ISSN 2375-0715
Research Article
African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (8), pp. 001-010, August, 2020. © International Scholars Journals
Full Length Research Paper
Small-scale continuous production of a tropical marine copepod, Nitocra affinis californica Lang and its potential as live food for aquaculture
Hazel Monica Matias-Peralta1, Fatimah Md. Yusoff1,2*, Mohamed Shariff2 and Suhaila Mohamed3
1Department of Biology, Faculty of Science, Institute of Bioscience, University Putra Malaysia, 43400 UPM-Serdang, Selangor, Malaysia.
2Marine Science and Aquaculture Laboratory, Institute of Bioscience, University Putra Malaysia, 43400 UPM-Serdang, Selangor, Malaysia.
3Department of Food Science, Faculty of Food Science and Biotechnology, University Putra Malaysia, 43400 UPM-Serdang, Selangor, Malaysia.
Accepted 21 February, 2020
Abstract
A study to establish a relatively simple and reliable small scale mass production and the nutritional profile of Nitocra affinis was undertaken. The result confirmed the feasibility of maintaining N. affinis on a small scale for a long period using cheaply available culture vessels. Within six weeks (42 days) a minimum harvest of 43.6 x 103 copepod.L-1 and maximum of 44.5 x 103 copepod.L-1 were obtained. Using several numbers of vessels (2L-capacity) for mass production, it was feasible to harvest 15.0 x 103 copepod .L-1 daily after two weeks of inoculation. Nitocra affinis has a great potential as live food because it contained high protein (39 to 52%), lipid (13 to 23%) and carbohydrates (8 to 11%). It also contained high level of n-3 HUFA (up to 44%) and n-6 HUFA (up to 14%). In addition it contained high amount of DHA (up to 19%) and EPA (up to 25%). Moreover, levels and ratios of fatty acids closely matched both the requirements of marine finfish and shrimp larvae.
Key words: Mariculture, live food, marine copepod, Nitocra affinis, fatty acids.
Mohamed Shariff and Suhaila Mohamed, Fatimah Md. Yusoff*, Hazel Monica Matias-Peralta
Page: 1 - 10
https://doi.org/10.46882/AJFS/1104Research Article
African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (7), pp. 001-007, July, 2020. © International Scholars Journals
Full Length Research Paper
Different cell disruption methods for astaxanthin recovery by Phaffia rhodozyma
Renata Aline dos Santos da Fonseca1, Ruan da Silva Rafael1, Susana Juliano Kalil2, Carlos André Veiga Burkert1, and Janaína Fernandes de Medeiros Burkert1*
1Bioprocess Engineering Laboratory, Universidade Federal do Rio Grande, 96201-900, Rio Grande, RS, Brazil.
2Microbiology Laboratory, Universidade Federal do Rio Grande, 96201-900, Rio Grande, RS, Brazil.
Accepted 17 May, 2020
Abstract
Astaxanthin (3,3'-dihydroxy-b,b'-carotene-4,4'-dione) is carotenoid of high market value whose demand has increased in such fields as aquaculture, pharmaceutical supplements and natural coloring. Cell disruption is the first step for isolating intracellular materials and it depends on the cell wall permeability. In order to maximize the recovery of astaxanthin from Phaffia rhodozyma NRRL-Y17268, drying and freeze pretreatments were tested by different cell disruption methods: abrasion with celite, glass pearls in vortex agitator, ultrasonic waves, sodium carbonate (Na2CO3) and dimethyl sulfoxide (DMSO). The method with Na2CO3 was not effective; meanwhile, the agitator with glass pearls, the abrasion with celite and the ultrasonic waves were found as promising for future studies. As a result, the DMSO in freeze-dried biomass with 4 process cycles and biomass/DMSO relation of 0.025 g/ml was found to be the most efficient for analytical determination, increasing about up to 25 times the astaxanthin recovery.
Key words: Carotenoids, yeast, chemical disruption, dimethyl sulfoxide.
Ruan da Silva Rafael, and JanaÃna Fernandes de Medeiros Burkert*, Susana Juliano Kalil, Renata Aline dos Santos da Fonseca, Carlos André Veiga Burkert
Page: 1 - 7
https://doi.org/10.46882/AJFS/1103Short Communication
African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (7), pp. 001-003, July, 2020. © International Scholars Journals
Short Communication
In vitro susceptibility of commonly used antibiotics against Vibrio spp. isolated from Lobster (Panulirus homarus)
Mahsa Ansari1* and Mehdi Raissy2
1Young Researchers Club, Islamic Azad University-Shahrekord Branch, Shahrekord, Iran.
2Faculty of Veterinary Medicine, Islamic Azad University-Shahrekord Branch, Shahrekord, Iran.
Accepted 21 June, 2020
Abstract
The sensitivity of 28 isolates of Vibrio spp. isolated from the edible muscle of lobster was compared using commonly used antibiotics. The in vitro susceptibility of the isolates was studied by disk diffusion method using disks contained tetracycline, ampicillin, penicillin, doxycycline, streptomycin and erythromycin. All bacterial strains studied in this research showed high degree of resistance to the antibiotics used in both human medicine and those employed in aquaculture which is of great importance.
Key words: Vibrio spp., antibiotic susceptibility, lobster.
Mehdi Raissy, Mahsa Ansari*
Page: 1 - 3
https://doi.org/10.46882/AJFS/1102Research Article
African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (7), pp. 001-004, July, 2020. © International Scholars Journals
Full Length Research Paper
Test and gonad characteristics in different genders of cultivated sea urchins (Strongylocentrotus intermedius, Agassiz): First insight into sexual identification
Chong Zhao, Weijie Zhang, Yaqing Chang* and Pingjin Liu
Key Laboratory of Mariculture, Ministry of Agriculture, Dalian Ocean University, Dalian-116023, China.
Accepted 08 May, 2020
Abstract
Ten test and gonad characters in both genders of cultured sea urchins (Strongylocentrotus intermedius, Agassiz) were investigated for sexual identification and sex ratio. Both test (test height-diameter ratio) and gonad characters (gonad index, gonad color and gonad moisture content) were significantly different between male and female sea urchins. For the first time, we report that cultivated female sea urchins are flatter than males. This could provide some new insight into the sexual identification of S. intermedius. The sex ratio of cultured sea urchins kept 1:1 at the density of 5 × 103g/m3, suggests that land-based aquaculture of sea urchins at a density of 5 × 103g/m3 can keep the balanced equilibrium on the sex ratio.
Key words: Strongylocentrotus intermedius, test height-diameter ratio, sexual identification, sex ratio in aquaculture.
Weijie Zhang, Chong Zhao, Yaqing Chang* and Pingjin Liu
Page: 1 - 4
https://doi.org/10.46882/AJFS/1101Short Communication
African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (6), pp. 001-003, June, 2020. © International Scholars Journals
Short Communication
Techniques in the improvement of consumers’ taste of Heterotis niloticus
A. P. Ekanem1*, C. B. Ndome2 and M. N. Osuagwu3
1Department of Fisheries and Aquaculture Institute of Oceanography, University of Calabar, P. M. B 1115, Calabar, Nigeria.
2Department of Zoology and Environmental Biology, University of Calabar, Calabar Nigeria.
3Department of Genetics and Biotechnology, University of Calabar, Calabar, Nigeria.
Accepted 24 April, 2020
Abstract
Improvement of the consumers’ taste of Heterotis niloticus was investigated by salting techniques. Table size fish were degutted, cut into uniform sizes, and soaked in salt solutions at concentrations that ranged from 0 - 100 g/l for 6 h. The salted pieces of H. niloticus were allowed to drain for an hour before been subjected to fire wood smoking in a kiln for 48 h. The taste of H. niloticus was greatly improved at 50 g/l salt as reported by all members of a 5- man organoleptic taste panel constituted to determine the taste by consuming fish soaked in different concentration of salt solutions. The improvement of the consumers’ taste of H. niloticus by simple salting methods showed in this study would improve the market value and aquaculture potentials of the species which has been discriminated because of its poor consumers taste, despites its excellent muscle quality.
Key word: Heterotis niloticus, taste, salting.
A. P. Ekanem*, C. B. Ndome and M. N. Osuagwu
Page: 1 - 3
https://doi.org/10.46882/AJFS/1100Research Article
African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (6), pp. 001-010, June, 2020. © International Scholars Journals
Full Length Research Paper
Potentials of short term and long term cryopreserved sperm of the African giant catfish (Clarias gariepinus Burchell, 1822) for aquaculture
O. G. Omitogun1*, O. F. Olaniyan1, O.O. Oyeleye1, C. Ojiokpota1, S.E. Aladele2 and W. T. Odofin2
1Biotechnology Laboratory, Department of Animal Science, Obafemi Awolowo University (OAU), Ile-Ife, 210001, Nigeria.
2National Centre of Genetic Resources and Biotechnology (NACGRAB), P.M.B 5382, Moor Plantation, Ibadan, Nigeria.
Accepted 12 April, 2020
Abstract
To service the growing demand for male African giant catfish (Clarias gariepinus) broodstock for aquaculture in Nigeria, and to conserve valuable genetic resources, we improved both short-term (in deep freezer at -35°C) and long-term cryopreservation (in liquid nitrogen at -296°C) of catfish sperm. Catfish sperm cryopreserved at -35°C using three different types of cryodiluents composed of 10% methanol, glycerol or dimethylsulphoxide (DMSO) with 15% non-permeating cryoprotectant (skim milk) and 75% phosphate-buffered saline (PBS) as extender was evaluated at day 1 to 28. Sperm motilities on thawing for the two cryodiluents that contained glycerol and DMSO were the same (p > 0.05) while those for the cryodiluent that contained methanol were significantly lower (p < 0.05). Sperm cryopreserved in DMSO and glycerol provided hatching at least 50% of catfish eggs. Liquid nitrogen (LN2) was with the same 3 cryoprotectants and one new extender based on glucose and skim milk (Ginzburg fish Ringer, GFR). Two thawing procedures were tried: 1) In the first trial, one set of sperm was frozen with different cryodiluents with extenders in the freezer at -10°C and 2) Stored for up to 8 months in LN2. Sperm with up to eight months cryopreservation from the first trial when thawed at room temperature at 27°C for 15 min gave 0 - 6.25% fertilization rate (FR). The sperm stored for two months in the second trial when rapidly thawed at 35°C for 5 min gave better results. The FR of 94% was achieved with a cryodiluent of DMSO with 5% glucose solution and PBS when the cryopreserved sperm was thawed at 35°C. Also, DMSO in combination with PBS resulted in a higher FR than either glycerol or methanol. However, sperm cryopreserved with glycerol had the lowest motility rate in the 2 trials (p < 0.05). The use of cryopreserved sperm did not significantly affect (p < 0.05) the survivability of the fry. The use of cryopreserved sperm of the African catfish for fry production will be especially beneficial in Nigeria where reliable sperm supply is a major bottleneck in the catfish aquaculture industry.
Key words: Cryopreservation, sperm motility, Clarias gariepinus, African giant catfish.
O. G. Omitogun*, C. Ojiokpota, S.E. Aladele and W. T. Odofin, O. F. Olaniyan, O.O. Oyeleye
Page: 1 - 10
https://doi.org/10.46882/AJFS/1099