Cover, Editorial Boards, Table of Contents

Journal of Fish Health

A Mini- review : Effect of Phyllantus niruri L. on Growth and Health of Fish

Phyllanthus niruri L. is one of the herbal ingredients that has been widely used to treat various diseases in humans such as intestinal infections, kidney stones, chronic liver disease, diabetes, hepatitis B, asthma, gonorrhea, bronchitis, syphilis and boost the immune system. The ability of P. niruri in overcoming various diseases is based on its phytochemical content and pharmacological properties. Based on these properties, the plant may possibly be used as a drug to treat diseases in fish. So the purpose of writing this article is to review the extent to which P. niruri can be used as an alternative medicine to treat disease and maintain fish health. Secondary metabolites and phyllanthine as specific compounds present in P. niruri have antibacterial effects for types of bacteria that usually attack fish such as Aeromonas hydrophila, Edwardsiella tarda, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa. In addition, it has the effect of being an antioxidant, immunostimulant and can be used for treatment and to increase fish growth. So it can be concluded that P. niruri can be used as an alternative material to maintain health and help fish growth.

Blood Performance: A New Formula for Fish Growth and Health

Monitoring fish health in a repeatable and accurate manner can contribute to the profitability and sustainability of aquaculture. Haematological and blood biochemistry parameters have been powerful tools and becoming increasingly common in aquaculture studies. Fish growth is closely related to its health status. A fish with a higher growth rate is more likely to be a healthy one. Any change in the physiological status of the fish, from pollution to nutritional stress, can cause changes in the blood parameters. Various aquaculture studies have measured the following components: red blood cells, white blood cells, haemoglobin, haematocrit, and total protein. However, because these parameters do not always follow the same trend across experimental fish, it is difficult to draw a firm conclusion about which parameter should be considered. Therefore, Blood Performance (BP) as a new formula is introduced, which is a more reliable indicator. This formula is simple and sums up the natural logarithm of the five above-mentioned parameters. More than 90 published peer-reviewed articles that measured these five parameters in the last six years confirmed the reliability and validity of this formula. Regardless of which supplements were added to the diets, the fish with a higher growth rate had higher BP as well. In addition, in 44 studies out of 53 articles, there was a significant positive correlation between specific growth rate and BP. Under different stressful situations, from pollution to thermal stress, the fish under stress had a lower BP than the control. Fish meal and fish oil replacement studies were further evidence for this formula and showed that adding excessive alternative proteins decreased growth along with BP. In conclusion, BP can be a reliable indicator of fish health and growth when it is compared between groups in the same experiment or farm. Although there was a positive correlation between specific growth rate and BP, comparing BP between experiments is not recommended. Standardising the haematological assays can improve the reliability and accuracy of BP across experiments.

Ecological Assessment of Fish Culture Water Bodies Around Dhaka City, Bangladesh

This study was conducted during the period November, 2014 - June, 2015 in two urban fish culture pond, at Kalshi and Namapara area of Dhaka city. These ponds are connected to Baunia canal. Water samples were collected seasonally for water quality and zooplankton analyses. Except DO all other measured water quality parameters (pH, TDS, TSS, total ammonia-N, total nitrite-N, total nitrate-N, total phosphate, total sulphate, alkalinity and hardness) were found higher in water. A total of 10 heavy metals (Zn, Fe, Pb, Cd, Al, As, Cu, Na, Mn and Cr) were measured for determining its concentrations in waters in two seasons. A total of 10 zooplankton species were recorded at Kalshi during the study period and on an average, the density of zooplankton in dry season and in wet season were estimated to be 1386 indiv./L and 244 indiv./L respectively. On the other hand, a total of 19 zooplankton species were identified from Namapara water body and on an average, the density of zooplankton in dry season and in wet season were estimated to be 1760 indiv/L and 343 indiv./L respectively. Bacteriological analysis included the total plate count (TPC), total coliform (TC) and total faecal coliform (TFC) counts in waters, both in wet and dry seasons. In general, water qualities of the studied fish culture water bodies are highly deviated from the permissible standard levels of Environment conservation rules, 1997 and unsuitable for fish culture from fish health point of view. The measured high levels of metals in waters are likely to bioaccumulate in fish body. High abundance of bacterial flora in fish culture waters is also likely to be associated with fish health and may cause enteric diseases. Therefore, fish culture in these urban water bodies is likely pose potential health risks for human through consuming these fishes. Bangladesh J. Zool. 49 (2): 267-276, 2021

Microcystin-Induced Immunotoxicity in Fishes: A Scoping Review

Cyanobacteria (blue-green algae) have been present on Earth for over 2 billion years, and can produce a variety of bioactive molecules, such as cyanotoxins. Microcystins (MCs), the most frequently detected cyanotoxins, pose a threat to the aquatic environment and to human health. The classic toxic mechanism of MCs is the inhibition of the protein phosphatases 1 and 2A (PP1 and PP2A). Immunity is known as one of the most important physiological functions in the neuroendocrine-immune network to prevent infections and maintain internal homoeostasis in fish. The present review aimed to summarize existing papers, elaborate on the MC-induced immunotoxicity in fish, and put forward some suggestions for future research. The immunomodulatory effects of MCs in fish depend on the exposure concentrations, doses, time, and routes of exposure. Previous field and laboratory studies provided strong evidence of the associations between MC-induced immunotoxicity and fish death. In our review, we summarized that the immunotoxicity of MCs is primarily characterized by the inhibition of PP1 and PP2A, oxidative stress, immune cell damage, and inflammation, as well as apoptosis. The advances in fish immunoreaction upon encountering MCs will benefit the monitoring and prediction of fish health, helping to achieve an ecotoxicological goal and to ensure the sustainability of species. Future studies concerning MC-induced immunotoxicity should focus on adaptive immunity, the hormesis phenomenon and the synergistic effects of aquatic microbial pathogens.

Role of Eleutherine bulbosa (Mill.) Urb. in shrimp and fish: a mini review

Medicinal plants have been commonly used in aquaculture to increase growth and immunity and control fish diseases as an effort to replace or as alternative to uses of chemical antibiotics and compounds. The use of medicinal plants in aquaculture provides safe and environmentally friendly compounds. Natural products of medicinal plants have been used in humans for thousands of years to treat disease. One of them is Eleutherine bulbosa (Mill.) Urb. This article describes the potential of E. bulbosa as an antibacterial, prebiotic, and antioxidant as well as its efficacy on aquatic organisms. Addition of extracts and powders of E. bulbosa through feed to white shrimp Litopenaeus vannamei was able to improve growth performance, immune response, and resistance against infection from pathogenic bacteria. Optimal use of E. bulbosa needs to pay attention to dose and size of shrimp cultured. So far, administration of E. bulbosa powder through feed was more effective and efficient than the use of E. bulbosa extract in a large scale. Research on E. bulbosa as an immunostimulant in fish is still limited. Further research on the use of E. bulbosa should be conducted to examine the effect of E. bulbosa on growth performance and fish health on a large scale aquaculture.

Maintaining of good water quality – a prerequisite for healthy farmed fish

Water quality is one of the key factors in maintenance of fish health. The current article revises the effects of various water quality parameters on fish health, methods of quality analysis and diagnosis of fish health, as well as methods for improving the water quality in fish ponds, aiming to reduce the fish health risks. The synthesis is a joint work of an international consortium formed from scientists of the Institute of Zoology and Ion Ionescu de la Brad Iasi University of Life Sciences, which allows a broader view on the fish health issue for identification of sustainable solutions for fish farmers from the Republic of Moldova and Romania.