INFECTIOUS FISH PATHOLOGY IN FRESHWATER BODIES OF BELARUS (REVIEW)

The article provides information on the detection of infectious pathology of fish in reservoirs and watercourses of Belarus. The infectious pathology of fish occurs regularly in the wild and fish pounds and in important in maintain-ing the health of fish.

Blood Transcriptomics of Turbot Scophthalmus maximus: A Tool for Health Monitoring and Disease Studies

Blood transcriptomics is emerging as a relevant tool to monitor the status of the immune system and assist in diagnosis, prognosis, treatment and pathogenesis studies of diseases. In fish pathology, the potential of transcriptome profiling of blood is still poorly explored. Here, RNA sequencing was applied to analyze the blood transcriptional profile of turbot (Scophthalmus maximus), the most important farmed flatfish. The study was conducted in healthy specimens and specimens parasitized by the myxozoan Enteromyxum scophthalmi, which causes one of the most devastating diseases in turbot aquaculture. The blood of healthy turbot showed a transcriptomic profile mainly related to erythrocyte gas transportation function, but also to antigen processing and presentation. In moderately infected turbot, the blood reflected a broad inhibition of the immune response. Particularly, down-regulation of the B cell receptor signaling pathway was shared with heavily parasitized fish, which showed larger transcriptomic changes, including the activation of the inflammatory response. Turbot response to enteromyxosis proved to be delayed, dysregulated and ineffective in stopping the infection. The study evinces that blood transcriptomics can contribute to a better understanding of the teleost immune system and serve as a reliable tool to investigate the physiopathological status of fish.

Fish Pathology Research and Diagnosis in Aquaculture of Farmed Fish; a Proteomics Perspective

One of the main constraints in aquaculture production is farmed fish vulnerability to diseases due to husbandry practices or external factors like pollution, climate changes, or even the alterations in the dynamic of product transactions in this industry. It is though important to better understand and characterize the intervenients in the process of a disease outbreak as these lead to huge economical losses in aquaculture industries. High-throughput technologies like proteomics can be an important characterization tool especially in pathogen identification and the virulence mechanisms related to host-pathogen interactions on disease research and diagnostics that will help to control, prevent, and treat diseases in farmed fish. Proteomics important role is also maximized by its holistic approach to understanding pathogenesis processes and fish responses to external factors like stress or temperature making it one of the most promising tools for fish pathology research.

PREVALENSI DAN INTENSITAS EKTOPARASIT PADA IKAN NILA (Oreocromis niloticus) YANG DIBERI PAKAN BUNGKIL KELAPA HASIL FERMENTASI DALAM WADAH TERKONTROL

An ectoparasitic infection is one of the causes of losses for the farmers of red tilapia (Oreochromis niloticus). This study was aimed to determine the types of parasites, the level of attack includes the prevalence, intensity and dominance of ectoparasites in red tilapia by adding fermented copra meal to the feed. The research was carried out at the Maros Fish Farming Center, South Sulawesi, while observing parasites in fish were carried out at the BRBAPPP Fish Pathology and Health Laboratory, Maros. The treatments were tested by addition of fermented copra meal as follows: (A) 0% control; (B) 15%; (C) 30% and (D) 45%. The experimental feed was applied to the fish once a day by satiation. The parameters observed were 1) identification of parasites; 2) prevalence rate; 3) attack intensity; 4) dominance and 5) water quality. A total of 30 tilapia from containers were taken to observe the fish organs included, ectoparasites were observed using a smear method on the target organ (gills, scales and fins and eyes), then examined microscopically. The ectoparasites were identified based on Kabata (1985), Grabda (1981) and Moller and Anders (1986). The result found two types of parasites namely Argulus sp. and Epistylis sp. The result of the prevalence of Argulus sp. of treatments A, B, and D were obtained (3.33%) and intensity (1 ind/fish) except that Treatment C was obtained prevalence and intensity (0%). While the highest prevalence rate of Vorticella sp. in A (Control) was 20% (frequent infections) while other treatments were still relatively low at 3.33% - 13.3% (sometimes infections) with intensity of attacks 0-1 ind / fish (low infection rate). The dominance value in all treatments ranged from 0.1 to 0.85%. The range of water quality of fish container were temperature 26.3-29.2 °C, pH 7.5-7.8, DO 5.8-6.4 ppm and ammonia 0.02-0.26 ppm. The value was within good range for Red Tilapia.

Occurrence of diseases in fish used for experimental research

The objective of the present study was to evaluate the occurrence of pathogens and diseases in laboratory fish over a 10-year period at the Centre for Experimental Fish Pathology of Sicily, University of Messina. This report also emphasizes the adverse effects of subclinical infections on research endpoints, as well as the importance of animal health with respect to welfare. Infections in fish used for research can alter experimental outcomes, increase the variability of data, and impede experimental reproducibility. For this purpose, 411 diseased fish of different species (out of a total of 2820 fish) that belonged to four marine species ( Dicentrarchus labrax, Sparus aurata, Argyrosomus regius and Mugil cephalus) and to four fresh water species ( Danio rerio, Carassius auratus, Xiphophorus variatus and Poecilia reticulata) were examined in this study. Our results showed that mycobacteriosis and myxosporidiosis were the most important diseases found in our research fish, and the results represent a useful tool to obtain wider knowledge on the incidence of various diseases in different fish species. Further studies in this field are necessary to improve knowledge on the state of the health of fish used for research.

Contemporary threats of bacterial infections in freshwater fish

Changes occurring in freshwater ecosystems seem to be fundamental in the development of all microorganisms, including those pathogenic to fish. This has been especially evident in recent years during which dynamic variations in bacterial fish pathology have been observed. Gram-negative bacteria commonly known to be pathogenic to fish, likeAeromonasspp.,Flavobacteriumspp.,Pseudomonasspp., andShewanella putrefaciensare replaced by other species, which until now have not been known to be virulent or even conditionally pathogenic to fish. Nowadays, among these other speciesAcinetobacterspp.,Plesiomonas shigelloides,Sphingomonas paucimobilis, andStenotrophomonas maltophiliaare the most frequently isolated from fish exhibiting clinical signs of disease. Two Gram-positive bacteria have become pathogens of particular importance in fish pathology in Poland:Lactococcus garviaeandStreptococcus iniae. In addition, infections caused by the Gram-positive bacteriumKocuria rhizophilahave appeared in recent years. This bacterium has not been known until now to be pathogenic to fish. Therefore, this infection could be called an emergent disease.

Editorial 2018: The Croatian Journal of Fisheries: Ribarstvo 80th Anniversary

The Croatian Journal of Fisheries (Croat J Fish) was launched 80 years ago, in 1938, as Ribarstvo, so the current issue of Croat J Fish celebrates this significant event. Since 1992, the Journal was issued quarterly on a regular basis under the name Ribarstvo. However, in 2012 the Journal changed its name to Croatian Journal of Fisheries: Ribarstvo to attract more international audiences. The scope of the Journal has not changed much during its development and has mainly focused on ichthyology, aquaculture, ecology, fish pathology, marine and inland waters and other issues related to fisheries. Nowadays, the Journal tends to be a highquality open-access scientific journal, visible online, of interest to a wide scientific community. Expanding the number of international associate editors also indicates this process. In the segment of publishing strategies, more effort is needed to increase citation activity of the Journal. The Editorial 2018 also provides information on the articles published and the list of reviewers who participated in the review process in 2017.