Pathology of cells and tissues of the gastrointestinal tract of African catfish in high-tech industrial aquaculture

Abstract

There is a possibility of developing a pathological process in the body of fish in the conditions of high-tech industrial aquaculture and at high planting densities, creating chronic stress. Histological studies allow early detection of the initial stages of possible pathology at the cellular level. The studies have shown that apparently healthy individuals of African catfish grown in recirculating aquaculture systems (RAS) revealed pathology of cells and tissues of the gastrointestinal tract. They had edema of the internal muscle layer of the stomach and intestines, detachment of the epithelial layer from the gastric mucosa, violation of the structural organization of gastric fields on histological sections. Thinning of intestinal villus, reduction of their length and branching, violation of their structure up to destruction were also revealed. The study of the tissues of the stomach and intestines was carried out using a research motorized universal microscope Axio Imager.M2 (Carl Zeiss, Germany). To correct the pathological process, the experimental group of fish received a “sporothermin” probiotic with feed, which belongs to the probiotics of the last generation. It is an antagonist of a wide range of pathogenic and opportunistic microbiota and is used as an alternative to antibiotics. The composition of “sporothermin” includes spore forms of bacteria Bacillus subtilis and Bacillus licheniformis, which in the gastrointestinal tract of fish turn into vegetative forms. Bacteria Bacillus subtilis and Bacillus licheniformis are not representatives of the intestinal microbiocenosis of the African catfish, but they regulate its structure by reducing the level of pathogenic and opportunistic microbiota. Pathology of cells and tissues of the gastrointestinal tract have been identified in the fish of the experimental group treated with the sporothermin probiotic.

Monitoring of productive and biochemical parameters of young Clarias gariepinus during feeding of Skretting and Roycher AQUA feeds in experimental conditions

“…Біологічні особливості африканського кларієвого сома Clarias gariepinus визначають його перспективним об'єктом вирощування в установках із замкнутим циклом водозабезпечення (УЗВ). Позитивними якостями вирощування є: легке пристосовуння до умов басейнового вирощування; висока стійкість до дефіциту кисню; можливість вирощування при великій щільності посадки; висока стійкість до каламутності води; просте розмноження; вигідні програми годівлі; стійкість до захворювань (Kachnyi, 2009;Romanova et al, 2018;Spirina et al, 2019;Vlasov, 2019;Hrynevych et al, 2019).…”

Effectiveness of the Use of the Adaptogen Trekrezan in the Cultivation of African Catfish

“…Growing fish in an artificial environment is accompanied by "extreme" living conditions for them, as their waste products are toxic and provide additional stress on the body [1,2]. So, in the artificial environment there are food leftovers and products of fish metabolism, decomposition of which leads to an increase in concentration of nitrogen and phosphorus.…”

“…Recently, African catfish has become one of the most promising objects grown in artificial conditions [1,2], since the peculiarities of its biology allow it to be grown in RAS, pools at a water temperature of 25-30 °C and a fairly low oxygen content in water, due to the fact that it has a well-developed epibranchial organ that allows it to breathe atmospheric oxygen.…”

Effects of Bacillus subtilis and Bacillus licheniformis on catfish in industrial aquaculture

“…Today, aquaculture is one of the rapidly growing sectors of agriculture. Its progress allows to increase the production of marketable products, primarily due to the optimization of hydrochemical regime parameters, feed composition and the use of probiotics [1,2].…”

“…This fish species has a very high growth rate and surpasses all 49 fish species grown in Russian industrial aquaculture by this indicator. [1,2]. Catfish has a high palatability and is considered to be delicious.…”