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Food and Feeding, Length-Weight and Condition Factor of the Catfish Synodontis membranaceus (EtieneGeoffroy Saint Hilaire, 1809) (Osteichthyes: Mochokidae) from Lower Benue River, Makurdi, Nigeria
Atile John I.,
Shima Judith N.,
Akombo Pauline M.
Issue:
Volume 5, Issue 4, August 2016
Pages:
87-96
Received:
7 March 2016
Accepted:
25 March 2016
Published:
13 July 2016
Abstract: Food and Feeding, length-weight and condition factor of the Catfish Synodontis membranaceus from the Lower Benue River at Makurdi, Nigeria, was studied for 12- month period from July, 2013 to June, 2014. A total number of 202 specimens, comprising of 101 males and 101 females at a ratio of 1:1 were studied. The Length-Weight Relationship (LWR), correlation coefficient (r) for all males and females were highly positive and significant at (P<0.01), with r values of 0.972 for males, 0.899 for females and 0.952 for combined sexes. The mean b values (regression coefficient) were 2.68 in all the males, 2.46 in all the females and 2.63 in combined sexes indicating that all the sexes had negative allometric growth pattern. The mean condition factor (K) for both sexes ranged from 2.21-3.35. The lowest K range (1.81) for males was observed in July, 2013 while the highest K range (3.05) was observed in April, 2014. Similarly, the lowest K range (1.83) for females was observed in August, 2013 with the highest K range of 3.14 in the same month. Out of the 202 stomachs examined, only 9 males (8.91%) and 5 females (4.95%) had empty stomachs, about 91.09% of males and 95.0% of females had varied quantities of food items in their stomachs. Synodontis membranaceus in the Lower Benue River was found to be omnivorous, feeding on food items, which included artificial meal, plant remains, variety of algae, insect parts and larvae, bivalves (Molluscs), crustaceans, protozoa, worms, detritus, sand particles and mud and many unidentified quantities of food items.
Abstract: Food and Feeding, length-weight and condition factor of the Catfish Synodontis membranaceus from the Lower Benue River at Makurdi, Nigeria, was studied for 12- month period from July, 2013 to June, 2014. A total number of 202 specimens, comprising of 101 males and 101 females at a ratio of 1:1 were studied. The Length-Weight Relationship (LWR), cor...
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Stock Assessment and Estimation of Maximum Sustainable Yield for Tilapia Stock (Oriocromis niloticus) in Lake Hawassa, Ethiopia
Negese Kebtieneh,
Yitayal Alemu,
Mulugeta Tesfa
Issue:
Volume 5, Issue 4, August 2016
Pages:
97-107
Received:
1 September 2015
Accepted:
16 September 2015
Published:
18 July 2016
Abstract: The study was conducted on Lake Hawassa, one of the series Ethiopian rift valleys lakes. Data were collected from the area where fish are landed at one major landing site called fish market informally known as Amora Gedel, for one year (365days) on a daily basis. The length composition of tilapia caught by the fishery, total tilapia yield, fishing effort expanded as well as the price of tilapia and the cost of fishing operation were the basic information collected from the site. The aim of the analysis was to assess sustainability of fish stock, fishing level and to predict optimum yield and the bio-economic features of Lake Hawassa fisheries. Jones length based cohort analysis Model and length-based Thompson and Bell yield Prediction Model have been employed to estimate the maximum sustainable yield and maximum economic yield with their corresponding effort level. The estimated current annual yield was 182.94 tons of tilapia with the annual sale value of 4,158,760 ETB and 3,199,210 ETB of net profit for the fishermen cooperative. The predicted value of MSY was 186.72 tons/yr and this is obtained at fishing mortality factor of 1.6. And also MEY was 178.20 tons/yr and this is obtained at fishing mortality factor of 0.8. The fishery sector was found inefficient; the production was below its maximum sustainable yield level. Therefore harvest level should increase to its maximum sustainable yield level this might be possible by reducing the operating cost in order to increase both the level of yield as well as the net profit gained by the fishery sector.
Abstract: The study was conducted on Lake Hawassa, one of the series Ethiopian rift valleys lakes. Data were collected from the area where fish are landed at one major landing site called fish market informally known as Amora Gedel, for one year (365days) on a daily basis. The length composition of tilapia caught by the fishery, total tilapia yield, fishing ...
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Preliminary Studies on Population Status of Mona Monkey (Cercopithecus Mona) in Afi Mountain Wildlife Sanctuary, Cross River State, Southern Nigeria
Daniel Ibiang Edet,
Samuel Sunday Odunlami,
Ovat Innocent Ovat
Issue:
Volume 5, Issue 4, August 2016
Pages:
108-114
Received:
14 March 2016
Accepted:
5 June 2016
Published:
21 July 2016
Abstract: Preliminary study on the population status of mona monkeys (Cercopithecus mona) was conducted in Afi Mountain Wildlife Sanctuary (AMWS) in April (wet season) and December (dry season) of 2014. Data were collected from 20 transects randomly selected from the Northern Sector (12 transects) and Southern Sector (8 transects) using the systematic segmented trackline sampling option. Data generated were analysed with density equation (D) and chi-square (χ2) statistical analysis at 5% level of significance. Population parameters assessed are troop density and troop size. Wet season troop densities for the Northern Sector, Southern Sector and entire sanctuary were 8.69±1.80, 7.71±1.93 and 8.20±1.87 troops/km2 respectively. Troop sizes recorded were 4.44±0.30, 3.80±0.36 and 4.12±0.33 individuals/troop for the Northern Sector, Southern Sector and entire sanctuary respectively for the same season. Dry season troop densities of 7.80±0.23, 6.66±2.04 and 7.23±1.14 troops/km2 were also obtained for the Northern Sector, Southern Sector and entire sanctuary respectively. Within the same period, the values for troop sizes (individuals/troop) were 3.16±0.91 (Northern Sector), 3.20±3.30 (Southern Sector) and 3.18±0.61 (entire sanctuary). There is no significant difference (p>0.05) between the wet and dry seasons as well as between the Northern and Southern Sectors in relation to troop sizes and troop densities. The AMWS habours a high population of Cercopithecus mona as indicated in this study. It is recommended that regular population census should be conducted to ascertain more population parameters for effective conservation of the species.
Abstract: Preliminary study on the population status of mona monkeys (Cercopithecus mona) was conducted in Afi Mountain Wildlife Sanctuary (AMWS) in April (wet season) and December (dry season) of 2014. Data were collected from 20 transects randomly selected from the Northern Sector (12 transects) and Southern Sector (8 transects) using the systematic segmen...
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Models Predicting Above- and Belowground Biomass of Thicket and Associate Tree Species in Itigi Thicket Vegetation of Tanzania
Joseph Sitima Makero,
Rogers Ernest Malimbwi,
Tron Eid,
Eliakimu Zahabu
Issue:
Volume 5, Issue 4, August 2016
Pages:
115-125
Received:
24 June 2016
Accepted:
5 July 2016
Published:
21 July 2016
Abstract: Itigi thicket is a unique vegetation type for Tanzania and is regarded as ecologically sensitive, thus earmarked for conservation. The objective of this study was to develop species-specific biomass models for two dominating thicket species and mixed-species biomass models for associate trees in Itigi thicket vegetation. Data were collected through destructive sampling (60 thicket clumps and 30 associate trees) and covered two dominant thicket species: Combretum celastroides Laws and Pseudoprosopsis fischeri (Tab) Harms and five dominant associate tree species: Canthium burtii Bullock sensu R. B. Drumm, Cassipourea mollis (R. E. Fr.) Alston, Haplocoelum foliolosum L, Lannea fulva (Engl.) England Vangueria madagascariensis J. F. Gmelin. Different nonlinear multiplicative model forms were tested, and models were selected based on Akaike Information Criterion. Large parts of the variation in biomass of thicket clumps were explained by basal area weighed mean diameter at breast height of stems in the clump and number of stems in the clump, i.e. for aboveground biomass (AGB) and belowground biomass (BGB) of C. celastroides up to 89% and 82% respectively and for AGB and BGB of P. fischeri up to 96% and 95% respectively. For associate trees most variation was explained by diameter at breast height (dbh) alone, i.e. up to 85% and 69% for ABG and BGB respectively. Although there will be some uncertainties related to biomass estimates for large areas, for practical reasons, we recommend the selected models to be applied to the entire area where Itigi thicket extends outside our study site, and also to those thicket and associate tree species present that were not included in the data used for modelling.
Abstract: Itigi thicket is a unique vegetation type for Tanzania and is regarded as ecologically sensitive, thus earmarked for conservation. The objective of this study was to develop species-specific biomass models for two dominating thicket species and mixed-species biomass models for associate trees in Itigi thicket vegetation. Data were collected through...
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Sugar-Induced Tolerance to the Salt Stress in Maize Seedlings by Balancing Redox Homeostasis
Zhao Ying,
Xu Jing-yu,
He Lin,
Yang Ke-jun,
Zhao Chang-jiang,
Wang Zhi-hui,
Li Zuo-tong
Issue:
Volume 5, Issue 4, August 2016
Pages:
126-134
Received:
5 August 2016
Published:
8 August 2016
Abstract: Effects of exogenous glucose (Glc) and sucrose (Suc) on salt resistance, (glucose-6-phosphate dehydrogenase) G6PDH activity, ASA-GSH cycle and reactive oxygen species metabolism in maize leaves were studied. Seedings at two leaf stage were pretreated by 1/2 Hoagland nutrient solution with 0.5 mmol•L-1 Glc, Suc and mannitol for 3 days, some seedlings were left in normal nutrient solution and isotonic maninitol as control and permeability control respectively. Then the plants were cultured by 1/2 Hoagland solution at the concentration of 150 mmol•L-1 NaCl for 4 days or 6 days. The results showed that pretreatment with 0.5 mmol•L-1 glucose and sucrose for 3 days significantly decreased the thiobarbituric acid reactive substances (TBARS), H2O2 contents and increased ASA, GSH contents, ASA/DHA, GSH/GSSG ratio and G6PDH activity in leaves of maize seedings under salt stress. We also found that sucrose pretreatment induced the increase of Ca2+-ATPase and maintained the balance of Ca2+ contents under salt stress. In addition, compared with S treatment, isotonic mannitol pretreatment did not induce any changes of the physiological and biochemical indicators that meant it could not cause improvement of biological indicators of maize seedings. These results indicate that exogenous glucose and sucrose improved ASA-GSH cycle efficiency by participating in the pentose phosphate pathway (OPP), therefore enhanced antioxidant capacity and reduced the damage of active oxygen free radical, and the G6PDH activity induced by glucose and sucrose might serve as signal molecules and be involved in salt resistance of maize seedings.
Abstract: Effects of exogenous glucose (Glc) and sucrose (Suc) on salt resistance, (glucose-6-phosphate dehydrogenase) G6PDH activity, ASA-GSH cycle and reactive oxygen species metabolism in maize leaves were studied. Seedings at two leaf stage were pretreated by 1/2 Hoagland nutrient solution with 0.5 mmol•L-1 Glc, Suc and mannitol for 3 days, some seedling...
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