰. The SOD and CAT activities were significantly higher than the control group after 96 h of treatment at different salinities (P < 0.05). The MDA contents of the experimental groups at salinities of 5‰ and 10‰ were not significantly different from the control group after 96 h of treatment (P > 0.05). While the MDA contents of the experimental groups at salinities of 15‰ and 20‰ were still significantly higher than the control group after 96 h of treatment (P < 0.05). The experimental results indicated that elevated salinity could lead to oxidative stress in the guppy, altering their anxiety behavior as well as the activity of antioxidant enzymes. In conclusion, drastic changes in salinity during culture should be avoided.

Optimised neem oil-bilayer tablets: A safe, effective and stable tool for the prevention of vector-borne disease outbreaks by Aedes albopictus

The control of mosquito breeding is an essential step towards the reduction of vector-borne disease outbreaks. Synthetic larvicidal agents produce resistance in vectors and cause safety concerns in humans, animals and aquatic species. The drawback of synthetic larvicides opened a new avenue for natural larvicidal agents, but poor dosage accuracy, need for frequent applications, low stability and sustainability are the major challenges with them. Hence, this investigation aimed to overcome those drawbacks by developing bilayer tablets loaded with neem oil to prevent mosquito breeding in stagnant water. The optimised batch of neem oil-bilayer tablets (ONBT) had 65%w/w hydroxypropyl methylcellulose K100M and 80%w/w ethylcellulose in its composition. After the completion of 4th week, 91.98 ± 0.871% azadirachtin was released from the ONBT, which was followed by a subsequent drop in the in vitro release. ONBT reported long-term larvicidal efficacy (>75%) and a good deterrent effect which was better than neem oil-based marketed products. The acute toxicity study on a non-target fish model (Poecilia reticulata), OECD Test No.203 confirmed the safety of the ONBT on non-target aquatic species. The accelerated stability studies predicted a good stability profile for the ONBT. The neem oil-based bilayer tablets can be used as an effective tool for the control of vector-borne diseases in society. The product may be a safe, effective and eco-friendly replacement for the existing synthetic as well as natural products in the market.

Changes in movement characteristics in response to private and social information acquisition of socially foraging fish

To overcome the cost of competition resulting from foraging socially, individuals may balance their use of private (i.e. acquired from personal sampling) and social (i.e. acquired by watching other individuals) information to adjust their foraging strategy accordingly. Reliability of private information about environmental characteristics, such as the spatial distribution of prey, is thus likely to affect individual movement and social interactions. We aimed to investigate how movement characteristics of foraging individuals changed as they acquired reliable information about the spatial occurrence of prey in a foraging context. We allowed guppies, Poecilia reticulata, to develop the reliability of their private knowledge about prey spatial occurrence by repeatedly testing shoals in a foraging task under three experimental distributions of prey: (1) aggregated prey forming three patches located in fixed locations, (2) scattered distribution of prey with random locations, or (3) no prey (used as a control). Using individual time series of spatial coordinates, we computed a suite of movement variables reflecting search effort, social proximity and locomotion characteristics during foraging, to examine changes occurring over repeated trials. Over time, individuals foraging on either scattered or aggregated prey travelled greater distances, showed an increasing distance to their closest neighbour and became slightly more stochastic in their acceleration profile, compared to control individuals. We found that behaviour changed as private information increased over time, with a clear behavioural shift and an increase of collective foraging efficiency occurring on the third testing day. Social proximity was the major predictor of foraging success in the absence of prior foraging information, while search effort became the most important predictor of foraging success as information increased. In conclusion, we showed that individuals' movement patterns changed as they acquired private information. Contrary to our predictions, the spatial distribution of prey did not affect any of the movement variables of interest.

Kualitas Kinerja Reproduksi Induk Ikan Guppy Albino Full Platinum (Poecilia reticulata) Yang diberi Tepung Taoge (Bean sprouts) Dalam Pakan

This study aims to determine the level of addition of bean sprout flour in feed as vitamin E to help the reproductive system in rearing guppy fish (Poecilia reticulate). The design used was a Completely Randomized Design (CRD) with 4 treatments 3 replications, each treatment was: A. Without Sprout Flour 0% (SF 0%), B Sprout Flour 2% (SF 2.0%), C Sprout Flour 4% (SF 4.0%), D Sprout Flour 6% (SF 6,0%). The fish used in this study were female guppy fish measuring 0,38 – 0,51 gram. Growth of gonads for all treatments ranged from 0.61% - 0.68%, gonadal maturity index ranged from 0.61 –0.81 gram, number of pups born ranged from 10 – 23 per head, guppy birth duration ranged from 13 - 19 days, feed conversion ratio ranged from 2.53 - 2.89. The results of the analysis of the water quality of the rearing medium showed that the water quality was still in the proper range for the maintenance of guppy fish. The best reproductive performance and stress response to the addition of bean sprout flour to guppy fish feed (Poecilia reticulate) was treatment C (the addition of bean sprout flour was 4%).

Growth, mucosal immune responses, and total carotenoid content of juvenile red fantail male guppy fish (Poecilia reticulata) fed with different herbal supplements

ABSTRACT One hundred and twenty red fantail male guppies (Poecilia reticulata) with an average weight of 0.64 ± 0.07 g were fed ad libitum a control diet without any herbals (0), 20 g/kg garlic, 20 g/kg red onion, and 20 g/kg sweet red pepper powders in 12 circular tanks for 60 d. The herbal treatments had significantly higher weight gain (94.70 ± 0.89 to 96.26 ± 0.90%), protein (3.58 ± 0.05 to 3.72 ± 0.06 mg/ml), ACH50 (1.41 ± 0.00 to 1.56 ± 0.00 U/ml), Ig (0.16 ± 0.00 to 0.32 ± 0.02 mg/ml), lysozyme activity (60.33 ± 0.88 to 68.00 ± 1.15 U/ml), carotenoids in lateral skin body (5.75 ± 0.025 to 8.26 ± 0.003 µg/g), and caudal fin (6.49 ± 0.003 to 10.10 ± 0.005 µg/g) than the control. Therefore, dietary garlic and sweet red pepper can be used for immunity and coloration in red fantail male guppies.

Ovaries of guppies (Poecilia reticulata) investigated in pre-embryonic, embryonic and post-embryonic stages after exposure to maghemite nanoparticles (y-Fe2O3) associated with Roundup® and glyphosate, followed by recovery period evaluation

Iron oxide nanoparticles (IONP) are promising alternatives to environmental remediation, so this study investigates IONP single and associated to contaminants, in this case, glyphosate (GLY) and Roundup® (GBH) in Poecilia reticulata (guppy). The guppies have internal development, therefore this study analyzed female gonads to establish the developmental stages of P. reticulata and evaluate effects of exposure (7, 14 and 21 days) and post-exposure (same period) to the treatments with Iron ions 0.3 mg Fe/L (IFe); IONP 0.3 mg Fe/L; IONP 0.3 mgFe/L + GBH 0,65 mgGLY/L (IONP+GBH1); IONP 0.3 mgFe/L + GBH 1.30 mgGLY/L (IONP+GBH2); and IONP 0.3 mgFe/L + GLY 0.65 mg/L (IONP+GLY). The development was organized in immature, development, and gestation phases. The damage in all treatments after 21 days of exposure was evident in reaction patterns regressive inflammatory, and circulatory including total histopathologic index of liver, nevertheless there was a damage recovery trend during post-exposure period.