A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

  Subjects -> WATER RESOURCES (Total: 160 journals)
We no longer collect new content from this publisher because the publisher has forbidden systematic access to its RSS feeds.
Similar Journals
Journal Cover
Journal of Aquatic Sciences
Number of Followers: 3  
 
  Full-text available via subscription Subscription journal
ISSN (Print) 0189-8779
Published by African Journals Online Homepage  [261 journals]
  • Cockroach (Periplaneta Americana) as fishmeal replacer in diets of African
           catfish (Clarias gariepinus) Juveniles

    • Free pre-print version: Loading...

      Authors: S.O Sule, A.O Sotolu, S.O Yakubu, R Mohammed
      Pages: 119 - 132
      Abstract: The utilization of insects as feed has witnessed dramatic inclusion in livestock and aquaculture diets. The farming of cockroach (Periplaneta americana) is gaining acceptance among industries. However, research on its use in livestock and fish nutrition is scanty. This study aimed at investigating the growth of Clarias gariepinus juveniles fed cockroach insect meal (CIM) as fishmeal (FM) replacer. One hundred and fifty Clarias gariepinus juveniles (6.29 ± 0.06 g) were stocked at 10 fish/tank/replicate and fed 40% crude protein diets formulated thus: Diet 1 (0% CIM; control), Diet 2 (25% CIM), Diet 3 (50% CIM), Diet 4 (75% CIM) and Diet 5 (100% CIM). Fish were fed at 5% of their body weight twice daily for 56-day experimental period. The results showed that final weight, mean weight gain, specific growth rate, protein efficiency and food conversion ratios of fish fed 25 and 50% insect meal-based diets were not significantly different (p>0.05) from those treated with the control diet. Survival rates were not significantly different in all dietary treatments. Quadratic regression analysis revealed that insect meal can be used at up to 58% inclusion level in diets of C. gariepinus juveniles for optimal growth. Keywords: Amino acid, Blattodea, fish-nutrition, growth performance, C. gariepinus
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.11
      Issue No: Vol. 36, No. 2 (2022)
       
  • Length/weight relationships and condition factor of Trachinotus goreensis
           from Bonny Estuary, Nigeria

    • Free pre-print version: Loading...

      Authors: K.O Chukwu, M Pepple
      Pages: 133 - 138
      Abstract: The length-weight relationships and condition factor of golden pompano (Trachinotus goreensis) from Bonny Estuary, Rivers State, Nigeria, was studied for a period of three months (January – March, 2021). Fish samples were collected from local fishers at the landing sites in the estuary. A total of 246 samples of T. goreensis with total lengths ranging from 18.00 -70.00cm and a corresponding weight range of between 470.00- and 3000.00g were recorded. Samples were identified using standard fish identification keys. Length – weight relationships and condition factor were calculated according to standard methods. Data were subjected to FAO ICLARM Stock Assessment Tools (FISAT II) and Microsoft Excel for regression analysis. The mean intercept constant (a) obtained for T. goreensis was 0.39. The slope (b) value was 2.33, showing a negative allometric growth pattern. The correlation coefficient (r) value for the species was 0.94 indicating a positive relationship between the length and weight. The overall monthly condition factor (K) of the species was 1.56 indicating that the fish was in good condition. It could be inferred that T. goreensis from Bonny Estuary had negative allometric growth and was found to be doing well judging from its condition factor. Keywords: Growth, Allometry, Trachinotus, Condition factor, Estuary
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.12
      Issue No: Vol. 36, No. 2 (2022)
       
  • Preliminary study on the utilization of aqueous bark extracts of Khaya
           ivorensis in diets of Clarias gariepinus fingerlings

    • Free pre-print version: Loading...

      Authors: A.A Alimi, G. Igili, O.K. Adeboyejo, N.B Ikenweiwe
      Pages: 139 - 147
      Abstract: Mortality of fish seeds is recognised as one of the major factors responsible for serious economic losses in fish culture business. A preliminary investigation on the effects of aqueous extracts of dried African mahogany, Khaya ivorensis bark on the growth, survival, haematology and histology of Clarias gariepinus fingerlings was conducted. A total of 135 C. gariepinus fingerlings (1.41±0.03 g/fish) were randomly allocated into three treatments, T1 (Control), T2 and T3, and fed with three different diets (40% CP) D1, D2 and D3 containing 0g/L, 25g/L and 50g/L aqueous extracts of K. ivorensis bark respectively. The experimental fish were fed ad-libitum for a period of 28 days in rectangular plastic containers (15x25x30cm3 ) and water exchange was done daily. Experimental data were analyzed for statistical differences in the growth, survival indices, haematology and histology of experimental fishes using analysis of variance (ANOVA). There was no significant difference (p>0.05) in mean weight gain of Control (2.91±0.68g) and T2 (2.20±0.20g) but T3 (1.79±0.39g) was significantly low. There was a significant difference in the survival (S) of experimental fish with the S (%) values of 73.67±13.50, 68.67±16.50 and 57.00±10.00 for T2, T3 and control respectively, no significant different in the feed conversion ratio (p>0.05) in the experimental groups. The haematological characteristics of all experimental fish were not significantly different, though the packed cell volume, PCV (%), haemoglobin count, HB (g/dl) and red blood cell, RBC (million/mm) were in the order T2˃T3˃Control having mean values of 22.71±4.5˃21.67±5.1˃19.67±1.53 (PCV); 22.67±4.51˃2.67±6.51˃19.67±1.53 (HB) and 2.09±0.47>1.99±0.57>1.73±0.13 (RBC) for T2, T3 and control respectively. The white blood cell, (No/mm) was highest in T1 (4.03±0.25) and least in T3 (3.67±1.35). Although there was no degeneration, the histological characteristics of liver of the experimental fish ranged from moderately diffused to fewer hepatocytes when compared to the normal liver, of the control. It is therefore concluded that Khaya ivorensis bark can be included in the diet of Clarias gariepinus fingerlings at 25g/L aqueous extract for good growth and high survival rates of fish under culture Keywords: Medicinal herbs, Extracts, African catfish, Fish culture
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.13
      Issue No: Vol. 36, No. 2 (2022)
       
  • Fatty acid composition of fish feeds vended in Lagos state, Nigeria

    • Free pre-print version: Loading...

      Authors: M.O Ezekiel, M.M Salaudeen, O.M. Esan, I.A Uzoalu, C. L Igwe
      Pages: 149 - 155
      Abstract: Fatty acid compositions of the lipids extracted from various fish feeds (Eco-float, Blue-crown, Uncle - frances, Triton, Stretting, Crown, Jik, Shaldac, Solace, Coppens, Vital, Local sinking, Local feed, Aqualis and Local floating) vended in Lagos State were determined. These feeds were designated as Feeds A to O respectively. Feed samples were procured from major fish feed markets and fish farms within Lagos metropolis and transported to the laboratory for analysis. Methylation was carried out after oil extraction to convert the fats to their methyl esters and the fatty acids methyl esters (FAME) were separated by gas chromatography. Fatty acids were analysed using a HP Agilent 5890 system gas chromatograph equipped with SP-2330 and a flame ionization detector (FID). Results revealed that the highest values for polyunsaturated fatty acid (PUFA), saturated fatty acid (SFA) and ∑n-3 unsaturated fatty acid (HUFA) were 58.26% in feed F, 38.7% in feed M and 3.59% in feed N respectively while the lowest values for PUFA (19.76%) and SFA (15.53%) were recorded in feeds M and J respectively. The results also showed that, though feed samples were high in monounsaturated fatty acid (MUFA) (55- 22%) and PUFA (58-19%), they were low in n-3 HUFA {eicosapentaenoic acids (EPA, 20:5n-3) and docosahexaenoic acids (DHA, 22:6n-3)} with the values of 0.3-3%. The shortfall in EPA and DHA of these feeds may imply that fish fed these feeds may be nutritionally deficient in these fatty acid compositions. Thus, further manipulation may be needed to improve the value of these feeds in terms of EPA and DHA. Keywords: Fish feeds, n-3 HUFA, n-6 HUFA, Nutritional quality, aquaculture
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.14
      Issue No: Vol. 36, No. 2 (2022)
       
  • Socio-economic factors affecting fisherfolks in Otuocha and Ebenebe
           fishing communities in Anambra state, Nigeria

    • Free pre-print version: Loading...

      Authors: C.C. Ikechukwu, M.M Chukwurah, C.G Nwankwo, H.F Ogbonnaya, I.C Edeh
      Pages: 157 - 166
      Abstract: Fishing is an important source of income contributing to the economy of fishing communities living around Ezu and Omamabala Rivers in Ebenebe and Otuocha areas in Anambra State, Nigeria. A total of 120 structured questionnaires were distributed to obtain the socio-economic information from the respondents. Descriptive statistic was used for the data analysis. Results from the study revealed significant differences (p < 0.05) between Ebenebe and Otuocha fishing communities, in terms of level of education attained, with no significant difference (p > 0.05) in the average monthly income earned. The study also showed that 71.7% of the respondents were males which engaged in fish farming while 28.3% were females involving in fish processing and trading, both of which were mostly within the age bracket of 30-39 years. The highest household size (35.9%) comprised of 6 members while 92.3% of the respondents had one form of education or the other. Most of the respondents (69.6%) took fishing as their major occupation while 30.4% also involved in other activities in addition to fishing operations. A 5-point likert scale was employed to record challenges of the respondents, and could be concluded that the socio-economic conditions of the fisherfolks in the study areas were not highly excellent due to lack of basic social amenities and modern fishing facilities amongst other factors. Keywords: Fisher folks, Social-Economic factors, Ebenebe, Otuocha, Anambra
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.15
      Issue No: Vol. 36, No. 2 (2022)
       
  • Prevalence of gastrointestinal parasites in tilapia (Oreochromis
           niloticus) in Port Harcourt, Rivers state, Nigeria

    • Free pre-print version: Loading...

      Authors: O.A Bubu-Davies, O.V Abraham-Akosubo, A.I Ilesanmi, G Umah
      Pages: 167 - 176
      Abstract: The study aimed to investigate the prevalence of gastrointestinal parasites in Oreochromis niloticus sold in major markets in Port Harcourt, Rivers State, Nigeria. A total of 120 specimens of different size groups were randomly sampled from three (3) markets in Port Harcourt and examined for parasites. The overall frequency and percentage prevalence recorded was 80 (66.67%) with the highest parasitic infection obtained in Rumuokoro market samples. Out of the total fish sampled, the prevalence of gastrointestinal parasite in O. niloticus sampled from Oil Mill market was 26 (21.6%), Rumuokoro market 30 (25%) and Rumuola market 24 (20%). The overall prevalence showed significant difference (p = 0.005) in all the markets. However, percentage prevalence between sex showed no significant difference (p = 2.46), with male fishes known to have a higher prevalence of infection. The recovered parasites were protozoans>nematodes>cestodes>trematodes in order of prevalence as 40 (33.3%) > 30 (25%) >16 (13.33%) >12 (10%) respectively. Thus, protozoans showed the highest prevalence in O. niloticus. In conclusion, fish specimens were found to be infected with various gastrointestinal parasites, this may lead to reduction in productivity. Keywords: Parasites, digestive system, prevalence, Oreochromis niloticus, Port Harcourt
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.16
      Issue No: Vol. 36, No. 2 (2022)
       
  • Recovery rate, haematological parameters and growth responses of
           Heterobranchus longifilis exposed to zinc oxide nanoparticles

    • Free pre-print version: Loading...

      Authors: S.I. Abdulkareem, O.D Owolabi
      Pages: 177 - 186
      Abstract: The present study investigated the toxicity effects of zinc oxide nano-particles (ZnO-NPs) on haematological parameters and growth responses of Heterobranchus longifilis. Catfish juveniles were exposed to sub-lethal concentrations (0.00, 6.00, 8.00, 10.00 and 12.00 mg/l) of zinc oxide nano-particles in static renewal bioassays for 60 days. The ZnO-NPs-exposed fish were then subjected to depuration phase for 30 days to monitor the recovery ability of the fish. After each experimental stage, fish were sacrificed and blood was collected for haematological variables such as: erythrocytes {Red blood cells (RBC), packed cell volume (PCV) and haemoglobin (HB)} and leucocytes {White blood cells (WBC), platelets (PLT), lymphocyte (LYMPH) and neutrophil (NEUT)} using standard procedure. Results revealed reduction (p < 0.05) in the values of RBC counts (0.70 x 106 /µl) in 10.00 and 12.00mg/l ZnO-NPs treated fish when compared to control group (3.70 x 106 /µl). A reverse trend was observed with significantly (p < 0.05) high WBC counts (220.70 x 103 /µl) in group treated with the highest concentration (12.00mg/l) of ZnO-NPs after 60 days of exposure. The recovery experiment followed a different trend with a gradual decrease in RBC values from 2.2 x 106 /µl in 6.00mg/l to 2.00 x 106 /µl in 12.00mg/l while WBC counts increased from 182.00 x 103 /µl in 6.00 mg/l to 194.30 x 103 /µl in 12.00mg/l. The highest percentage weight gain (58%) was recorded in the control group with the lowest (26%) in the ZnO-NPs-exposed group. However, fish growth increased as the depuration period increased. The results of this findings indicated that ZnO-NPs may have some adverse effects on the physiology of H. longifilis, however, the fish showed some ability to recover from the effects over time. Keywords: Depuration, Haematology, Heterobranchus longifilis, ZnO-NPs
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.17
      Issue No: Vol. 36, No. 2 (2022)
       
  • Spawning performance and survival of Clarias gariepinus fry bred under
           different water sources in Abakaliki Metropolis

    • Free pre-print version: Loading...

      Authors: J.S Awoke, E.E. Oti, C.B Okoro
      Pages: 187 - 198
      Abstract: The study was conducted to compare effects of three different water sources on hatchability and survival of Clarias gariepinus fry. The water sources used were: rain (RNW), borehole (BHW) and well (WLW). The experiment involved artificial induced breeding of C. gariepinus and rearing the resultant larvae/hatchlings for 14 days to assess reproductive performance. Hatchability was estimated 24 hours after incubation, while larval survival was determined at 14 days’ post hatching. Data resulting from the experiment were subjected to one-way analysis of variance (ANOVA). Percentage hatchability in all water sources were relatively high with the highest mean value of 93.1±1.60% obtained in RNW experiment. Larval survival after 14 days’ post hatching was above average with the highest mean value of 63.7±2.41% recorded in BHW while RNW recorded the lowest mean value of 44.2±0.55%. The results of this study has demonstrated that borehole water may be a suitable water source for induced artificial spawning of the African catfish and subsequent larval rearing. Keywords: Brood Stock, Hypophysation, Propagation, Water quality, Milt, Hatching
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.18
      Issue No: Vol. 36, No. 2 (2022)
       
  • Microbiological properties of water and sediment of New Calabar River,
           Port Harcourt, Nigeria

    • Free pre-print version: Loading...

      Authors: B.B Otene, K.O Chukwu, F.S Pepple
      Pages: 199 - 209
      Abstract: Microbiological characteristics of water and sediment of New Calabar, River, Port Harcourt, Nigeria were investigated. Water and sediment samples were collected from three stations {Aluu, ARAC (Station 1; Choba Bridge (Station 2) and Rumuokparali (Station 3)} on a monthly basis between February and April, 2020 and analyzed using standard methods. The results showed that Total Heterotrophic Bacteria in water (THBw) ranged between 2.20 x 102 and 2.6x104 cfu/ml with the overall mean value of 7,313.33 + 1039.09 cfu/ml while that of sediment (THBs) ranged between 3.1 x 103 and 3.9 x 104 cfu/g with the overall mean value of 42,566.67 + 71199cfu /g. The THB counts were higher in sediment than in water with Station 2 significantly different from other stations. Total Coliform Bacteria (TCB) in water ranged between 1.1 x 103 cfu/ml and 2.9 x 103 cfu/ml with the mean value of 1988.89±532.55cfu/ml while that of sediment ranged between 1.3 x 103 cfu/g and 2.5 x 104 cfu/g with the mean value of 9422.22 ±9595.41cfu/g. TCB counts in water showed no significant difference across the stations at p<0.05 but Station 2 statistically differed from Stations 1 and 3 in the sediment. Morphological and biochemical tests showed that 8 bacteria species were isolated from sediment and and 9 specimens were recovered from water. Some isolated specimens were: Bacillus spp, Staphylococcus. sp, Bacillus cereus and Bacillus subtilis while Escherichia coli was the only bacterium found in water but absent in sediment. Two species: Staphylococcus spp and Bacillus subtilis dominated the study area. Fungal counts in water ranged between 3.0 x102 and 2.6 x 103 cfu/ml with the overall mean value of 1911.11±67.51cfu/ml while that of sediment ranged between 1.7 x101 and 3x102 with the overall mean value of 173.00±78.52 cfu/g. Fungi counts showed significant difference (p < 0.05) across the stations in water and sediment. Macroscopic and microscopic characterization of fungi showed that 6 fungi species were recovered in water and sediment. These included Aspergillus niger, Rhizopus oligospora and Pennicillium species. The species Fusarium solani and Aspergillus flavor were found in Station 1 but absent in Stations 2 and 3. It could be observed that microbial counts in both water and sediment exceeded the 1.0x102 cfu/ml and 0 cfu/ml recommended levels by WHO and EPA respectively. Thus, the study area may be under threat and the water may be unsafe for human consumption. Keywords: Microbiological Properties, Sediment, Water, New Calabar River, Port Harcourt
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.19
      Issue No: Vol. 36, No. 2 (2022)
       
  • Survival rate, growth and condition index of tank-raised Clarias
           gariepinus under different salinities

    • Free pre-print version: Loading...

      Authors: E.M. Ayim, S.M Ameh, C.B Ndome, E. U Okon
      Pages: 211 - 218
      Abstract: The study evaluated varying levels of salinity on survival, growth and condition index of tank raised Clarias gariepinus for ten weeks. A total of 120 healthy C. gariepinus fingerlings having a bulk weight and average length of 131.73 ± 0.85 g and 5.06 ± 0.24 cm respectively were procured from the hatchery complex of University of Calabar fish farm and used for the study. Sea water was collected from Ibeno Beach and diluted with borehole water to obtain various salinity concentrations of ≤1, ≤5, ≤10 and ≤15 ppt. This represented four treatments(Tanks A to D) and each treatment had three replicates. Evaluation of growth indices and culture water parameters followed standard procedure. Results revealed significant (p < 0.05) differences with regards to food intake in the treatment Tanks A (≤1ppt), B (≤5ppt), C (≤10ppt) and D (≤15ppt). Food conversion efficiency (FCE), ratio (FCR) and protein efficiency ratio (PER) were significantly different (p < 0.05). Body weight gain were observed to be higher in Tank A with a value of 75.83± 0.07g/kg and a total length of 11.13 ±0.38cm and the lowest weight gain was recorded in Tank D with a value of 43.56 ± 0.76g/kg and a mean total length of 6.67± 0.43cm. There were significant differences (p < 0.05) in the final condition factor (K) of the fish. Hence, it could be established that C. gariepinus fingerlings can survive and be reared in 5ppt saline water without any adverse effect on growth. At salinity level above 5ppt, fish growth rate may be slow. Keywords: Survival rate, Growth, Clarias gariepinus, Salinity, Physicochemical parameters
      PubDate: 2022-06-13
      DOI: 10.4314/jas.v36i2.20
      Issue No: Vol. 36, No. 2 (2022)
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 3.235.140.84
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-