Lernaeid parasites prevalence in commercial freshwater fish species at various fish farms in Pakistan

Reports abound on Lernaea parasitizing the brood stock, fingerlings, and marketable-sized culturable freshwater fish species in various parts of the world. We investigated seven small-scale aquaculture farms and how the prevailing Lernaea is impacting them. Randomly seven fish farms were selected to determine the prevalence percentage of lernaeid ectoparasites. Relevant information of the fishponds to estimate the various aspects such as effects of water source and quality, feed, stocking density, treatment used, and weight and length of fish, concerned with Lernaea infestation and prevalence was gathered. The results indicated that Catla catla (F. Hamilton, 1822) showed highest prevalence (41.7%) among the seven fish species, whereas Oreochromis niloticus showed zero. Other five fish species Ctenopharyngodon idella, Cirrhinus cirrhosis, Cyprinus carpio, Labeo rohita and Hypophthalmichthys molitrix showed 13.2%, 8.1%, 7.7%, 7.4%, 0.9% prevalence, respectively. In Royal Fish Farm 84.3% lernaeid infestation was observed, while no parasite was observed in the Vicent’s Chunnian fish farm. The water source, quality, feed, fertilizers, stocking density, water temperature, and potential treatment options displayed varying tendencies among fish farms and prevalence. Depending on the weight and length, the highest prevalence (56.7%, and 66.7%) was observed in 3501-4000 g and 81-90 cm groups. The infestation rate varied in various fish body parts with the dorsal fin the most vulnerable organ and showed 2.3% overall prevalence (while 18.4% contribution within total 12.6% infestation). Out of 147 infected fish samples, 45 were extensively contaminated by Lernaea spread. In conclusion, our findings confirm that Lernaea could pose a considerable threat to marketable fish, and various treatment options should be educated to the farmers to help mitigate the spread and potential losses. Furthermore, Catla catla is more vulnerable to Lernaea infestation (41.7%), so are the fish species being cultured at higher stocking densities.

Does Fish Farming Improve Household Nutritional Status? Evidence from Bangladesh

In the present study, nutritional status was assessed using dietary diversity of fish and non-fish farming households in Mymensingh district of Bangladesh. It has determined the incidence of poverty in fish and non-fish farm households through a comparative analysis of family profile, food consumption, calories, and protein intake. A total of 420 farms were selected for data collection using structured questionnaires with 210 fish and 210 non-fish farm families. The study using both descriptive and functional analysis revealed that the respondent age of both farms was 45.10 years, family size was 5.70, average education was 4.64 schooling years, and average farm size was 0.514 hectares. As a result, due to the increase in household income, fish farm families improved their food consumption, calories, and protein intake in comparison with non-fish farms. On a direct calorie intake (DCI) basis, the overall absolute and hardcore poverty levels of fish farm households were 32 percent and 18 percent, respectively, while those of non-fish farm households were 22 percent and 10 percent, respectively. Therefore, the incidence of poverty was higher in non-fish farming families than in fish farming families. In principle, provision of various forms of government assistance through the Department of Fisheries (DOF) will further intensify and strengthen fish farming, which will easily bring fallow and uncultivated lands of the area under fish farming. Moreover, it is possible to inspire the younger generation through this research that will help them to become a fish farm-based entrepreneur. The main conclusion of the present study is that fish farming is more positively related to household income, family food intake, and nutritional status than any other type of farming.

Penguatan usaha kelompok budidaya ikan tawar “Mujur Fish Farm” dimasa pandemi Covid-19 dengan membangun mindset and spirit entrepreneur

The rapid spread of Covid-19 in Indonesia led the government to impose physical distancing and Large-Scale Social Restrictions (PSBB) resulting in declining sales activity. One of the business groups affected by Covid-19 is the Fish Farming Group "Mujur Fish Farm". This devotion aims to foster the mindset and spirit of entrepreneurs, as well as increase knowledge related to the right steps so that products can be sold. The implementation method uses Participatory Rural Appraisal (PRA) by involving the local community. The stage of implementation is through the stage of preparation, planning, implementation and evaluation, and assessment stages. The achievement of this activity is that group members know how to build an entrepreneur mindset in the Covid-19 pandemic by staying positive and creative. The rapid spread of Covid-19 in Indonesia led the government to impose physical distancing and Large-Scale Social Restrictions (PSBB) resulting in declining sales activity. One of the business groups affected by Covid-19 is the Fish Farming Group "Mujur Fish Farm". This devotion aims to foster the mindset and spirit of entrepreneurs, as well as increase knowledge related to the right steps so that products can be sold. The implementation method uses Participatory Rural Appraisal (PRA) by involving the local community. The stage of implementation is through the stage of preparation, planning, implementation and evaluation, and assessment stages. The achievement of this activity is that group members know how to build an entrepreneur mindset in the Covid-19 pandemic by staying positive and creative.

​Study of the Zootechnical Performance of Tilapia cabrae and Oreochromis schwebischi in a Controlled Environment: The Case of the Mbolet Fish Farm in Lambaréné, Gabon

Background: The study of the zootechnical performance of Tilapia cabrae and Oreochromis schwebischi was carried out at the Mbolet fish farm in Lambaréné in Gabon in order to evaluate the growth and reproductive performance of these two species. Methods: For this purpose, 226 fish (113 of T. cabrae with an average weight of 30.55±9.5 g and 113 O. schwebischi with an average weight of 20.64±10.5 g), were distributed in four 6 m2 tanks with two replicates per species for the growing phase which lasted 60 days. For the reproductive phase, 42 selected mature fish, including 6 males and 36 females of each species, were placed in six 2 m2 ponds with three replicates per species for 78 days. Result: The survival rate, the number of reproductions per species and the absolute, relative and system productivities were determined. It was found that the average weight gain, daily individual growth and specific growth rate were significantly (p less than 0.05) higher in T. cabrae, 48.1±5.51 g, 0.8±0.092 g/day and 1.57±0.066% g/day respectively, than in O. schwebischi, 27.11±9.23 g, 0.45±0.15 g/day and 1.38±0.051% g/day respectively. At the end of reproduction, the absolute productivity of T. cabrae (234.75±24.71 larvae/female/egg-laying) was significantly higher (p less than 0.05) than that of O. schwebichi (104.68±46.64 larvae/female/laying). System productivity was significantly higher (p less than 0.05) in O. schwebichi (11.34±2.29 larvae/m2/day) compared to that of T. cabrae (4.12±1.73 larvae/m2/day). Thus, on a fish farm, the use of these species may be possible.

Selection and breeding work with a modern population of Sarboyan carp

Carp breeding in Western Siberia has been going on for about 1960. Here two breeds of Sarboyan and Altai mirror carp were bred and put into economic use. The Sarboyan carp is a cross with 1/8 of the blood of the Amur carp. The Sarboyan carp has now disappeared in the fish farm, there are its descendants who have not been subjected to selection for 4 generations. To work on the selection of a new intra-breed type, specimens corresponding to classes 1 and 2 were selected from the head reservoir of the fish farm. Specimens of class 1 accounted for 2.6% of all selected fish. The analysis of the exterior showed that as a result of the lack of selection and mating disorderly, the physique of the fish changed. It deviated and is closer to the wild Amur carp. In males, the length index increased by 21.30%, the body became longer and smaller. In females, the same changes are observed in exterior, in addition, there is a decrease in fertility, since in the studied population the correlation between progenity and fecundity is 0.42-0.72. The relative growth of the main exterior features has decreased.

Fish Farm Wastewater Treatment using Moringa oleifera Seed Powder as Natural Coagulant

In view of the huge amount of wastewater being generated from the aquaculture sector in Malaysia, Moringa oleifera seed powder was utilized as effective bio-coagulant to minimize the deterioration of fish farm wastewater quality. In this study, optimization of a coagulation-flocculation process was examined through response surface model toolkit established on a central composite design. A quadratic polynomial model was eventually selected to fit its turbidity removal response. The effect of four crucial parameters, namely pH, coagulant dosage, mixing time and settling time was optimized at pH 10, 400 mg/L coagulant dosage, 15 minutes mixing time and 10 minutes settling time for M. oleifera seed extract at a 47.11% turbidity removal efficiency. M. oleifera seed powder substantially removed (>30%) the concentration of total suspended solids, ammonia content, total volatile solids, and phosphate content as compared with the control group without any coagulant addition.

Seasonal Variation in the Nutritional Analysis of Caprella scaura (Amphipoda: Caprellidae) from the Biofouling of Fish Farm Cages in Central Greece

The total lipid and protein content of the invasive caprellid amphipod Caprella scaura, from the biofouling communities of fish farm cages in the Pagasitikos Gulf were analyzed and compared among seasons. Proteins were the most abundant component (48.5 – 49.3%). Lipid content was relatively lower, with a wider range (6.7 – 34%) and showed a distinct seasonal fluctuation with high values in the winter population and a gradual decrease in spring and summer, with the lowest values in Autumn. Composition of the fatty acids profile was consistent among the seasons, with palmitic (16:0), Oleic (18:1n-9), Eicosapentanoic (20:5n-3)(EPA) and Docosahexanoic acid (22:6n-3 )(DHA) being the most abundant fatty acids. The presence of high levels of EPA and DHA fatty acids makes the species a potential candidate for use of these organisms in aquaculture.

Connectivity Patterns for Direct Developing Invertebrates in Fragmented Marine Habitats: Fish Farms Fouling as Source Population in the Establishment and Maintenance of Local Metapopulations

Artificial structures can be considered as high spatially structured habitats in the marine pelagic system, where patch connectivity would be strongly dependent on the exchange of larvae or dispersing individuals. Fish-farms located offshore may alter ecological connectivity, modifying trophic resources, and species dispersal among patches. High population densities of invertebrates can be found associated with fish-farm fouling communities, which can act as a seed source, contributing to the patterns of connectivity through individuals exchange between subpopulations or with sink populations. A field experiment was performed to analyse the role of fish-farms in the colonisation of new uninhabited habitats (floating experimental units) located at different positions relative to the fish farm and the main current, containing artificial habitats with and without feed pellets similar to those used in the fish farm. Amphipods were used as example of direct developing invertebrates for studying dispersing individuals from the fish farm to the new habitats. The richest and most abundant populations in this study were found close to and downstream of the fish farm, surpassing 1,000 amphipods at their maximum. Moreover, some floating habitats located more than 2 km from the fish farm were colonised in only 15 days. Thus, the role of fish farms has been shown to extend beyond a ‘stepping-stones’ effect in species dispersal, and have an additional effect on ecological connectivity by increasing population sizes and acting as population source. Our study aims to provide recommendations for coastal zone management in order to predict potential spread from fish farms to other platforms in the future and promote solutions related to interactions and consequences of connectivity within and between marine facilities.