Open Access Minireview Article
Feeding is an important aspect of fish farming activities and could determine the quality of fish. African catfish (Clarias gariepinus) is an omnivorous freshwater fish that is high in protein and economical value. Catfish nursery generally uses natural feed and artificial feed to ensure the diet requirements fullfiled. Good feeding, in quality or quantity, is an important aspect to produce a high quality breed. A good feed is the basis of improving cultured catfish growth and survival performance. The purpose of this article is to review types of feed, feeding practices, and their enriched alternatives for catfish rearing.
Open Access Original Research Article
This research aimed to analyze the quality of water in pond irrigation channels by examining the community structure of macrozoobenthos in Legonkulon, Subang Regency, West Java. The research was conducted in the Pond Irrigation Channels, Subang Regency, West Java starting from July until September 2020. This research method used a survey method using primary data in the form of physical chemistry of aquatic data, macrozoobenthos density, diversity index, uniformity index. The method used in data collecting techniques was purposive sampling in determining 4 stations and 3 repetitions. Data analysis in this research used descriptive analysis. Research results found 28 species consisting of 3 phyla, namely Mollusca, Arthropoda, and Annelida. The species that dominate the four stations are Filopaludinajavanica and Tarebiagranifera. Makrozoobenthos density ranges from 40 – 295 ind/m2. Makrozoobenthos diversity index in the medium category 1.0 < H’ <3.322. Uniformity values ranged from 0,43 to 0,81 with low to high category. The highest uniformity index was found at station 3, and the lowest uniformity index was at station 4, while at station 1 and station 2 had a moderate uniformity index. The results of the macrozoobenthos community structure showed that the water quality of the pond irrigation channels in Legonkulon was classified as being medium polluted.
Open Access Original Research Article
Aims: The study investigated the impacts of COVID-19 on livelihood status of coastal Shrimp farmers using farm size, production and income of South-west Bangladesh.
Study Design: This study is empirical in its design. Data on socio-economic factors were collected randomly from selected Shrimp farmers. Both open and closed ended questionnaire and directed to the Shrimp farmers of South-west coastal region of Bangladesh.
Place and Duration of Study: The present study was carried out at Khulna district (seven selected Shrimp farming locations; viz., Paikgacha, Lasker, Goroikhali, Lata, Kapilmuni, Amadi and Koyra) of Bangladesh for a period of five months during pandemic of COVID-19 (April-August, 2020).
Methodology: The key data were collected from face to face interview of 120 respondents. A brief outline about the nature and aim of the study was given to each respondent before the interview was commenced. The information of the respondents were written in the questionnaire immediately after completing the interview. Collected data were tabulated and analyzed using Microsoft Excel (version 2016).
Results: Most of the respondents were middle aged (68 %) and living in nuclear families (71 %). Majority of the Shrimp farmers were illiterate (53 %). A greater proportion (66 %) involved in small scale Shrimp farming as a primary occupation followed by moderate (27 %) and large scale (7 %) Shrimp farming. More than half of the respondents earned >20000 BDT (USD$ 1 = 85 BDT) in each month before the pandemic. The production activities were seriously hampered due to unavailability of inputs including aquamedicine, disinfectants, labor crisis, seed and feed, growing the price of production materials and interrupted communication etc. due to the pandemic. However the outbreak of COVID-19 pandemic reduced the production from their Shrimp ghers, drastically curtailed the market price, and consequently greatly compressed their income and livelihoods.
Conclusion: The pandemic known as COVID-19 has had a catastrophic impact on human activities, with the Shrimp farming sector being no exception. This study revealed that the socio-economic and income status of the Shrimp farmers was noticeably vulnerable during the COVID-19 pandemic. Thus, large numbers of farmer families were unable to fulfill their minimum needs (food, income, and medical care).
Open Access Original Research Article
Changes in Oreochromis niloticus blood cells were investigated after 96-h of exposure to cadmium chloride. One hundred and eighty (180) Oreochromis niloticus with average weight of 26.07±1.23g and mean length of 17.50 + 0.50cm were divided into 5 groups (T1-T5) at ten (10) fish per group and in triplicates after being acclimatized for 14 days. They were then exposed to various concentrations (0, 28, 30, 32, 34 and 36 mg/l) of cadmium chloride. The packed cell volume (PCV) of the treatments decreased significantly relative to that of the control, while their platelet counts increased compared with the control. There was also a reduction in the RBC (2.70, 2.51, 2.24, 1.98, 1.64 and 1.22) of treatments. Other blood parameters did not vary significantly in comparison with the control group, but it is worth noting that, the mean corpuscular volume (MCV) (70.78, 76.09, 83.71, 90.55, 105.49 and 128.68fL), mean corpuscular haemoglobin (MCH) (24.66, 24.49, 27.37, 29.83, 33.14 and 42.18pg) and mean corpuscular haemoglobinconcentration (MCHC) (34.83, 32.19, 32.71, 32.95, 34.41 and 34.78%) increased considerably in all treatments compared to the control. These alterations have been attributed to direct or feedback responses of structural damage to RBC membranes resulting in haemolysis and impairment inhaemoglobin synthesis, stress related release of RBCs from the spleen and hypoxia, which was induced by exposure to cadmium chloride. This study therefore gives an insight into toxic effect of cadmium chloride on fish.
Open Access Review Article
Biofloc technology is a new alternative in addressing water quality problems in aquaculture which is adapted from conventional domestic waste processing techniques. The main principle applied in this technology is water quality management which is based on the ability of heterotrophic bacteria to utilize organic and inorganic N in water. In a balanced C and N condition in water, heterotrophic bacteria which will utilize N, both in organic and inorganic form, are present in water for the formation of biomass so that the concentration of N in water is reduced. Several types of bacteria that are often used in biofloc are Bacillus sp., Bacillus subtilis, Pseudomonas sp., Bacillus lichenoformis, Bacillus pumilus; Lactobacillus sp.; Bacillus megaterium . Microbes play key role in the biofloc systems. Microbes associated with floc after consumption help to improve digestion, reduces FCR reduces dietary protein level and heterotrophic bacteria, which together probiotic bacteria, inhibit the development of potential pathogen bacteria. With biofloc there are some improves in different aspects during culture like higher growth rates, increased survival, improved water quality, reduced amount of water used and decrease in diseases. Thus, role of microorganisms is important in biofloc system; therefore, it is necessary to carry out more studies related to identification of microbes that can be present in biofloc systems.