Influence of garlic extract on larval performance and survival of juvenile angelfish Pterophyllum scalare during transport

The objective of this study was to evaluate the properties of garlic as a growth promoter in larvae of angelfish Pterophyllum scalare and its benefits during transport of juveniles of this species. The experiment was conducted in recirculation aquaculture system, consisting of 20 tanks of 40 L equipped with independent water input and output. We used 1,400 larvae distributed among five treatments, with four repetitions, which totaled 20 experimental units. The treatments were 0, 50, 100, 200, and 400 mg of garlic extract per kilo of feed. The results showed that the inclusion of levels of garlic extract in the feed did not significantly effect the fish’s development or their transport. Neither did the inclusion of levels of garlic extract affect the survival of the larvae during the trial period. New research with extracts of higher dosages should be performed to elucidate the effect of garlic extract as a growth promoter.

Examination of white blood cell indicators for three different ploidy level sturgeon species reared in an indoor recirculation aquaculture system for one year

Functional diploid Acipenser ruthenus, functional tetraploid Acipenser gueldenstaedtii and functional hexaploid Acipenser brevirostrum juveniles were sampled monthly for one year, and the white blood cell indicators were determined. The total number of leukocytes (TL) was 40.93 ± 17.24 × 10⁹/l for the diploids, 20.63 ± 11.20 × 10⁹/l for the tetraploids, 14.13 ± 7.72 × 10⁹/l for the hexaploids. The TL decreased with an increasing ploidy level. The highest number of leukocytes was reached during September and October for A. ruthenus and A. brevirostrum, from October to January for A. gueldenstaedtii (a statistically significant finding). The lymphocytes dominated (76.89–80.14%) in the differential counts and were found to be reduced in June and July in each group. Granulocytes were represented by neutrophils and eosinophils. Counting from all the leukocytes, the neutrophils represented 13.0–18.7% and eosinophils represented 5.7–6.1%. Increasing number of nuclear segments in the granulocytes was dependent on the increasing ploidy level. Nuclear segmentation in the lymphocytes was a common finding in higher ploidy level groups. The data suggest a significant effect of ploidy level on the total number of leukocytes and morphological nuclear changes in the granulocytes and lymphocytes. The seasonal variation in the differential leukocyte counts depends on the species and the influence of various external conditions rather than the ploidy level.

Smart and Sustainable Aquaculture Farms

This paper presents the design and construction of a smart and sustainable fish farm. The farm is based on the hybrid aquaculture concept that combines the advantages of the recirculation aquaculture system (RAS), the zero-water discharge (ZWD), and smart technology. The system’s smartness consists of using the latest technology, including monitoring and automation, ensuring zero water discharge, good water quality, reduced energy consumption, and high biosecurity. In addition, the system does not use chemicals in the aquaculture process. The paper describes the design of this system, including the hydraulic system, the smart monitoring system, the feeding regime, and the control of the biological parameters. Tests conducted in Tabuk, Saudi Arabia, showed high performance of this system with around 90% survival rate. In addition, observations showed the system’s capacity to maintain the water quality parameters within the optimal water quality ranges, reduce energy consumption, and sustain efficient shrimp waste recycling.

Effects of ozonation on water quality and pikeperch (Sander lucioperca) performance in a recirculating aquaculture system

The aim of this study was to examine the effects of ozonation on the water quality, and growth, blood biochemistry, antioxidant capacity and survival of pikeperch (Sander lucioperca) reared in a recirculation aquaculture system for 30 weeks. A group without ozone treatment was used as a control. The ozone application led to a significant reduction of the water chemical oxygen demand, biological oxygen demand and unsuspended solids concentration. The results revealed that an ozone treatment as a water treatment method has a positive influence on the intensive culture of pikeperch ensuring a higher survival rate (77%) compared to the non-treated control group (67.2%). Moreover, the ozonation prevented fin damage to a large extent and reduced the prevalence of an Ichthyophthirius multifiliis infection. Furthermore, the ozone application led to a reduction in the thiobarbituric acid reactive substance level and enhanced the superoxide dismutase activity in the fish gills. However, the effect of ozonation was null on the plasma biochemical parameters. Overall, these findings suggest that an ozone treatment, using adequate technological equipment to destroy the residual ozone, improves the water quality and protects pikeperch against any possible infection and fin damage in a recirculation aquaculture system.

The Role of Filter with Different Media Compositions on Water Quality and Survival of Pangasius (Pangasius sp.) in Recirculation Aquaculture System

The high market demand for Pangasius (Pangasius sp.) has encouraged farmers to adopt a cultivation system with high stocking densities and high feeding rates. This causes fish farming waste to increase and ammonia in the waters also increases, resulting in a decrease in water quality. One of the efforts to overcome this problem is by using Recirculation Aquaculture System (RAS). This study aims to examine the effect of filters with different media compositions in RAS of Pangasius. Test fish, average weight of 4.59 g, kept for 30 days in aquarium with a density of 1.15 g.L-1. The feed is given at satiation, twice a day. There were five treatments and four replications during study. The treatments were the difference composition of filter media, i.e. A (100% zeolite), B (25% net + 75% zeolite), C (50% net + 50% zeolite), D (75% net + 25% zeolite), and E (100% net). Dacron was used as a mechanical filter in all treatments. The results showed that the composition of different filter materials had a significant effect (P <0.05) on Survival Rate (SR), Total Amount of Feed Fed (TFF), Relative Growth Rate (RGR), and Feed Conversion Efficiency (FCE). The best performance was showed by media biofilter composition of 25% nets + 75% zeolite, with the value of VTR (Volumetric Total Ammonia Nitrogen Removal) were 55.45-66.32 g.m-3.day-1, SR was 93.75%; TFF was 124.84 g; RGR was 2.13%.day-1, and FCE was 46.87%. Various different compositions of net and zeolite as filter media on RAS were able to manage TAN below tolerance limit.Keywords: catfish, recirculation system, filter composition, dacron, net, zeolite.

Comparison of Growth for Cultivated Common carp, Cyprinus carpio Larvae between Earthen Ponds and Recirculation Aquaculture System

A comparison was conducted for growth criteria of common carp, Cyprinus carpio larvae cultivated in earthen ponds and recirculation aquaculture system (RAS) depending on live foods (phytoplankton and zooplankton stimulated by buffalo fertilizers in earthen ponds, while the larvae cultivated in RAS were feed on Artemia larvae reproduced in vitro, in addition to manufactured pellets (38% crude protein) for common carp in both systems. Three 2500 m2 earthen ponds were cultivated for 90 days with larvae of initial weight 0.002 g at different numbers (40800 larvae for pond 1, 55600 larvae for pond 2 and 36400 larvae for pond 3). These larvae depend on natural food for 19 days, then fed on manufactured feed. Fishes were weighed every 19 days to change daily feed. Three replicates of RAS plastic tanks (100 letter capacity) cultivated for 90 days with 0.002 g larvae at a density of 2 larvae per one liter (160 larvae at each plastic tank). These larvae fed for 15 days to saturation (4 meals daily) with Artemia larvae and small Artemia, then fed on manufactured feed. Subsequently, fishes were weighed every 15 days to change daily feed. Larvae cultivated in earthen ponds recorded weight gain of 26.90 g, daily growth of 0.30 gday-1, relative growth of 1345000%, specific growth of 10.56 %day-1, feed conversion of 1.25 and survival rate of 13.16%. Larvae cultivated in RAS system recorded weight gain of 1.53 g, daily growth of 0.02 gday-1, relative growth of 76200%, specific growth of 7.37 %day-1, feed conversion of 2.82 and survival rate of 72.32%. Statistical analysis of results revealed significant differences (p>0.05) in all growth criteria for larvae cultivated in both systems. Final conclusion that earthen pond was better than RAS systems in producing fingerlings of common carp.