Inventory of Animal Contamination by Cyanotoxins in Africa

This study reviews work on the accumulation of cyanotoxins in fish and various animals in Africa. Microcystins (MC-LR, MC-RR, and MC-YR) appear to be the main contaminating toxin in fish and other animals. In fish, the highest concentration (1917 μg.kg-1) was detected in the whole body of a small species of fish (Rastrineobola argenta) consumed whole by the populations around Lake Victoria. In large species, the intestine (followed by the liver) is the organ that accumulates the most cyanotoxins; up to 3059 ng.g-1 in Algerian common carp. Fish muscle accumulates little or no cyanotoxins in most publications and Oreochromis niloticus, a phytoplanktonophagous species widely consumed by the African populations, remains the most studied species. In other animal species, cases of cyanotoxin mortality were reported in most publications in southern and central Africa and only one publication in North Africa. No study on this subject has been referenced in other parts of Africa.

Influence of Drying Techniques on the Physicochemical, Nutritional, and Morphological Properties of Bighead Carp (Hypophthalmichthys nobilis) Fillets

Different experiment analyses were performed to evaluate the influence of two drying techniques (oven drying and microwave drying) on the fillets of bighead carp fish (Hypophthalmichthys nobilis). The processed and fresh samples were subjected to the chemical analysis of (amino acids, minerals, volatile compounds, fatty acids, and vitamins) as well as scanning electron microscopy, thermal analysis, and color measurement, in order to identify nutritional components that can be additives or supplementary in food industries. The drying techniques increased the protein content significantly. Amino acids were identified, and the level of essential amino acid (EAA) was higher under the microwave treatment compared with the oven drying process. The Ca+2 and K+1 were presented in high values, followed by Na+1 and Mg+2. In addition, the drying techniques showed and released more volatile compounds in the processed samples compared with the unprocessed samples. Under the drying process, polyunsaturated fatty acids were increased in the processed fillets, whereas the level of saturated and monounsaturated fatty acids reduced. Thermal degradation occurred from 100 to 150 °C. However, the processed samples were subjected to an intensive endothermic response, but remained stable until 100 °C. Therefore, the microwave technique showed some enhancements in the nutritional value and has the potential to be applied as an effective preservation method of bighead carp fish. Furthermore, dried fillets could be an alternative source of bighead carp fish for the food industry.

Effect of The Type of Solvent in Azolla Extracts Added to The Ratio on The Growth of Common Carp Cyprinus Carpio L

The study was conducted in the fisheries laboratory of the Department of Animal Production in the College of Agriculture and Forestry/the University of Mosul. The experiment included feeding common carp fish using ten experimental diets containing azalea plant extract in proportions (0.5, 1, 1.5%) of each solvent, ether, acetone, and ethanol, and the control was free of additives. Glass tanks were used in the growth experiment of carp fish for a period of 49 days. The results of the statistical analysis of the final weight values, total and daily weight gain (gm/fish), and the relative and qualitative growth rate % showed that there were significant differences (P≤ 0.05) for the experimental treatments, and the third treatment (ether 1%) was significant compared to the rest of the treatments. While the results of the analysis of the amount of food consumed and the ratio of food efficiency in the presence.

IMPLEMENTATION OF AQUAPONICS IN ARTIFICIAL POOLS FOR GROWING CARP AND STURGEON FISH

Показана актуальность проблемы, связанной с особенностями ведения рыболовного хозяйства и растениеводства в условиях неблагоприятного климата, ограниченных территорий. Приведено описание опыта по внедрению аквапоники в схему выращивания осетровых и карповых рыб в искусственных бассейнах с использованием оборотной воды, включающую узлы очистки. В ходе исследования была разработана установка, принцип работы которой может быть использован, как решение проблематики выращивания рыб и растений в искусственно созданных условиях. Определены и описаны узлы фильтрации и очистки воды. Приведены показатели воды, показывающие работоспособность и эффективность установки. Проведено сравнение показателей оборотной воды при проведении опытов по выращиванию карповых и осетровых рыб. Приведены результаты экспериментального исследования скорости роста растений в аквапонной установке с использованием различных субстратов и воды. Выявлены преимущества проращивания семян растений при использовании оборотной воды из рыбоводного бассейна в сравнении с использованием водопроводной воды. We demonstrated the relevance of the problem associated with the difficulty of fishing and plant growing in an unfavorable climate, limited territories. We described the experience of introducing aquaponics into the scheme of growing sturgeon and carp fish in artificial pools using circulating water, including purification units. In the course of the study we developed an installation, the principle of operation of which can be used as a solution to the problem of growing fish and plants in artificially created conditions. As well we identified and described the nodes of water filtration and its purification. We demonstrated indicators of water that show the operability and efficiency of the installation. We also carried out comparison of indicators of circulating water during experiments with growing carp and sturgeon fish. As well we made a comparison of the efficiency and growth rate of plants in an aquaponic installation using various substrates and water. The advantages of germination of plant seeds with the use of circulating water from the fish-breeding basin in comparison with the use of tap water have been revealed.

Revelation of candidate genes and molecular mechanism of reproductive seasonality in female rohu (Labeo rohita Ham.) by RNA sequencing

Background Carp fish, rohu (Labeo rohita Ham.) is important freshwater aquaculture species of South-East Asia having seasonal reproductive rhythm. There is no holistic study at transcriptome level revealing key candidate genes involved in such circannual rhythm regulated by biological clock genes (BCGs). Seasonality manifestation has two contrasting phases of reproduction, i.e., post-spawning resting and initiation of gonadal activity appropriate for revealing the associated candidate genes. It can be deciphered by RNA sequencing of tissues involved in BPGL (Brain-Pituitary-Gonad-Liver) axis controlling seasonality. How far such BCGs of this fish are evolutionarily conserved across different phyla is unknown. Such study can be of further use to enhance fish productivity as seasonality restricts seed production beyond monsoon season. Result A total of ~ 150 Gb of transcriptomic data of four tissues viz., BPGL were generated using Illumina TruSeq. De-novo assembled BPGL tissues revealed 75,554 differentially expressed transcripts, 115,534 SSRs, 65,584 SNPs, 514 pathways, 5379 transcription factors, 187 mature miRNA which regulates candidate genes represented by 1576 differentially expressed transcripts are available in the form of web-genomic resources. Findings were validated by qPCR. This is the first report in carp fish having 32 BCGs, found widely conserved in fish, amphibian, reptile, birds, prototheria, marsupials and placental mammals. This is due to universal mechanism of rhythmicity in response to environment and earth rotation having adaptive and reproductive significance. Conclusion This study elucidates evolutionary conserved mechanism of photo-periodism sensing, neuroendocrine secretion, metabolism and yolk synthesis in liver, gonadal maturation, muscular growth with sensory and auditory perception in this fish. Study reveals fish as a good model for research on biological clock besides its relevance in reproductive efficiency enhancement.

ICHTHYOFAUNA OF THE OB RIVER AND ITS FLOODPLAIN IN THE OKTYABRSKY DISTRICT OF THE KHANTY-MANSI AUTONOMOUS OKRUG-YUGRA

В статье рассмотрен видовой состав уловов в Октябрьском районе Ханты-Мансийского округа - Югры в 2020-2021 гг. Совокупно в промышленных, любительских и браконьерских уловах отмечено 23 вида из 9 семейств. Набольшее видовое разнообразие отмечено в русле и протоках Оби (соответственно 18 и 20 видов). По числу видов и объемам добычи в любительском и промышленном рыболовстве лидируют карповые рыбы. The article considers the species composition of catches in the Oktyabrsky district of the Khanty-Mansiysk district - Yugra in 2020-2021. In total, 23 species from 9 families were recorded in industrial, amateur and poaching catches. The greatest species diversity was noted in the riverbed and channels of the Ob (18 and 20 species, respectively). In terms of the number of species and production volumes, carp fish are the leaders in amateur and industrial fishery.