Effect of dietary supplementation with propolis and Aloe barbadensis extracts on hematological parameters and parasitism in Nile tilapia

Cytoprotective effect of propolis on heat stress induces alteration to histological, ultrastructural, and oxidative stress in catfish (Clarias gariepinus)

Our study helps to evaluate the immune response, antioxidative status, and resistance against heat stress (HS) in Clarias gariepinus treated with propolis extraction; the results will contribute to theories of fish physiology and immunity under high-temperature conditions. Forty-five fish were divided into three equal groups: the control, the HS group at 36 °C, and the HS treated with alcoholic extraction of propolis that dissolved in water for 3 weeks. The results of our study suggested that the stress response differs among tissues thymus, spleen, and liver. All the tissues showed alteration in morphological and cytological structure at the light microscope (LM) and transmission electron microscope (TEM); thymus showed edema and thymocyte destruction; the spleen detected collagen deposition, and the liver displayed endoplasmic reticulum amplification (ER). In addition, we examined oxidative stress and antioxidant defenses (lipid peroxidation, catalase, and glutathione) of the spleen and measured blood biochemical parameters (alanine transaminase and aspartic transaminase levels) after heat stress. However, this toxic effect of HS was neutralized by the propolis extraction. To conclude, propolis is recommended to cope with the impacts of heat stress on catfish (Clarias gariepinus) by improving immunity and antioxidative resistance.

Propolis: Properties and composition, health benefits and applications in fish nutrition

Propolis is a viscous, waxy, resinous substance that is produced from the exudates of flowers and buds by the action of salivary enzymes of honey bees. Propolis may differ in color (brown, red or green), with color being influenced by the chemical composition and age of the product. Propolis has a special distinctive odor owing to the high concentration of volatile essential oils. It is composed of 5% pollen grains, 10% essential and aromatic oils, 30% wax, 50% resin and balsams, and other minor trace substances. Natural propolis products may be useful for a range of applications in aquaculture systems instead of relying on the application of synthetic compounds to manage many ailments that affect business profitability. It has been reported in several studies that propolis enhances performance, economics, immunity response and disease resistance in different fish species. This present review discusses the functional actions of propolis and the prospects of its use as an antimicrobial, antioxidant, immune-modulatory, antiseptic, antiparasitic, anti-inflammatory and food additive in aquaculture production. In summary, propolis could be a natural supplement that has the potential to improve fish health status and immunity thereby enhancing growth and productivity of the fish industry as well as economic efficiency.

Responses of monogenean species to variations in abiotic parameters in tilapiculture

Fish farming is becoming an increasingly popular agricultural activity, and water quality in these environments is a major concern. Fish parasites, such as monogeneans, respond to changes in abiotic conditions, either with an increase or decrease in population. This study aimed to identify gill monogeneans and analyse their relationships with abiotic factors during the ontogenetic development of Nile tilapia over the fish culture cycle in Mato Grosso do Sul, Brazil. Fish were sampled monthly for eight months, and a total of 200 fish were collected. The physical and chemical water parameters were measured and correlated with the abundance of each monogenean species. Over the fish culture cycle, the physical and chemical parameters fluctuated, and the water quality decreased. The parasites found included Cichlidogyrus tilapiae, Cichlidogyrus thurstonae, Cichlidogyrus sclerosus, Cichlidogyrus halli and Scutogyrus longicornis. The abundances of all species showed significant differences during ontogenetic development (body size) and C. tilapiae, C. sclerosus, C. thurstonae and S. longicornis were correlated with changes in abiotic conditions. However, C. halli was not significantly correlated with any of the evaluated physical or chemical parameters. Understanding how different monogenean species respond to changes in the physical and chemical parameters of water during a production cycle can prevent peaks in abundance and subsequent sanitary problems.

Effect of Propolis, a Honeybee Product, Against a Parasite (Ligictaluridus floridanus) from Catfish (Ictalurus punctatus) Gills

PURPOSE

The aim of this study was to evaluate the in vitro and in vivo efficacy of propolis against Ligictaluridus floridanus on Ictalurus punctatus gills.

METHODS

This study used an ethanol extract of propolis at a concentration of 300 mg mL^-1, with a total polyphenol concentration of 2.77 mg mL^-1 as determined by chromatography. In vitro trial used propolis concentrations at 5, 30 as well as 60 mg L^-1 and a 70% ethanol control group to treat naturally infected catfish. The in vivo experiment was 16 weeks in duration, consisting of seventy-two fish infected by cohabitation and subjected to one-hour baths every 72 h during the trial.

RESULTS

In vitro studies showed that parasites exposed to 60 mg L^-1 of propolis displayed a significant reduction (p < 0.05) in their survival time. In vivo studies confirmed the reduction of intensity and abundance of Ligictaluridus floridanus on the gills of channel catfish.

CONCLUSION

This study has provided the first challenge of propolis against L. floridanus on I. punctatus gills and shows that propolis has an anthelmintic effect.

Aspilia mossambicensis and Azadirachta indica medicinal leaf powders modulate physiological parameters of Nile tilapia (Oreochromis niloticus)

Growing mixed-sex Nile tilapia, Oreochromis niloticus in earthen ponds to table size is a major challenge due to its early maturity and prolific breeding. This study determined the effects of two medicinal plants; Aspilia plant, Aspilia mossambicensis and Neem tree, Azadirachta indica on hatchlings production, growth performance, feed utilization, survival and haematology of O. niloticus. Experimental diets were prepared by adding 1.0, 2.0, 4.0 and 8.0 g of either A. mossambicensis or A. indica leaf powders into a kg of the control diet subsequently administered daily to twenty triplicates of O. niloticus for three months. Both A. mossambicensis and A. indica leaf powder at the used doses, reduced significantly hatchlings production of O. niloticus when compared to the control (P < .05). The lowest value of hatchlings count was found in A. indica dose 8.0 g kg⁻¹ (P < .05). The use of A. mossambicensis leaf powder at a dose of 4.0 g kg⁻¹ improved significantly growth performance and feed utilization (P < .05). In contrast, survival rate was not affected significantly by the two plants (P > .05). Both plants differentially increased significantly haematological parameters such as Hb concentration, packed cell volume (PCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), white blood cells (WBC), monocyte and lymphocytes while reduced significantly neutrophils and eosinophils (P < .05). In conclusion, A. mossambicensis and A. indica leaf powders control prolific breeding of O. niloticus, modulate its growth performance and feed utilization. The two plants also modulate haematological parameters of O. niloticus indicating immunological response towards stress or intoxication, however, the values obtained were not beyond the recommended range for healthy fish.

Evidence-Based Advances in Aquatic Animal Medicine

Fish and aquatic invertebrates deserve evidence-based medicine. Pharmacologic information is available; most pharmacokinetic studies are derived from the aquaculture industry and extrapolated to ornamental fish. Conversely, advanced diagnostics and information regarding diseases affecting only ornamental fish and invertebrates require more peer-reviewed experimental studies; the examples of carp edema virus, sea star wasting disease, seahorse nutrition, and gas bubble disease of fish under human care are discussed. Antinociception is also a controversial topic of growing interest in aquatic animal medicine. This article summarizes information regarding new topics of interest in companion fish and invertebrates and highlights some future avenues for research.

Redescription of Cichlidogyrus tiberianus Paperna, 1960 and C. dossoui Douëllou, 1993 (Monogenea: Ancyrocephalidae), with special reference to the male copulatory organ

The flatworms of the genus Cichlidogyrus Paperna, 1960 (Monogenea: Ancyrocephalidae) are gill parasites of freshwater fish, affecting predominantly the family Cichlidae. Cichlidogyrus tiberianus Paperna, 1960 and Cichlidogyrus dossoui Douëllou, 1993 are among the most widely distributed species of the genus, occurring in several African river basins and infecting many different host species, including the economically important Nile tilapia Oreochromis niloticus (Linnaeus) and redbreast tilapia Coptodon rendalli (Boulenger). Despite their wide distribution, C. tiberianus and C. dossoui have so far been studied only by light microscopy. In this paper they are redescribed on the basis of scanning electron microscopy of newly-collected material. The new material was obtained from redbreast tilapia caught in the Luapula River (D. R. Congo). The haptoral sclerites and genitalia are redescribed and illustrated in detail. Special attention is given to the complex morphology of the male copulatory organ.