International Journal of Aquaculture and Fishery Sciences
Latest articles in this journal
Published: 15 October 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 098-102; https://doi.org/10.17352/2455-8400.000084
In order to contribute to the increase of table fish production in the world in general and particularly in Cameroon through an optimal valorization of local by-products, the zootechnical performance of Clarias gariepinus fry was evaluated in concrete tanks according to the replacement levels of soya bean meal by water hyacinth flour (Eichhornia crassipes). For this purpose, a trial was conducted at the Logbaba Intensive Aquaculture Pilot Unit (LN: 4°02’ and 4°34’; LE: 9°41’ and 9°18’). A total of 240 Clarias gariepinus fry of initial mean weight 5 ± 0.22 g were divided into 12 batches of 20 fry each into 0.5 m3 baits in concrete tanks in a completely randomized device. These fries were fed for 56 days. The feed rations consisted of 4 iso-protein feeds with 47% protein. Either T0+ (positive proof) an imported food (Coppens), T0- (Negative proof) local food without soya bean meal and two other experimental foods whose soya bean meal has been replaced at 5% (T5) and 10% (T10) by Eichhornia crassipes flour. The results obtained showed that the highest survival rate (98.33% ± 2.88%) was recorded with the imported feed T0+ and lower (93.33% ± 2.76%) with the food containing 5% water hyacinth powder. The final mean weight and daily weight gain were significantly (P < 0.05) higher (26.08 ± 1.25 g and 1.49 ± 0.08 g/d respectively) with the T0+ diet and lower with the T1 local food (11, 92 ± 0, 90; 48 ± 0,06 g/d respectively). The average daily gain was comparable between the T5 and T10 diets (0.67 ± 0.14 g/d; 0.93 ± 0.12 g/d respectively). The specific growth rate (P < 0.05) and consumption index (P < 0.05) were significantly higher (2.87 % ± 0.08% g/d and 0.34 ± 0.04 respectively) compared to treatments containing 5% (T5) and 10% (T10) of water hyacinth powder (1.83 ± 0.24 g/d; 2.24 ± 0.17% g/d) and 1.08 ± 0.31; 0.66 ± 0.14) respectively. Thus, water hyacinth flour can be used to replace the soya bean meal as a protein source in the diet of Clarias gariepinus fry for optimal growth.
Published: 27 September 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 092-097; https://doi.org/10.17352/2455-8400.000083
Lake Victoria is known for its rich fish biodiversity having been home to over 500 fish species. However, over 200 species have become extinct and as a result, it is classified as a world hotspot of species loss. Some of the examples of endemic species that disappeared from the lake and are endangered include the Haplochromines and the Barbus species. The Barbus species is currently not seen in the fish landings from Lake Victoria. It is deemed to have sought refuge in the riverine ecosystems, dams and the adjacent satellite lakes within the Lake Victoria Basin. This has resulted in several gaps emerging including its current status as its taxonomical identification still remains a puzzle to many scientists. This paper, therefore, tries to unearth the foregoing by reviewing the already available literature with an emphasis on the LVB Kenyan part. The Labeobarbus altianalis is still named Barbus altianalis even in the most recent publications thus complicating further. In its distribution, the Barbus species does not occur in the lake currently but is a common candidate in the rivers, dams and satellite lakes within the basin. Some of the cited reasons for its disappearance: are predation by Lates niloticus, overfishing, competition from exotic species, pollution and climate change. However, different studies try to pinpoint its presence in some rivers and this according to an observation made in this study is due to biased sampling, which excludes some rivers in the basin. It is concluded that the taxonomic identification of Barbus species in LVB Kenya remains elusive and this has been blamed on skewed sampling with little regard to all ecosystems in the basin. The paper recommends that an elaborate simultaneous study be done in all the rivers within the LVB, Kenya to collect reliable data for use in Barbus species taxonomy and general biology. Further, county governments in the basin should develop sound policy frameworks on how to sustainably manage riverine fisheries including the domestication of the species in aquaculture.
Published: 17 September 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 087-091; https://doi.org/10.17352/2455-8400.000082
This study evaluated the use of either blue or silver vertically-suspended environmental enrichment in two experiments, with one rearing Chinook salmon (Oncorhynchus tshawytscha) for 29 days and the other rearing rainbow trout (Oncorhynchus mykiss) for 98 days. In both experiments, there were no significant differences in total tank weight, gain, percent gain, feed conversion ratio, or percent mortality between tanks with either silver (unpainted aluminum) or blue vertically-suspended environmental enrichment. Individual fish total length, weight, specific growth rate, and condition factor were also not significantly different between the two colors for both fish species. These results indicate that either silver (unpainted aluminum) or blue vertically-suspended environmental enrichment can be used during the hatchery rearing of juvenile Chinook salmon or rainbow trout.
Published: 26 August 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 080-081; https://doi.org/10.17352/2455-8400.000081
This paper describes how fish can be located using sound, especially in the sea, but also in rivers and lakes. It describes the use of sound detections, including both passive and active acoustics, and it reviews each of these technologies and shows how they can be used to understand the distribution of sound-producing species and to examine information on the spawning habitats of fishes, and their spawning behavior, and also their movement patterns. Sounds generated by humans can have detrimental effects upon fishes, and some stocks of fishes are exploited close to their safe biological limits, requiring restrictions upon those human activities that may harm them. There is a need to regulate those human activities that have adverse effects on fish.
Published: 6 June 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 059-065; https://doi.org/10.17352/2455-8400.000079
The conventional assessment of the specific growth rate (SGR) avoiding intermediary data is highly criticized by scholars as to the data of the beginning and the end of the production cycle usually considered for the measurement. To evaluate the SGR, the study was conducted in six concrete tanks under an outdoor laboratory shed from 10th May to 29th July 2017. Tilapia (Oreochromis niloticus) fry was released at the rate of 8 fries per tank as per the recommended stocking density of 320 fishes/decimal in an intensive aquaculture system. To evaluate the experiment, sinking and floating feeds as treatment 1 (T1) and treatment 2 (T2) were used for feeding the fish, respectively. There were three replications for each treatment. During the experimental period, the feed was supplied at the rate of 20%, 15%, and 10% of the body weight in the 1st, 2nd, and 3rd months, respectively. The daily ration of fish was divided into two parts and delivered to fish in the morning and in the evening. Aeration facilities were installed for 24 hours using an air stone aerator. Digital balance was used for measuring the weight of fish in 3 days intervals to assume the trend of SGR while a customized scoop net was used to sample the fish minimizing the stress on the fish. The weight gains of fish were 126.08±5.65 and 132.23±1.29 for T1 and T2, respectively. The mean percent weight gain was found higher in T2 (1715.03±0.00) than in T1 (1639.43±0.00). Feed conversion ratio (FCR) in T1 and T2 were 1.97±0.11 and 2.13±0.18, respectively. The specific growth rates (SGR) of tilapia in T1 and T2 were 4.90±3.03 and 4.98±2.28 considering the data at the beginning and the end of the production cycle, respectively. However, the SGR for floating feed was higher at the initial stage of the production cycle and lower in the later stages. The SGR was almost static for sinking feed from the beginning to the end of the experimental period. The higher FCR in T2 was correlated with the lower SGR in the later stage of the culture period. This ascertains that the pre-determined required amount of feeding ration imparted by the farmers in case of floating feed which wastes the high-cost feed and money. Higher total production was obtained in T2 (1119.52 g) than in T1 (1070.19 g) with 100% survival in both treatments. Therefore, determining SGR in a specific interval might be a useful tool at the farmer’s level.
Published: 28 May 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 054-058; https://doi.org/10.17352/2455-8400.000078
This study evaluates the nutrient utilization and growth performance of African catfish (Clarias gariepinus) fed alternative animal protein composite meal for 42 days. The composite meal is composed of feather meal, blood meal, tilapia meal, and maggot meal each in a 25% proportion. Five isonitrogenous diets (T1, T2, T3, T4, and T5) containing 40% crude protein were formulated with the composite meal replacing fish meal at 0% control (T1), 25% (T2), 50% (T3), 75% (T4) and 100%(T5) respectively. The weight gain, protein intake, protein efficiency ratio, and specific growth rate in the 75% and 100% inclusion levels were not significantly different from the control diet. Fish survival ranged between 90-95% with the highest weight gain of 10.57g observed in the 100% inclusion level. The Feed conversion ratio varied between (1.17 and 1.37). The results from growth, feed utilization, and survival levels showed an overall good growth of the fish in the experimental diets, and this indicates that the composite meal is a potential replacement for fish meal in the diets of Clarias gariepinus fingerlings.
Published: 23 May 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 037-044; https://doi.org/10.17352/2455-8400.000076
The study was conducted on the nutritional and biochemical composition of the Moringa oleifera plant (Seed, Seed Cake, and leaf meal) at two different locations. The proximate and mineral composition were carried out at the Central Laboratory of the National Institute for Fresh-water Fisheries Research (NIFFR), New Bussa, Niger State, while the Biochemical and phytochemical analyses were conducted at Usmanu Danfodiyo University, Sokoto. The result for the proximate composition of the M. oleifera plant revealed that the moisture content for the M. oleifera leaves sample (8.88 ± 0.39%) was significantly higher when compared with the M. oleifera seed (4.81 ± 0.99%) and seed cake (7.43 ± 0.24%) while the seed having the lowest moisture content (4.81 ± 0.99). The crude protein content for M. oleifera seed cake (53.23 ± 0.42) was significantly (p<0.05) higher than that of M. oleifera seed (40.66 ± 0.34%) and the leaves meal had the lowest crude protein (27.26 ± 0.55). The ash contents for M. oleifera leaves meal (10.61 ± 0.14%) were significantly higher compared with M. oleifera seed cake (8.34 ± 0.07%), and the seed had the lowest ash content (3.44 ± 0.14%). The lipid content of M. oleifera leaves meal (17.17 ± 0.65%) was significantly higher when compared with M. oleifera seed, and the seed cake had the lowest lipid content (13.51 ± 1.23). The fiber content for M. oleifera seed (17.08 ± 0.61) was significantly higher when compared with M. oleifera leaves meal (8.91 ± 0.33%), and the seed has the lowest fiber content (2.48 ± 0.16). The NFE for M. oleifera leaves meal (27.17 ± 0,45%) was significantly higher when compared with M. oleifera seed (18.24 ± 0.94), and the seed cake had the least NFE content (15.02 ± 1.42%). The result of mineral composition showed that the plant contained a higher amount of some minerals; This includes potassium, calcium sodium, magnesium, and manganese. For the amino acid composition, it clearly stated that the plant contains some essential and non-essential amino acids. The results of the phytochemical test revealed that all the plant parts analyzed contain anti-nutritional factors. Further research should be carried out to test the nutritional and biochemical values of Moringa oleifera seed cake and leaf meal using culture fish species.
Published: 23 May 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 045-053; https://doi.org/10.17352/2455-8400.000077
The objective of this study was to establish an effective method of artificial reproduction and larval rearing to improve the fry production of the African catfish Clarias gariepinus. Thus, a hormonal treatment using ovaprim was used to induce maturity in males and females. Two breeding trials were first conducted on captive populations by crossing a male and female Senegalese strain (♂ss/♀ss), and a male and female Beninese strain (♂bs/♀bs). A third reproduction test was carried out by crossing ♀ss/♂bs and ♂ss/♀bs but for this test, the ♀ss and ♂ss are wild breeders that were collected from the natural environment. For the first two breeding tests (♂ss/♀ss and ♂bs/♀bs, respectively), fertilized eggs either did not hatch or some hatched but the fry did not survive. Although the number of broodstock used in these first two breeding tests is small, this lack of hatching and poor larval survival may reflect inbreeding depression. The third breeding test was successful as females and males, respectively, produced large quantities of eggs (13g of eggs for ♀ss and 32g of eggs for ♀bs) and sufficient quantities of sperm to fertilize the eggs (approximately 12g for the Benin strain and 5g for the Senegal strain). Hatching rates of 90% and 60% were obtained for the ♀ss/♂bs and ♀bs/♂ss breeding’s, respectively, after incubation of fertilized eggs on water hyacinth (natural substrate) and pompon (artificial substrate). Comparisons of growth rates of larvae fed two different diets (combination of natural and artificial food, and artificial food alone) showed that artificial food alone was more effective for growth, especially after one month of rearing. The high larval mortalities recorded especially at the end of the experiment were mainly due to poor water quality. Thus, this study provided a better understanding of the conditions in the hatchery and larval culture systems that are critical to the success of artificial reproduction and optimal growth of C. gariepinus fry.
Published: 27 April 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 025-036; https://doi.org/10.17352/2455-8400.000075
This study was designed to investigate the physiological and biochemical response of the diatom microalgae Halamphora sp. (SB1 MK575516.1) to the toxicity of lead (Pb) as well as its ability as phytoremediation. Four different concentrations of Pb (50, 100, 150, and 200 mg L-1) were applied for 10 days. Fatty acid profile, mineral composition, secondary metabolite contents, and physiological responses have been determined in Halamphora biomass. We found that this metal was mainly removed by bio adsorption on cell surfaces and that Halamphora sp. could acclimatize upon long-term exposure to Pb stress. A decrease in the cell’s number and size, polyunsaturated fatty acids as well as mineral content in Halamphora sp were observed under Pb stress. However, an increase in polyphenol, flavonoid, and carotenoid contents has been recorded at 100 mg Pb L-1, with stimulation of the antioxidant capacity as measured by DPPH and ABTS radical scavenging activities. An increase in MDA, proline, and H2O2 levels were also observed. On the other hand, the deleterious effect of Pb resulting from the cellular oxidative state can be alleviated by the enzymatic system such as Superoxide dismutase (SOD), Glutathione peroxidase (GPx), and catalase (CAT). The present study indicates the ability of Halamphora sp. to remove heavy metals from the aquatic environment and produce antioxidant biomolecules.
Published: 10 March 2022
International Journal of Aquaculture and Fishery Sciences, Volume 8, pp 010-024; https://doi.org/10.17352/2455-8400.000074
The study was conducted in Dhaka, Bangladesh, and was carried out for twelve (12) months from March 2018 to February 2019 with a view to represent the trading diagram of ornamental fish in Bangladesh. During the current study 270 varieties (230 freshwater, 36 marine, and 4 brackish water) belong to 149 species (109 freshwater 73%, 36 marines 24%, and 4 brackish water 3%) of 38 families under 10 orders and 6 crossbreeds’ varieties were recorded. Considering the number of species maximum 83 (55.70%) was found under the order Perciformes followed by Cypriniformes 24 (16.10%), Characiformes 18 (12.08%), Siluriformes 11 (7.38%), Osteoglossiformes 05 (3.35%), Atheriniformes 03 (2.01%), Lepisosteiformes 02 (1.34%), Polypteriformes 01 (0.6%), Myliobatiformes 01 (0.67%) and Cyprinodontiformes 01 (0.67%). The top five popular species were guppy (13.16%) followed by goldfish (12.39%), molly (8.54%), angelfish (6.23%), platy (5.93%). Most of the ornamental fish species were imported by importers from Thailand, Singapore, Indonesia, India, Malaysia, and Japan on the basis of demand. Then the imported shipment of aquarium fish and fish products was distributed among Dhaka Katabon fish shops, wholesalers, and retailers, according to their given order. After that, these were again distributed locally, to aquarium shops, breeders, ornamental fish farms all over the country. General customers and hobbyists purchase ornamental fish and aquarium products from local aquarium shops and businesses. The increasing tendency of the number of fish species was 5.96 times in the last 15 years and 3.31 times in the last 10 years. Local farms and aquarists’ breeders bred 76 varieties under 23 species due to its high demand and profitability. Pricing varied on varieties, species, size, and breeding status (local or abroad), availability and ranged from BDT 40.00-80,000.00 per pair. Considering the findings, aquarium fisheries is highly profitable at present and it will be a potential sector in Bangladesh.