Effect of fluoxetine on food intake and feeding behavior of goldfish Carassius auratus

Serotonin is one of the monoamines that play an important role in food intake in mammalian species. The increase in serotonergic activity may reduce appetite. Fluoxetine as an active ingredient of Prozac is increased in serotonin content by blocking reuptake of it. Due to the release of these substances into the ecosystem, the role of fluoxetine on food intake and feed behavior of goldfish, Carassius auratus was investigated. In experiment 1, fish with 21-49 g weight divided in four groups of control: with no injection; saline injected; and two groups with 1 µg g-1 and 10 µg g-1 body weight fluoxetine. Animals were injected every other day for a total of 5 injections. Food intake calculated after each injection and fish reweighted at the end of the experiment to achieved weight changes. In experiment 2, 20 goldfish were selected in two groups of control and injected with 10 µg g-1 body weight fluoxetine to asses feed behavior test. Fish were injected every other day for a total of 5 injections and feed behavior was investigated after each injection. Food intake was significantly decreased after fluoxetine injections. In the Flu-10 group, low intake of food resulted in minimum weight gain among all treatments. Also, fluoxetine affected the feed behavior of goldfish and significantly was decreased in search and consumption of food. Results showed that this recently toxic environmental material can largely affect the food and weight parameters of goldfish

Fluoxetine alters reproductive performance of female fighting fish, Betta splendens

This study was aimed to investigate the effects of waterborne fluoxetine on the reproduction performance of female fighting fish (Betta splendens). For this purpose, mature, ready for spawning females were exposed to concentrations of 0, 0.54 and 54.0 µg/l fluoxetine for 7 days. Then they were introduced into the spawning tank containing pre-acclimated male and reproductive consequences including number of copulations per spawning, number of eggs per copulation, duration of spawning, fecundity and hatching rate were assessed. Fluoxetine concentration of 54.0 µg/l, was significantly affected on the number of produced eggs per copulation, fecundity and hatching rate. In addition, the mean number of copulations per spawning was not different between treatments but significantly different for the spawning duration between control and 54.0 µg/l treatments. The results suggest that fluoxetine can impacts on reproductive performance of female fighting fish at concentrations greater than those found in the aquatic environments

The effects of mate switching tacticon reproductive performance of the severum cichlid, Heros severus

This study investigated the effects of mate switching on the reproductive performance of the severum cichlid, Heros severus, by advancing the egg and larval production in hatcheries. Two reproductive tactic treatments of “monogamous pair” and “mate switching” were used for evaluating 4 reproductive traits of egg production, hatching rate, spawning intervals, and starvation tolerance of the larvae in 6 spawning activities. The number of eggs was not significantly different between the two reproductive tactic treatments in the 6 spawning activities, but the spawning intervals, hatching rate, and survival activity index were all significantly different. Daily average egg and larval production in the mate switching treatment were estimated to be 87.3 eggs and 43.1 larvae per pair of fish, respectively, which was 2.89 times and 1.99 times of those in the monogamous pair treatment, who produced about 30.2 eggs and 21.6 larvae per pair. Our results clearly showed that the reproductive tactic of mate switching is a suitable method for increasing the egg and larval production rate of the severum cichlid

Effect of testosterone and fluoxetine on aggressive behaviors of fighting fish, Betta splendens

Effects of oral administration of testosterone and fluoxetine exposure on aggressive behavior of the fighting fish, Betta splendens, were investigated. Testosterone diluted in ethanol and sprayed on pre-weighted pellet to achieve concentrations of 0, 1, 2 and 4 mg/kg of hormone in food. Two main behaviors were recorded: the time in front of mirror and duration of the gill flaring using a mirror 8 and 15 days after the start of the experiment. Then, half of the specimens in each treatment subjected to waterborne fluoxetine at a concentration of 100 µg/L for 24 hours and the behavior was recorded. After 8 days of feeding, the time in front of mirror and duration of gill flaring were not significantly different between the treatments. Duration of the gill flaring increased significantly after 15 days; however there was no significant difference for the behavior in front of the mirror. Over time the aggressive behaviors were reduced significantly after fluoxetine exposure. This study indicated that fluoxetine in the aquatic environment alters the aggressive behaviors of the fighting fish

The Use of Dietary Additives in Fish Stress Mitigation: Comparative Endocrine and Physiological Responses

In the last years, studies on stress attenuation in fish have progressively grown. This is mainly due to the interest of institutions, producers, aquarists and consumers in improving the welfare of farmed fish. In addition to the development of new technologies to improve environmental conditions of cultured fish, the inclusion of beneficial additives in the daily meal in order to mitigate the stress response to typical stressors (netting, overcrowding, handling, etc.) has been an important research topic. Fish are a highly diverse paraphyletic group (over 27,000 species) though teleost infraclass include around 96% of fish species. Since those species are distributed world-wide, a high number of different habitats and vital requirements exist, including a wide range of environmental conditions determining specifically the stress response. Although the generalized endocrine response to stress (based on the release of catecholamines and corticosteroids) is detectable and therefore provides essential information, a high diversity of physiological effects have been described depending on species. Moreover, recent omics techniques have provided a powerful tool for detecting specific differences regarding the stress response. For instance, for transcriptomic approaches, the gene expression of neuropeptides and other proteins acting as hormonal precursors during stress has been assessed in some fish species. The use of different additives in fish diets to mitigate stress responses has been deeply studied. Besides the species factor, the additive type also plays a pivotal role in the differentiation of the stress response. In the literature, several types of feed supplements in different species have been assayed, deriving in a series of physiological responses which have not focused exclusively on the stress system. Immunological, nutritional and metabolic changes have been reported in these experiments, always associated to endocrine processes. The biochemical nature and physiological functionality of those feed additives strongly affect the stress response and, in fact, these can act as neurotransmitters or hormone precursors, energy substrates, cofactors and other essential elements, implyingmulti-systematic and multi-organic responses. In this review, the different physiological responses among fish species fed stress-attenuating diets based on biomolecules and minerals have been assessed, focusing on the endocrine regulation and its physiological effects

Lateralization of Aggression during Reproduction in Male Siamese Fighting Fish

A preference for the left-eye use during aggressive interactions has been widely reported in the literature, even though in some cases the direction of lateralization varies among individuals within populations. Laterality of aggression in male Siamese fighting fish has been described in a number of studies, yet very little is known about lateralization of aggression during reproduction and/or parental care in fish. Here, we aimed to investigate the relationship between the different reproductive phases and lateralization in eye use during aggressive interactions in males of Siamese fighting fish. Lateralization in eye use is influenced during the early reproductive state, before and after the bubble nest construction stages. We found that nest-holding males preferentially used the right eye before and after bubble nest construction independent of the sex of the intruder. During the later reproductive phases, aggressiveness increased whereby the direction of lateralization rather than the degree was influenced supporting the hypothesis that reproductive state influences behavioral consistency in Siamese fighting fis

Fluoxetine alters reproductive performance of female fighting fish, Betta splendens

This study was aimed to investigate the effects of waterborne fluoxetine on the reproduction performance of female fighting fish (Betta splendens). For this purpose, mature, ready for spawning females were exposed to concentrations of 0, 0.54 and 54.0 µg/l fluoxetine for 7 days. Then they were introduced into the spawning tank containing pre-acclimated male and reproductive consequences including number of copulations per spawning, number of eggs per copulation, duration of spawning, fecundity and hatching rate were assessed. Fluoxetine concentration of 54.0 µg/l, was significantly affected on the number of produced eggs per copulation, fecundity and hatching rate. In addition, the mean number of copulations per spawning was not different between treatments but significantly different for the spawning duration between control and 54.0 µg/l treatments. The results suggest that fluoxetine can impacts on reproductive performance of female fighting fish at concentrations greater than those found in the aquatic environments

The Toxicological effect of Ruta graveolens extract in Siamese fighting fish : a behavioral and histopathological approach

The effects of pharmacological waste on aquatic ecosystems are increasingly highlighted in ecotoxicology research. Many of these products are designed for human physiology but owing to the conservative nature of vertebrate evolution they also tend to have effects on aquatic organisms and fishes in particular when they find their way into aquatic systems via wastewater effluent. One area of research has focused on reproductive control and the associated hormone treatments. Many of these hormones affect the reproductive physiology of fishes and may cause feminization of male reproductive traits. Alternative medicines have also been widely used particularly in traditional cultures but few of these alternative treatments have been assessed with respect to their potential impact on aquatic ecosystems. Rue (Rutagraveolens) has been used as a male contraceptive in traditional medicines but its effects on fish behavior and reproductive anatomy have yet to be established. Here we show that treating Siamese fighting fish, Bettasplendens, with extract of rue has a significant effect on key aggressive/reproductive behaviors and the propensity to explore novel objects (boldness). In all cases the respective behaviors were reduced relative to controls and sham injected fish. Histological analysis of the testes revealed that rue exposure reduced the number of spermatozoa but increased the number of spermatocytes relative to controls.11 page(s

“Not tonight zebrafish”: the effects of Ruta graveolens on reproduction

Context: There is growing interest in the pharmacological evaluation of Rue due to its potential to treat a variety of clinical diseases. The plant seems to present potent endocrine disrupting effects, and its excretion and disposal are not a concern. Objective: The effects of Ruta graveolens L. (Rutaceae) ethanol extract (RE) on reproductive behaviour, fertility, and steroid and thyroid hormone levels in zebrafish were investigated. Material and methods: We exposed subjects to varying concentrations of RE, and one-tenth the LC50 concentration (2.37 ppm) was established as the sublethal dose. After 2 weeks exposure, reproductive behaviour, cumulative number of eggs laid, percentage of fertilized eggs, and whole body steroid and thyroid hormones were measured. Results: Reproductive association behaviour did not differ between control and RE-exposed animals, but spawning attempts were reduced in RE exposed animals. Cumulative egg production between days 9 to 14, RE exposed fish laid 672 eggs while control fish laid 1242 eggs. Also, percentage of fertilized eggs was higher for the control than for the RE exposed fish. Estradiol-17β (E2) levels were reduced in females exposed to RE and testosterone (T) was statistically lower in both males and females treated with RE. Furthermore, thyroid hormones (T3 and T4) declined in fish treated with RE. Conclusion: RE has endocrine disrupting potential in fish, which has important implications for studying the effects of unintentional pharmaceutical exposure. Moreover, the results demonstrate that drug exposure may affect more than just the overall level of behaviour, emphasizing the relevance of examining the effects of individual exposure. We reinforce the use of zebrafish as a model organism in physiology and behaviour, and raise concerns about the toxic effects of RE in non-target organisms such as aquatic vertebrates, which may ultimately affect human health