African Journal of Fisheries Science

African Journal of Fisheries Science ISSN 2375-0715 Vol. 11 (1), pp. 001-007, January, 2023. © International Scholars Journals

Full Length Research Paper

Proximate composition and breeding description of an unidentified Cichlid of Epe Lagoon, Lagos, Southwest, Nigeria commonly called ‘Wesafu’

H. Fashina-Bombata¹* and I. Megbowon²

¹Department of Fisheries, Faculty of Science, Lagos State University, Lagos, Nigeria.

²Biotechnology Section, Nigerian Institute for Oceanography and Marine Research, Victoria Island, P. M. B. 12729 Lagos, Nigeria.

Accepted 21 November, 2022

Abstract

A common cichlid of the Epe Lagoon, Lagos, Nigeria is an important food fish and viable candidate for culture in meeting the millennium goal and vision 2020 in the subregion. The intense fisheries of this ecotype also pose a conservation issue. The comparative protein contents of the cichlid fishes were 21.80, 18.34, 19.13, 18.71 and 18.08% for Wesafu, Sarotherodon galileaus, Sarotherodon melanotheron, Tilapia guineensis and Tilapia mariae, respectively. The highest percentage of protein was obtained for Wesafu. The results of the lipid determination showed that Wesafu had 0.9% lipid which is higher than others with T. guineensis having the least (0.4%) value for lipid. The result showed that all the fish studied belong to low oil category and therefore can be classified as lean fish. The major component of fish muscle is moisture. There was a progressive increase in the number of ripe eggs (absolute fecundity) from larger fish to smaller one. However, the relative fecundity followed a reverse order. Female Wesafu produce only a few hundreds to less than 2,000 eggs per spawn but inter-spawning period varied from 25 to 30 days in the present study. It was observed that this parameter (spawning frequency) was not affected by the weight of the broodstock. Although Wesafu could be seen as a commercially important fish species based on its credentials of deeper body, high economic value, in terms of price, white flesh and good taste, its aquaculture potential may be affected by its low fecundity. On the courtship behavior, Wesafu exhibits a characteristic golden yellow radiation during breeding period. During courtship, the fish display a characteristics kissing lifestyle. This appears different from that of Oreochromis niloticus which displays a poking courtship behavior with the female swimming in front while the male pokes the side. The result of this finding showed that of all the brooders in all hapas, only females that had eggs/hatchlings in their mouthparts. This comes to show that Wesafu probably belong to the genus, Oreochromis. Although this study has identified Wesafu as a probable member of the genus, Oreochromis, there is the need to identify the fish at a molecular level to see if it belongs to any of the known species of Oreochromis, or perhaps a simple strain.

Key words: Ecotype cichlid, Wesafu, Tilapiine spp., breeding behavior, proximate composition.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 10 (4), pp. 001-007, April, 2022. © International Scholars Journals

Full Length Research Paper

The effects of replacement of soybean meal by shrimp shell meal on the growth of hybrid tilapia (Oreochromis niloticus x Oreochromis aureus) reared under brackish water

Jean Fall^1,2*, Yi-Theng Tseng¹, Diegane Ndong¹ and Shin-Shyn Sheen¹

¹Department of Aquaculture, National Taiwan Ocean University, Keelung, 202, Taiwan.

²Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

Accepted 21 October, 2021

Abstract

To evaluate the effects of complete replacement of soybean meal (SBM) protein by shrimp shell meal (SSM) on the growth performance of hybrid tilapia (O. niloticus x O. aureus), five approximately isoenergetic and isonitrogenous (30% crude protein) diets containing 0, 33, 50, 67 and 100% SSM were fed to triplicate groups of ten fry with an initial mean weight 1.54 ± 0.03 g/fish under brackish water (15 ppt) for sixty (60) days. Fish fed diet containing 100% SSM exhibited the lowest specific growth rate (SGR). There was no significant difference of SGR in the fish fed 0, 33, 50 and 67% SSM. The fish fed 0, 33 and 50% SSM had better feed conversion rate (FCR) value than those fish fed with 67 and 100% SSM supplement. The survival of juveniles ranged from 97 to 100%, being 97% for 0, 50, 67% SSM and 100% for 33 and 100% SSM. The weight gain was highest in fish fed diet without SSM, intermediate in fish fed diets with 33, 50 and 67% SSM, and lowest in fish fed diet with 100% SSM. The highest body protein content was observed in fish fed diets with 50 and 67% SSM compared to the initial fish. The lowest body protein content was obtained with the fish fed diet with 100% SSM. The tilapia fed diet containing 33 and 67% SSM had the highest body lipid content compared to the initial fish. There were no significant differences in body lipid content among the fish fed diet with 0, 50 and 100% SSM. No difference in body ash content was observed among treatments.

Key words: Hybrid tilapia, Oreochromis niloticus x Oreochromis aureus, soybean meal, shrimp shell meal, brackishwater.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 10 (3), pp. 001-011, March, 2022. © International Scholars Journals

Full Length Research Paper

The procedures for strategic management of new products for small, medium and large firms in Cameroon: An exploratory study

N. I. Gouanlong* and V. Tsapi

Department of Marketing, Faculty of Economics and Management, University of Ngaoundere, Cameroon.

Accepted 17 March, 2021

Abstract

The aim of this study is to contribute to the understanding of the relationships between the activities of product innovation and business performance. In those relationships, the importance given to forms of action necessary for the new product strategic management for small, medium and large enterprises were particularly highlighted. A survey was administered to collect data from a representative sample of sixty five (65) innovative firms in Douala and Yaounde cities, Cameroon. The findings indicate that significant differences exist between the perceived importance of cross-functional team composition and firm size. However, no significant differences exist between the perceived importance of customer orientation decision and firm size. The risk of inherent failure in the activities of product innovation is still actual in debates in marketing research; this research helps to illuminate certain aspects of the management of these activities at the level of strategic. The strategic importance of the new product development decisions by Cameroonians firms is highly recommended.

Key words: New product, cross-functional teams, customer orientation, strategic management, innovative firms.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 10 (2), pp. 001-008, February, 2022. © International Scholars Journals

Full Length Research Paper

Physico-chemical properties of indigenous micro organism-composts and humic acid prepared from selected agro-industrial residues

A. Norida Hanim¹, A. M. Nik Muhamad², O. H. Ahmed¹*, K. Susilawati¹ and A. Khairulmazmi¹

¹Department of Crop Science, Faculty of Agriculture and Food Science, Universiti Putra Malaysia, Bintulu Sarawak Campus, 97008 Bintulu, Sarawak, Malaysia.

²Department of Forest Management, Faculty of Forest, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

Accepted 23 February, 2021

Abstract

Paddy husk (PH) and corn stalks (CS) residues are managed through burning. Besides contributing to environmental pollution, burning causes loss of vegetation cover, erosion, run off and loss of organic matter. In order to minimize this problem, a study was conducted to manage PH and CS residues through composting and to determine the physical and chemical properties of different composts and humic acid extracted from the final product. The study had six treatments namely: (T1) indigenous microorganisms (IMOIV)_{Steamed white rice (SWR)}(30%)+PH (40%)+Chicken Dung (30%), (T2) _SWR (30%)+CS (40%)+Chicken Dung (30%), (T3) IMOIV_{Aerated Fish Pond Water (AFPW)}(30%)+Paddy husk (40%)+Chicken Dung(30%), (T4) IMOIV _AFPW (30%)+CS (40%)+Chicken Dung(30%), (T5) IMOIV_{Kitchen Waste (KW)}(30%)+PH (40%)+Chicken Dung (30%) and (T6) IMOIV _KW (30%)+CS (40%)+Chicken Dung (30%). Composting was conducted in a white polystyrene box with a size of 30 x 15 x 25 cm. The composts produced in this study were analyzed for C:N and C:P ratio, pH (H₂O and KCl), nutrients, heavy metals, organic carbon, organic matter, ash, cation exchange capacity (CEC), humic acid (HAs) and total microbial count. The HAs were evaluated for elemental composition, acidic functional groups, E₄/E₆ ratio and spectral characteristics using standard procedures. Results show that all IMO-composts were granular, dark brown in colour without foul odour and attained an ambient temperature at 34 days of composting indicating the stable nature of the composts. The number of bacteria and filamentous fungi involved during composting decreased at the end of the all treatments. The E₄/E₆, acidic functional groups; carboxyl-COOH, phenolic-OH and total acidity of the compost were consistent with the standard range. IMO-compost from CS had better quality (chemical characteristics) compared to that of paddy husk. High quality compost could be produced from CS.

Key words: Paddy husk (PH), corn stalks (CS), indigenous microorganisms (IMO)-compost, humid acid (HA).

African Journal of Fisheries Science ISSN 2375-0715 Vol. 10 (1), pp. 001-010, January, 2022. © International Scholars Journals

Full Length Research Paper

Crystal phases of calcium carbonate within otoliths of CYPRINUS  CARPIO. L. from Miyun Reservoir and Baiyangdian Lake, China

Liang-Feng Yang¹*, Sheng-Rong Li², Guo-Wu Li² and Jun-Yan Luo²

¹The Geological Museum of China, Beijing 100034, China.

²State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences, Beijing, 100083, China.

Accepted 12 April, 2021

Abstract

Asteriscus (lagenar otolith) of CYPRINUS CARPIO. L. (Cyprinida, common carp) from the serious intermittent polluted Baiyangdian Lake and the little polluted Miyun Reservoir, all located in northern China, were chemically and mineralogically analyzed. All the analyzed fish showed that the composition of asterisci is dominated by calcium carbonate, with the minor elements As, Ba, Sr, and Zn; and the polymorph of CaCO₃ in the asterisci is vaterite. Three different vaterite X-ray diffraction (XRD) patterns were found in the analyzed samples. For the 60% fish from both localities, two different vaterite XRD patterns coexist in the core area and the edge area in same asteriscus sample. Significant differences of the dimensions of crystalline cells of vaterites exist between these two localities, which reveals that crystal structure of vaterite polymorphs seem sensitive to water quality and water environment, its crystalline cell dimensions might be a potential proxy for monitoring the change of water quality.

Key words: Vaterite, biocrystallization, otoliths, microchemistry, proxy, Cyprinus Carpio. L.

African Journal of Fisheries Science ISSN 2375-0715 Vol. 9 (4), pp. 001-008, April, 2021. © International Scholars Journals

Full Length Research Paper 

Toxicity bioassay and effects of sub-lethal exposure of malathion on biochemical composition and haematological parameters of Clarias gariepinus

Zubair Ahmad

Department of Zoology, College of Science, P. O. Box 2455, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia. Email: [email protected] or [email protected].

Accepted 13 March, 2020

Abstract

Clarias gariepinus were exposed to different concentrations of malathion to determine the 96 h LC₅₀ value and its sub-lethal effects on haematological parameters and biochemical composition were also investigated. The 96 h LC₅₀ value concluded was 8.22 mg/L. Specimens of C. gariepinus were exposed to sub-lethal concentrations (0.5, 1.0 and 2.0 mg/L) of pesticide for 4 weeks, which revealed that the pesticide had an adverse effects on various blood parameters. Red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin (Hb) concentration and haematocrit (Ht) values decreased after the exposure of malathion. Plasma glucose level was elevated as plasma protein decreased. Liver and muscle glycogen also decreased in the fish exposed to Malathion. Alanine amino transferase (ALT), glutamate oxaloacetate transaminase (GOT) and glutamate pyruvic transaminase (GPT) activities increased in the fish exposed to malathion. Magnesium and calcium ions were also affected, but the effects were insignificant.

Key words: Malathion, bioassay, sub-lethal exposure, Clarias gariepinus, biochemical and haematological changes.