African Journal of Fisheries Science

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (3), pp. 001-006, March, 2023. © International Scholars Journals

Full Length Research Paper

Effect of productive inputs of pond fish production on the output of fish in Owerri agricultural zone of Imo State, Nigeria

Nwosu, C.S. and Onyeneke, R.U.

Department of Agricultural Economics, Extension and Rural Development, Imo State University Owerri

Accepted 19 January, 2023

Abstract

The study focused on effect of productive inputs of pond fish production on the output of fish in Owerri Agricultural Zone of Imo State, Nigeria. A total of forty pond fish farmers selected through a random sampling effort were interviewed using questionnaire. Data collected were analysed using descriptive statistics and multiple regression analysis. The average age of the fish farmers was 59.7 years, majority (62.50%) of the fish farmers were males, majority (47.50%) of the fish farmers had tertiary education, average fish farming experience of the farmers was 5.4 years, and majority (85.00%) of the fish farmers were married. From the regression result, four regression coefficients were significantly and positively signed (pond size, feed consumed, start up capital and stock rate) related fish farming output. Majority 60.00%, 52.50%, 50.00% and 45.00% of the pond fish farmers reported that inadequate finance, high cost of feeds, scarcity of good sources of fingerlings and high cost of transportation respectively were their major constraints to increased pond fish production. Hence, for increased production of fish in the study area, these constraints must be reduced to the barest minimum. It is recommended that policies be directed to the establishment of commercial pelleted and floating fish feed mills, modern fish hatcheries, provision of credit facilities, provision of adequate infrastructural facilities and intensification of extension services. Government should provide good feeder roads so that this produce can be transported easily and cheaply into areas where they are not produced.

Keywords: productive inputs, output, pond fish, multiple regression, constraints

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (3), pp. 001-004, March, 2023. © International Scholars Journals

Full Length Research Paper

Interaction of polygalacturonase enzymes from Fusarium oxysporum with tomato polygalacturonase inhibiting protein

Ali Salehzadeh

Microbiology Department, Islamic Azad University, Rasht Branch, Rasht, Iran. E. mail: [email protected]. Tel: +989126932196.

Accepted 20 January, 2023

Abstract

Polygalacturonases (PGs) are important pectolytic enzymes produced by phytopathogenic fungi during the process of infection and colonisation of the host plants. In this work to study the inhibiting effect of polygalacturonase inhibiting protein (PGIP) on polygalacturonase (PG) enzyme from Fusarium oxysporum f.sp lycopersici, (highly virulent isolates), protein extraction was carried out from various tissues (stem, leaf and root) of 40, 60 and 80 days old tomato plants (Lycopersicon esculentum cv. FDT 202). Study of PGIP- PG interaction showed correlation between the plant age and increasing effect of inhibition activity of PGIP, with stem PGIP having the most effect. There were some differences in protein patterns of induced and non-induced tomato plants by F. oxysporum. Tomato PGIP showed different inhibitory activity on PG extracted from different phytopathogenic isolates of F. oxysporum.

Key words: Polygalacturonase inhibiting protein (PGIP), Fusarium oxysporum f.sp lycopersici, polygalacturonase (PG).

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (2), pp. 001-007, February, 2023. © International Scholars Journals

Full Length Research Paper

Effects of stocking density on the growth and survival of Oreochromis niloticus cultured in hapas in a concrete tank

Elliot Haruna Alhassan*, Emmanuel Delwin Abarike and Christian Larbi Ayisi

Department of Fisheries and Aquatic Resources Management, University for Development Studies, P. O. Box TL 1882, Tamale, Ghana.

Accepted 12 October, 2022

Abstract

The study was conducted over a 90 day period to investigate the effects of stocking density on the growth and survival of fry Oreochromis niloticus cultured in hapas in a concrete tank. Fish of average initial weight 0.3 g ± 0.03 were stocked at three different rates: 8, 10 and 12 fish/m³ corresponding to 56, 70 and 84 fish per hapa. Fish were fed twice daily with powdered pito mash at 10% of the biomass. The average initial weights of the fish varied slightly but not significant (P > 0.05) among all the treatments. At the end of the trial, the average final weights varied significantly (P < 0.05). Fish stocked at 8 m³ exhibited the highest average weight gain (4.65 ± 0.19 g) whiles; fish stocked at 12 m³ recorded the lowest average weight gain (2.50 ± 0.27 g). Feed conversion ratio and specific growth rate were not significantly different (P > 0.05) for all treatments. Survival rate were similar (P > 0.05) among treatments. The results demonstrate that increasing rearing density in fry O. niloticus resulted in heterogeneous growth rates. Feed conversion ratios, specific growth and survival rates were not affected by different stocking densities.

Key words: Nile tilapia, aquaculture, fish nutrition, fry fish, survival rate.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (2), pp. 001-007, February, 2023. © International Scholars Journals

Full Length Research Paper

Effect of direct injection of shark DNA into skeletal muscles on the productive performance characteristics of red tilapia (Oreochromis sp.) fed at different dietary regimes

Samy Yehya El-Zaeem^1,3*, Nader Ezzat El-Tawil² and Talaat Nagy Amer²

¹DNA Research Chair, Zoology Department, College of Sciences, P.O. Box 2455, King Saud University, Riyadh 11451, Saudi Arabia.

²Experimental Station for Aquaculture Research (ESAR), Central Laboratory for Aquaculture Research, Agriculture Research Center, Alexandria, Egypt.

³Animal and Fish Production Department, Faculty of Agriculture (Saba-Bacha), Alexandria University, Alexandria, Egypt.

Accepted 08 November, 2022

Abstract

The present work aims to study the effect of direct injection of shark (Squalus acanthias L.) DNA into skeletal muscles of red tilapia (Oreochromis sp.) fingerlings fed at different dietary regimes (three protein levels; 18, 22 and 26% each with two metabolizable energy levels; 244 and 260 kcal/100 g diet) on the productive performance. The results showed that growth performance, body composition and feed utilization of red tilapia injected with shark DNA had significant superiority (P≤0.05) compared with non-injected fish. Red tilapia fed 22% protein diet had significant improving (P≤0.05) most of the productive performance traits. Moreover, final body weight, weight gain, percent body weight increases, feed intake and protein retention percentage of red tilapia fed on diet containing 244 kcal/100 g, were significantly higher (P≤0.05) than those of fish fed on diet containing 260 kcal/100 g. These data suggests that dietary protein can be spared down to 22% protein by direct injection of shark DNA into skeletal muscles of fish. Thus, feed costs can be reduced by a further reduction in dietary protein. Therefore, the result of the present work indicates a possible easy and rapid way for improving fish characteristics.

Key words:  Red tilapia, Oreochromis  sp., deoxyribonucleic acid (DNA) transfer, productive performance, dietary regimes.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (1), pp. 001-006, January, 2023. © International Scholars Journals

Full Length Research Paper

Socio-economic determinants of consumer fish purchase in Windhoek, Namibia

E. C. Musaba* and M. Namukwambi

Department of Agricultural Economics, University of Namibia, Faculty of Agriculture and Natural Resources, Neudamm Campus, Windhoek, Namibia.

Accepted 05 January, 2023

Abstract

Based on data collected from 120 shoppers, in the City of Windhoek, capital of Namibia, this study used the logit model to analyze the influence household characteristics have on consumers’ decision to purchase horse mackerel, hake, and snoek. Specific factors considered in the model were gender, age, education, household size and income. The results revealed, firstly that education, income and household size have negative significant effect on consumers’ decision to purchase mackerel. Secondly, it was found that age and income have positive significant effect on the probability to purchase hake. Thirdly, household size and income have positive significant effect on the probability to purchase snoek but marital status had a significant negative effect on the decision to purchase snoek. In brief, the results confirmed strong income, age and household size effects on the purchase of fish species. The implication of the findings is that fish marketers and processors should consider these factors in the formulation of marketing strategies aimed at promoting fish consumption in the study area.

Key words: Socio-economic characteristics, fish, hake, mackerel, purchase, snoek, logit regression.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (1), pp. 001-006, January, 2023. © International Scholars Journals

Full Length Research Paper

Harvest, export and economic status of freshwater crayfish (Astacus leptodactylus Esch.1823) in Turkey

Hamdi Aydin¹* Muzaffer Mustafa Harlıoğlu² and Tomris Deniz (Bök)³

¹Gazanfer Bilge Vocational School, Kocaeli University, Karamürsel, Kocaeli, Turkey.

²Faculty of Fisheries, Fırat University, 23119, Elazığ, Turkey.

³Faculty of Fisheries, Istanbul University, Laleli, Istanbul, Turkey.

Accepted 15 October, 2022

Abstract

This study was carried out on the export and economic status of freshwater crayfish (Astacus leptodactylus Esch. 1823) in Turkey. Due to the fact that there is a very low domestic consumption of freshwater crayfish in the country, Turkey had been the largest provider of A. leptodactylus to Western Europe from 1970 until 1986. The peak production of the country was attained in the early 1980s, with over 5.000 tons being exported in 1984. After the occurrence of crayfish plague in Turkish waters, crayfish stocks reduced dramatically and harvest declined from approximately 5.000 (in 1984) to 200 (in 1991) tons annually. The harvest of crayfish in Turkey between 2005 and 2009 was 809, 797, 816, 783 and 734 tons, respectively and the commercial values of crayfish, based on these years were 3.033.371, 3.209.396, 3.381.094, 3.366.426 and 2.713.494 USA dollars. The harvest of crayfish in total was 13.648 tons from 2000 to 2009 in Turkey, and the total commercial value was approximately 40.343.870 USA dollars. Majority of crayfish harvest has been exported to European countries and especially Sweden.

Key words: Astacus leptodactylus, freshwater crayfish, harvest, exports, economy, Turkey.